Chronic Unpredictable Stress Impairs the Reactivity of the Pudendal Artery and Corpus Cavernosum in Male Mice

Abstract

Erectile dysfunction (ED) can be associated with psychological disorders as well as vascular disorders. It is known that stress is associated with erectile dysfunction, however, it is not clear if psychological stressors could lead to a vascular and cavernosal dysfunction that could contribute to a vasculogenic erectile dysfunction. A recent study reported a positive correlation between hyperprolactinemia, stress and erectile dysfunction, and interestingly, prolactin was shown to decrease endothelium nitric oxide and endothelium‐ dependent vasorelaxation of aorta and coronary arteries. In this study, we aimed to evaluate the relaxation of the corpus cavernosum and pudendal artery of mice subject to chronic unpredictable stress (CUS). We hypothesize that CUS will lead to an impairment of the relaxation of the pudendal artery and corpus cavernosum leading to erectile dysfunction.MethodsMale C57Bl/6 mice were submitted to 28 days of chronic unpredictable stress (CUS). The pudendal artery and corpus cavernosum were removed and mounted in a myograph to evaluate reactivity. Tissues were kept in physiological salt solution at 37°C, constantly aerated with 95%O2/5%CO2 and concentration‐response curves to acetylcholine (ACh; 1 nM – 30 uM)) were obtained. Using non‐linear regression, we obtained the maximal response (Emax) and potency (pEC50) of ACh. Data are expressed as mean ± S.E.M. P<0.05 was considered statistically different.ResultsNeither the potency nor the maximal response to acetylcholine was changed in the pudendal artery of stressed animals (Fig. 1A) whereas in the corpus cavernosum, there was a significant decrease in the maximal relaxation induced by acetylcholine (control: 88 ± 4% vs stress: 75 ± 4%, n=7 each group; Fig. 1B).ConclusionOur findings demonstrate that CUS for 4 weeks impairs acetylcholine‐induced relaxation of the corpus cavernosum. This may contribute to the development of erectile dysfunction in stressed males.