We investigated the sex-dependent effects of inflammatory responses in visceral adipose tissue (VAT) and perivascular adipose tissue (PVAT), as well as hematological status, in relation to cardiovascular disorders associated with prediabetes. Using male and female hereditary hypertriglyceridemic (HHTg) rats-a nonobese prediabetic model featuring dyslipidemia, hepatic steatosis, and insulin resistance-we found that HHTg females exhibited more pronounced hypertriglyceridemia than males, while HHTg males had higher non-fasting glucose levels. Additionally, HHTg females had higher platelet counts, larger platelet volumes, and lower antithrombin inhibitory activity. Regarding low-grade chronic inflammation, HHTg males exhibited increased serum leptin and leukocyte levels, while females had increased serum interleukin-6 (IL-6). Both sexes had increased circulating plasminogen activator inhibitor-1 (PAI-1), higher PAI-1 gene expression in VAT and PVAT, and elevated intercellular adhesion molecule-1 (ICAM-1) gene expression in the aorta, contributing to endothelial dysfunction in the HHTg strain. However, HHTg females had lower tumor necrosis factor alpha (TNFα) gene expression in the aorta. Severe dyslipidemia in this prediabetic model was associated with hypercoagulation and low-grade chronic inflammation. The increase in PAI-1 expression in both VAT and PVAT seems to indicate a link between inflammation and vascular dysfunction. Despite the more pronounced dyslipidemia and procoagulation status in females, their milder inflammatory response may reflect an association between reduced cardiovascular damage and prediabetes.

• Keywords
• cardiovascular disease, hypertriglyceridemia, inflammation, perivascular adipose tissue, plasminogen activator inhibitor-1, visceral adipose tissue,
• MeSH
• Dyslipidemias * metabolism   pathology   complications   genetics   MeSH
• Plasminogen Activator Inhibitor 1 * metabolism   genetics   MeSH
• Rats MeSH
• Disease Models, Animal MeSH
• Intra-Abdominal Fat * metabolism   pathology   MeSH
• Sex Characteristics MeSH
• Inflammation * metabolism   pathology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Plasminogen Activator Inhibitor 1 * MeSH

BACKGROUND: The activity of perivascular adipose tissue (PVAT), a specific deposit of adipose tissue surrounding blood vessels, could contribute to sex differences in vascular tone control, particularly in dyslipidemic disorders; however, the mutual associations remain unclear. This study aimed to evaluate the relationships among sex, PVAT and vascular function in Wistar and hereditary hypertriglyceridemic (HTG) rats. Vasoactive responses of the isolated thoracic aorta with preserved or removed PVAT were compared in adult male and female Wistar and HTG rats, and the roles of nitric oxide (NO), hydrogen sulfide (H2S), cyclooxygenase (COX) and inflammatory signaling in vascular function were monitored in females. RESULTS: HTG rats were hypertensive, but females less than males. Increased 2-h glycemia was observed in HTG rats regardless of sex; however, HTG females exhibited better glucose utilization than males did. Females, independent of strain, had better preserved endothelial function than males did. PVAT inhibited endothelium-dependent relaxation in all the rats except HTG females. In HTG males, pathologically increased aortic contractility was noted; however, in HTG females, the contractile responses were lower, thus approaching physiological levels despite the pro-contractile action of COX products. In HTG females, NO contributed to endothelial function to a lesser extent than it did in controls, but the presence of PVAT eliminated this difference, which corresponded with increased NO synthase activity. Although increased protein expression of several proinflammatory factors (TNFα, IL-6, iNOS, and NfκB) was confirmed in the aortic and PVAT tissue of HTG females, the protein expression of factors regulating the adhesion and infiltration of monocytes (ICAM-1 and MCP-1) was decreased in PVAT. Moreover, in HTG females, unlike in controls, H2S produced by PVAT did not inhibit endothelial relaxation, and regardless of PVAT, endogenous H2S had beneficial anticontractile effects, which were associated with increased protein expression of H2S-producing enzymes in both aortic and PVAT tissues. CONCLUSIONS: Despite increased inflammation and the pathological impact of cyclooxygenase signaling in female HTG rats, protective vasoactive mechanisms associated with milder hypertension and improved endothelial function and contractility linked to PVAT activity were triggered. Sulfide and nitroso signaling represent important compensatory vasoactive mechanisms against hypertriglyceridemia-associated metabolic disorders and may be promising therapeutic targets in prediabetic females.

• Keywords
• Hereditary hypertriglyceridaemic rats, Hydrogen sulfide, Nitric oxide, Perivascular adipose tissue, Sex,
• MeSH
• Aorta, Thoracic physiopathology   MeSH
• Endothelium, Vascular physiopathology   MeSH
• Rats MeSH
• Nitric Oxide * metabolism   MeSH
• Rats, Wistar * MeSH
• Prediabetic State * physiopathology   metabolism   MeSH
• Sex Factors MeSH
• Signal Transduction * physiology   MeSH
• Hydrogen Sulfide * metabolism   MeSH
• Adipose Tissue metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Nitric Oxide * MeSH
• Hydrogen Sulfide * MeSH