High cholesterol is known to negatively affect uterine contractility in conditions. The aim of the present study was to reveal the effect of hypercholesterolemia on spontaneous and oxytocin-induced uterine contractility in late pregnant mouse uterus. Female Swiss albino mice were fed with high cholesterol (HC) diet (0.5% sodium cholate, 1.25% cholesterol and 15% fat) for 6 weeks and then throughout the gestation period after mating. On day 19 of gestation, serum cholesterol level was increased more than 3-fold while triglycerides level was reduced in HC diet-fed animals as compared to control animals fed with a standard diet. In tension experiments, neither the mean integral tension of spontaneous contractility nor the response to CaCl in high K-depolarized tissues was altered, but the oxytocin-induced concentration-dependent contractile response in uterine strips was attenuated in hypercholesterolemic mice as compared to control. Similarly, hypercholesterolemia dampened concentration-dependent uterine contractions elicited by a GNAQ protein activator, toxin. However, it had no effect on endogenous oxytocin level either in plasma or in uterine tissue. It also did not affect the prostaglandin release in oxytocin-stimulated tissues. Western blot data showed a significant increase in caveolin-1 and GRK6 proteins but decline in oxytocin receptor, GNAQ and RHOA protein expressions in hypercholesterolemic mouse uterus. The results of the present study suggest that hypercholesterolemia may attenuate the uterotonic action of oxytocin in late pregnancy by causing downregulation of oxytocin receptors and suppressing the signaling efficacy through GNAQ and RHOA proteins.

Molecular level information related to buffalo (Bubalus bubalis) reproduction and related genes is not present at appropriate level. If such exploration is made in the form of comparison between expression of genes is made between non-pregnant and pregnant phase, it may be helpful to aid manipulate the reproduction. Hence, the present study was carried out to reveal mRNA quantitative real time expression of oxytocin receptor (OTR) mRNA. IFN-τ is considered as the substance of maternal recognition of pregnancy and shut down the probable mechanisms which lead to luteolysis. Such mechanism includes shutting down of OTR. Therefore, relative expression of OTR was studied in endometrial tissue of three groups. The groups were non-pregnant late luteal phase, pregnancy stage I (pregnancy of <42 days) and pregnancy stage II (>42 days of pregnancy). With designed primer and GAPDH as house-keeping gene, relative mRNA expression was measured in Real-time PCR. After statistical analysis of results, the gene found to be expressed in all three stages with non-significant difference.