During aerobic exercise, hemodynamic alterations occure; while blood flow in skeletal muscle arteries increases, it decreases in visceral vessels due to mesenterial vasoconstriction. However, maintaining renal blood flow during intensive sport is also a priority. Our aim was to investigate the changes of vascular reactivity and histology of isolated renal artery of male and female rats in response to swim-training. Wistar rats were distributed into four groups: male sedentary (MSed), male trained (MTr), female sedentary (FSed), and female trained (FTr). Trained animals underwent a 12-week-long intensive swimming program. Vascular function of isolated renal artery segments was examined by wire myography. Phenylephrine-induced contraction was lower in FSed compared to MSed animals, and it was decreased by training in male but not in female animals. Inhibition of cyclooxygenases by indomethacin reduced contraction in both sedentary groups, and in MTr but not in FTr animals. Inhibition of nitric oxide production increased contraction in both trained groups. Acetylcholine induced relaxation was similar in all experimental groups showing predominant NO-dependency. Elastin and smooth muscle cell actin density was reduced in female rats after aerobic training. This study shows that, as a result of 12-weeks-long training, there are sex differences in renal arterial responses following exercise training. Swimming moderates renal artery vasoconstriction in male animals, while it depresses elastic fiber and smooth muscle actin density in females.
Blood flow increases in arteries of the skeletal muscles involved in active work. Our aim was to investigate the gender differences as a result of adaptation to sport in the femoral arteries. Vascular reactivity and histology of animals were compared following a 12-week swimming training. Animals were divided into sedentary male (MS), trained male (MTr), sedentary female (FS), and trained female (FTr) groups. Isolated femoral artery rings were examined by wire myography. Contraction induced by phenylephrine (Phe) did not differ between the four groups. The contractile ability in the presence of indomethacin (INDO) was decreased in both sedentary groups. However, we found a specific cyclooxygenase-2 (COX-2) role only in FS rats. After exercise training, we observed increased vasoconstriction in both sexes, when nitro-L-arginine methyl ester (L-NAME) was present. The COX-dependent vasoconstriction effect disappeared in MTr animals, and the COX-2-dependent vasoconstriction effect disappeared in FTr ones. Relaxation was reduced significantly, when L-NAME was present in MTr animals compared to in FTr rats. The training was associated with greater endothelial nitric oxide synthase (eNOS) protein expression in males, but not in females. The present study proves that there are gender differences regarding adaptation mechanisms of musculocutaneous arteries to sports training. In males, relaxation reserve capacity was markedly elevated compared to in females.
Objective:Hypertension accelerates vascular aging, and changes associated with vascular aging play a role in hypertension. Andropause also contributes to age – related vascular damage and increases cardiovascular risk. Our aim is to investigate the combined effect of hypertension and androgen deficiency on the contractility of intramural coronary resistance arteries.Design and method:Male Sprague-Dawley rats were distributed into 4 groups: control (Co, n = 10); orchidectomized (OCT, n = 13), angiotensin II infused (AII, n = 10) and AII infused plus orchidectomized (AII+OCT, n = 8). Early hypertension was established using osmotic minipumps containing angiotensin II (100 ng / min / kg), while testosterone deficiency achieved via orchidectomy. After 4 weeks, spontaneous, thromboxane- and bradykinin-induced tones of intramural coronary resistance arterioles were investigated by in vitro pressure microarteriography.Results:Inner radius was reduced in the AII+OCT group compared to all other groups. Spontaneous tone was significantly higher in AII and AII+OCT groups than in Co and OCT groups. U46619-induced vasoconstriction was significantly smaller in OCT and AII+OCT groups compared to Co and AII rats. Bradykinin-induced relaxation was also significantly reduced in orchidectomized rats (OCT and AII+OCT groups) to a greater extent than in Co and AII animals.Conclusions:Spontaneous vascular tone is increased in AII hypertension. As a result of orchidectomy, adaptation range of the blood vessels narrows both regarding vasoconstriction and vasodilation. Therefore, the reactivity of the coronary arterioles deteriorates due to testosterone deficiency. In case of parallel manifestation of hypertension and testosterone deficiency, these two effects add up, which may increase age-related cardiovascular risk significantly in men.
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