Decreased basal insulin secretion from pancreatic islets of pups in a rat model of maternal obesity.

Maternal obesity (MO) is a deleterious condition that enhances susceptibility of adult offspring to metabolic diseases such as type 2 diabetes. The objective is to study the effect of MO on in vitro insulin secretion and pancreatic cellular population in offspring. We hypothesize that a harmful antenatal metabolic environment due to MO diminishes the basal glucose-responsive secretory function of pancreatic beta cells in offspring. Mothers were fed a control (C) or high-fat diet from weaning through pregnancy (120 days) and lactation. At postnatal days (PNDs) 36 and 110, pups were killed, peripheral blood was collected and pancreatic islets were isolated. Basal insulin secretion was measured in vitro in islets for 60 min. It was found that blood insulin, glucose and homeostasis model assessment (HOMA) index were unaffected by maternal diet and age in females. However, male MO offspring at PND 110 showed hyperinsulinemia and insulin resistance compared with C. Body weight was not modified by MO, but fat content was higher in MO pups compared with C pups. Triglycerides and leptin concentrations were higher in MO than in C offspring in all groups except in females at PND 36. Pancreatic islet cytoarchitecture was unaffected by MO. At PND 36, islets of male and female C and MO offspring responded similarly to glucose, but at PND 110, male and female MO offspring islets showed a 50% decrease in insulin secretion. It was concluded that MO impairs basal insulin secretion of offspring with a greater impact on males than females, and this effect mainly manifests in adulthood.

Differential mRNA expression of alpha and beta estrogen receptor isoforms and GnRH in the left and right side of the preoptic and anterior hypothalamic area during the estrous cycle of the rat.

Asymmetric mRNA expression was found in preoptic anterior and hypothalamic anterior areas of the two estrogen receptor isoforms and the gonadotropin-releasing hormone. On the right side of these areas, estrogen receptor alpha mRNA expression reached its peak on estrus day, while on the left side the peak was reached on proestrus day. Estrogen receptor beta mRNA expression peaked on both sides on the same day, diestrous-2 day, but at different hours, showing a sustained expression for the next measured hour on the left side, while peaking and dropping abruptly on the right side. Gonadotropin-releasing hormone also peaked on both sides on diestrous-2 day, being the left side peak expression significantly lower than the peak expression at the right side. The side expression differences suggest that different sides of the before mentioned areas may play different roles of endocrine reproductive functions, while differences of expression at different times may suggest interaction between sides for the same functions.