The effect of fetectomy on prostaglandin receptors of the rat myometrium.
It has been postulated that intrauterine volume plays a role in the timing of parturition. In previous studies we found that the onset of parturition in the rat was associated with significant increases in the concentration of receptors for PGF2 alpha in the myometrium. To determine the effect of intrauterine volume on the concentrations of this myometrial receptor, we compared receptor levels in pregnant and fetectomized horns from unilaterally fetectomized pregnant rats near the time of parturition (n = 3). Myometria from pregnant horns contained substantially greater concentration of protein than did those from the contralateral fetectomized horns. The amounts of receptors per horn for PGF2 alpha were about 3 times greater in myometria from pregnant horns than in those from fetectomized horns. However, near term the concentration of receptors per protein contents was the same in pregnant and fetectomized horns. These results suggest that uterine stretch causes hyperplasia and hypertrophy of the myometrium being indicative of more protein per pregnant than fetectomized horns. However, the rise in the concentration of receptors for PGF2 alpha about the time of labour appears to be induced by hormonal and not by physical factors.
D000818:Animals; D005314:Embryonic and Fetal Development; D005260:Female; D009215:Myometrium / Q000502:physiology*; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D011980:Receptors, Progesterone / Q000502:physiology*; D011982:Receptors, Prostaglandin / Q000502:physiology; D018078:Receptors, Prostaglandin E; D014590:Uterine Contraction
D011980:Receptors, Progesterone; D011982:Receptors, Prostaglandin; D018078:Receptors, Prostaglandin E