Quantitative zytochemische Untersuchungen der Veränderungen des Nukleoproteins von Spermien bei Fertilitätsstörungen des Mannes

Abstract

Introduction There is some evidence that fluctuations of the Feulgen-DNA content of spermatozoa associated with male infertility do not represent true differences in DNA content. It is rather the changes of the nuclear proteins modifying the stoichiometry of the Feulgen reaction which seem to be responsible for these facts ( Gledhill et al., 1966 ). These phenomena should be more precisely defined, as proposed by Sandritter et al. (1965) by investigating the kinetics of the “Feulgen hydrolysis curve” of the spermatozoa. Material and Methods Ejaculated spermatozoa were fixed immediately in 96% ethanol, hydrolyzed, as proposed by Bachmann (1968) at 39.5°C in 0.75 N HCL for 2, 3.5 and 5 hours, and stained with Schiff's reagent ( Graumann, 1953 ) according to the Feulgen procedure. The total dye content of the stained spermatozoa was determined using a type GN 2 scanning integrating microdensitometer (Barr & Stroud, Glasgow, Scotland). The nuclei of 50 sperm heads of each slide were measured at 570 nm, the mean value and the variation of the measurements calculated. The significance of this variation between the spermatozoa of fertile and infertile men was checked by an F-test. Furthermore, the hydrolysis curves of spermatozoa of fertiles and infertiles were compared. Fertility and infertility were identified by standard andrological examinations. Results and Discussion The hydrolysis curve of spermatozoa shows a fertility-linked significant difference as can be demonstrated by Figure 1. The mean values of dye content in arbitrary units (AE) of the spermatozoa of fertile male are lower and the curve does not reach a maximum after 5 hours of hydrolysis, indicating a different stoichiometry of the Feulgen reaction. The variations (s 2) of our cytophotometric measurements also show a difference between the populations of fertile and infertiles spermatozoa. The latter show a significant higher scattering of the cytophotometrically determined dye content after different hydrolysis times. The results of these calculations are summarized in Figure 2 and Table 1, insignificant values being drawn with heavy-faced typs. All these findings are considered as fertility-linked disturbances in synthesis and structure of acid nuclear proteins and the so-called (acid-insoluble) “residual proteins” of the sperm heads. Considering data of Bahr and Wied (1971) this control of protein synthesis seems to be lax under physiological conditions with respect to quantity but not to quality. This means that the macromolecular components of sperm cells are assembled without regard to strict proportionality. It now seems obvious that under pathological conditions linked to infertility, which is expressed by the abnormal histological pattern of spermiogenesis (Fig. 3), the lack of control of protein synthesis may increase. This simple investigation of the structure of nucleoproteins of the sperm head enables us to investigate the complex problems of male infertility.