TY - JOUR
T1 - Photoperiod-dependent regulation of inhibin in Siberian hamsters
T2 - I. Ovarian inhibin production and secretion
AU - Kenny, H. A.
AU - Bernard, D. J.
AU - Horton, T. H.
AU - Woodruff, T. K.
PY - 2002
Y1 - 2002
N2 - Follicle-stimulating hormone (FSH) stimulates ovarian follicle development and the production of protein hormones including inhibin A and inhibin B. The inhibins are dimeric proteins (α-βA or α-βB) secreted by growing follicles that suppress FSH in a classical endocrine negative feedback loop. Siberian hamsters, Phodopus sungorus, exhibit seasonal variation in FSH levels. Given the role of inhibin in FSH regulation, we hypothesized that ovarian inhibin expression differs between animals reared in long (16 h light:8 h darkness) and short (6 h light:18 h darkness) photoperiods. To examine inhibin expression in animals housed under long or short photoperiods, hamster inhibin α-, βA-, and βB-subunits were cloned and used to detect and localize inhibin subunit mRNA in developing follicles. Ovarian inhibin α-subunit mRNA levels were significantly higher in long day-exposed (LD) than in short day-exposed (SD) hamsters. In addition, dimeric inhibin, as well as inhibin α-, βA-, and βB,-subunit protein levels were higher in the LD than in the SD hamster ovaries.
AB - Follicle-stimulating hormone (FSH) stimulates ovarian follicle development and the production of protein hormones including inhibin A and inhibin B. The inhibins are dimeric proteins (α-βA or α-βB) secreted by growing follicles that suppress FSH in a classical endocrine negative feedback loop. Siberian hamsters, Phodopus sungorus, exhibit seasonal variation in FSH levels. Given the role of inhibin in FSH regulation, we hypothesized that ovarian inhibin expression differs between animals reared in long (16 h light:8 h darkness) and short (6 h light:18 h darkness) photoperiods. To examine inhibin expression in animals housed under long or short photoperiods, hamster inhibin α-, βA-, and βB-subunits were cloned and used to detect and localize inhibin subunit mRNA in developing follicles. Ovarian inhibin α-subunit mRNA levels were significantly higher in long day-exposed (LD) than in short day-exposed (SD) hamsters. In addition, dimeric inhibin, as well as inhibin α-, βA-, and βB,-subunit protein levels were higher in the LD than in the SD hamster ovaries.
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U2 - 10.1677/joe.0.1740071
DO - 10.1677/joe.0.1740071
M3 - Article
C2 - 12098665
AN - SCOPUS:0036319159
SN - 0022-0795
VL - 174
SP - 71
EP - 83
JO - Journal of Endocrinology
JF - Journal of Endocrinology
IS - 1
ER -
