Effect of physiological (in Lamb) or drug-induced (in adult) immaturity of ram spermatozoa on seminal plasma α-glucosidase activity

Alpha‐glucosidase activity in the rat epididymis under different physiological conditions

“…A signi®cant decrease in alpha-glucosidase activity in the epididymis after administration of two known antifertility agents, gossypol and alpha-chlorohydrin, strongly suggests that both of the drugs impair epididymal function. Besancon et al (1985b) have also reported low enzyme activity in ram semen after chlorohydrin administration. However, on the basis of present investigations and other reports, it is dif®cult to conclude whether a decrease in enzyme activity occurs because of a direct effect of the drugs on enzyme activity or because of a deleterious effect of these drugs on the functional capacity and morphology of the epididymis as documented in several other studies ( Jones 1978;Qian & Wang 1984).…”

Alpha-1,4-Glucosidase Activity in Ram Seminal Plasma Is Inversely Related to Serum Testosterone

“…Preliminary evidence concerning a pu tative role of testosterone in a-glucosidase modulation at the epididymal level was ob tained when we were fortunate enough to col lect ejaculates in rams prior to sexual maturi ty. Then it was noted that the acquisition of normal adult epididymal function, as re flected by a progressive increase in sperm concentration and motility percentage, was associated with an increased fructolysis and an elevation of a-glucosidase activity [4], The present study which was conducted in adult rams eliminates a bias that could have been introduced by the observation of only imma ture rams [4], Indeed, it has been reported that an array of esterases and carbohydratases present in seminal fluid [12,13] could act on extracellular proteins and glycopro teins to modify spermatozoa membrane function with consequences on sperm motil ity [14,15] or on sperm-egg binding [16], but we suggest that a-glucosidase should be ex cluded from this list of enzymes because of the opposite correlations between enzyme and sperm motility. A rather naive but testa ble hypothesis could be that testosterone maintains low levels of a-glucosidase to pre vent deleterious effects of the enzyme on sperm membrane glycoproteins.…”

“…Three months prior to the beginning of the study, and during our protocol, semen was collected fort nightly from each of all 16 rams with an artificial vag ina in the presence of an immobilized nonoestrus ewe as described by Besançon et al [4]. On the day of semen collection, blood samples were taken from the jugular vein between 9 and 10 a.m., prior to other manipulations of the animals.…”

“…It was therefore of interest to ascertain whether ram epididymal a-l,4-glucosidase was under androgenic control, be cause of our initial observations indicating a net increase of the enzyme in the seminal plasma of lambs progressing to sexual matu rity [4], We postulated that the optimal physiological condition to observe this puta tive hormonal influence was to determine the enzyme activity in relationship with the In 1985, Besançon et al [1] observed that the enzyme a-l,4-glucosidase was localized mainly in the caput epididymis of adult rams. This observation corroborated pre vious results from this laboratory indicating the presence of a-l,4-glucosidase in the cauda epididymis of men [2] and rats [3].…”

“…The role of this enzyme in the reproductive tract of mammals has been a matter of inter est for our group as mammalian spermato zoa are exposed to various epithelial secre tions of the seminiferous tubule and of the epididymal duct during their development. Among the variety of minor epididymal a-Glucosidase-Specific Activity and Testosterone Concentrations Seminal plasma a-glucosidase-specific activity and blood plasma testosterone concentration were measured according to the methods previously de scribed by Besançon et al [1,4], The inter-assay coef ficient of variation of the method for the a-glucosidase assay was 2 % after dozens of determinations in duplicate at weekly intervals. serum testosterone variations which exhibit typical seasonal variations in two breeds of rams.…”