Prolactin acts in the pathway of photoperiod regulating the reproduction of the Striped Hamsters

Abstract To study the effects of prolactin (PRL) in pituitary on the reproduction of the Striped Hamsters via the photoperiods. Mature female striped hamsters were raised under various photoperiods to study the differential expression pattern of PRL in pituitary, and prolactin receptor (PRLR) in the hypothalamus, pituitary and ovary. Photoperiods affect the pituitary PRL mRNA level and pituitary, hypothalamus and ovaries PRLR mRNA levels in striped hamsters. Positive correlations of PRL mRNA expression in the pituitary with that of PRLR in hypothalamus and ovaries, and that of GnRH in hypothalamus were determined. The serum concentration of PRL, FSH, LH and GnRH were significantly different among the striped hamsters from different photoperiods. Serum concentration of PRL is positively correlated with that of FSH, LH and GnRH of the striped hamsters. Photoperiod was important environment factor modulating the expression profile of PRL and PRLR in the striped hamsters.