Effect of luteinizing hormone on progesterone production by the follicular granulosa in the ovarian hierarchy of the domestic fowl (Gallus domesticus).
A LH function test was used to assess the effect of a previously administered dose of ovine LH on the granulosa from the four largest preovulatory follicles, F1-F4, of laying hens. At intervals of 1, 3, and 6 hr after intravenous ovine LH (40 micrograms; a dose previously shown to cause atresia) or carrier solution (1% bovine serum albumin solution, BSA), a second dose of LH or carrier was injected. The progesterone contained in the dissected granulosa of the F1-F4 follicles 45 min after the second injection was measured by radioimmunoassay. With birds injected with BSA, the mean basal levels ranged from 17 to 59 ng progesterone per granulosa, irrespective of the follicular type. In short-term experiments, i.e., 45 min after LH, the mean progesterone contents of F1 (262 ng) and F2 (137 ng) were significantly higher than their controls, whereas those of F3 (59 ng) and F4 (21 ng) did not change. The response per cell was greater in the F1 granulosa than in that of F2-F4; other evidence is presented to support a hypothesis that the F1 granulosa contains a larger LH receptor population. The effect of LH over a longer period (6 hr) was shown by a decline in the steroidogenic response of the F1 granulosa only. The kinetics of this decline (estimated t1/2 13.7 hr) resembled that previously reported for adenylate cyclase activity in granulosa cells from postovulatory follicles (POF) (t1/2 about 14.4 hr).(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D002645:Chickens / Q000378:metabolism*; D005260:Female; D007986:Luteinizing Hormone / Q000494:pharmacology*; D010053:Ovary / Q000187:drug effects / Q000378:metabolism*; D011374:Progesterone / Q000096:biosynthesis*; D012710:Serum Albumin, Bovine / Q000494:pharmacology
D012710:Serum Albumin, Bovine; D011374:Progesterone; D007986:Luteinizing Hormone