Trajano Francisco Mateus Gonçalves, Gomes Luana Talinne da Costa, Dantas Pedro Brüch, Sena Maele Oliveira de, Oliveira Jonas Ivan Nobre, Ventura Sabatino, Gavioli Elaine Cristina, da Silva Junior Edilson Dantas
Mode of Drug Action Laboratory, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
Eur J Pharmacol. 2023 Apr 15;945:175603. doi: 10.1016/j.ejphar.2023.175603. Epub 2023 Feb 17.
The motor activity of the epididymis duct is an essential process for male fertility and it is regulated by hormonal, neuronal and epithelial mechanisms. However, although there is evidence for the presence of histamine in the epididymis, its effects on epididymal motor activity are unknown. This study sought to evaluate the contractile effects of histamine on the rat distal cauda epididymis duct. Segments of the distal cauda epididymis duct from male Wistar rats were isolated and used in isolated organ bath experiments to evaluate the contractile effects of histamine in the absence or presence of antagonists of histamine receptors, α-adrenoceptors and muscarinic acetylcholine receptors. The effects of histamine on noradrenaline induced contractions were also investigated. Histamine was able to induce phasic contractions on rat distal cauda epididymis duct which were prevented by promethazine 10-1000 nM (H receptor antagonist), ranitidine 1-100 μM (H receptor antagonist), atropine 100 nM (muscarinic antagonist), and prazosin 100 nM (α-adrenoceptor antagonist). In addition, histamine was also able to modify noradrenaline-induced contractions possibly via activation of H and H receptors. In conclusion, this study demonstrates that histamine can induce phasic contractions of rat distal cauda epididymis via H receptors and autonomic neurotransmitters. Histamine may also exert modulatory actions on contractions of rat distal cauda epididymis duct induced by adrenergic receptor agonists. Further studies are necessary to unveil the localization of histamine receptors within the epididymal duct and the consequences of manipulation of the histaminergic system on epididymal function and male fertility.
