Endopeptidase inhibition attenuates the contraction induced by big endothelin‐1 of isolated human penile erectile tissue

Abstract

Peptides, such as C-type natriuretic peptide (CNP), vasoactive intestinal polypeptide (VIP) and endothelin 1 (ET-1), are involved in the control of penile erectile tissue (corpus cavernosum = CC). Inhibiting the degradation of CNP and VIP or conversion of Big ET-1 into ET-1 by endopeptidase enzymes should result in an enhancement of CC smooth muscle relaxation. Using the tissue bath technique, responses of isolated CC, challenged by noradrenaline (NA, 1 μm), to increasing concentrations of the endopeptidase inhibitor KC 12615 (1 nm - 10 μm), CNP and VIP (0.1 nm - 1 μm), were investigated. Effects of CNP, VIP and Big ET-1 (0.1 nm - 100 nm) on the tissue tension were also evaluated following pre-exposure to 10 μm of KC 12615. Big ET-1 induced contraction of the CC amounting to a force generation of 1,200 mg. The contraction was attenuated in the presence of KC 12615 by 35% and 50%, respectively. The tension induced by NA was reversed by VIP and CNP to 38.7% ± 15.8% and 61% ± 13%, respectively, of the initial force. The findings might be of significance with regard to future pharmacological treatment options for male ED, where an endothelial dysfunction exists.

Courses of Arginine-Vasopressin in the Systemic and Cavernous Blood through Different Stages of Sexual Arousal in Healthy Males and Patients with Erectile Dysfunction

“…Penile erectile tissue (corpus cavernosum) was obtained from 5 individuals who had been subjected to gender reassignment surgery (male-to-female). Tissue bath experiments were conducted according to standard procedures, as has been described earlier [18,19]. A passive tension of 0.5 gr (5 mN) was applied to the strip preparations, followed by a resting period of 60 min.…”

Efficiency of C-type natriuretic peptide on improvement of Iraqi local ram’s epididymal sperms

“…Comparatively, the mechanism of action of CNP is diverse and researchers in the last decade showed that CNP affects coronary blood flow regulation electrophysiology, vascular integrity, endothelial cell and smooth muscle proliferation, angiogenesis, leukocyte activation, and vascular tone ( Perez-Ternero et al ., 2019 ). In the male reproductive system, several studies showed that testicular function and fertility and regulation of erectile tissue can be regulated by CNP ( Hannema et al ., 2013 ; Shahin et al ., 2018 ; Ückert et al ., 2019 ).…”