ANDROLOGIA 28, 43-51 (1996) ACCEPTED: JUNE 12, 1995 zy Lipid peroxidation and morphology of rat testis in magnesium deficiency H. J. Merker', T. Gunther2, V. Hollrieg12, J. Vormann2 and K. Schumann3 'Anatomisches Institut; *Institut fur Molekularbiologie und Biochemie, Freie Universitat Berlin, Berlin, Germany; 3Walther Straub-Institut fur Pharmakologie und Toxikologie, zyxwvut Ludwig-Maximilians-Universitat, Miinchen, Germany Key words. Testis zyxwvutsrq - magnesium deficiency - lipid peroxidation - vitamin E - iron ~ rat Summary. Male Wistar rats were fed diets with different Mg content, ranging from 70 to 850 ppm Mg, for 30 days. After 0, 10, 20 and 30 days, some of the rats were sacrificed for measuring weight, lipid peroxidation, Fe, vitamin E, Na+, K+, Mg2+ and Ca2+ content of testes. After 30 days, the morphology of the testes was investigated by electron microscopy. Mg deficiency induced an increase in weight, Na+, Ca2+and Fe content and a reduction of K+ and Mg2+ content. Vitamin E content was reduced and the content of malondial- dehyde as an indicator of lipid peroxidation was increased. Mg deficiency induced morphological alterations in up to 40% of the spermatids in the 70 ppm Mg group, which consisted: 1) in injured stretching of spermatids; 2) in an irregular arrange- ment of coarse fibres with missing microtubulus complex (axoneme) and microtubulus sheath; 3) in the development of up to 4 bundles of outer fibrils in one spermatid. The increase of Fe content, lipid peroxidation and the onset of morphological alterations occurred already at a mild degree of Mg deficiency. Introduction In previous experiments, testis weight was increased by Mg deficiency (McCoy & Kenney, 1975; Merker & Gunther, 1994) and, as found by light microscopy, testis expressed oedema localized beneath the capsule and between the tubuli semini- feri (Merker & Gunther, 1994). The number of spermatozoa was significantly reduced in most tubuli seminiferi and hyaline material occurred within the tubuli (Merker & Gunther, 1994). The Correspondence: Professor Dr H. J. Merker, Anatomisches Institut, Freie Universitat Berlin, Konigin-Luke Str. 15, D-14195 Berlin, Germany. present experiment was undertaken for further analysis and characterization of these alterations. Pathological mechanisms of Mg deficiency may be induced by alterations of extracellular and intracellular electrolytes, such as Na', Ca2+, Mg2+(Gunther, 1981) or Fe (Gunther zyx et al., 1992), and in part secondarily by Fe-induced lipid peroxi- dation (LPO) (Gunther et al., 1992). An increase of Fe-induced LPO occurred in injured spermato- zoa (Aitken & Clarkson, 1987; Iwasaki & Gagnon, 1992; Aitken et al., 1993) and was correlated to defects of their midpiece (Rao et al., 1989) and to abnormal motility (Rao et al., 1989). Therefore, we investigated electrolytes, LPO and ultra- structure of testes from Mg-deficient rats. In order to ascertain whether Mg deficiency plays a pathogenetic role in infertility, the rats were exposed to a graded degree of Mg deficiency, since in humans there may be only mild Mg deficiency. Material and methods Male Wistar rats (Interfauna, Tuttlingen, Germany, initial weight 140- 150 g) were used for the experiment. Five rats were randomly assigned to each experimental group. Five groups received diets with different Mg2+ content zyx ad libitum. The diets were prepared by adding MgC1, to a basal Mg-deficient diet (Ssnif€, Soest, Germany) achiev- ing the following Mg2 + contents: 70 ppm, 110 ppm, 208 ppm, 320 ppm, and 850 ppm. Since reduced food intake may lead to infertility (Brinkworth et al., 1992), an additional group of 5 rats receiving the 850 ppm diet was pair-fed to the 70ppm group. All rats were housed under stan- dard conditions (dark-light period: 12 h, 12 h; temperature 22 "C, 60% humidity) and received