Regulation of pituitary inhibin/activin subunits and follistatin gene expression by GnRH in female rats.

Pituitary inhibin B, activin B, and follistatin are local regulators of FSH. Activin B is a homodimeric molecule (β(B)-β(B)), while inhibin B contains an α and a β(B) subunit. The regulation of gene expression of α, β(B), and follistatin by local and endocrine hormones was examined in pituitaries from female rats and in perifused pituitary cells by RT-PCR. Ovariectomy (OVX) induced an elevation in the mRNA level of α and β(B) subunits and follistatin. Short-term (4 h) treatment of pituitary cells with GnRH decreased both the inhibin α and the inhibin/activin β(B) subunit mRNA levels, while long-term treatment (20 h) with 100 nM GnRH stimulated the expression of both subunits. In contrast, the mRNA level of follistatin was elevated after the short-term GnRH treatment. Long-term exposure of pituitary cells to estradiol and inhibin B suppressed the mRNA expression of β(B) and had no effect on the expression of α subunit and follistatin. Our results demonstrate that the increased expressions of inhibin/activin subunits and follistatin in the post-OVX period can be induced by the lack of gonadal negative feedback, resulting in a high GnRH environment in the pituitary. This study reports for the first time that GnRH administered in high doses and for a long period stimulates the gene expression of inhibin/activin subunits and thereby may contribute to the stimulatory effect of OVX on the expression of these genes.

Popovics P ，Rekasi Z ，Stewart AJ ，Kovacs M ... -  《-》

Variation in pituitary expression of mRNAs encoding the putative inhibin co-receptor (betaglycan) and type-I and type-II activin receptors during the chicken ovulatory cycle.

Lovell TM ，Knight PG ，Gladwell RT 《JOURNAL OF ENDOCRINOLOGY》

Pituitary follistatin and inhibin subunit messenger ribonucleic acid levels are differentially regulated by local and hormonal factors.

Bilezikjian LM ，Corrigan AZ ，Blount AL ，Vale WW ... -  《ENDOCRINOLOGY》

Pituitary follistatin gene expression in female rats: evidence that inhibin regulates transcription.

Prendergast KA ，Burger LL ，Aylor KW ，Haisenleder DJ ，Dalkin AC ，Marshall JC ... -  《BIOLOGY OF REPRODUCTION》

Anterior pituitary gene expression with reproductive aging in the female rat.

Zheng W ，Jimenez-Linan M ，Rubin BS ，Halvorson LM ... -  《BIOLOGY OF REPRODUCTION》