Smith M F, Kemper C N, Smith G W, Goetz T L, Jarrell V L
Department of Animal Sciences, University of Missouri-Columbia 65211.
J Anim Sci. 1994 Apr;72(4):1004-12. doi: 10.2527/1994.7241004x.
The objectives of the first experiment were to characterize the pattern of protein secretion by 1) porcine follicles before and after the preovulatory gonadotropin surge and 2) corpora lutea on d 4 and 11 after estrus (d 0 = estrus). Gilts were ovariectomized 1) on d 20 after estrus and before the preovulatory gonadotropin surge (pre-estrus group; n = 3), 2) 18 to 36 h after the onset of estrus and after the preovulatory gonadotropin surge (estrus group; n = 3), 3) on d 4 after estrus (n = 3), and 4) on d 11 after estrus (n = 4). Changes in pattern of protein secretion were determined by densitometric scanning of fluorographs. In the pre-estrus group, the major proteins secreted by follicular shells (FS) and granulosa cells (GC) had relative molecular masses (M(r)) of approximately 40,000, 46,000, and 55,000. In the estrus group (FS and GC), secretion of a M(r) 40,000 protein was decreased (P < .05) and secretion of a M(r) 30,000 protein was increased (P < .05) relative to the pre-estrus group. A predominant M(r) 30,000 protein was also secreted by corpora lutea on d 4 and 11. The objective of Exp. 2 was to determine whether synthesis of the M(r) 30,000 protein could be increased during the follicular phase by treatment with hCG, suggesting a role for the preovulatory gonadotropin surge in altering the pattern of protein secretion. Gilts were injected (i.m.) with saline (n = 3) or 500 IU of hCG (n = 3) on d 18 of the estrous cycle.(ABSTRACT TRUNCATED AT 250 WORDS)
