Ovarian steroid production in vitro during gonadal regression in the turkey. II. Changes induced by forced molting

• Published in: Biology of reproduction Vol. 45; no. 4; pp. 587 - 591
• Main Authors: PORTER, T. E, SILSBY, J. L, HARGIS, B. M, FEHRER, S. C, EL HALAWANI, M. E
• Format: Journal Article
• Language: English
• Published: Madison, WI Society for the Study of Reproduction 01.10.1991
• Subjects: Androgens - metabolism; Animals; Biological and medical sciences; Cells, Cultured; Estrogens - metabolism; Female; Follicular Atresia - physiology; Fundamental and applied biological sciences. Psychology; Granulosa Cells - metabolism; Hormone metabolism and regulation; Incubators; Luteinizing Hormone - blood; Luteinizing Hormone - pharmacology; Mammalian female genital system; Nesting Behavior - physiology; Ovary - physiology; Progesterone - metabolism; Prolactin - blood; Prolactin - physiology; Theca Cells - metabolism; Turkeys - blood; Turkeys - physiology; Vertebrates: reproduction; Ovary; Vertebrata; Androgen; Female genital system; Atresia; Regression; Turkey(bird); Steroidogenesis; Aves; Ovarian follicle; Ovarian hormone
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod45.4.587

In the turkey, the onset of incubation behavior is associated with altered ovarian steroidogenesis, ovarian regression, decreased, LH secretion, and increased serum prolactin (Prl) levels. To clarify the relative contribution of circulating LH and Prl to the initiation of ovarian regression, laying hens were exposed for 0, 3, 7, or 14 days to a forced molting procedure (exposure to reduced day length of 6L:18D and removal of feed and water for the initial 3 days) that induces ovarian regression and decreased LH levels but does not increase Prl levels. On each of these days, hens were killed and granulosa and theca interna cells from the largest (F1) and fifth largest (F5) preovulatory follicles and total cells from the small white follicles (SWF) were incubated for 5 h in the presence or absence of ovine LH (oLH; 0-1,000 ng/ml). Force-molted hens exhibited diminished levels of circulating LH, Prl, progesterone (P), androgen (A), and estradiol (E) by Day 3 of treatment. Ovarian atresia began in F1 by the third day of treatment, and included F1 and F5 by the seventh day. No preovulatory follicles were present on the fourteenth day. With both F1 and F5 granulosa cells, production of P in the presence of oLH was initially enhanced (Day 3) and later absent (Day 7). In contrast, production of A by F5 theca interna cells in the presence of oLH was initially suppressed (Day 3) and then returned to pretreatment levels (Day 7).