Summary. In 146 males aged between 20 years and 40 years attending an infertility service, the secretory activity of the seminal vesicles was assessed by ...
International Journal of Andrology, 1989, 12, pages 286-294
The secretory activity of the seminal vesicles and its relationship to sperm motility: effects of infection in the male reproductive tract G . F. G O N Z A L E S , M . A . GARCIA-HJARLES, R . G U T I E R R E Z and R . G U E R R A - G A R C I A lnstituto de lnvestigaciones de La Altura, Departments of Physiology and Obstetrics and Gynecology, Universidad Peruana Cayetano Heredia, PO 6083, Lima, Peru
Summary In 146 males aged between 20 years and 40 years attending an infertility service, the secretory activity of the seminal vesicles was assessed by measurement of corrected seminal fructose concentration. This value was related to the presence of a positive semen culture, other evidence of inflammatory processes in the reproductive tract and sperm motility. Only 48% of subjects with a positive semen culture showed evidence of inflammation in the reproductive tract, as assessed by the presence of more than 20 white blood cells per high power field, and > 10% spermagglutination in the ejaculate. There was a relationship between the inflammatory process, hypofunction of the seminal vesicles and poor sperm motility. When the semen culture was positive but there was no evidence of inflammation neither seminal vesicle function nor sperm motility was affected. When the semen culture was negative, i.e. no evidence of inflammation and the subjects were asthenozoospermic, the corrected fructose levels were normal. It is proposed that in these conditions the cause of asthenozoospermia may be factors other than accessory sex organ dysfunction. In conclusion, there was no close relationship between the bacteriological results and evidence of inflammation of the accessory glands. A positive semen culture was related to lower levels of corrected fructose (hypofunction of the seminal vesicles) when the positive sperm culture was associated with inflammation of the reproductive tract and asthenozoospermia. Keywords: seminal vesicles, sperm motility, corrected fructose level, infections, inflammatory reaction, asthenospermia. Introduction Recent studies have demonstrated that adequate function of the seminal vesicles is important for sperm motility (Okamura & Sugita, 1983; Okamura et al., 1985; 1986; Oliw, Fahlstadius & Hamberg, 1986; Gottlieb, 1988). The seminal vesicles produce fructose among other substances, but its measurement cannot be used as a Correspondence: Gustavo F. Gonzales, Instituto de Investigaciones de la Altura, PO 6083, Lima, Peru.
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Seminal vesicles and sperm motility in infection 287 marker of their function since its content in seminal fluid is related inversely to the sperm count (Phadke, Samant & Deval, 1973; Biswas et al., 1978; Schirren, 1972; Gonzales et al., 1986). In addition there is no correlation between fructose and sperm motility (Biswas et al., 1978; Gonzales et al., 1986). The inverse relationship between sperm count and seminal fructose has been postulated to be due to the time elapsed between ejaculation and the assay of fructose (Schirren, 1972; Rui, Morkan & Purvis. 1986). In an attempt to correct for this an index of seminal vesicle function has been developed by multiplying the seminal fructose concentration by the sperm count (Gonzales et al., 1986; 1988) and this has been termed ‘corrected fructose’. Use of this index demonstrates a significant direct correlation with sperm motility, such that subjects with poor sperm motility have lowered levels of corrected fructose (Gonzales et al., 1986; 1988). In addition, subjects with values of corrected seminal fructose below normal have lower levels of seminal plasma prolactin (Gonzales et al., 1989), another compound found in the seminal vesicles (Wahlstrom & Rante, 1983). A relationship between diminished seminal vesicle function and asthenospermia has also been demonstrated by measuring other compounds secreted by the seminal vesicles, such as bicarbonate (Okamura et al.. 1986), prostaglandins (Bendvold et al., 1984), and prolactin (Gonzales et a [ . , 1989). In addition, the administration of prolactin (Velazquez-Ramirez, Vilar-Roja & Hicks, 1980), bicarbonate (Okamura et al., 1985) or prostaglandins (Gottlieb, 1988) to the seminal ejaculate in vitro improves sperm motility. From these studies it can be suggested that diminished function of the seminal vesicles, may influence sperm motility negatively. The most common cause of seminal vesicle dysfunction is bacterial infection producing vesiculitis. This inflammatory process may produce hypofunction of the glands by obstruction of the ducts of secretion and consequently diminished secretion of fluid. However, the fact that subjects with male accessory gland infection may have normal or diminished sperm motility (McGowan et al., 1981), and that the pattern of seminal quality is the same in subjects with positive and negative sperm culture (Naessens et al., 1986) raises the question of why some men with a positive sperm culture have diminished sperm motility whereas others do not. In this paper we have investigated whether diminished seminal vesicle function, as measured by the ‘corrected fructose’ level, is related to asthenozoospermia and whether the correlation is influenced by the results of sperm cultures, with or without evidence of inflammation in the reproductive tract.
Materials and methods Patients Semen samples were obtained over a period of 6 months from 146 consecutive males between 20 and 40 years of age who attended an infertility service. Among the subjects studied were fertile and infertile males, but this status was not evaluated for the purpose of the present work. None of the subjects had had prior surgery on the reproductive tract. Three subjects were excluded from the study, one because he was azoospermic and the other two because of incomplete results for seminal evaluation.
288 G. F. Gonzales et al. Semen collection Specimens of semen were collected into sterile plastic containers after 3-5 days of sexual abstinence. Subjects were instructed to wash their genitalia and hands before performing the test and to void urine prior to ejaculation. The semen sample was obtained by masturbation and an aliquot was taken for culture prior to semen analysis. Semen analysis All samples were analysed by the same person using laboratory methods of semen assessment based on those described in the World Health Organization Laboratory Manual (Belsey er al., 1980). The analysis comprised of measurement of ejaculate volume, pH, fructose and citric acid levels, sperm count, percentage of motile sperm (at 2 and 4 h after ejaculation) and morphology. Differentiation between leucocytes and other round cells was made using a peroxidase staining method (WHO, 1979). Seminal fructose was assayed 4 h after ejaculation using a colourimetric method (Mann, 1964). The fructose was corrected for sperm count by multiplying it by the Iogarithm of the sperm count as described previously (Gonzales er al., 1986). The sperm count was transformed to logarithms to normalize the distribution (Rehan, Sobrero & Fertig, 1975). The normal range for fructose was 1.2-4.0 mg/ml (10th and 90th percentiles), and the normal range for corrected fructose was 2.5-8.0 mg/ ml X lo6 sperm/ml. Seminal fructose was measured 4 h after ejaculation since the prevalence of subjects with lowered levels of corrected fructose remained unaltered whether the assay for fructose was carried out at 2 or 4 h after ejaculation. Sperm motility was graded as poor, good or excellent. A subject was considered asthenozoospermic if the semen sample had < 60% motile sperm or < 30% sperm with excellent motility. As the prevalence of asthenozoospermia obtained after evaluation of the sperm motility at 2 h is almost the same as that obtained after 4 h (Gonzales, 1985), and as subjects who have normal motility at 2 h maintain this at 4 h (Bilgeri et al., 1987; Mandal & Bhattacharyya, 1987) we have used values at 4 h to correlate sperm motility with corrected values of seminal fructose assayed at the same time. Evaluation of the inflammatory response The inflammatory response was evaluated in degrees according to the number of white blood cells (WBC)/high power field (HPF). A value > 10 WBC/HPF represents > 1 x 106WBC/ml. An inflammatory process in the male reproductive tract was diagnosed if there were >20 WBC/HPF ( x 400) and > 10% sperm agglutination was evident in the semen sample. We have not tested for sperm autoimmunity since the prevalence of sperm antibodies in infertile men is low (6.5%) (Jennings, McGowan & Baker, 1985), and because infections in the reproductive tract may also produce antisperm antibodies (Shahmanesh, Stedronska & Hendry, 1986). Semen culture Liquefied semen was diluted 1:2 (v/v) with sterile distilled water and aliquots of 50 p1 were spread uniformly in Neisseria and blood agar, and incubated aerobically
Seminal vesicles and sperm motility in infection 289
at 37°C for 48 h. A sperm culture was considered positive when uniform growth of 2 1000 pathogens, or 3 10 000 non-pathogens were detected per millilitre semen (Comhaire, Rowe & Farley, 1986). Isolation of chlamydia, mycoplasma or viruses was not attempted. Statistical analysis Data were evaluated by Student's t-test for unpaired samples when means were compared, and by the Chi-square test when categorized data were compared. Results Forty-five out of 146 men (30.8%) presenting for evaluation of infertility showed a positive semen culture. One of these was azoospermic and was omitted from further analysis. Of the positive results 93.3% were Enterococcus, 4.4% Staphylococcus aureus and 2.2% Streptococcus viridans. The sperm count and sperm motility were reduced significantly in the group with positive semen cultures (PkO.01 and P < 0.02 respectively). Seminal volume, pH, fructose, corrected fructose and citric acid were not different between the groups (Table 1). Table 1. Semen analysis in men with and without positive semen cultures
Semen culture
Semen variable Volume (ml) PH Sperm count ( x 1O6/m1) Sperm motility (%) Fructose (mg/ml) Corrected fructose value (mg/ml x lo6 sperm/ml) Citric acid (mg/ml)
Negative? (n= 99) 3.2 ? 0.1 7.5 f 0.03 144.2 f 0.85 66.7 f 1.70 2.8 f 0.16 5.2 zk 0.30 8.8 f 0.40
Positive$ ( n = 44) 2.9 ? 7.6 k 91.3 k 56.6 f 2.6 f 4.2 f 7.9 f
0.2 0.06 13.0" 4.2* 0.22 0.39 0.66
Values represent means f SEM. *P
