Relaxin protein and gene expression in ovarian follicles of immature pigs.
Relaxin production by the ovarian follicle of gonadotropin-primed, prepubertal gilts is well documented. As far as we are aware, a source of relaxin in pig follicles, independent of gonadotropins, has not yet been reported. Therefore, the objective of this study was to determine whether relaxin is produced in porcine follicles in the absence of exogenous or cyclic gonadotropins. In immature pigs, immunoreactive relaxin was detected in fluids from small (1-3 mm), medium (4-5 mm) and large (>6 mm) follicles and localized to the theca interna of large follicles. Relaxin levels in follicular fluid significantly increased with follicle size (P<0.05). Relaxin mRNA was detected in whole small- and medium-sized follicles. In large follicles, the relaxin gene was expressed in thecal layers, but not granulosa cells. The abundance of relaxin transcript did not change with follicle size. In summary, relaxin protein and mRNA were detected in porcine follicles from immature animals, indicating that relaxin is produced in the porcine follicle in the absence of exogenous or cyclic gonadotropins. Relaxin's in vitro growth effects on porcine granulosa and theca cells support this follicular relaxin as a growth modulator during porcine follicular development.
Ohleth
K M
KM
Department of Animal Sciences, Rutgers University, New Brunswick, New Jersey 08901-8525, USA.
Zhang
Q
Q
Bagnell
C A
CA
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D005260:Female; D015571:Follicular Fluid / Q000378:metabolism; D015870:Gene Expression; D007150:Immunohistochemistry; D006080:Ovarian Follicle / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D012065:Relaxin / Q000235:genetics / Q000378:metabolism*; D013552:Swine
D017931:DNA Primers; D012333:RNA, Messenger; D012065:Relaxin