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

Lysosomal glycosidase activities in rat testis during sexual maturation

Concentrations of testosterone and its metabolite dihydrotestosterone were determined in whole rat testis during the transition from the prepuberal to the mature status. The activities of five glycosidases (beta-N-acetylhexosaminidase, alpha-L-fucosidase, beta-D-galactosidase, alpha-D-glucosidase and alpha-D-mannosidase) were also investigated in the seminiferous tubules and interstitial tissues. The same androgens and enzyme activities were measured in testis of rats treated with 17-beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5-alpha-androstan-3-on e, a potent inhibitor of the 5-alpha-reductase-mediated conversion of testosterone into dihydrotestosterone. Lysosomal glycosidic activities in seminiferous tubules were found to vary slightly with the age of the animals, and thus seemed not to depend on the hormonal status of the tested animals. In contrast, the enzyme activities were low in the immarure interstitium but increased sharply during the onset of sexual maturity. The activity of each glycosidase reached a maximum between the 45th and the 65th day, except for beta-N-acetylhexosaminidase which did not decrease significantly following the 55th day. The five lysosomal enzyme activities decreased in the interstitial compartment of rat testis treated with DMAA, suggesting a relationship between these glycosidic enzyme activities and dihydrotestosterone.

Opposite variations of two epididymal components and blood plasma testosterone in two breeds of rams

1. Testicular volume (T Vol), blood plasma testosterone (T) concentration, seminal plasma alpha-glucosidase (alpha-G) specific activity, L-carnitine (L-C) concentration as well as semen characteristics were compared in eight Finnish Landrace (F) and eight Suffolk (S) rams throughout 21 months. 2. Only T Vol and T exhibited a typical seasonal variation in both breeds, whereas L-C, alpha-G and live sperm output presented a seasonal profile only in S rams. 3. L-C and alpha-G variations were opposite to those of T in S rams, while they fluctuated in F rams throughout the entire experiment, as did live sperm output. 4. Only the number of ejaculates and T were significantly higher in F rams (3.50 +/- 0.08 in 5 min and 7.62 +/- 0.40 ng/ml) than in S rams (2.30 +/- 0.05 in 5 min and 5.5 +/- 0.30 ng/ml); these two characteristics might therefore be considered as two indexes of sexual activity in rams. 5. By contrast, among all characteristics measured, only alpha-G was significantly higher in S rams than in F rams (1.33 +/- 0.04 vs 0.77 +/- 0.03 mU/mg proteins); this result, as well as seasonal alpha-G profile present in only S rams, allowed us to conclude that alpha-G might be considered as an additional index of seasonal reproduction in rams.

Purification of ram seminal plasma acid alpha-glucosidase

1. Ram seminal plasma alpha-glucosidase has been purified in order to increase our knowledge of this enzyme and of its role in epididymal physiology. 2. Since the enzyme behaved differently from other known acid alpha-glucosidases and was not affinity-adsorbed on dextran gels, another approach had to be used. 3. The final procedure included an ethanol precipitation step, sequential chromatography on hydroxylapatite and DEAE Sepharose CL-6B, isoelectric focusing in polyacrylamide gels and ultrafiltration. 4. The resulting purification factor of alpha-glucosidase was 9822 with an overall yield of 5%. 5. The purified material consisted of several isoforms with a mol. wt of 105,000 and isoelectric points varying between 4 and 5.