Background/Objectives: Both hyperandrogenism (HA) and vitamin D deficiency (VDD) can separately lead to impaired vascular reactivity and ovulatory dysfunction in fertile females. The aim was to examine the early interactions of these states in a rat model of PCOS. Methods: Four-week-old adolescent female rats were divided into four groups: vitamin D (VD)-supplemented (n = 12); VD-supplemented and testosterone-treated (n = 12); VDD- (n = 11) and VDD-and-testosterone-treated (n = 11). Animals underwent transdermal testosterone treatment for 8 weeks. Target VD levels were achieved with oral VD supplementation and a VD-free diet. Estrous cycles were followed by vaginal smear, and quantitative histomorphometric measurements of the ovaries were also taken. In the 8th week, testosterone- and estrogen-induced relaxation of coronary arterioles was examined with pressure angiography. Estrogen receptor (ER) density and oxidative and nitrative stress parameters (Poly-(ADP-Ribose)-Polymerase and 3-nitrotyrosine) in the vessel wall were investigated with immunohistochemistry. Results: VDD caused impaired estrous cycles, and testosterone caused anovulatory cycles (the cycles were stopped at the diestrous phase). VDD combined with testosterone treatment resulted in reduced testosterone and estrogen vasorelaxation, lower ER density, and higher oxidative and nitrative stress in the vessel wall. Conclusions: PCOS with vitamin D deficiency may be associated with increased oxidative–nitrative stress in coronary arterioles. This oxidative and nitrative stress, potentially caused by hyperandrogenism and/or vitamin D deficiency, could impair estrogen-induced relaxation of the coronary arterioles, possibly by decreasing NO bioavailability and disrupting the estrogen-induced relaxation pathway.

Background: Chronic exercise has been linked to positive effects on cognitive function and brain health. The aim of our study was to investigate how exercise affects cerebral resistance artery morphology, with an underlying focus on potential sex differences. Methods: Wistar rats were divided into male exercising (M.Ex; n = 6), female exercising (F.Ex; n = 5), male sedentary (M.Sed; n = 5), and female sedentary (F.Sed; n = 5) groups. After a 12-week swimming program, histological examinations of the intracerebral and pial arterioles were performed. SMA-DAB (smooth muscle actin) and resorcin-fuchsin (elastica) stained brain coronal sections were used for quantitative colorimetric analysis. Results: Investigating the effect of exercise, we found that in both pial and intracerebral arterioles, the elastic fiber density increased in both female and male exercising animals compared to the sedentary groups (p < 0.05 (M.Sed vs. M.Ex); p < 0.0001 (F.Sed vs. F.Ex)). As sex differences, we found that in female animals’ pial arterioles, the density of elastic fiber was increased compared to the male exercising group (p < 0.001 (M.Ex vs. F.Ex)). In pial arterioles, the smooth muscle density was higher in the male sedentary animals (p < 0.01 (M.Sed vs. F.Sed)); in intracerebral arterioles, the smooth muscle density increased with exercise in the male animals as well (p < 0.0001 (M.Ex vs. F.Ex)). Conclusions: Our results demonstrate that the increase in vascular elasticity is more pronounced overall in female animals.