Inhibin Production by Sertoli Cells During Testicular Regression in the Golden Hamster

Berkowitz, Albert S.; Heindel, Jerrold J.

doi:10.1002/j.1939-4640.1987.tb03321.x

Cited by 9 publications

(7 citation statements)

References 25 publications

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“…Consequently, SD suppression of CTH may depend on 1) increased sensitivity of the SD pituitary to inhibin negative feedback or 2) decreased dependence on inhibin feedback in SDs. The former is congruent with increased sensitivity of SD pituitaries to Sertoli cell products in vitro [55], whereas the latter is compatible with the notion that increases in steroid negative feedback sensitivity [21,22,24] render inhibin feedback unnecessary in SDs [25]. Thus, the absence of CTH in SDs is likely due to either parallel increases in the sensitivity to steroid and inhibin negative feedback, or increased sensitivity to steroid negative feedback that renders inhibin superfluous for restraint of FSH.…”

Section: A Possible Mechanism For Photoperiodic Regulation Of Cthsupporting

confidence: 63%

Photoperiodic Regulation of Compensatory Testicular Hypertrophy in Hamsters1

Paul¹,

Park²,

Horton³

et al. 2006

Biology of Reproduction

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In mammals, removal of one testis results in compensatory testicular hypertrophy (CTH) of the remaining gonad. Although CTH is ubiquitous among juveniles of many species, laboratory rats, laboratory mice, and humans unilaterally castrated in adulthood fail to display CTH. We documented CTH in pre- and postpubertally hemi-castrated Syrian and Siberian hamsters and tested whether day length affects CTH in juvenile and adult Siberian hamsters. Robust CTH was evident in long-day hemi-castrates of both species and was preceded by increased serum FSH concentrations in juvenile Siberian hamsters. In sharp contrast, CTH was undetectable in short-day hemi-castrated Siberian hamsters for several months and only made its appearance with the development of neuroendocrine refractoriness to short day lengths; serum FSH concentrations of juveniles also did not increase above sham-castrate values until the onset of refractoriness. Long-day hemi-castrated Siberian hamsters with hypertrophied testes underwent complete gonadal regression after transfer to short days, albeit at a reduced rate for the first 3 weeks of treatment. Blood testosterone concentrations of adult hamsters did not differ between long-day hemicastrates and sham-castrates 9-12 weeks after surgery. We conclude that CTH is suppressed by short day lengths in Siberian hamsters at all ages and stages of reproductive development; in short day lengths, but not long day lengths, the remaining testis produces sufficient negative feedback inhibition to restrain FSH hypersecretion and prevent CTH.

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Section: A Possible Mechanism For Photoperiodic Regulation Of Cthsupporting

confidence: 63%

Photoperiodic Regulation of Compensatory Testicular Hypertrophy in Hamsters1

Paul¹,

Park²,

Horton³

et al. 2006

Biology of Reproduction

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“…However, it is possible that the increased sensitivity of Sertoli cells from S hamsters to FSH reflects either upregulation of FSH receptors in response to sup¬ pression of endogenous FSH release (Yellon & Goldman, 1984) or the ability of FSH to increase, rather than deplete, the number of FSH-binding sites in S animals. Berkowitz & Heindel (1987) reported that the inhibin-like activity ofconditioned media of golden hamster Sertoli cells was greatest from cells isolated from S hamsters. Moreover, the pituitaries from S hamsters were more sensitive to the action of inhibin.…”

Section: Discussionmentioning

confidence: 99%

Effects of age, photoperiod and follicle-stimulating hormone on lactate production by cultured Sertoli cells from prepubertal Siberian hamsters (Phodopus sungorus)

Newton¹,

Welsh²,

Bartke³

1992

Reproduction

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To define a functional difference in Sertoli cells of animals exposed to different photoperiodic conditions, we isolated Sertoli cells from the testes of juvenile Siberian hamsters and cultured them in serum-free medium. In all age groups studied, Sertoli cells isolated from hamsters with delayed and normal puberty responded to follicle-stimulating hormone (FSH) with an increase in lactate production. The increase in lactate production induced by 1000 ng FSH ml-1 was significantly greater in Sertoli cells isolated from hamsters with delayed puberty than in those with normal puberty. These results suggest that Sertoli cells of Siberian hamsters exposed to short photoperiod in vivo may respond to increases in plasma FSH concentrations associated with photostimulation or spontaneous sexual maturation by an increase in secretory activity that may be critical for the initiation of spermatogenesis.

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Section: Testismentioning

confidence: 99%

“…Using a hamster pituitary cells bioassay, Berkowitz and Heindel (98) reported that Sertoli cells obtained from the testes of blinded, gonadally regressed hamsters produced more inhibin than those obtained from the active gonads of animals maintained in a long photoperiod. These investigators suggested that increased inhibin production, combined with increased responsiveness of the pituitary cells to inhibin, may contribute to the decline in FSH levels during testicular regression (98). Using a radioimmunoassay for measurements of inhibin, we have noted a progressive decrease in serum inhibin levels after 6 and 9 weeks of exposure to short photoperiod, with changes in serum FSH clearly preceding the changes in serum inhibin levels (B. D. Schanbacher and A. Bartke, unpublished observations).…”

Section: Testismentioning

confidence: 99%

Seasonal Changes in the Function of the Hypothalamic-Pituitary-Testicular Axis in the Syrian Hamster

Bartke

Steger²

1992

Experimental Biology and Medicine

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n the overwhelming majority of animal species, reproductive functions exhibit pronounced annual I rhythmicity. Fertility is usually restricted to a particular and often a very brief period of the year, the breeding season. The Syrian (golden) hamster, Mesocricetus auratus, is a very popular model for the study of seasonal breeding, and a substantial part of what is known about the mechanisms of environmental control of mammalian reproduction is derived from experiments conducted in this species. Golden hamsters have a relatively restricted geographic range and commercially available laboratory stocks are derived from a few animals collected over 50 years ago in northern Syria (1). In their natural habitat, hamsters breed in the spring and fall and hibernate during the winter. Under laboratory conditions, they remain reproductively active throughout the year, as long as they are exposed to long photoperiods, i.e., at least 12.5 hr of light per day. However, the transfer of adult animals to a short photoperiod (i.e., less than 12 hr/day) or complete darkness at any time of the year triggers a sequence of changes in their neuroendocrine and reproductive functions that appears to mimic the processes that normally occur during the fall, winter, and early spring. These changes include (i) repression of the testes, (ii) a period of gonadal atrophy and functional quiescence, and (iii) spontaneous recovery ("recrudescence") of testicular size and activity. The amplitude of these changes is enormous, with reduction of testicular weight by at least 80%, comparable decreases in the size of other parts of the male reproduc-tive system, complete cessation of spermatogenesis, substantial reduction in the blood levels of the male sex hormone, testosterone, and loss of libido (2, 3). These responses to a short photoperiod can be prevented by surgical removal of the pineal gland and mimicked by properly timed melatonin injections and thus are obviously mediated by photoperiod-related changes in the secretory function of the pineal (2). There is a substantial amount of evidence that photoperiod indeed influences the pineal, that the pineal product melatonin alters hypothalamic control of synthesis and secretion of several hormones by the anterior pituitary gland, and that reduced release of these hormones is, in turn, responsible for testicular atrophy. Although these responses of male golden hamsters to photoperiods providing less than 12.5 hr of light per day are extremely consistent, their exact timing and, to a lesser extent, their magnitude depend also on ambient temperature (4), previous photoperiod history (5), strain (6), and the social environment (7) of the animals.Changes in the pituitary and testicular function opposite to those described above take place some 3 '/2-4 l/2 months after the transfer to inhibitory photoperiods. They are apparently driven by an endogenous "biological clock" and lead to complete recovery of testicular function and fertility (2,3). It is the purpose of this brief review to discuss pineal, hyp...

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Inhibin Production by Sertoli Cells During Testicular Regression in the Golden Hamster

Cited by 9 publications

References 25 publications

Photoperiodic Regulation of Compensatory Testicular Hypertrophy in Hamsters1

Photoperiodic Regulation of Compensatory Testicular Hypertrophy in Hamsters1

Effects of age, photoperiod and follicle-stimulating hormone on lactate production by cultured Sertoli cells from prepubertal Siberian hamsters (Phodopus sungorus)

Seasonal Changes in the Function of the Hypothalamic-Pituitary-Testicular Axis in the Syrian Hamster

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