Influence of age and photoperiod on steroidogenic function of the testis in the golden hamster
The golden (Syrian) hamster is a seasonal breeder, and exposure of adult animals to short days results in severe gonadal regression with morphological features that resemble the immature testis. The purpose of this study was to investigate testicular steroidogenic capacity in the golden hamster and...
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1999
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01056263_v22_n4_p243_Frungieri http://hdl.handle.net/20.500.12110/paper_01056263_v22_n4_p243_Frungieri |
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paper:paper_01056263_v22_n4_p243_Frungieri2023-06-08T15:10:33Z Influence of age and photoperiod on steroidogenic function of the testis in the golden hamster 3α-diol 5α-reductase Dihydrotestosterone Golden hamster Leydig cells Photoperiod Testis Testosterone androgen androstanediol androstanolone chorionic gonadotropin steroid 5alpha reductase testosterone age androgen synthesis animal experiment animal tissue article controlled study hamster hormone blood level Leydig cell male nonhuman photoperiodicity priority journal puberty steroidogenesis testis testosterone blood level Aging Androgens Androstane-3,17-diol Animals Body Weight Chorionic Gonadotropin Cricetinae Dihydrotestosterone Male Mesocricetus Organ Size Photoperiod Sexual Maturation Steroids Testis Testosterone Testosterone 5-alpha-Reductase The golden (Syrian) hamster is a seasonal breeder, and exposure of adult animals to short days results in severe gonadal regression with morphological features that resemble the immature testis. The purpose of this study was to investigate testicular steroidogenic capacity in the golden hamster and to analyse the influence of age and photoperiod on this process. Hamsters aged 36 days were maintained on a long photoperiod (14L:10D), and adult animals were then exposed to a long or a short photoperiod (6L:18D) for 14 weeks (the period of time required to achieve maximal gonadal regression), to assess circulating levels and in vitro production of testosterone, dihydrotestosterone and androstane-3α,17β-diol. In peripubertal hamsters, androstane-3α,17β-diol was the main circulating androgen detected, whereas in active adult animals, testosterone showed the highest serum levels. In hamsters exposed to a short photoperiod, blood testosterone levels were significantly lower than levels in adult hamsters exposed to a long photoperiod. Exposure of adult hamsters to a short photoperiod produced a marked reduction in serum concentrations of dihydrotestosterone and androstane-3α,17β-diol, which was not accompanied by a decrease in testicular 5α-reductase activity. In the in vitro experiments, active adult testes were less sensitive than inactive adult testes to stimulation of androgen production with hCG, but showed similar sensitivity to the gonads from hamsters aged 36 days. In accordance with circulating androgen concentrations, the principal androgens produced in the in vitro assays from peripubertal and normal adult testes were androstane-3α,17β-diol and testosterone, respectively. Unexpectedly, the main androgen produced from regressed testes under in vitro conditions was androstane-3α,17β-diol. Inactive gonads released more androstane-3α,17β-diol than did normal adult testes and total in vitro androgen production (testosterone + dihydrotestosterone + androstane-3α,17β-diol) from adult testes was not diminished by exposure to a short photoperiod. However, in spite of the significant increase detected in production of androstane-3α, 17β-diol in vitro from regressed testes, inactive gonads produced less androstane-3α,17β-diol than did peripubertal testes. In summary, our studies suggest that testicular androgen biosynthetic capacity in adult hamsters exposed to short photoperiod is not reduced and these regressed testes represent an intermediate physiological state between peripubertal and active adult testes. The significant decrease detected in serum androgen concentrations during the involution phase could result from the absence of stimulating pituitary factors, together with a negative regulation of steroidogenesis by different non-steroidal signals originating within and/or outside of the testis. 1999 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01056263_v22_n4_p243_Frungieri http://hdl.handle.net/20.500.12110/paper_01056263_v22_n4_p243_Frungieri |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
3α-diol 5α-reductase Dihydrotestosterone Golden hamster Leydig cells Photoperiod Testis Testosterone androgen androstanediol androstanolone chorionic gonadotropin steroid 5alpha reductase testosterone age androgen synthesis animal experiment animal tissue article controlled study hamster hormone blood level Leydig cell male nonhuman photoperiodicity priority journal puberty steroidogenesis testis testosterone blood level Aging Androgens Androstane-3,17-diol Animals Body Weight Chorionic Gonadotropin Cricetinae Dihydrotestosterone Male Mesocricetus Organ Size Photoperiod Sexual Maturation Steroids Testis Testosterone Testosterone 5-alpha-Reductase |
| spellingShingle |
3α-diol 5α-reductase Dihydrotestosterone Golden hamster Leydig cells Photoperiod Testis Testosterone androgen androstanediol androstanolone chorionic gonadotropin steroid 5alpha reductase testosterone age androgen synthesis animal experiment animal tissue article controlled study hamster hormone blood level Leydig cell male nonhuman photoperiodicity priority journal puberty steroidogenesis testis testosterone blood level Aging Androgens Androstane-3,17-diol Animals Body Weight Chorionic Gonadotropin Cricetinae Dihydrotestosterone Male Mesocricetus Organ Size Photoperiod Sexual Maturation Steroids Testis Testosterone Testosterone 5-alpha-Reductase Influence of age and photoperiod on steroidogenic function of the testis in the golden hamster |
| topic_facet |
3α-diol 5α-reductase Dihydrotestosterone Golden hamster Leydig cells Photoperiod Testis Testosterone androgen androstanediol androstanolone chorionic gonadotropin steroid 5alpha reductase testosterone age androgen synthesis animal experiment animal tissue article controlled study hamster hormone blood level Leydig cell male nonhuman photoperiodicity priority journal puberty steroidogenesis testis testosterone blood level Aging Androgens Androstane-3,17-diol Animals Body Weight Chorionic Gonadotropin Cricetinae Dihydrotestosterone Male Mesocricetus Organ Size Photoperiod Sexual Maturation Steroids Testis Testosterone Testosterone 5-alpha-Reductase |
| description |
The golden (Syrian) hamster is a seasonal breeder, and exposure of adult animals to short days results in severe gonadal regression with morphological features that resemble the immature testis. The purpose of this study was to investigate testicular steroidogenic capacity in the golden hamster and to analyse the influence of age and photoperiod on this process. Hamsters aged 36 days were maintained on a long photoperiod (14L:10D), and adult animals were then exposed to a long or a short photoperiod (6L:18D) for 14 weeks (the period of time required to achieve maximal gonadal regression), to assess circulating levels and in vitro production of testosterone, dihydrotestosterone and androstane-3α,17β-diol. In peripubertal hamsters, androstane-3α,17β-diol was the main circulating androgen detected, whereas in active adult animals, testosterone showed the highest serum levels. In hamsters exposed to a short photoperiod, blood testosterone levels were significantly lower than levels in adult hamsters exposed to a long photoperiod. Exposure of adult hamsters to a short photoperiod produced a marked reduction in serum concentrations of dihydrotestosterone and androstane-3α,17β-diol, which was not accompanied by a decrease in testicular 5α-reductase activity. In the in vitro experiments, active adult testes were less sensitive than inactive adult testes to stimulation of androgen production with hCG, but showed similar sensitivity to the gonads from hamsters aged 36 days. In accordance with circulating androgen concentrations, the principal androgens produced in the in vitro assays from peripubertal and normal adult testes were androstane-3α,17β-diol and testosterone, respectively. Unexpectedly, the main androgen produced from regressed testes under in vitro conditions was androstane-3α,17β-diol. Inactive gonads released more androstane-3α,17β-diol than did normal adult testes and total in vitro androgen production (testosterone + dihydrotestosterone + androstane-3α,17β-diol) from adult testes was not diminished by exposure to a short photoperiod. However, in spite of the significant increase detected in production of androstane-3α, 17β-diol in vitro from regressed testes, inactive gonads produced less androstane-3α,17β-diol than did peripubertal testes. In summary, our studies suggest that testicular androgen biosynthetic capacity in adult hamsters exposed to short photoperiod is not reduced and these regressed testes represent an intermediate physiological state between peripubertal and active adult testes. The significant decrease detected in serum androgen concentrations during the involution phase could result from the absence of stimulating pituitary factors, together with a negative regulation of steroidogenesis by different non-steroidal signals originating within and/or outside of the testis. |
| title |
Influence of age and photoperiod on steroidogenic function of the testis in the golden hamster |
| title_short |
Influence of age and photoperiod on steroidogenic function of the testis in the golden hamster |
| title_full |
Influence of age and photoperiod on steroidogenic function of the testis in the golden hamster |
| title_fullStr |
Influence of age and photoperiod on steroidogenic function of the testis in the golden hamster |
| title_full_unstemmed |
Influence of age and photoperiod on steroidogenic function of the testis in the golden hamster |
| title_sort |
influence of age and photoperiod on steroidogenic function of the testis in the golden hamster |
| publishDate |
1999 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01056263_v22_n4_p243_Frungieri http://hdl.handle.net/20.500.12110/paper_01056263_v22_n4_p243_Frungieri |
| _version_ |
1768543793925062656 |