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Frits A J Muskiet - One of the best experts on this subject based on the ideXlab platform.
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in vitro manipulation of l1210 cell cycle kinetics with 4 amidinoindan 1 one 2 Amidinohydrazone alpha difluoromethylornithine and n 1 acetylspermine
Biochimica et Biophysica Acta, 1998Co-Authors: B Dorhout, Aw Kingma, P J Poortenga, E De Hoog, Frits A J MuskietAbstract:We investigated whether in vitro L1210 growth inhibition by alpha-difluoromethylornithine (DFMO; 740 microM) and 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A; 1.7 microM) is reversible with N1-acetylspermine (N1-acSp). Influences of N1-acSp dose (1-100 microM), time (0-12 h at 100 microM), aminoguanidine (AG, 1 mM) and cell numbers (at 1 microM N1-acSp) on percentage S-phase, polyamine contents and viability were determined. DFMO/CGP 48664A decreased percentage S-phase from 58 to 26%, decreased spermidine (Sd) and spermine (Sp) contents 3-fold, but did not affect viability. With increasing N1-acSp dose, S-phase percentage and Sd contents increased concomitantly, reaching plateau values that were comparable with those of untreated controls. S-phase and Sd content increased from 4-6 h after N1-acSp administration, reaching plateau values from 11 and 6 h, respectively. N1-acSp content was dose dependent and increased linearly to reach plateau values from 8 h. AG did not affect any of these parameters. Addition of 1 microM N1-acSp to decreasing numbers of DFMO/CGP 48664A-treated cells caused increasing S-phase percentage, Sd and N1-acSp contents. We conclude that cell cycle kinetics of cultured L1210 cells can be manipulated by the induction of growth inhibition with DFMO/CGP 48664A and its subsequent abolishment with N1-acSp. N1-acSp accumulation rate and its subsequent conversion to Sd is relatively slow compared with intracellular Sd needs. The data support the notion that Sd is the most important polyamine for growth.
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in vivo manipulation of l1210 cell cycle phase distribution with α difluoromethylornithine 4 amidinoindan 1 one 2 Amidinohydrazone and n1 acetylspermine
Biochimica et Biophysica Acta, 1998Co-Authors: B Dorhout, Harri Ferwerda, Aw Kingma, E De Hoog, Frits A J MuskietAbstract:We investigated whether the in vivo growth inhibitory effect of the combination of 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A) and alpha-difluoromethylornithine (DFMO) is reversible by treatment with N1-acetylspermine (N1-acSp). DBA-2 mice were inoculated with 10(5) L1210 cell i.p. on day 0. From day 1 they received 2.50 mg CGP 48664A/kg i.p. once daily and 500 mg DFMO/kg i.p. twice daily. On day 5 they received 3 x 2500 nmol N1-acSp i.p. with 15-min intervals. L1210 cell numbers, S-phase percentage and polyamine contents, and liver and spleen polyamine contents were monitored in the following 48 h. Four days treatment with CGP 48664A/DFMO reduced L1210 cell numbers, S-phase, and spermidine. N1-acSp treatment increased L1210 spermidine from < or = 8 h and percentage S-phase from 12 h. Maxima for spermidine and S-phase were reached at < or = 8 and 18 h, respectively. These were below levels of untreated controls. Decreases were noted from 12 and 18 h, respectively. N1-acSp was detectable in L1210 from 0-18 h. Liver spermidine was decreased by CGP 48664A/DFMO. After N1-acSp treatment, liver N1-acSp and N1-acSd increased from < or = 8 h, reached maxima at < or = 8 and 10 h, respectively, and were undetectable from 15 h. We conclude that the in vivo growth inhibitory effect of CGP 48664A/DFMO is reversible by N1-acSp treatment. The liver is probably involved in N1-acSp terminal catabolism. The effect of the polyamine depletion-repletion scheme on S-phase cell numbers may be much more profound than present estimates from 5-bromo-2'-deoxyuridine incorporation.
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4 amidinoindan 1 one 2 Amidinohydrazone cgp 48664a exerts in vitro growth inhibitory effects that are not only related to s adenosylmethionine decarboxylase samdc inhibition
Biochimica et Biophysica Acta, 1997Co-Authors: B Dorhout, Marinca F G Odink, Elly De Hoog, Anneke W Kingma, Eveline Van Der Veer, Frits A J MuskietAbstract:Abstract The competitive S -adenosylmethionine decarboxylase (SAMdc; EC 4.1.1.50) inhibitor 4-amidinoindan-1-one 2′-Amidinohydrazone (CGP 48664A) inhibits growth more effectively than the irreversible SAMdc inhibitor 5′-{[( Z )-4-amino-2-butenyl]methylamino}-5′-deoxyadenosine (AbeAdo), while having similar effects on polyamine contents. We hypothesized that growth inhibition by CGP 48664A is not merely accomplished by SAMdc inhibition. Concentration-related growth inhibitory effects of AbeAdo, CGP 48664A and methylglyoxal bis(guanylhydrazone) (MGBG) were investigated in L1210 cells that were additionally exposed to 10 μ M AbeAdo. This concentration causes maximal growth inhibition, profound SAMdc inhibition and plateau polyamine contents. Almost complete inhibition of functional SAMdc activity by 10 μ M AbeAdo was confirmed by demonstration of poor conversion of tetradeuterated spermidine to tetradeuterated spermine by gas chromatography–mass spectrometry. Increasing AbeAdo did not affect L1210 cell numbers, viability, nor polyamine contents. MGBG proved highly toxic. CGP 48664A did not affect L1210 polyamine contents, but cell numbers and viability decreased dose-dependently to 50% and 70% of control, respectively. We conclude that CGP 48664A inhibits L1210 growth not only through SAMdc inhibition, but also by an as yet poorly understood second effect with higher IC 50 . The alleged second effect of CGP 48664A appears important for its potent antitumor effect.
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in vivo effects of 4 amidinoindan l one 2 Amidinohydrazone cgp 48664a and α difluoromethylornithine dfmo on l1210 growth cell cycle phase distribution and polyamine contents
International Journal of Cancer, 1995Co-Authors: B Dorhout, Harri Ferwerda, Elly De Hoog, Anneke W Kingma, Roelf Jakob Te Velde, Frits A J MuskietAbstract:We studied the in vivo effects of 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A), alpha-difluoromethylornithine (DFMO) and a combination of CGP 48654A-DFMO on tumor growth, cell-cycle phase distribution and polyamine contents. DBA-2, mice were inoculated i.p. with 10(5) L1210 cells on day 0, treated i.p. on days 1-4 and killed on day 5. As compared to controls, CGP 48664A, DFMO and the CGP 48664A-DFMO combination reduced L1210 cell numbers by 33, 43 and 85%, respectively. CGP 48664A did not affect cell-cycle phase distribution. DFMO and the CGP 48664A-DFMO combination caused a moderate and a heavy accumulation in G(0)/G(1)- and G(2)/M-phases, respectively. Compared with controls, the CGP 48664A-DFMO combination reduced putrescine, spermidine and total polyamines, but did not affect spermine. Compared with CGP 48664A, the CGP 48664A-DFMO combination caused lower putrescine and total polyamines, higher spermine, but no change in spermidine. Compared with DFMO, the CGP 48664A-DFMO combination caused higher putrescine and spermidine, lower spermine, but no change in total polyamine levels. We conclude that CGP 48664A potentiates the cystostatic effect of DFMO in vivo. The resulting growth inhibition is accompanied by an accumulation in G(0)/G(1)- and G(2)/M-phases and a reduction of putrescine and spermidine. The data suggest that perturbed polyamine composition rather than reduced spermidine or total polyamine pool size causes a profound growth inhibition. (C) 1995 Wiley-Liss, Inc.
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in vivo growth inhibition of l1210 leukemia by 4 amidinoindan 1 one 2 Amidinohydrazone cgp 48664a a new inhibitor of s adenosylmethionine decarboxylase
International Journal of Cancer, 1995Co-Authors: B Dorhout, Rjt Velde, Harri Ferwerda, Aw Kingma, E Dehoog, Frits A J MuskietAbstract:We studied the in vivo growth-inhibitory effect of the new S-adenosylmethionine decarboxylase inhibitor 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A). L1210-bearing DBA-2 mice were treated with increasing CGP 48664A doses from I day after i.p. L1210 cell inoculation. Treatment was continued for 4 days, after which all mice were killed. CGP 48664A caused dose-related exponential decreases of L1210 cell numbers and spermidine and spermine contents. Putrescine contents increased exponentially. Polyamine changes in spleen and liver were less profound. L1210 growth inhibition was not accompanied by changes in cell cycle phase distribution. It is concluded that CGP 48664A is an effective inhibitor of S-adenosylmethionine decarboxylase but that CGP 48664A-induced changes in intracellular polyamine compositions are not necessarily the cause of growth inhibition. (C) 1995 Wiley-Liss, Inc.
B Dorhout - One of the best experts on this subject based on the ideXlab platform.
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in vitro manipulation of l1210 cell cycle kinetics with 4 amidinoindan 1 one 2 Amidinohydrazone alpha difluoromethylornithine and n 1 acetylspermine
Biochimica et Biophysica Acta, 1998Co-Authors: B Dorhout, Aw Kingma, P J Poortenga, E De Hoog, Frits A J MuskietAbstract:We investigated whether in vitro L1210 growth inhibition by alpha-difluoromethylornithine (DFMO; 740 microM) and 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A; 1.7 microM) is reversible with N1-acetylspermine (N1-acSp). Influences of N1-acSp dose (1-100 microM), time (0-12 h at 100 microM), aminoguanidine (AG, 1 mM) and cell numbers (at 1 microM N1-acSp) on percentage S-phase, polyamine contents and viability were determined. DFMO/CGP 48664A decreased percentage S-phase from 58 to 26%, decreased spermidine (Sd) and spermine (Sp) contents 3-fold, but did not affect viability. With increasing N1-acSp dose, S-phase percentage and Sd contents increased concomitantly, reaching plateau values that were comparable with those of untreated controls. S-phase and Sd content increased from 4-6 h after N1-acSp administration, reaching plateau values from 11 and 6 h, respectively. N1-acSp content was dose dependent and increased linearly to reach plateau values from 8 h. AG did not affect any of these parameters. Addition of 1 microM N1-acSp to decreasing numbers of DFMO/CGP 48664A-treated cells caused increasing S-phase percentage, Sd and N1-acSp contents. We conclude that cell cycle kinetics of cultured L1210 cells can be manipulated by the induction of growth inhibition with DFMO/CGP 48664A and its subsequent abolishment with N1-acSp. N1-acSp accumulation rate and its subsequent conversion to Sd is relatively slow compared with intracellular Sd needs. The data support the notion that Sd is the most important polyamine for growth.
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in vivo manipulation of l1210 cell cycle phase distribution with α difluoromethylornithine 4 amidinoindan 1 one 2 Amidinohydrazone and n1 acetylspermine
Biochimica et Biophysica Acta, 1998Co-Authors: B Dorhout, Harri Ferwerda, Aw Kingma, E De Hoog, Frits A J MuskietAbstract:We investigated whether the in vivo growth inhibitory effect of the combination of 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A) and alpha-difluoromethylornithine (DFMO) is reversible by treatment with N1-acetylspermine (N1-acSp). DBA-2 mice were inoculated with 10(5) L1210 cell i.p. on day 0. From day 1 they received 2.50 mg CGP 48664A/kg i.p. once daily and 500 mg DFMO/kg i.p. twice daily. On day 5 they received 3 x 2500 nmol N1-acSp i.p. with 15-min intervals. L1210 cell numbers, S-phase percentage and polyamine contents, and liver and spleen polyamine contents were monitored in the following 48 h. Four days treatment with CGP 48664A/DFMO reduced L1210 cell numbers, S-phase, and spermidine. N1-acSp treatment increased L1210 spermidine from < or = 8 h and percentage S-phase from 12 h. Maxima for spermidine and S-phase were reached at < or = 8 and 18 h, respectively. These were below levels of untreated controls. Decreases were noted from 12 and 18 h, respectively. N1-acSp was detectable in L1210 from 0-18 h. Liver spermidine was decreased by CGP 48664A/DFMO. After N1-acSp treatment, liver N1-acSp and N1-acSd increased from < or = 8 h, reached maxima at < or = 8 and 10 h, respectively, and were undetectable from 15 h. We conclude that the in vivo growth inhibitory effect of CGP 48664A/DFMO is reversible by N1-acSp treatment. The liver is probably involved in N1-acSp terminal catabolism. The effect of the polyamine depletion-repletion scheme on S-phase cell numbers may be much more profound than present estimates from 5-bromo-2'-deoxyuridine incorporation.
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4 amidinoindan 1 one 2 Amidinohydrazone cgp 48664a exerts in vitro growth inhibitory effects that are not only related to s adenosylmethionine decarboxylase samdc inhibition
Biochimica et Biophysica Acta, 1997Co-Authors: B Dorhout, Marinca F G Odink, Elly De Hoog, Anneke W Kingma, Eveline Van Der Veer, Frits A J MuskietAbstract:Abstract The competitive S -adenosylmethionine decarboxylase (SAMdc; EC 4.1.1.50) inhibitor 4-amidinoindan-1-one 2′-Amidinohydrazone (CGP 48664A) inhibits growth more effectively than the irreversible SAMdc inhibitor 5′-{[( Z )-4-amino-2-butenyl]methylamino}-5′-deoxyadenosine (AbeAdo), while having similar effects on polyamine contents. We hypothesized that growth inhibition by CGP 48664A is not merely accomplished by SAMdc inhibition. Concentration-related growth inhibitory effects of AbeAdo, CGP 48664A and methylglyoxal bis(guanylhydrazone) (MGBG) were investigated in L1210 cells that were additionally exposed to 10 μ M AbeAdo. This concentration causes maximal growth inhibition, profound SAMdc inhibition and plateau polyamine contents. Almost complete inhibition of functional SAMdc activity by 10 μ M AbeAdo was confirmed by demonstration of poor conversion of tetradeuterated spermidine to tetradeuterated spermine by gas chromatography–mass spectrometry. Increasing AbeAdo did not affect L1210 cell numbers, viability, nor polyamine contents. MGBG proved highly toxic. CGP 48664A did not affect L1210 polyamine contents, but cell numbers and viability decreased dose-dependently to 50% and 70% of control, respectively. We conclude that CGP 48664A inhibits L1210 growth not only through SAMdc inhibition, but also by an as yet poorly understood second effect with higher IC 50 . The alleged second effect of CGP 48664A appears important for its potent antitumor effect.
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in vivo effects of 4 amidinoindan l one 2 Amidinohydrazone cgp 48664a and α difluoromethylornithine dfmo on l1210 growth cell cycle phase distribution and polyamine contents
International Journal of Cancer, 1995Co-Authors: B Dorhout, Harri Ferwerda, Elly De Hoog, Anneke W Kingma, Roelf Jakob Te Velde, Frits A J MuskietAbstract:We studied the in vivo effects of 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A), alpha-difluoromethylornithine (DFMO) and a combination of CGP 48654A-DFMO on tumor growth, cell-cycle phase distribution and polyamine contents. DBA-2, mice were inoculated i.p. with 10(5) L1210 cells on day 0, treated i.p. on days 1-4 and killed on day 5. As compared to controls, CGP 48664A, DFMO and the CGP 48664A-DFMO combination reduced L1210 cell numbers by 33, 43 and 85%, respectively. CGP 48664A did not affect cell-cycle phase distribution. DFMO and the CGP 48664A-DFMO combination caused a moderate and a heavy accumulation in G(0)/G(1)- and G(2)/M-phases, respectively. Compared with controls, the CGP 48664A-DFMO combination reduced putrescine, spermidine and total polyamines, but did not affect spermine. Compared with CGP 48664A, the CGP 48664A-DFMO combination caused lower putrescine and total polyamines, higher spermine, but no change in spermidine. Compared with DFMO, the CGP 48664A-DFMO combination caused higher putrescine and spermidine, lower spermine, but no change in total polyamine levels. We conclude that CGP 48664A potentiates the cystostatic effect of DFMO in vivo. The resulting growth inhibition is accompanied by an accumulation in G(0)/G(1)- and G(2)/M-phases and a reduction of putrescine and spermidine. The data suggest that perturbed polyamine composition rather than reduced spermidine or total polyamine pool size causes a profound growth inhibition. (C) 1995 Wiley-Liss, Inc.
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in vivo growth inhibition of l1210 leukemia by 4 amidinoindan 1 one 2 Amidinohydrazone cgp 48664a a new inhibitor of s adenosylmethionine decarboxylase
International Journal of Cancer, 1995Co-Authors: B Dorhout, Rjt Velde, Harri Ferwerda, Aw Kingma, E Dehoog, Frits A J MuskietAbstract:We studied the in vivo growth-inhibitory effect of the new S-adenosylmethionine decarboxylase inhibitor 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A). L1210-bearing DBA-2 mice were treated with increasing CGP 48664A doses from I day after i.p. L1210 cell inoculation. Treatment was continued for 4 days, after which all mice were killed. CGP 48664A caused dose-related exponential decreases of L1210 cell numbers and spermidine and spermine contents. Putrescine contents increased exponentially. Polyamine changes in spleen and liver were less profound. L1210 growth inhibition was not accompanied by changes in cell cycle phase distribution. It is concluded that CGP 48664A is an effective inhibitor of S-adenosylmethionine decarboxylase but that CGP 48664A-induced changes in intracellular polyamine compositions are not necessarily the cause of growth inhibition. (C) 1995 Wiley-Liss, Inc.
Harri Ferwerda - One of the best experts on this subject based on the ideXlab platform.
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in vivo manipulation of l1210 cell cycle phase distribution with α difluoromethylornithine 4 amidinoindan 1 one 2 Amidinohydrazone and n1 acetylspermine
Biochimica et Biophysica Acta, 1998Co-Authors: B Dorhout, Harri Ferwerda, Aw Kingma, E De Hoog, Frits A J MuskietAbstract:We investigated whether the in vivo growth inhibitory effect of the combination of 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A) and alpha-difluoromethylornithine (DFMO) is reversible by treatment with N1-acetylspermine (N1-acSp). DBA-2 mice were inoculated with 10(5) L1210 cell i.p. on day 0. From day 1 they received 2.50 mg CGP 48664A/kg i.p. once daily and 500 mg DFMO/kg i.p. twice daily. On day 5 they received 3 x 2500 nmol N1-acSp i.p. with 15-min intervals. L1210 cell numbers, S-phase percentage and polyamine contents, and liver and spleen polyamine contents were monitored in the following 48 h. Four days treatment with CGP 48664A/DFMO reduced L1210 cell numbers, S-phase, and spermidine. N1-acSp treatment increased L1210 spermidine from < or = 8 h and percentage S-phase from 12 h. Maxima for spermidine and S-phase were reached at < or = 8 and 18 h, respectively. These were below levels of untreated controls. Decreases were noted from 12 and 18 h, respectively. N1-acSp was detectable in L1210 from 0-18 h. Liver spermidine was decreased by CGP 48664A/DFMO. After N1-acSp treatment, liver N1-acSp and N1-acSd increased from < or = 8 h, reached maxima at < or = 8 and 10 h, respectively, and were undetectable from 15 h. We conclude that the in vivo growth inhibitory effect of CGP 48664A/DFMO is reversible by N1-acSp treatment. The liver is probably involved in N1-acSp terminal catabolism. The effect of the polyamine depletion-repletion scheme on S-phase cell numbers may be much more profound than present estimates from 5-bromo-2'-deoxyuridine incorporation.
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in vivo effects of 4 amidinoindan l one 2 Amidinohydrazone cgp 48664a and α difluoromethylornithine dfmo on l1210 growth cell cycle phase distribution and polyamine contents
International Journal of Cancer, 1995Co-Authors: B Dorhout, Harri Ferwerda, Elly De Hoog, Anneke W Kingma, Roelf Jakob Te Velde, Frits A J MuskietAbstract:We studied the in vivo effects of 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A), alpha-difluoromethylornithine (DFMO) and a combination of CGP 48654A-DFMO on tumor growth, cell-cycle phase distribution and polyamine contents. DBA-2, mice were inoculated i.p. with 10(5) L1210 cells on day 0, treated i.p. on days 1-4 and killed on day 5. As compared to controls, CGP 48664A, DFMO and the CGP 48664A-DFMO combination reduced L1210 cell numbers by 33, 43 and 85%, respectively. CGP 48664A did not affect cell-cycle phase distribution. DFMO and the CGP 48664A-DFMO combination caused a moderate and a heavy accumulation in G(0)/G(1)- and G(2)/M-phases, respectively. Compared with controls, the CGP 48664A-DFMO combination reduced putrescine, spermidine and total polyamines, but did not affect spermine. Compared with CGP 48664A, the CGP 48664A-DFMO combination caused lower putrescine and total polyamines, higher spermine, but no change in spermidine. Compared with DFMO, the CGP 48664A-DFMO combination caused higher putrescine and spermidine, lower spermine, but no change in total polyamine levels. We conclude that CGP 48664A potentiates the cystostatic effect of DFMO in vivo. The resulting growth inhibition is accompanied by an accumulation in G(0)/G(1)- and G(2)/M-phases and a reduction of putrescine and spermidine. The data suggest that perturbed polyamine composition rather than reduced spermidine or total polyamine pool size causes a profound growth inhibition. (C) 1995 Wiley-Liss, Inc.
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in vivo growth inhibition of l1210 leukemia by 4 amidinoindan 1 one 2 Amidinohydrazone cgp 48664a a new inhibitor of s adenosylmethionine decarboxylase
International Journal of Cancer, 1995Co-Authors: B Dorhout, Rjt Velde, Harri Ferwerda, Aw Kingma, E Dehoog, Frits A J MuskietAbstract:We studied the in vivo growth-inhibitory effect of the new S-adenosylmethionine decarboxylase inhibitor 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A). L1210-bearing DBA-2 mice were treated with increasing CGP 48664A doses from I day after i.p. L1210 cell inoculation. Treatment was continued for 4 days, after which all mice were killed. CGP 48664A caused dose-related exponential decreases of L1210 cell numbers and spermidine and spermine contents. Putrescine contents increased exponentially. Polyamine changes in spleen and liver were less profound. L1210 growth inhibition was not accompanied by changes in cell cycle phase distribution. It is concluded that CGP 48664A is an effective inhibitor of S-adenosylmethionine decarboxylase but that CGP 48664A-induced changes in intracellular polyamine compositions are not necessarily the cause of growth inhibition. (C) 1995 Wiley-Liss, Inc.
Aw Kingma - One of the best experts on this subject based on the ideXlab platform.
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in vivo manipulation of l1210 cell cycle phase distribution with α difluoromethylornithine 4 amidinoindan 1 one 2 Amidinohydrazone and n1 acetylspermine
Biochimica et Biophysica Acta, 1998Co-Authors: B Dorhout, Harri Ferwerda, Aw Kingma, E De Hoog, Frits A J MuskietAbstract:We investigated whether the in vivo growth inhibitory effect of the combination of 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A) and alpha-difluoromethylornithine (DFMO) is reversible by treatment with N1-acetylspermine (N1-acSp). DBA-2 mice were inoculated with 10(5) L1210 cell i.p. on day 0. From day 1 they received 2.50 mg CGP 48664A/kg i.p. once daily and 500 mg DFMO/kg i.p. twice daily. On day 5 they received 3 x 2500 nmol N1-acSp i.p. with 15-min intervals. L1210 cell numbers, S-phase percentage and polyamine contents, and liver and spleen polyamine contents were monitored in the following 48 h. Four days treatment with CGP 48664A/DFMO reduced L1210 cell numbers, S-phase, and spermidine. N1-acSp treatment increased L1210 spermidine from < or = 8 h and percentage S-phase from 12 h. Maxima for spermidine and S-phase were reached at < or = 8 and 18 h, respectively. These were below levels of untreated controls. Decreases were noted from 12 and 18 h, respectively. N1-acSp was detectable in L1210 from 0-18 h. Liver spermidine was decreased by CGP 48664A/DFMO. After N1-acSp treatment, liver N1-acSp and N1-acSd increased from < or = 8 h, reached maxima at < or = 8 and 10 h, respectively, and were undetectable from 15 h. We conclude that the in vivo growth inhibitory effect of CGP 48664A/DFMO is reversible by N1-acSp treatment. The liver is probably involved in N1-acSp terminal catabolism. The effect of the polyamine depletion-repletion scheme on S-phase cell numbers may be much more profound than present estimates from 5-bromo-2'-deoxyuridine incorporation.
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in vitro manipulation of l1210 cell cycle kinetics with 4 amidinoindan 1 one 2 Amidinohydrazone alpha difluoromethylornithine and n 1 acetylspermine
Biochimica et Biophysica Acta, 1998Co-Authors: B Dorhout, Aw Kingma, P J Poortenga, E De Hoog, Frits A J MuskietAbstract:We investigated whether in vitro L1210 growth inhibition by alpha-difluoromethylornithine (DFMO; 740 microM) and 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A; 1.7 microM) is reversible with N1-acetylspermine (N1-acSp). Influences of N1-acSp dose (1-100 microM), time (0-12 h at 100 microM), aminoguanidine (AG, 1 mM) and cell numbers (at 1 microM N1-acSp) on percentage S-phase, polyamine contents and viability were determined. DFMO/CGP 48664A decreased percentage S-phase from 58 to 26%, decreased spermidine (Sd) and spermine (Sp) contents 3-fold, but did not affect viability. With increasing N1-acSp dose, S-phase percentage and Sd contents increased concomitantly, reaching plateau values that were comparable with those of untreated controls. S-phase and Sd content increased from 4-6 h after N1-acSp administration, reaching plateau values from 11 and 6 h, respectively. N1-acSp content was dose dependent and increased linearly to reach plateau values from 8 h. AG did not affect any of these parameters. Addition of 1 microM N1-acSp to decreasing numbers of DFMO/CGP 48664A-treated cells caused increasing S-phase percentage, Sd and N1-acSp contents. We conclude that cell cycle kinetics of cultured L1210 cells can be manipulated by the induction of growth inhibition with DFMO/CGP 48664A and its subsequent abolishment with N1-acSp. N1-acSp accumulation rate and its subsequent conversion to Sd is relatively slow compared with intracellular Sd needs. The data support the notion that Sd is the most important polyamine for growth.
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In vitro manipulation of L1210 cell cycle kinetics with 4-amidinoindan-1-one 2 '-Amidinohydrazone, alpha-difluoromethylornithine and N-1-acetylspermine
1998Co-Authors: Dorhout B, Aw Kingma, P J Poortenga, De Hoog E, Muskiet FajAbstract:We investigated whether in vitro L1210 growth inhibition by alpha-difluoromethylomithine (DFMO; 740 mu M) and 4-amidinoindan-l-one 2'-Amidinohydrazone (CGP 48664A; 1.7 mu M) ii reversible with N-1-acetylspermine (N-1-acSp). Influences of N-1-acSp dose (1-100 mu M), time (0-12 h at 100 mu M), aminoguanidine (AG, 1 mM) and cell numbers (at 1 mu M N-1-acSp) on percentage S-phase, polyamine contents and viability were determined. DFMO/CGP 48664A decreased percentage S-phase from 58 to 26%, decreased spermidine (Sd) and sl,ermine (Sp) contents 3-fold, but did not affect viability. With increasing N-1-acSp dose, S-phase percentage and Sd contents increased concomitantly, reaching plateau values that were comparable with those of untreated controls. S-phase and Sd content increased from 4-6 h after N-1-acSp administration, reaching plateau values from 11 and 6 h, respectively. N-1-acSp content was dose dependent and increased linearly to reach plateau values from 8 h. AG did not affect any of these parameters. Addition of 1 mu M N-1-acSp to decreasing numbers of DFMO/CGP 48664A-treated cells caused increasing S-phase percentage, Sd and N-1-acSp contents. We conclude that cell cycle kinetics of cultured L1210 cells can be manipulated by the induction of growth inhibition with DFMO/CGP 48664A and its subsequent abolishment with N-1-acSp. N-1-acSp accumulation rate and its subsequent conversion to Sd is relatively slow compared with intracellular Sd needs. The data support the notion that Sd is the most important polyamine for growth. (C) 1998 Elsevier Science B.V. All rights reserved
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In vivo manipulation of L1210 cell cycle phase distribution with alpha-difluoromethylornithine, 4-amidinoindan-1-one 2 '-Amidinohydrazone and N-1-acetylspermine
1998Co-Authors: Dorhout B, Aw Kingma, De Hoog E, Ferwerda H, Muskiet FajAbstract:We investigated whether the in vivo growth inhibitory effect of the combination of 4-amidinoindan-l-one 2'-Amidinohydrazone (CGP 48664A) and alpha-difluoromethylornithine (DFMO) is reversible by treatment with N-1-acetylspermine (N-1-acSp). DBA-2 mice were inoculated with 10(5) L1210 cells i.p. on day 0. From day 1 they received 2.50 mg CGP 48664A/kg i.p. once daily and 500 mg DFMO/kg i.p. twice daily. On day 5 they received 3 X 2500 nmol N-1-acSp i.p. with 15-min intervals. L1210 cell numbers, S-phase percentage and polyamine contents, and liver and spleen polyamine contents were monitored in the following 48 h. Four days treatment with CGP 48663A/DFMO reduced L1210 cell numbers, S-phase, and spermidine. N-1-acSp treatment increased L1210 spermidine from less than or equal to 8 h and percentage S-phase from 12 h. Maxima for spermidine and S-phase were reached at less than or equal to 8 and 18 h, respectively. These were below levels of untreated controls. Decreases were noted from 12 and 18 h, respectively. N-1-acSp was detectable in L1210 from 0-18 h. Liver spermidine was decreased by CGP 48664A/DFlVIO. After N-1-acSp treatment, liver N-1-acSp and N-1-acSd increased from less than or equal to 8 h, reached maxima at less than or equal to 8 and 10 h, respectively, and were undetectable from 15 h. We conclude that the in vivo growth inhibitory effect of CGP 48664A/DFMO is reversible by N-1-acSp treatment. The liver is probably involved in N-1-acSp terminal catabolism. The effect of the polyamine depletion-repletion scheme on S-phase cell numbers may be much more profound than present estimates from 5-bromo-2'-deoxyuridine incorporation. (C) 1998 Elsevier Science B.V. All rights reserved
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in vivo growth inhibition of l1210 leukemia by 4 amidinoindan 1 one 2 Amidinohydrazone cgp 48664a a new inhibitor of s adenosylmethionine decarboxylase
International Journal of Cancer, 1995Co-Authors: B Dorhout, Rjt Velde, Harri Ferwerda, Aw Kingma, E Dehoog, Frits A J MuskietAbstract:We studied the in vivo growth-inhibitory effect of the new S-adenosylmethionine decarboxylase inhibitor 4-amidinoindan-1-one 2'-Amidinohydrazone (CGP 48664A). L1210-bearing DBA-2 mice were treated with increasing CGP 48664A doses from I day after i.p. L1210 cell inoculation. Treatment was continued for 4 days, after which all mice were killed. CGP 48664A caused dose-related exponential decreases of L1210 cell numbers and spermidine and spermine contents. Putrescine contents increased exponentially. Polyamine changes in spleen and liver were less profound. L1210 growth inhibition was not accompanied by changes in cell cycle phase distribution. It is concluded that CGP 48664A is an effective inhibitor of S-adenosylmethionine decarboxylase but that CGP 48664A-induced changes in intracellular polyamine compositions are not necessarily the cause of growth inhibition. (C) 1995 Wiley-Liss, Inc.
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anti arrhythmia action of Amidinohydrazone substituted benzophenones 6 parenteral drug forms of z 2 amino 5 chlorobenzophenone Amidinohydrazone acetate g 256
Die Pharmazie, 1994Co-Authors: M Schleuder, P H Richter, A Keckeis, T JiraAbstract:The combination of lyophilized G 256 and a solvent ampoule is recommended as an optimal variant for the application of the compound. In the lyophilized substance both the hydrolysis and the isomerisation are reduced so it is stable enough for the required period of usability.
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cytochrome p450 dependent n hydroxylation of an aminoguanidine Amidinohydrazone and microsomal retroreduction of the n hydroxylated product
Xenobiotica, 1994Co-Authors: Bernd Clement, M H Schultzemosgau, P H Richter, A BeschAbstract:1. The first example of a P450-dependent N-hydroxylation of an aminoguanidine (Amidinohydrazone) is reported for 2-amino-5-chlorobenzophenone Amidinohydrazone 1 (G 256) as substrate. 2. The N-hydroxylated metabolite 2 (2-amino-5-chlorobenzophenone N-hydroxyAmidinohydrazone NOH-G256) and a further metabolite of 1, the phenol 3, were identified by tlc and ms analysis. 3. The microsomal reduction of an N-hydroxyaminoguanidine (N-hydroxy-amidino-hydrazone) was also demonstrated for the transformation of 2 to 1. 4. Both the N-hydroxylation of the aminoguanidine and the retroreduction of the N-hydroxyaminoguanidine were characterized by quantitative hplc analysis. 5. The conversion of the aminoguanidine 1 to N-hydroxyaminoguanidine 2 may be considered as an analogue of the physiological N-hydroxylation of arginine to N-hydroxyarginine by NO synthases.
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antiarrhythmia active Amidinohydrazone substituted benzophenones 5 the stability of z 2 amino 5 chlorobenzophenone Amidinohydrazone acetate in solution
Die Pharmazie, 1993Co-Authors: M Schleuder, P H Richter, A Keckeis, T JiraAbstract:The aqueous solution of the title compound can be used for injection for one year if it is stored at room temperature and under light protection. Under these conditions 8% of the E-isomer are produced. The reaction is reversible at day light. Red coloured products of decomposition are formed by long lasting influence of light. At higher temperatures or at sterilisation several products of decomposition are formed which structure is elucidated. For these decomposition a scheme is proposed.
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antiarrhythmic Amidinohydrazone substituted benzophenones 2 preparation and determination of configuration of z and e 2 amino 5 chlorobenzophenone Amidinohydrazone salts
Die Pharmazie, 1992Co-Authors: P H Richter, M Schleuder, G Reck, A HagenAbstract:The configurational isomers of the 2-amino-5-chlorbenzophenoneAmidinohydrazones could be obtained as TLC pure samples by fractionating crystallization of the product mixture. The determination of their configuration by comparison of the UV spectra with the corresponding oximes could be confirmed by X-ray structure analysis.
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anti arrhythmic action of some Amidinohydrazone substituted benzophenones 1 synthesis of new Amidinohydrazone and n phenylAmidinohydrazone substituted benzophenones
Die Pharmazie, 1992Co-Authors: P H Richter, A Besch, K Kasbohm, A HagenAbstract:The title compounds are synthesized as a rule by condensation of substituted benzophenones and derivatives of aminoguanidine in the presence of up to 2.5 moles of an anorganic acid. They can be obtained alternatively via corresponding hydrazones, thiosemicarbazones or methylthiothiocarbonylhydrazones.