EFFECT OF TUMOR-NECROSIS-FACTOR-ALPHA ON PROGESTERONE PRODUCTION BY GRANULOSA-CELLS IN LAYING HENS OF DIFFERENT GENETIC LINES

In vitro progesterone production by granulosa cells in the presence or absence of human recombinant tumor necrosis factor-alpha (hrTNF-alpha ) was measured at 10, 20, and 30 wk of egg production in White Leghorn hens selected for high (HA)- or low-antibody (LA) response to sheep r ed blood cell challenge. Isolated granulosa cells from the three large st preovulatory follicles (F1-F3) were incubated with 5 or 250 ng/ml h rTNF-alpha, and progesterone production was determined by the use of a validated radioimmunoassay. F1, F2, and F3 granulosa cells from HA he ns produced more (P less than or equal to 0.05) progesterone (140.8, 1 07.2, and 49.7 ng/ml) than LA hens (109.4, 78.9, and 26.9 ng/ml). The treatment of granulosa cells with hrTNF-alpha consistently inhibited ( P less than or equal to 0.05) progesterone secretion by all follicles among HA and LA hens, but not always at both doses. Generally, 5 ng/ml hrTNF-alpha was the maximum inhibitory dose. In the laying hen, a dec rease in steroid production in response to cytokines may upset the ste roid balance created by follicular hierarchy and inhibit or delay ovul ation. (C) Elsevier Science Inc. 1997.