Guinea Pig

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Charles Advenier - One of the best experts on this subject based on the ideXlab platform.

  • the effect of s boldine on the α1 adrenoceptor of the Guinea Pig aorta
    British Journal of Pharmacology, 1996
    Co-Authors: Susana Chuliá, E. Naline, Joelle Moreau, Antonia M Noguera, Dolores M Ivorra, Pilar M Docon, Charles Advenier
    Abstract:

    1. The cardiovascular activity of S-(+)-boldine, an aporphine alkaloid structurally related to papaverine, was determined. The work includes functional studies on Guinea-Pig isolated aorta contracted with noradrenaline, caffeine, KCl or Ca2+, and on Guinea-Pig trachea contracted with acetylcholine or histamine. 2. S-(+)-boldine inhibited in a concentration-dependent manner the contractile response evoked by noradrenaline (10 microM) in Guinea-Pig aorta (IC50 = 1.4 +/- 0.2 microM) while the KCl depolarizing solution (60 mM)- or the Ca2+ (1 mM)-induced contractions were only partially affected by boldine up to 300 microM. In contrast, papaverine relaxed noradrenaline (NA), KCl or Ca2+ induced contractions showing similar IC50 values in all cases. S-(+)-boldine had a greater potency on the contraction elicited by NA whereas papaverine acted in a non-selective manner. 3. S-(+)-boldine was found to be an alpha 1-adrenoceptor blocking agent in Guinea-Pig aorta as revealed by its competitive antagonism of noradrenaline-induced vasoconstriction (pA2 = 5.64 +/- 0.08), and its potency was compared with that of prazosin (pA2 = 8.56 +/- 0.24), a known potent alpha 1-adrenoceptor antagonist. In contrast, papaverine caused rightward shifts of the NA concentration-response curves with depression of maximal response indicating that it acts as a non-competitive antagonist. 4. Contraction of Guinea-Pig aorta induced by caffeine (60 mM) in a Ca(2+)-containing Krebs solution was not affected by a 60 min incubation period with different doses of S-(+)-boldine (1-300 microM). Papaverine inhibited partially this caffeine-induced contraction at the maximal dose used (100 microM). 5. Inositol phosphates formation induced by noradrenaline (10 microM) in Guinea-Pig thoracic aorta was inhibited by S-(+)-boldine (30 microM) but not by papaverine (10 microM). 6. Contractions of Guinea-Pig trachea caused by acetylcholine (100 microM) or histamine (10 microM) were not modified by S-(+)-boldine (0.1-100 microM). 7. These results provide evidence that S-(+)-boldine, an aporphine alkaloid, has interesting properties as an alpha 1-adrenoceptor blocker in vascular smooth muscle, and acts as a competitive antagonist of the alpha 1-adrenoceptor present in the Guinea Pig aorta.

  • The effect of S‐(+)‐boldine on the α1‐adrenoceptor of the GuineaPig aorta
    British journal of pharmacology, 1996
    Co-Authors: Susana Chuliá, E. Naline, Joelle Moreau, M. Antonia Noguera, M. Dolores Ivorra, M. Pilar D'ocon, Charles Advenier
    Abstract:

    1. The cardiovascular activity of S-(+)-boldine, an aporphine alkaloid structurally related to papaverine, was determined. The work includes functional studies on Guinea-Pig isolated aorta contracted with noradrenaline, caffeine, KCl or Ca2+, and on Guinea-Pig trachea contracted with acetylcholine or histamine. 2. S-(+)-boldine inhibited in a concentration-dependent manner the contractile response evoked by noradrenaline (10 microM) in Guinea-Pig aorta (IC50 = 1.4 +/- 0.2 microM) while the KCl depolarizing solution (60 mM)- or the Ca2+ (1 mM)-induced contractions were only partially affected by boldine up to 300 microM. In contrast, papaverine relaxed noradrenaline (NA), KCl or Ca2+ induced contractions showing similar IC50 values in all cases. S-(+)-boldine had a greater potency on the contraction elicited by NA whereas papaverine acted in a non-selective manner. 3. S-(+)-boldine was found to be an alpha 1-adrenoceptor blocking agent in Guinea-Pig aorta as revealed by its competitive antagonism of noradrenaline-induced vasoconstriction (pA2 = 5.64 +/- 0.08), and its potency was compared with that of prazosin (pA2 = 8.56 +/- 0.24), a known potent alpha 1-adrenoceptor antagonist. In contrast, papaverine caused rightward shifts of the NA concentration-response curves with depression of maximal response indicating that it acts as a non-competitive antagonist. 4. Contraction of Guinea-Pig aorta induced by caffeine (60 mM) in a Ca(2+)-containing Krebs solution was not affected by a 60 min incubation period with different doses of S-(+)-boldine (1-300 microM). Papaverine inhibited partially this caffeine-induced contraction at the maximal dose used (100 microM). 5. Inositol phosphates formation induced by noradrenaline (10 microM) in Guinea-Pig thoracic aorta was inhibited by S-(+)-boldine (30 microM) but not by papaverine (10 microM). 6. Contractions of Guinea-Pig trachea caused by acetylcholine (100 microM) or histamine (10 microM) were not modified by S-(+)-boldine (0.1-100 microM). 7. These results provide evidence that S-(+)-boldine, an aporphine alkaloid, has interesting properties as an alpha 1-adrenoceptor blocker in vascular smooth muscle, and acts as a competitive antagonist of the alpha 1-adrenoceptor present in the Guinea Pig aorta.

Lawrence Toll - One of the best experts on this subject based on the ideXlab platform.

  • Comparison of κ2-opioid receptors in Guinea Pig brain and Guinea Pig ileum membranes
    European journal of pharmacology, 1993
    Co-Authors: Jay L. Webster, Willma E. Polgar, Susan R. Brandt, Ilona P. Berzetei-gurske, Lawrence Toll
    Abstract:

    Abstract The presence of κ -opioid receptor subtypes has been clearly established in Guinea Pig brain. Using [ 3 H]bremazocine in the presence of reversible blockers of μ, δ and κ 1 receptors, two additional binding sites can be determined in Guinea Pig brain membranes. The site with higher affinity for the opioid ligands represents κ 2 , while the other site has low affinity and is poorly characterized. The κ 2 site has high affinity for ethylketocyclazocine and other benzomorphans, as well as for the dynorphin gene products tested. The dynorphin analogs have no appreciable affinity for the low affinity site, so this site should not be called a κ receptor. With an appropriate membrane preparation, κ 2 binding can also be demonstrated in the Guinea Pig ileum. Binding affinities for selected ligands at κ 2 in Guinea Pig ileum membranes are very similar to affinities found in brain membranes.

J. F. Prchal - One of the best experts on this subject based on the ideXlab platform.

  • Guinea Pig serum erythropoietin (EPO) selectively stimulates Guinea Pig erythroid progenitors: human or mouse erythroid progenitors do not form erythroid burst-forming unit colonies in response to Guinea Pig serum EPO
    Experimental hematology, 1998
    Co-Authors: Tomas Stopka, J.h. Zivny, E Goldwasser, J. F. Prchal, Emanuel Necas
    Abstract:

    Erythropoietin (EPO) is the primary regulator of mammalian erythropoiesis, providing a proliferative and differentiative signal to the early EPO-responsive erythroid progenitors, burst-forming unit-erythroid (BFU-E) and colony-forming unit-erythroid, as well as to later EPO-responsive erythroid progenitors. EPO is secreted by the kidney in response to hypoxia and anemia. There is an extensive biological crossreactivity between human EPO and the EPOs of other mammals. Necas et al. have reported that this crossreactivity may not include the Guinea Pig (Cavia porcelllus). Because the specificity of the Guinea Pig's erythropoietic responses may be of biological significance, we compared Guinea Pig hypoxic serum with mouse (m) and human (h) recombinant (r) EPOs for their ability to induce erythroid progenitor proliferation and differentiation in semisolid cultures. Guinea Pig bone marrow mononuclear cells (BMMCs) formed BFU-E colonies in response to Guinea Pig hypoxic serum, rhEPO, or rmEPO in a dose-dependent fashion. Neither human nor mouse BMMCs responded to Guinea Pig hypoxic serum; however, Guinea Pig hypoxic serum exerted no inhibitory effect on human or mouse in vitro erythroid differentiation in the presence of rhEPO or rmEPO. The intensity of the EPO band on Western blotting analysis of Guinea Pig hypoxic serum was significantly greater than in nonhypoxic serum. This suggests that Guinea Pig erythropoiesis is mediated by EPO and stimulated by hypoxia in a fashion similar to that observed in human and mouse erythropoiesis. Furthermore, Guinea Pig EPO did not stimulate human or mouse erythroid differentiation in vitro, whereas Guinea Pig erythroid progenitors could be stimulated by human or mouse EPO, suggesting structural differences in Guinea Pig EPO and EPO receptor (EPOR) compared with human or mouse EPO and EPOR. These differences probably evolved after the Guinea Pig's ancestors diverged from myomorph rodents. Further characterization of the Guinea Pig EPO and EPOR should facilitate our understanding of the interaction between EPO and EPOR.

Susana Chuliá - One of the best experts on this subject based on the ideXlab platform.

  • the effect of s boldine on the α1 adrenoceptor of the Guinea Pig aorta
    British Journal of Pharmacology, 1996
    Co-Authors: Susana Chuliá, E. Naline, Joelle Moreau, Antonia M Noguera, Dolores M Ivorra, Pilar M Docon, Charles Advenier
    Abstract:

    1. The cardiovascular activity of S-(+)-boldine, an aporphine alkaloid structurally related to papaverine, was determined. The work includes functional studies on Guinea-Pig isolated aorta contracted with noradrenaline, caffeine, KCl or Ca2+, and on Guinea-Pig trachea contracted with acetylcholine or histamine. 2. S-(+)-boldine inhibited in a concentration-dependent manner the contractile response evoked by noradrenaline (10 microM) in Guinea-Pig aorta (IC50 = 1.4 +/- 0.2 microM) while the KCl depolarizing solution (60 mM)- or the Ca2+ (1 mM)-induced contractions were only partially affected by boldine up to 300 microM. In contrast, papaverine relaxed noradrenaline (NA), KCl or Ca2+ induced contractions showing similar IC50 values in all cases. S-(+)-boldine had a greater potency on the contraction elicited by NA whereas papaverine acted in a non-selective manner. 3. S-(+)-boldine was found to be an alpha 1-adrenoceptor blocking agent in Guinea-Pig aorta as revealed by its competitive antagonism of noradrenaline-induced vasoconstriction (pA2 = 5.64 +/- 0.08), and its potency was compared with that of prazosin (pA2 = 8.56 +/- 0.24), a known potent alpha 1-adrenoceptor antagonist. In contrast, papaverine caused rightward shifts of the NA concentration-response curves with depression of maximal response indicating that it acts as a non-competitive antagonist. 4. Contraction of Guinea-Pig aorta induced by caffeine (60 mM) in a Ca(2+)-containing Krebs solution was not affected by a 60 min incubation period with different doses of S-(+)-boldine (1-300 microM). Papaverine inhibited partially this caffeine-induced contraction at the maximal dose used (100 microM). 5. Inositol phosphates formation induced by noradrenaline (10 microM) in Guinea-Pig thoracic aorta was inhibited by S-(+)-boldine (30 microM) but not by papaverine (10 microM). 6. Contractions of Guinea-Pig trachea caused by acetylcholine (100 microM) or histamine (10 microM) were not modified by S-(+)-boldine (0.1-100 microM). 7. These results provide evidence that S-(+)-boldine, an aporphine alkaloid, has interesting properties as an alpha 1-adrenoceptor blocker in vascular smooth muscle, and acts as a competitive antagonist of the alpha 1-adrenoceptor present in the Guinea Pig aorta.

  • The effect of S‐(+)‐boldine on the α1‐adrenoceptor of the GuineaPig aorta
    British journal of pharmacology, 1996
    Co-Authors: Susana Chuliá, E. Naline, Joelle Moreau, M. Antonia Noguera, M. Dolores Ivorra, M. Pilar D'ocon, Charles Advenier
    Abstract:

    1. The cardiovascular activity of S-(+)-boldine, an aporphine alkaloid structurally related to papaverine, was determined. The work includes functional studies on Guinea-Pig isolated aorta contracted with noradrenaline, caffeine, KCl or Ca2+, and on Guinea-Pig trachea contracted with acetylcholine or histamine. 2. S-(+)-boldine inhibited in a concentration-dependent manner the contractile response evoked by noradrenaline (10 microM) in Guinea-Pig aorta (IC50 = 1.4 +/- 0.2 microM) while the KCl depolarizing solution (60 mM)- or the Ca2+ (1 mM)-induced contractions were only partially affected by boldine up to 300 microM. In contrast, papaverine relaxed noradrenaline (NA), KCl or Ca2+ induced contractions showing similar IC50 values in all cases. S-(+)-boldine had a greater potency on the contraction elicited by NA whereas papaverine acted in a non-selective manner. 3. S-(+)-boldine was found to be an alpha 1-adrenoceptor blocking agent in Guinea-Pig aorta as revealed by its competitive antagonism of noradrenaline-induced vasoconstriction (pA2 = 5.64 +/- 0.08), and its potency was compared with that of prazosin (pA2 = 8.56 +/- 0.24), a known potent alpha 1-adrenoceptor antagonist. In contrast, papaverine caused rightward shifts of the NA concentration-response curves with depression of maximal response indicating that it acts as a non-competitive antagonist. 4. Contraction of Guinea-Pig aorta induced by caffeine (60 mM) in a Ca(2+)-containing Krebs solution was not affected by a 60 min incubation period with different doses of S-(+)-boldine (1-300 microM). Papaverine inhibited partially this caffeine-induced contraction at the maximal dose used (100 microM). 5. Inositol phosphates formation induced by noradrenaline (10 microM) in Guinea-Pig thoracic aorta was inhibited by S-(+)-boldine (30 microM) but not by papaverine (10 microM). 6. Contractions of Guinea-Pig trachea caused by acetylcholine (100 microM) or histamine (10 microM) were not modified by S-(+)-boldine (0.1-100 microM). 7. These results provide evidence that S-(+)-boldine, an aporphine alkaloid, has interesting properties as an alpha 1-adrenoceptor blocker in vascular smooth muscle, and acts as a competitive antagonist of the alpha 1-adrenoceptor present in the Guinea Pig aorta.

Robert M. Weiss - One of the best experts on this subject based on the ideXlab platform.

  • Neurokinin Induced Inositol Phosphate Production in Guinea Pig Bladder
    The Journal of Urology, 1997
    Co-Authors: Thomas V. Martin, Marcia A. Wheeler, Robert M. Weiss
    Abstract:

    ABSTRACTPurpose: To examine second messenger pathways involved in neurokinin induced bladder contractions.Materials and Methods: Neurokinin induced changes in inositol phosphate production and in adenylyl cyclase activity are measured in the Guinea Pig bladder.Results: Substance P, substance P methyl ester, neurokinin A, and neurokinin B each increase [sup 3 H]-inositol phosphate production in the Guinea Pig bladder. Substance P (10 sup -6 M) increases [sup 3 H]-inositol trisphosphate levels within 30 sec. Substance P and neurokinin A have an additive effect on inositol phosphate production, however substance P (10 sup -5 M) or neurokinin A (10 sup -5 M) induced inositol phosphate production is less than that induced by carbachol (10 sup -5 M). Neurokinin B and to a lesser extent neurokinin A inhibit forskolin-activated adenylyl cyclase activity.Conclusions: These data are compatible with neurokinin-induced inositol phosphate production being coupled to increases in contractile force of the Guinea Pig uri...