TY - JOUR
T1 - Up-regulation of oxytocin receptors in porcine endometrium by adenosine 3',5'-monophosphate
AU - Uenoyama, Yoshihisa
AU - Hattori, Shin Ichi
AU - Miyake, Mari
AU - Okuda, Kiyoshi
PY - 1997/10
Y1 - 1997/10
N2 - Porcine endometrial cells (a mixture of epithelial, stromal, and glandular cells) were examined for the presence of oxytocin (OT) receptors using a cell culture system and a 125I-labeled OT antagonist. Binding specificity was tested in displacement studies with various related peptides. Scatchard analyses revealed the presence of a binding site with a dissociation constant (K(d)) = 0.9 nM and a capacity of 1.9 fmol/105 cells. These cells, which were obtained from prepubertal gilts and thus had not been exposed to endogenous ovarian steroids, were used as a model to evaluate the possible action of ovarian steroids and intracellular cAMP on OT receptors. Although ovarian steroids showed no effect on OT receptors, forskolin (an adenylate cyclase activator) and dibutyryl cAMP caused 1.5- to 1.6-fold increases in specific binding of OT without changing the binding affinity. When the endometrial cells were exposed to OT (0.1-1000 nM) in combination with arachidonic acid (10 μM), OT stimulated prostaglandin F(2α) secretion in a dose-dependent manner. These results indicate the presence of functional OT receptors in prepubertal porcine endometrial cells and suggest that the concentration of OT receptors may be regulated by one or more substances that raise intracellular cAMP levels.
AB - Porcine endometrial cells (a mixture of epithelial, stromal, and glandular cells) were examined for the presence of oxytocin (OT) receptors using a cell culture system and a 125I-labeled OT antagonist. Binding specificity was tested in displacement studies with various related peptides. Scatchard analyses revealed the presence of a binding site with a dissociation constant (K(d)) = 0.9 nM and a capacity of 1.9 fmol/105 cells. These cells, which were obtained from prepubertal gilts and thus had not been exposed to endogenous ovarian steroids, were used as a model to evaluate the possible action of ovarian steroids and intracellular cAMP on OT receptors. Although ovarian steroids showed no effect on OT receptors, forskolin (an adenylate cyclase activator) and dibutyryl cAMP caused 1.5- to 1.6-fold increases in specific binding of OT without changing the binding affinity. When the endometrial cells were exposed to OT (0.1-1000 nM) in combination with arachidonic acid (10 μM), OT stimulated prostaglandin F(2α) secretion in a dose-dependent manner. These results indicate the presence of functional OT receptors in prepubertal porcine endometrial cells and suggest that the concentration of OT receptors may be regulated by one or more substances that raise intracellular cAMP levels.
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U2 - 10.1095/biolreprod57.4.723
DO - 10.1095/biolreprod57.4.723
M3 - Article
C2 - 9314572
AN - SCOPUS:0030987620
VL - 57
SP - 723
EP - 728
JO - Biology of Reproduction
JF - Biology of Reproduction
SN - 0006-3363
IS - 4
ER -