Seasonal Changes of Neutral α‐Glucosidase Activity in Human Semen

Abstract

ABSTRACT:Although there are contradictory reports, the biochemical evaluation of the seminal activity of neutral ␣-glucosidase (NAG) has repeatedly been described as an important parameter to test epididymal patency and is recommended by the WHO. Because, for a number of diagnostic parameters, seasonal variations have been described even in the human, it was the aim of this study to investigate possible circannual changes of NAG. This is an important aspect of andrological diagnosis, as seasonal changes of specific diagnostic parameters might have an impact on the accuracy and predictive power of these parameters, which in turn might have an effect on the therapeutic concept for the patients. In a total of 473 patients, sperm concentration, volume of the ejaculate, total motility, progressive motility, pH value, number of peroxidase-positive cells, concentration of fructose, and NAG as functional markers of the seminal vesicles and the epididymis, respectively, were analyzed according to standard procedures. Seminal activity of NAG was significantly correlated with the sperm concentration (P Ͻ .0001), ejaculate volume (P Ͻ .0001), and the pH (P ϭ .0025). Moreover, significant (P ϭ .0008) seasonal changes in the activity of seminal NAG with the maximum in spring (76.87 mU/ejaculate) and the minimum in autumn (58.55 mU/ejaculate) were found. The incidence of low-ranged activity of the enzyme was 9.2% in spring, while it was 20.3% in autumn. Thus, our data clearly demonstrate circannual changes of the seminal activity of neutral ␣-glucosidase. This in turn has clinical impact as the predictive power of the test system changes throughout the year.

Differential expression of mRNA aromatase in ejaculated spermatozoa from infertile men in relation to either asthenozoospermia or teratozoospermia

“…The pH increase noted within A2 subgroup could be related to the low seminal level of NAG and the increase level of aromatase mRNA. It has been demonstrated that pH was correlated positively with seminal activity of alpha‐glucosidase and negatively with citric acid (Obidoa et al ., ; Henkel et al ., ; Said et al ., ). Alterations of sperm motility cover multiple origins and the combination of additional tests such as aromatase transcripts, neutral alpha‐glucosidase, pH and vitality could bring new insights about the pathological causes of asthenospermic patients.…”

The Relevance of Neutral α-Glucosidase Activity in Andrology

“…After a 3-month storage period, about 30-40% of the activity remained [Dias et al 2004]. Circannual changes in the NAG activity have also been documented [Henkel et al 2006]. Considering these practical concerns as well as the poor correlation noted between the NAG activity and sperm motility or morphology (Table 1), routine assessment of NAG may not be advisable.…”

Effect of scrotal heating on sperm quality, seminal biochemical substances, and reproductive hormones in human fertile men

“…2 Spermatogenesis is a temperature-dependent process, which scrotal temperature is kept lower than 2°C to 8°C of the core body temperature and regulated by a specialized blood supply. [13][14][15][16] The epididymis is the main source of carnitine in human seminal plasma. [3][4][5][6] Previous studies on sperm parameters, sperm apoptosis, oxidative stress, and molecular mechanisms have been reported.…”