Perivascular Adipose Tissue Compensation for Endothelial Dysfunction in the Superior Mesenteric Artery of Female SHRSP.Z-Leprfa/IzmDmcr Rats.

Regulation of arterial tone by perivascular adipose tissue (PVAT) differs between sexes. In male SHRSP.Z-Leprfa/IzmDmcr rats (SHRSP.ZF), PVAT exerts a compensatory relaxation effect for the loss of endothelium-mediated vasorelaxation, which occurs during the early stages of metabolic syndrome. However, this effect deteriorates by 23 weeks of age. Here, therefore, we compared the effects of PVAT in female and male SHRSP.ZF. Acetylcholine-induced relaxation in superior mesenteric artery without PVAT did not differ between 23-week-old females and males. However, the presence of PVAT enhanced relaxation in 23-week-old females, but not in males. The mRNA levels of angiotensin II type 1 receptor (AT1R) in PVAT did not differ between sexes, but AT1R-associated protein (ATRAP) and apelin levels were higher in females than in males. We observed a positive relationship between differences in artery relaxation with and without PVAT and ATRAP or apelin mRNA levels. In 30-week-old females, PVAT-enhanced relaxation disappeared, and mRNA levels of AT1R increased, while apelin levels decreased compared to 23-week-old females. These results demonstrated that in SHRSP.ZF, PVAT compensation for endothelium dysfunction extended to older ages in females than in males. Apelin and AT1R/ATRAP expression in PVAT may be predictors of favorable effects.