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N. M. Biswas - One of the best experts on this subject based on the ideXlab platform.
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Effect of continuous light on spermatogenesis and testicular steroidogenesis in rats: possible involvement of Alpha 2u-Globulin.
Nepal Medical College journal : NMCJ, 2013Co-Authors: N. M. Biswas, R Biswas, Late H MandalAbstract:Male rats exposed to continous light for 70 days showed an increased weights of testis, accessory sex organs, serum levels of FSH, LH, testosterone, testicular 17beta-hydroxysteroid dehydrogenase (1beta-HSD) activity and Alpha 2u-Globulin, while 3beta-hydroxysteroid dehydrogenase activity showed no significant changes. Prolonged light exposure also stimulated sepermatogenesis in rats. These results suggest that Alpha 2u-Globulin possibly stimutates the male gonad by inducing pituitary gonadotropins in continuous light-exposed rats.
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Effect of gonadotropins and Alpha 2u-Globulin on testicular steroidogenesis and spermatogenesis in melatonin-treated rats
Journal of College of Medical Sciences-Nepal, 2012Co-Authors: R Biswas, N. M. Biswas, H. MandalAbstract:Administration of melatonin (400?g/100g bd.wt.) for 14 days caused a fall in weights of the testes and accessory sex organs and testicular 17?-hydroxysteroid dehydrogenase (17?-HSD) but rise in 3?-hydroxysteroid dehydrogenase (3?-HSD) activity, decreased spermatogenesis, serum level of gonadotropins, testosterone and Alpha 2u-Globulin, The animals treated with melatonin when received gonadotropins or Alpha 2u-Globulin for the last seven days reversed the weight of testis and accessory sex organs, 3?-HSD, 17?-HSD activities, serum level of gonadotropins, testosterone and Alpha 2u-Globulin when compared with melatonin-treated rats. It is concluded that Alpha 2u-Globulin prevents testicular degeneration in melatonin-treated rats by stimulating the synthesis of gonadotropins. Journal of College of Medical Sciences-Nepal,2012,Vol-8,No-1, 7-12 DOI: http://dx.doi.org/10.3126/jcmsn.v8i1.6819
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Effect of continual light deprivation and Alpha-2u-Globulin replacement therapy on serum concentration of gonadotropins and testicular activity in rats.
Andrologia, 2009Co-Authors: P. K. Ghosh, R Biswas, H. Mandal, N. M. BiswasAbstract:Prolonged darkness caused a fall in testicular 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) activity and diminished spermatogenesis, serum levels of gonadotropins, testosterone and Alpha 2u-Globulin. Administration of Alpha 2u-Globulin at a dose of 1.5 mg rat-1 per day for 7 days after 68 days of light deprivation, reversed the 17 beta-HSD activity and serum levels of gonadotropins, testosterone and Alpha 2u-Globulin, while spermatogenesis was restored to normal. The animals kept in prolonged darkness for 68 days and then received saline (7 days in light-dark cycle, 14 L: 10 D), showed no significant changes of testicular activity, serum levels of gonadotropins, testosterone and Alpha 2u-Globulin, when compared with dark-exposed animals (68 days) receiving rabbit serum (7 days in light-dark cycle, 14 L: 10 D). These results suggest that Alpha 2u-Globulin plays an important role in testicular function in dark-exposed rats by inducing gonadotropins and testosterone secretion.
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Effects of passive immunization against Alpha-2u-Globulin and supplementation with Alpha-2u-Globulin on serum gonadotrophins and testicular activity.
Life sciences, 1996Co-Authors: Romi Biswas, P. K. Ghosh, Mahitosh Sarkar, N. M. BiswasAbstract:Abstract The purpose of the present study was to evaluate the effects of anti-Alpha-2u-Globulin on pituitary-gonadal functions in male rats. Adult male rats were given injections of anti-Alpha-2u-Globulin (1 mg/day) for 14 days, when they were killed 7 days after the last injection, serum levels of gonadotrophins and testosterone measured by radioimmunoassays, were less, testicular Δ53β- and 17β-hydroxysteroid dehydrogenase (3β- and 17β-HSD) activities were suppressed, spermatogenesis was inhibited and serum level of Alpha-2u-Globulin was decreased in anti-Alpha-2u-Globulin treated rats. Administration of Alpha-2u-Globulin (1.5 mg/day) for 7 days to anti-Alpha-2u-Globulin treated rats reversed the 3β-HSD and 17β-HSD activities and serum levels of gonadotrophins, testosterone and Alpha-2u-Globulin, while spermatogenesis was restored to normal. The results indicate that changes in testicular steroidogenesis and spermatogenesis in rats after passive immunization against Alpha-2u-Globulin may be due to decrease in availability of endogenous Alpha-2u-Globulin.
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Effect of thyroidectomy, and thyroxine and α2u-Globulin replacement therapy on testicular steroidogenic and gametogenic activities in rats
The Journal of endocrinology, 1994Co-Authors: N. M. Biswas, P. K. Ghosh, R Biswas, Debidas GhoshAbstract:Adult male rats were thyroidectomized and killed after 22 days of treatment. Thyroidectomy lowered the weights of testes and accessory sex organs, decreased the activities of testicular delta 5-3 beta- and 17 beta-hydroxysteroid dehydrogenases (HSD), and diminished spermatogenesis, serum levels of testosterone and Alpha 2u-Globulin. Supplementation with thyroxine at a dose of 5 micrograms/100 g body weight per day for 21 days or supplementation with Alpha 2u-Globulin at a dose of 1.5 mg/rat per day for 21 days in thyroidectomized animals partially reversed the decrease in HSD activities and serum concentrations of testosterone and Alpha 2u-Globulin, while spermatogenesis was restored to normal. The weights of testes and accessory sex organs were also reinstated after supplementation with thyroxine or Alpha 2u-Globulin in thyroidectomized rats in comparison with thyroidectomized animals. It was concluded that Alpha 2u-Globulin may be an intermediary in the thyroid hormone control of testicular function.
Lois D. Lehman-mckeeman - One of the best experts on this subject based on the ideXlab platform.
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α2u-Globulin is the only member of the lipocalin protein superfamily that binds to hyaline droplet inducing agents
Toxicology and applied pharmacology, 1992Co-Authors: Lois D. Lehman-mckeeman, Douglas CaudillAbstract:The rate-limiting step in chemically induced, male rat-specific hyaline droplet nephropathy is the reversible binding of a xenobiotic to Alpha 2u-Globulin. In this study, equilibrium saturation binding experiments were conducted to evaluate the in vitro binding of d-limonene-1,2-oxide (dLO) and 2,4,4-trimethyl-2-pentanol (TMP-OH) to Alpha 2u-Globulin and members of the Alpha 2u-Globulin protein superfamily. Both dLO and TMP-OH bound to Alpha 2u-Globulin, with Scatchard analysis yielding dissociation constants of 5.6 and 6.4 x 10(-7) M, respectively. The Bmax for binding (nmol bound/mg protein) was 50.7 and 61.1 for dLO and TMP-OH, respectively, yielding a molar ratio of approximately 1 for both ligands. The ability of dLO and TMP-OH to bind to human-derived Alpha 1-acid glycoprotein, rat-derived retinol-binding protein, human protein-1, and bovine beta-lactoGlobulin was also studied. These superfamily proteins are generally abundant in plasma, are freely filtered across the glomerulus, and can bind a wide range of ligands. However, neither dLO nor TMP-OH bound to any of the superfamily proteins. In contrast, under identical experimental conditions, Alpha 1-acid glycoprotein did bind progesterone (Kd = 10(-6) M), whereas both beta-lactoGlobulin and retinol-binding protein bound retinol (Kd = 10(-8) M for both proteins). These results indicate that, under conditions where Alpha 2u-Globulin superfamily proteins bind to established ligands, the proteins do not interact with hyaline droplet inducing agents. Thus, the interaction between male rat-specific nephrotoxicants and Alpha 2u-Globulin is unique to this protein. More importantly, these results provide direct evidence that the presence of the Alpha 2u-Globulin superfamily proteins does not predispose humans to develop hyaline droplet nephropathy and renal cancer from this class of chemicals.
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Quantitation of urinary α2u-Globulin and albumin by reverse-phase high performance liquid chromatography
Journal of pharmacological methods, 1991Co-Authors: Lois D. Lehman-mckeeman, Douglas CaudillAbstract:A rapid, reproducible, and sensitive high-performance liquid chromatography (HPLC) method for the quantitation of Alpha 2u-Globulin, the major urinary protein excreted by adult male rats, and albumin has been developed. Total urinary proteins, isolated by a simple Sephadex G-25 gel filtration step, are separated and quantitated by reverse-phase HPLC on a C4 Macrosphere 300 column. The proteins are separated and eluted with a two-step gradient of acetonitrile in aqueous trifluoroacetic acid. Detection limits of 9 and 25 micrograms/mL of urine were established for albumin and Alpha 2u-Globulin, respectively. Quantitation of urinary excretion of the two proteins in young adult male and female rats and aging male rats showed that values obtained with this method compared favorably with values from previously developed immunological techniques. To quantitate total urinary protein excretion, we modified the Bradford protein assay to use rat urinary protein as standard. Given the established importance of Alpha 2u-Globulin in the development of male rat-specific nephrotoxicity and nephrocarcinogenicity, these methods should be useful for studying the renal handling of this protein under normal and nephrotoxic conditions.
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The human relevance of the renal tumor-inducing potential of d-limonene in male rats: implications for risk assessment.
Regulatory toxicology and pharmacology : RTP, 1991Co-Authors: W.gary Flamm, Lois D. Lehman-mckeemanAbstract:The monoterpene d-limonene is a naturally occurring chemical which is the major component in oil of orange. Currently, d-limonene is widely used as a flavor and fragrance and is listed to be generally recognized as safe (GRAS) in food by the Food and Drug Administration (21 CFR 182.60 in the Code of Federal Regulations). Recently, however, d-limonene has been shown to cause a male rat-specific kidney toxicity referred to as hyaline droplet nephropathy. Furthermore, chronic exposure to d-limonene causes a significant incidence of renal tubular tumors exclusively in male rats. Although d-limonene is not carcinogenic in female rats or male and female mice given much higher dosages, the male rat-specific nephrocarcinogenicity of d-limonene may raise some concern regarding the safety of d-limonene for human consumption. A considerable body of scientific data has indicated that the renal toxicity of d-limonene results from the accumulation of a protein, Alpha 2u-Globulin, in male rat kidney proximal tuble lysosomes. This protein is synthesized exclusively by adult male rats. Other species, including humans, synthesize proteins that share significant homology with Alpha 2u-Globulin. However, none of these proteins, including the mouse equivalent of Alpha 2u-Globulin, can produce this toxicity, indicating a unique specificity for Alpha 2u-Globulin. With chronic exposure to d-limonene, the hyaline droplet nephropathy progresses and the kidney shows tubular cell necrosis, granular cast formation at the corticomedullary junction, and compensatory cell proliferation. Both d-limonene and cis-d-limonene-1,2-oxide (the major metabolite involved in this toxicity) are negative in in vitro mutagenicity screens. Therefore, the toxicity-related renal cell proliferation is believed to be integrally involved in the carcinogenicity of d-limonene as persistent elevations in renal cell proliferation may increase fixation of spontaneously altered DNA or serve to promote spontaneously initiated cells. The scientific data base demonstrates that the tumorigenic activity of d-limonene in male rats is not relevant to humans. The three major lines of evidence supporting the human safety of d-limonene are (1) the male rat specificity of the nephrotoxicity and carcinogenicity; (2) the pivotal role that Alpha 2u-Globulin plays in the toxicity, as evidenced by the complete lack of toxicity in other species despite the presence of structurally similar proteins; and (3) the lack of genotoxicity of both d-limonene and d-limonene-1,2-oxide, supporting the concept of a nongenotoxic mechanism, namely, sustained renal cell proliferation.(ABSTRACT TRUNCATED AT 400 WORDS)
R Biswas - One of the best experts on this subject based on the ideXlab platform.
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Effect of continuous light on spermatogenesis and testicular steroidogenesis in rats: possible involvement of Alpha 2u-Globulin.
Nepal Medical College journal : NMCJ, 2013Co-Authors: N. M. Biswas, R Biswas, Late H MandalAbstract:Male rats exposed to continous light for 70 days showed an increased weights of testis, accessory sex organs, serum levels of FSH, LH, testosterone, testicular 17beta-hydroxysteroid dehydrogenase (1beta-HSD) activity and Alpha 2u-Globulin, while 3beta-hydroxysteroid dehydrogenase activity showed no significant changes. Prolonged light exposure also stimulated sepermatogenesis in rats. These results suggest that Alpha 2u-Globulin possibly stimutates the male gonad by inducing pituitary gonadotropins in continuous light-exposed rats.
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Effect of gonadotropins and Alpha 2u-Globulin on testicular steroidogenesis and spermatogenesis in melatonin-treated rats
Journal of College of Medical Sciences-Nepal, 2012Co-Authors: R Biswas, N. M. Biswas, H. MandalAbstract:Administration of melatonin (400?g/100g bd.wt.) for 14 days caused a fall in weights of the testes and accessory sex organs and testicular 17?-hydroxysteroid dehydrogenase (17?-HSD) but rise in 3?-hydroxysteroid dehydrogenase (3?-HSD) activity, decreased spermatogenesis, serum level of gonadotropins, testosterone and Alpha 2u-Globulin, The animals treated with melatonin when received gonadotropins or Alpha 2u-Globulin for the last seven days reversed the weight of testis and accessory sex organs, 3?-HSD, 17?-HSD activities, serum level of gonadotropins, testosterone and Alpha 2u-Globulin when compared with melatonin-treated rats. It is concluded that Alpha 2u-Globulin prevents testicular degeneration in melatonin-treated rats by stimulating the synthesis of gonadotropins. Journal of College of Medical Sciences-Nepal,2012,Vol-8,No-1, 7-12 DOI: http://dx.doi.org/10.3126/jcmsn.v8i1.6819
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Effect of continual light deprivation and Alpha-2u-Globulin replacement therapy on serum concentration of gonadotropins and testicular activity in rats.
Andrologia, 2009Co-Authors: P. K. Ghosh, R Biswas, H. Mandal, N. M. BiswasAbstract:Prolonged darkness caused a fall in testicular 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) activity and diminished spermatogenesis, serum levels of gonadotropins, testosterone and Alpha 2u-Globulin. Administration of Alpha 2u-Globulin at a dose of 1.5 mg rat-1 per day for 7 days after 68 days of light deprivation, reversed the 17 beta-HSD activity and serum levels of gonadotropins, testosterone and Alpha 2u-Globulin, while spermatogenesis was restored to normal. The animals kept in prolonged darkness for 68 days and then received saline (7 days in light-dark cycle, 14 L: 10 D), showed no significant changes of testicular activity, serum levels of gonadotropins, testosterone and Alpha 2u-Globulin, when compared with dark-exposed animals (68 days) receiving rabbit serum (7 days in light-dark cycle, 14 L: 10 D). These results suggest that Alpha 2u-Globulin plays an important role in testicular function in dark-exposed rats by inducing gonadotropins and testosterone secretion.
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Effect of thyroidectomy, and thyroxine and α2u-Globulin replacement therapy on testicular steroidogenic and gametogenic activities in rats
The Journal of endocrinology, 1994Co-Authors: N. M. Biswas, P. K. Ghosh, R Biswas, Debidas GhoshAbstract:Adult male rats were thyroidectomized and killed after 22 days of treatment. Thyroidectomy lowered the weights of testes and accessory sex organs, decreased the activities of testicular delta 5-3 beta- and 17 beta-hydroxysteroid dehydrogenases (HSD), and diminished spermatogenesis, serum levels of testosterone and Alpha 2u-Globulin. Supplementation with thyroxine at a dose of 5 micrograms/100 g body weight per day for 21 days or supplementation with Alpha 2u-Globulin at a dose of 1.5 mg/rat per day for 21 days in thyroidectomized animals partially reversed the decrease in HSD activities and serum concentrations of testosterone and Alpha 2u-Globulin, while spermatogenesis was restored to normal. The weights of testes and accessory sex organs were also reinstated after supplementation with thyroxine or Alpha 2u-Globulin in thyroidectomized rats in comparison with thyroidectomized animals. It was concluded that Alpha 2u-Globulin may be an intermediary in the thyroid hormone control of testicular function.
P. K. Ghosh - One of the best experts on this subject based on the ideXlab platform.
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Effect of continual light deprivation and Alpha-2u-Globulin replacement therapy on serum concentration of gonadotropins and testicular activity in rats.
Andrologia, 2009Co-Authors: P. K. Ghosh, R Biswas, H. Mandal, N. M. BiswasAbstract:Prolonged darkness caused a fall in testicular 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) activity and diminished spermatogenesis, serum levels of gonadotropins, testosterone and Alpha 2u-Globulin. Administration of Alpha 2u-Globulin at a dose of 1.5 mg rat-1 per day for 7 days after 68 days of light deprivation, reversed the 17 beta-HSD activity and serum levels of gonadotropins, testosterone and Alpha 2u-Globulin, while spermatogenesis was restored to normal. The animals kept in prolonged darkness for 68 days and then received saline (7 days in light-dark cycle, 14 L: 10 D), showed no significant changes of testicular activity, serum levels of gonadotropins, testosterone and Alpha 2u-Globulin, when compared with dark-exposed animals (68 days) receiving rabbit serum (7 days in light-dark cycle, 14 L: 10 D). These results suggest that Alpha 2u-Globulin plays an important role in testicular function in dark-exposed rats by inducing gonadotropins and testosterone secretion.
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Effects of passive immunization against Alpha-2u-Globulin and supplementation with Alpha-2u-Globulin on serum gonadotrophins and testicular activity.
Life sciences, 1996Co-Authors: Romi Biswas, P. K. Ghosh, Mahitosh Sarkar, N. M. BiswasAbstract:Abstract The purpose of the present study was to evaluate the effects of anti-Alpha-2u-Globulin on pituitary-gonadal functions in male rats. Adult male rats were given injections of anti-Alpha-2u-Globulin (1 mg/day) for 14 days, when they were killed 7 days after the last injection, serum levels of gonadotrophins and testosterone measured by radioimmunoassays, were less, testicular Δ53β- and 17β-hydroxysteroid dehydrogenase (3β- and 17β-HSD) activities were suppressed, spermatogenesis was inhibited and serum level of Alpha-2u-Globulin was decreased in anti-Alpha-2u-Globulin treated rats. Administration of Alpha-2u-Globulin (1.5 mg/day) for 7 days to anti-Alpha-2u-Globulin treated rats reversed the 3β-HSD and 17β-HSD activities and serum levels of gonadotrophins, testosterone and Alpha-2u-Globulin, while spermatogenesis was restored to normal. The results indicate that changes in testicular steroidogenesis and spermatogenesis in rats after passive immunization against Alpha-2u-Globulin may be due to decrease in availability of endogenous Alpha-2u-Globulin.
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Effect of thyroidectomy, and thyroxine and α2u-Globulin replacement therapy on testicular steroidogenic and gametogenic activities in rats
The Journal of endocrinology, 1994Co-Authors: N. M. Biswas, P. K. Ghosh, R Biswas, Debidas GhoshAbstract:Adult male rats were thyroidectomized and killed after 22 days of treatment. Thyroidectomy lowered the weights of testes and accessory sex organs, decreased the activities of testicular delta 5-3 beta- and 17 beta-hydroxysteroid dehydrogenases (HSD), and diminished spermatogenesis, serum levels of testosterone and Alpha 2u-Globulin. Supplementation with thyroxine at a dose of 5 micrograms/100 g body weight per day for 21 days or supplementation with Alpha 2u-Globulin at a dose of 1.5 mg/rat per day for 21 days in thyroidectomized animals partially reversed the decrease in HSD activities and serum concentrations of testosterone and Alpha 2u-Globulin, while spermatogenesis was restored to normal. The weights of testes and accessory sex organs were also reinstated after supplementation with thyroxine or Alpha 2u-Globulin in thyroidectomized rats in comparison with thyroidectomized animals. It was concluded that Alpha 2u-Globulin may be an intermediary in the thyroid hormone control of testicular function.
Debidas Ghosh - One of the best experts on this subject based on the ideXlab platform.
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Effect of thyroidectomy, and thyroxine and α2u-Globulin replacement therapy on testicular steroidogenic and gametogenic activities in rats
The Journal of endocrinology, 1994Co-Authors: N. M. Biswas, P. K. Ghosh, R Biswas, Debidas GhoshAbstract:Adult male rats were thyroidectomized and killed after 22 days of treatment. Thyroidectomy lowered the weights of testes and accessory sex organs, decreased the activities of testicular delta 5-3 beta- and 17 beta-hydroxysteroid dehydrogenases (HSD), and diminished spermatogenesis, serum levels of testosterone and Alpha 2u-Globulin. Supplementation with thyroxine at a dose of 5 micrograms/100 g body weight per day for 21 days or supplementation with Alpha 2u-Globulin at a dose of 1.5 mg/rat per day for 21 days in thyroidectomized animals partially reversed the decrease in HSD activities and serum concentrations of testosterone and Alpha 2u-Globulin, while spermatogenesis was restored to normal. The weights of testes and accessory sex organs were also reinstated after supplementation with thyroxine or Alpha 2u-Globulin in thyroidectomized rats in comparison with thyroidectomized animals. It was concluded that Alpha 2u-Globulin may be an intermediary in the thyroid hormone control of testicular function.