Immunoreactive dynorphin-A in bovine anterior pituitary and its in vitro release.
The anterior lobe (AL) of the bovine pituitary contained and released, during in vitro culture, a form of immunoreactive dynorphin-A (ir-DYN-A) larger than that occurring in neural tissue. Bovine AL tissue from intact females contained less ir-DYN-A than did AL tissue from castrated males. Enzymatically dispersed AL cells contained and released ir-DYN-A in vitro. Preincubation of dispersed AL cells for 18 hr, rather than 1.5 hr, increased the content and release of ir-DYN-A as well as LH. Addition of gonadotropin-releasing hormone (GnRH) to tissue slices or dispersed cells stimulated release of LH, but in contrast to published observations from rat AL, GnRH had no effect on release of ir-DYN-A. Addition of estradiol-17 beta, with or without progesterone, increased release of ir-DYN-A but not LH during 2-hr cultures. In summary, bovine AL contains and releases in vitro a large molecular weight form of ir-DYN-A. Although this ir-DYN-A was not coreleased with LH, a reproductive role was suggested by in vivo and in vitro effects of gonadal hormones on ir-DYN-A in the bovine anterior pituitary.
D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D002478:Cells, Cultured; D004399:Dynorphins / Q000032:analysis / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009919:Orchiectomy; D010903:Pituitary Gland, Anterior / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D011374:Progesterone / Q000494:pharmacology; D011863:Radioimmunoassay; D012737:Sex Factors
D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol; D004399:Dynorphins