Seminal plasma alpha-glucosidase activity and male infertility

Abstract

Measurement of alpha-glucosidase (alpha-GLUC) activity by means of a simple colorimetric test using a commercial kit (EpiScreen; FertiPro, Lotenhulle, Belgium) yielded results that were strongly correlated with the values obtained for the neutral iso-enzyme measured by a fluorimetric reference method (r=0.85, P=0.003, n=13). The former method was characterized by a low intra- and inter-coefficient of variation (6.6 and 4.3% respectively). Vasectomized men with azoospermia (n=27) had a significantly lower alpha-GLUC activity in semen than vasectomized men with residual spermatozoa present (n=11, P < 0.01) and men with azoospermia of primary testicular origin (n=33, P < 0.01). Receiver operating curve (ROC) analysis showed alpha-GLUC measurement to be reasonably accurate in differentiation between cases with obstructive versus testicular azoospermia at criterion value 13.5 U/l (sensitivity=82%, specificity= 70%). In cases with spermatozoa present, alpha-GLUC activity and output per ejaculate were positively correlated with sperm concentration (r=0.53 and 0.38, n=472), linear velocity (r=0.35 and 0.30, n=224), curvilinear velocity (r=0.32 and r=0.29, n=224), semen adenosine triphosphate (r=0.35 and 0.26, n=64), the concentration of 5alpha-dihydrotestosterone (r=0.31 and 0.29, n=74), and gamma-glutamyltransferase activity (r=0.62 and 0.32, n=275) in seminal plasma. The activity of alpha-GLUC was inversely correlated with ROS generation after 12-myristate, 13-acetate phorbol ester stimulation (r=-0.27, n=104), and both alpha-GLUC activity and total output were inversely correlated with the concentration of peroxidase-positive white blood cells among samples with > or =1x10(6)/ml of these cells (r=-0.30 and -0.19, n=165). It is concluded that simple photometric measurement of alpha-GLUC activity in seminal plasma reflects the functional state of the epididymis and may be helpful for the differential diagnosis of certain cases with azoospermia.

Impact of infection on the secretory capacity of the male accessory glands

“…Under normal conditions the epididymis secretory factors are involved in the maturation of sperm; its function can be evaluated by the measurement of L-carnitine, glycerylphosphoryl choline and alpha-glucosidase in seminal plasma. The secretion of alpha-glucosidase is used to reliably evaluate epididymal function; however, there is no consensus regarding the impact of chronic epididymitis on the level of this marker (7,9,10). The seminal vesicles produce: fructose, ascorbic acid, ergothioneine, prostaglandins and bicarbonate.…”

The Relevance of Neutral α-Glucosidase Activity in Andrology

“…The activity of neutral a-glucosidase (NAG) is significantly reduced when there is an occlusion distally to the epididymis [Cooper et al 1990;Dohle 2003;Guerin et al 1986;Kret et al 1995;Mahmoud et al 1998;Rivas et al 1981;Sandoval et al 1995;Schill and Henkel 1999]. Low NAG activity is also associated with functional deficiency of the epididymis in non-azoospermic patients [Comhaire et al 1999;2002].…”

Altered Profile of Seminal Plasma MicroRNAs in the Molecular Diagnosis of Male Infertility

“…In addition, because seminal plasma contains many biochemical molecules secreted from the specific organs or compartments of the male genital system, changes in some factors, including acid phosphatase, ␣-glucosidase, and others, have also been used as diagnostic indicators for evaluating the male reproductive system. For example, measurement of ␣-glucosidase in seminal plasma has been used to differentiate secretory azoospermia from the excretory type and to identify partial obstruction at the epididymal level (10 ). In addition, zinc is a spermatogenesis and prostate marker (11 ).…”