|
|
||||||||
Regular Article |
a Department of Biology, West Virginia University, Morgantown, West Virginia 26505
ABSTRACT
We have investigated which follicular compartment and stage of follicular development are associated with endothelin-1 (ET-1) gene expression in the porcine ovary. The localization of mature ET-1 peptide and of its mRNA was determined by immunohistochemistry and by in situ hybridization. Stage of follicular development associated with ET-1 expression was investigated in terms of follicular class and occurrence of atresia. The latter was investigated by determining the occurrence of DNA fragmentation in apoptotic cells on adjacent sections to those used for ET-1 gene expression. Fifteen ovaries from 10 prepubertal pigs stimulated with gonadotropin were collected; a total of 1050 follicles were examined. Specific ET-1 immunoreactivity was restricted to the ovarian vasculature and to the granulosa cell compartment of antral follicles. The pattern of ET-1 mRNA expression was similar to that found for ET-1 immunoreactivity. Primordial, primary, and most secondary follicles did not express ET-1. The theca cell layer did not express ET-1 regardless of follicle developmental stage. ET-1 expression occurred with a significantly greater probability (P < 0.001 by the likelihood ratio test) in the granulosa cell compartment of antral follicles than in any other follicle class. Furthermore, in antral follicles, ET-1 expression occurred with a greater likelihood in large antral follicles than in small antral follicles (P < 0.001 by the likelihood ratio test). In small antral follicles, only 16.8% expressed ET-1; in contrast, 66.7% of large antral follicles exhibited ET-1 expression. It is interesting that in follicles in which ovulation had already occurred, intense ET-1 expression was found only in the prominent developing vasculature, the other cells present in the luteinized follicle did not display any ET-1 expression. The pattern of ET-1 gene expression observed in this study would be in agreement with our previous suggestion of a plausible physiological role for ET-1 in preventing premature progesterone production by granulosa cells of an antral follicle. The occurrence of atresia and expression of ET-1 in the same follicle was rare. Small and large antral follicles constituted 5.1% and 5.6%, respectively, of the examined follicles in this category. The majority of atretic follicles did not express ET-1 and, conversely, follicles that expressed ET-1 were not atretic. To the best of our knowledge, this is the first report in which large, nonatretic follicles are clearly identified as the population of follicles expressing ET-1. The results of this study delineate the follicular developmental stage and the compartment of when and where ET-1 may be physiologically meaningful.
First decision: 20 March 2000.
1 Supported in part by USDA/CSREES award 98-35203-6634 to J.A.F. Research was conducted with the technical assistance of Hope Sasway, Dean Overmiller, Brian Wood, and Shane Swatts.
2 Correspondence: Jorge A. Flores, Department of Biology, West Virginia University, P.O. Box 6057, Morgantown, WV 26505. FAX: 304 293 6363; jaf5s{at}wvnvm.wvnet.edu
This article has been cited by other articles:
![]() |
C. Boiti, M. Maranesi, C. Dall'Aglio, L. Pascucci, G. Brecchia, A. Gobbetti, and M. Zerani Vasoactive Peptides in the Luteolytic Process Activated by PGF2alpha in Pseudopregnant Rabbits at Different Luteal Stages Biol Reprod, July 1, 2007; 77(1): 156 - 164. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. A. LaVoie The Role of GATA in Mammalian Reproduction Experimental Biology and Medicine, December 1, 2003; 228(11): 1282 - 1290. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Levy, M. Gordin, M. F. Smith, O. U. Bolden-Tiller, and R. Meidan Hormonal Regulation and Cell-Specific Expression of Endothelin-Converting Enzyme 1 Isoforms in Bovine Ovarian Endothelial and Steroidogenic Cells Biol Reprod, April 1, 2003; 68(4): 1361 - 1368. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Levy, M. Gordin, R. Mamluk, M. Yanagisawa, M. F. Smith, J. H. Hampton, and R. Meidan Distinct Cellular Localization and Regulation of Endothelin-1 and Endothelin-Converting Enzyme-1 Expression in the Bovine Corpus Luteum: Implications for Luteolysis Endocrinology, December 1, 2001; 142(12): 5254 - 5260. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |