Jeyakumar S M, Raja Gopal Reddy M, Garlapati C, Desi Reddy S, Vajreswari A
Lipid Biochemistry Division, ICMR-National Institute of Nutrition, Jamai Osmania, Hyderabad, 500 007, India.
Biochem Biophys Rep. 2020 Oct 11;24:100831. doi: 10.1016/j.bbrep.2020.100831. eCollection 2020 Dec.
The role of sexual dimorphic adipose tissue fat accumulation in the development of insulin resistance is well known. However, whether vitamin A status and/or its metabolic pathway display any sex- or depot (visceral/subcutaneous)-specific pattern and have a role in sexual dimorphic adipose tissue development and insulin resistance are not completely understood. Therefore, to assess this, 5 weeks old Wistar male and female rats of eight from each sex were provided either control or diabetogenic (high fat, high sucrose) diet for 26 weeks. At the end, consumption of diabetogenic diet increased the visceral fat depots ( < 0.001) in the males and subcutaneous depot ( < 0.05) in the female rats, compared to their sex-matched controls. On the other hand, it caused adipocyte hypertrophy ( < 0.05) of visceral depot (retroperitoneal) in the females and subcutaneous depot of the male rats. Although vitamin A levels displayed sex- and depot-specific increase due to the consumption of diabetogenic diet, the expression of most of its metabolic pathway genes in adipose depots remained unaltered. However, the mRNA levels of some of lipid droplet proteins (perilipins) and adipose tissue secretory proteins (interleukins, lipocalin-2) did display sexual dimorphism. Nonetheless, the long-term feeding of diabetogenic diet impaired the insulin sensitivity, thus affected glucose clearance rate and muscle glucose-uptake in both the sexes of rats. In conclusion, the chronic consumption of diabetogenic diet caused insulin resistance in the male and female rats, but did not corroborate with sexual dimorphic adipose tissue fat accumulation or its vitamin A status.
性二态性脂肪组织脂肪积累在胰岛素抵抗发展中的作用是众所周知的。然而，维生素A状态及其代谢途径是否呈现任何性别或储存部位（内脏/皮下）特异性模式，以及在性二态性脂肪组织发育和胰岛素抵抗中是否起作用，目前尚未完全明确。因此，为了评估这一点，将8只5周龄的雄性和雌性Wistar大鼠分别给予对照饮食或致糖尿病饮食（高脂肪、高蔗糖），持续26周。实验结束时，与性别匹配的对照组相比，致糖尿病饮食的摄入使雄性大鼠的内脏脂肪储存增加（<0.001），雌性大鼠的皮下脂肪储存增加（<0.05）。另一方面，它导致雌性大鼠内脏脂肪储存部位（腹膜后）和雄性大鼠皮下脂肪储存部位的脂肪细胞肥大（<0.05）。尽管由于摄入致糖尿病饮食，维生素A水平呈现出性别和储存部位特异性的增加，但其在脂肪储存部位的大多数代谢途径基因的表达仍未改变。然而，一些脂滴蛋白（围脂滴蛋白）和脂肪组织分泌蛋白（白细胞介素、脂质运载蛋白-2）的mRNA水平确实表现出性别二态性。尽管如此，长期喂食致糖尿病饮食会损害胰岛素敏感性，从而影响大鼠两性的葡萄糖清除率和肌肉葡萄糖摄取。总之，长期食用致糖尿病饮食会导致雄性和雌性大鼠产生胰岛素抵抗，但与性二态性脂肪组织脂肪积累或其维生素A状态无关。
