Identification and distribution of prostaglandin E receptors on porcine luteal cells.
This study examined whether pig luteal cells contain specific prostaglandin (PG) E receptors. Corpora lutea, from PG 600R -induced cycling prepubertal gilts or naturally cycling gilts, were dissociated enzymatically, and large, small, and mixed cells were obtained by elutriation. Preliminary experiments demonstrated that optimal [3H]PGE2 binding to mixed cells was obtained after incubation at 22 degrees C for 2 h in binding buffer containing 1% BSA at pH 7.38. In addition, [3H]PGE2 binding was displaced by prostaglandins in the order of PGE2 approximately or = to PGE1 > PGF2a > > PGI2. The mixed, large, and small cells were assayed for specific PGE2 binding by displacement analysis with [3H]PGE2 and varying concentrations of unlabeled PGE2. Each gilt was assigned to group A (n = 6) or group B (n = 3) on the basis of whether the serum progesterone concentrations in that pig had increased or decreased, respectively, from 2 days before ovary collection to the time of ovary collection. Luteal cells from PG 600R -induced cycling prepubertal gilts had similar (p > 0.1) affinities and numbers of PGE receptors. In group A, the mixed cells contained a PGE binding site with a Kd of 21.1 +/- 1.1 nM and a concentration of 5.0 x 10(5) sites per large cell. Affinities of PGE receptors were similar (p > 0.1) regardless of cell types and functional status. PGE receptor concentrations were higher on large cells than on small cells (p > 0.05) and in group A than in group B (p = 0.006). These data demonstrated that PGE receptors primarily exist on porcine large luteal cells and that the concentration of PGE receptors appeared to be related to corpus luteum functional status.
Feng
S M
SM
Department of Food Animal and Equine Medicine, College of Veterinary Medicine North Carolina State University, Raleigh 27606, USA.
Almond
G W
GW
D000818:Animals; D048429:Cell Size / Q000502:physiology; D003338:Corpus Luteum / Q000166:cytology / Q000378:metabolism*; D005260:Female; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007700:Kinetics; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D011374:Progesterone / Q000097:blood; D011453:Prostaglandins / Q000378:metabolism; D018078:Receptors, Prostaglandin E / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013552:Swine; D013696:Temperature
D011453:Prostaglandins; D018078:Receptors, Prostaglandin E; D012710:Serum Albumin, Bovine; D011374:Progesterone