Effects of sulphapyridine on sperm transport through the rat epididymis and contractility of the epididymal duct

Abstract

This study was undertaken to investigate the effects of sulphapyridine on the transport of spermatozoa through different regions of the epididymis and on the contractility of the epididymal duct in the rat. Sperm transport was investigated by labelling testicular spermatozoa with [3H]thymidine and measuring intraluminal pressures of the epididymis by micropuncture, using a servo-nulling pressure transducer system. In control rats, the transit times of epididymal spermatozoa from the initial segment to the caput, from the caput to the proximal cauda, and from the proximal cauda to the distal cauda were 2, 6 and 3 days, respectively, giving a total transit time of 11 days. The total transit time was shortened to 8 days after treatment with sulphapyridine at a dosage of 450 mg kg-1 for 38-52 days. The rate of sperm transport was most affected in the caput epididymidis. Measurements of intraluminal pressures showed that sulphapyridine had no effect on spontaneous contractions in any regions of the epididymis. However, the frequency of contraction of the corpus and cauda epididymides in response to administration of 10 micrograms noradrenaline kg-1 in the sulphapyridine-treated rats was significantly higher (P < 0.05) than it was in the controls. Methacholine, at a dose of 20 micrograms kg-1, produced a smaller increase in basal pressure in the caput epididymidis of sulphapyridine-treated rats (P < 0.05) compared with controls. The results led to the conclusion that sulphapyridine increases the rate of sperm transport from the caput through the cauda epididymidis, in part, by changes in the responsiveness of the epididymis to the autonomic nervous system.

Development of Sperm Granulomas in the Epididymides of L-Cysteine-Treated Rats

“…Despite the maturing testes and prostate glands, epididymal epithelial cells in L-cysteine-treated rats might not have developed sufficient functions by the end of this study, because their maturation was prolonged; this, in turn, might lead to aberrant flow and an increase in the viscosity of the epididymal fluid (39,40). Under such abnormal conditions, small ducts with pseudostratified epithelial cells might mechanically obstruct the flowing epididymal fluid (10). Additionally, small ducts might lack contraction of the smooth muscle layer that induce sperm stasis (28).…”

Regulation of Spontaneous Contractile Activity in the Bovine Epididymal Duct by Cyclic Guanosine 5′-Monophosphate-Dependent Pathways

“…During the 8 -17 d of passage through the tubule, mammalian spermatozoa are exposed to a constantly changing environment, which ensures their maturation, including the acquisition of fertilizing potential and progressive motility (2)(3)(4)(5). The propulsion of the immotile spermatozoa from the caput via the corpus to the epididymal cauda region occurs by means of spontaneous phasic contractions (SC) of the surrounding muscle layer of the duct, whereas the contractions in the richly innervated cauda are predominantly neurogenic in origin (see Ref.…”

Epididymal contraction and sperm parameters are affected by clonidine

“…The increase in the frequency or amplitude of spontaneous contraction induced by hormones or drugs can diminish the sperm transit time and, consequently, the sperm reserves, promoting fertility impairment (Din-Udom et al, 1985;Chaturapanich et al, 1999;Bellentani et al, 2011). Therefore, the decrease in the sperm transit time (accelerated transit) and sperm reserves (as shown in Table 4) can be related to the increase in the frequency and amplitude of spontaneous contractions of caput/corpus and cauda epididymis (showed in this study) induced by the in vivo treatment with crescent doses of clonidine.…”

“…Therefore, the decrease in the sperm transit time (accelerated transit) and sperm reserves (as shown in Table 4) can be related to the increase in the frequency and amplitude of spontaneous contractions of caput/corpus and cauda epididymis (showed in this study) induced by the in vivo treatment with crescent doses of clonidine. The transport of spermatozoa through the epididymis is mainly the result of spontaneous contractions of the smooth muscle surrounding the epididymal duct, and can be modified (accelerated) by cholinergic or adrenergic drugs in all regions of epididymis (Pholpramool & Triphrom, 1984;Chaturapanich et al, 1999). Although the distal cauda of epididymis presents an abundant sympathetic innervation comparing with other regions of this organ (Ricker, 1998), the presence of adrenoceptors are also suggested in caput and corpus (Pholpramool & Triphrom, 1984;Pholpramool et al, 1984;Queiroz et al, 2008), indicating a major functional role in the epididymis.…”

“…Changes on the sperm transit time through the epididymis impair the spermatozoa maturation process and induce oxidative stress, affecting the quantity and quality of spermatozoa (Gil-Guzman et al, 2001;Fernandez et al, 2008). The sperm transit time is modulated by androgens, spontaneous contractile activity of epididymal smooth muscle and autonomic (sympathetic and parasympathetic) nervous system (Sujarit & Pholpramool, 1985;Ricker, 1998;Chaturapanich et al, 1999).…”