Influence of Male Sex Hormones in Vascular Reactivity of Resistance Artery from Male Rats: a Temporal Evaluation

Influence of Male Sex Hormones in Vascular Reactivity of Resistance Artery from Male Rats: a Temporal Evaluation

• Autor
• Wender do Nascimento Rouver
• Co-autores
• Nathalie Tristão Banhos Delgado , Leticia Tinoco Gonçalves , Jéssyca Aparecida Soares Giesen , Charles Santos da Costa , Eduardo Merlo , Eduardo Damasceno Costa , Virgínia Soares Lemos , Jones Bernardes Graceli , Roger Lyrio dos Santos
• Resumo

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  Divergences have been pointed out regarding the role of androgens in vascular reactivity, mainly regarding the participation of them related to age. The objective of this study was to make a temporal assessment of the vascular reactivity of third-order mesenteric arteries, to clarify the participation of androgens in vascular function. Male 8-week-old Wistar rats were used (250-300g). Endothelium-induced relaxation response was characterized in third-order mesenteric arteries after 15, 30, 60 and 75 days after sham or orchiectomy surgery. Concentration-response curve (ACh, 0.1nM-10uM) was plotted in arteries previously contracted (PE, 3uM), before and after nitric oxide synthase or cyclooxygenase inhibition. Vascular nitric oxide (NO), superoxide anion (O2?-), and hydrogen peroxide (H2O2) were analyzed and histomorphometry analysis were performed by hematoxylin/eosin and scanning electron microscopy. Analysis of variance, Student’s t test or Mann-Whitney test were used when appropriate (p<0.05 was established). All procedures were previously approved (CEUA-UFES #07/2016). Sham-75d group showed impairment in endothelium-dependent relaxation (Sham-15d=238±14; Sham-30d=232±19; Sham-60d=215±20, and Sham-75d=153±22 a.u., n=7). This difference was not observed in orchiectomized animals. The ACh vasodilator effect appears to be NO-dependent (Sham-15d=238±14 to 26±5 and Sham-75d=153±22 to 31±9 a.u., n=6-7) and prostanoids-independent. However, this NO dependence appears to be lower in the Sham-75d group (Sham-15d=238±14 and Sham-75d=153±22 a.u.). Sham-75d group had a lower NO (Sham-15d=2.2±0.06 and Sham-75d=1.4±0.03 a.u., n=4), and H2O2 (Sham-15d=3.4±0.1 and Sham-75d=2.7±0.06 a.u., n=4) production and higher O2?- levels (Sham-15d=2.2±0.04 and Sham-75d=2.7±0.1 a.u., n=4). Besides functional impairment, Sham-75d showed morphological differences in the mesenteric arteries in comparison to the younger animals. Male sex hormones appear to play an important role in the development of vascular changes that can lead to impaired vascular reactivity in third-order mesenteric arteries, which could be related to the onset of cardiovascular changes promoted by age in males.

• Palavras-chave
• Androgens, third-order mesenteric artery, endothelium
• Modalidade
• Pôster
• Área Temática
• Sistema endócrino e doenças vasculares