Electrolyte Composition of Rete Testis Fluid and Cauda Epididymal Plasma and Spermatozoa from Rats Following Gossypol Treatment

Abstract

This investigation was undertaken to study the potassium and sodium concentrations in rete testis fluid and cauda epididymal plasma and spermatozoa following gossypol treatment. Rats were treated orally with gossypol acetic acid at a dose of 15 mg/ kg/day for 3 and 6 weeks respectively. There were not abnormal fmdings in the ionic concentrations of cauda epididymal plasma following 3 or 6-weektreatment. After 6 but not 3 weeks the spermatozoa in the cauda epididymidis were rendered almost completely immotile and malformed with a significant reduction in their potassium concentration and rise in their sodium concentration. No abnormal fmdings in the morphological picture of the germinal epithelium were observed under such circumstances and fluid and sperm from the rete testis were normal. Therefore, a direct action of gossypol may be exerted locally on the spermatozoa in the epididymis. Elektrolytzusammensetzung der Rete-testis-Flussigkeit, des Nebenhodenkopf-Plasmas und der Spermatozoen bei der Ratte unter Gossypol-BehandlungZusammenfassung: Die Untersuchung wird zwecks Kalium-und Natriumkonzentration in der Rete-Testis-Fliissigkeit, im Plasma des Nebenhodenkopfes und in den Spermatozoen unter Gossypol-Therapie vorgenommen. Hienu wurden Ratten mit Gossypolessigdure (1 5 mg/kg/die fir 3 bzw. 6 Wochen) gefittert. Es lieBen sich keine von der Norm abweichenden Ergebnisse bei den Elektrolyten i m Nebenhodenkopf nachweisen. Lediglich nach 6 Wochen Therapie ergab sich eine totale Unbeweglichkeit der Spermatozoen im Nebenhodenkopf bei signifkanter Reduzierung der Kaliumkonzentration und gleichzeitigem Anstieg des Natriums. Unter diesen Bedingungen ergab sich weiterhin kein von der Norm abweichendes Resultat in der Morphologie des Keimepithels; Flbigkeit und Spermatozoen aus dem Rete testis waren normal. Es diirfte sich deshalb bei der Wirkung von Gossypol um einen direkten EinfluB lokaler Art auf die Spermatozoen des Nebenhodens handeln .

Postweaning Exposure to Gossypol Results in Epididymis‐Specific Effects Throughout Puberty and Adulthood in Rats

“…The significant decrease in the number of sperm stored in the cauda epididymidis of the treated animals, both after puberty (day 61) and adulthood (day 91), in the absence of effects on spermatogenesis and sperm production, agrees with other authors who described absence of testicular effects after the administration of gossypol (Hadley et al, 1981;Wong et al, 1984;Giridharan et al, 1986;Wang et al, 1986;Soufir et al, 1989). Although it is generally agreed that a significant decrease in epididymal sperm numbers contributes to the contraceptive action of gossypol (Chang et al, 1980(Chang et al, , 1982Kaur et al, 1988;Srivastava et al, 1989;Swan et al, 1990;Taylor et al, 1991), the mechanisms for this decrease are unknown.…”

“…Damage to epididymal sperm and alterations within the epididymal epithelium are among the earliest effects observed after the administration of the gossypol. Indeed, infertility of rats has been observed before obvious alterations in spermatogenesis become evident (for references, see Wang et al, 1986 andSrivastava et al, 1989). Despite the data implicating the epididymis as a target of gossypol action, the fact that several weeks of exposure are required for gossypol effects to be manifest makes it experimentally difficult to negate the possibility that the epididymal effects are secondary to testicular insult.…”

“…In the present study there was a significant increase in the number of morphologically abnormal sperm recovered from the vas deferens on days 61 and 91 in gossypoltreated rats; the typical morphological defect was sperm decapitation. The presence of morphologically abnormal sperm is one of the most frequently reported consequences of gossypol treatment (Bozek et al, 1981;Chang et al, 1982;Giridharan et al, 1986;Wang et al, 1986;Kaur et al, 1988;Bhiwgade and Nair, 1989;Soufir et al, 1989;Srivastava et al, 1989;Swan et al, 1990). According to Baccetti et al (1986), gossypol may act on sperm differently in the testis and in the epididymis.…”

“…Despite considerable research, the exact mechanism responsible for the contraceptive effect of gossypol has not been clarified sufficiently. Several studies (Hoffer, 1983;Wong et al, 1983) suggest the testis as the main target organ, whereas others (Soufir et al, 1984;Baccetti et al, 1986;Wang et al, 1986) support the notion that gossypol acts directly on the epididymis, promoting alterations in the maturation of sperm, thereby rendering them unable to fertilize, and some (Giridharan et al, 1986;Shi et al, 1987) believe that gossypol alters the function of both the testis and the epididymis. These discrepancies can be attributed in part to fundamental differences in experimental design, including the purity and dosage of gossypol, the duration and route of gossypol administration, and the species of test animal.…”

“…The alterations frequently observed in studies using rats may manifest from either testicular or epididymal insults. These alterations include a decrease in the number of sperm stored in the cauda epididymidis (Chang et al, 1980(Chang et al, , 1982Kaur et al, 1988;Srivastava et al, 1989;Swan et al, 1990;Taylor et al, 1991); a decrease of sperm motility (Chang et al, 1980;Wang et al, 1988;Swan et al, 1990;Taylor et al, 1991); and morphologic alterations in the sperm, especially the separation of the heads and tails (Chang et al, 1982;Wang et al, 1986;Kaur et al, 1988;Bhiwgade and Nair, 1989;Srivastava et al, 1989;Swan et al, 1990).…”