Perivascular adipose tissue and vascular responses in healthy trained rats

Aims: The importance of perivascular adipose tissue (PVAT) in vascular function has recently been recognized. The aim of the study was to investigate the effects of exercise training on anticontractile responses of periaortic adipose tissue.Main methods: Male Wistar rats were divided into sedentary (SD) and trained (TR). Running training was performed for 60 min/day, 5 days/week, for 8 weeks. Concentration-response curves to acetylcholine (ACh), sodium nitroprusside (SNP), phenylephrine (PHE) and serotonin (5-HT) were obtained in aortic rings without (PVAT-) or with (PVAT+) PVAT. The protein expressions of eNOS, AMPK alpha, pAMPKThr172 and mtTFA were determined in PVAT. The contents of adiponectin, leptin and TNF-alpha were evaluated systemically and locally.Key findings: The PVAT+ rings did not modify the relaxing responses to ACh and SNP whereas it showed anticontractile effects for both PHE and 5-HT agents in the SD and TR groups. The amount of PVAT was markedly reduced in TR (3.6 +/- 03 mg/mm) compared with SD (6.8 +/- 0.6 mg/mm). Increased protein expressions of eNOS, pAMPKThr172 and mtTFA were observed in PVAT from TR animals, without modifications in PVAT-derived adiponectin, leptin and TNF-alpha. Circulatory leptin levels were reduced in TR without changes in adiponectin.Significance: Our findings show that exercise training for 8 weeks did not alter the anticontractile effects induced by PVAT in rat-isolated aorta. Moreover, PVAT-derived adipokine, adiponectin and leptin levels were not different in trained healthy animals despite a significant metabolic adaptation and reduction in periaortic adipose tissue amount. (C) 2015 Elsevier Inc. All rights reserved.