LAUSR

Biological sex plays an important role in cardiovascular disease (CVD) predisposition and incidence. Arterial stiffening assessed by pulse wave velocity is an independent marker for CVD and contributes to early vascular aging. Men have stiffer arteries than women, a sex difference that is diminished with aging. Sex hormones are indicated to play a role in stiffening arteries but the role for sex chromosomes is unknown. To assess the role for sex hormones, sex chromosomes or their interaction we used four core genotype (FCG) mice (N=5-8/group). 2-Way ANOVA and Sidak’s multiple comparison test was used for statistical analysis and P<0.05 was considered significant. In this mouse model, males (M) with testes and female (F) with ovaries have either XX or XY sex chromosome complement. Mice were either left gonadal intact or gonadectomized at 8 weeks followed by PWV assessment, blood pressure, and pressure myography at 16 weeks. In gonadal intact mice, males were significantly stiffer than females (P=0.002) with XYM (3.5 m/s) having greater PWV than XXM (3 m/s), XXF (2.8 m/s), and XYF (2.8 m/s), respectively without significant difference in blood pressure (BP). Gonadectomy increased PWV in all groups removing the sex difference in XYM (4.6 m/s), XXM (4.3 m/s), XXF (4.6 m/s), XYF (4.4 m/s) while BP remained unchanged. Pressure diameter relationship was greater in XYM than XXM (P<0.001) in both gonadal intact and gonadectomized mice. Aortic distensibility was greater in XXF than XYF (P=0.008) and XYM than XXM (P=<0.001). Stress-strain curves indicated significant leftward shift (P<0.05) XYM, XXM, and XYF mice after gonadectomy. Masson’s trichrome staining was increased (P<0.05) in mice with XX than XY sex chromosome complement after gonadectomy. In conclusion, we found that decline in sex hormones increases arterial stiffening, removes sex differences in distensibility, and shifts elastic modulus to the left in all groups but XXF mice. R00HL155841 and R25HL105400 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.