Two-generation Exposure to a High-fat Diet Alters Duct Cell Morphology and Induces Connexin 32 and 43 Expression in Rat Submandibular Salivary Glands

Abstract

Introduction：The consumption of a high fat diet (HFD)during pregnancy can adversely affect offspring development. Excess weight resulting for overconsumption of energy is associated with increased risk of cancer, morbidity, and mortality. In this study we examined the effects of HFD consumption during pregnancy and lactation in two generation on the duct cell morphology and the expression of connexin 32(Cx32)and connexin 43(Cx43)in the submandibular gland(SMG) . Materials and Methods：Six pregnant 11 week old Wistar rats were assigned to the standard diet(SD) or HFD groups(n＝3/group) . Rats in the SD group were fed a SD, whereas those in the HFD group received an HFD from day 7 of pregnancy throughout the lactation period. Male offspring in both SD and HFD groups were divided into four groups：weaning SD (WSD；3 week old) , weaning HFD (WHFD；3 week old) , adult SD(ASD；9 week old) , and adult HFD(AHFD；9 week old) . Results：The findings demonstrated that the duct cell nuclei were more aligned in adult rats than those in weaned rats. Duct nuclei size was significantly affected by age in the SD group. In contrast, the HFD fed groups had similar nuclei sizes. Immunohistochemical staining showed that Cx32 and Cx43 were expressed in the ductal cells. Conclusions：The consumption of a HFD during pregnancy and lactation periods appears to affect duct cell morphology in weaned and adult offspring. The expression of Cx32 was significantly lower in the AHFD group compared to weaned groups；however, the expression of Cx43 was increased with HFD although insignificant.