Changes in Endogenous Oxytocin Levels and the Effects of Exogenous Oxytocin Administration on Body Weight Changes and Food Intake in Polycystic Ovary Syndrome Model Rats

Polycystic ovary syndrome (PCOS) is frequently seen in females of reproductive age and is associated with metabolic disorders that are exacerbated by obesity. Although body weight reduction programs via diet and lifestyle changes are recommended for modifying reproductive and metabolic phenotypes, the drop-out rate is high. Thus, an efficacious, safe, and continuable treatment method is needed. Recent studies have shown that oxytocin (OT) reduces body weight gain and food intake, and promotes lipolysis in some mammals, including humans (especially obese individuals), without any adverse effects. In the present study, we evaluated the changes in endogenous OT levels, and the effects of acute and chronic OT administration on body weight changes, food intake, and fat mass using novel dihydrotestosterone-induced PCOS model rats. We found that the serum OT level was lower in PCOS model rats than in control rats, whereas the hypothalamic OT mRNA expression level did not differ between them. Acute intraperitoneal administration of OT during the dark phase reduced the body weight gain and food intake in PCOS model rats, but these effects were not observed in control rats. In contrast, chronic administration of OT decreased the food intake in both the PCOS model rats and control rats. These findings indicate that OT may be a candidate medicine that is efficacious, safe, and continuable for treating obese PCOS patients.     

Regular boundary integral solution with dual and complementary variational formulations applied to two-dimensional Laplace problems

Regular boundary integral elements are employed for the dual and complementary variational formulations of Laplace problems. The problems are defined only on the boundary as usual, but as in the manner of charge simulation method (CSM), the source terms are arranged outside the domain so that the singular integral can be avoided. The Laplace problems are analysed and the usefulness of the formulation is discussed in comparison with direct BEM. The scalar potential and electric displacement vector potential functions are used in the dual and complementary formulations, with which the upper and lower bounds of the system energy or the capacitance can also accurately be evaluated.