Melatonin prevents testicular damage in hyperlipidaemic mice.

The damaging effect of hyperlipidaemia on testicular structure was determined, and the influence of melatonin was evaluated in testicular damage related to hyperlipidaemia. Hyperlipidaemia was induced in ApoE-knockout C57BL/6J male mice fed with high-fat diet alone (group A), or with high-fat diet and melatonin (group B). Six ApoE wild-type C57BL/6J male mice were fed with normal diet, served as controls. At the end of the experimental period, ultrastructural observations showed dramatically histopathological alterations in testicular tissues of group A. The basement membranes of seminiferous tubules were partially thickened and wavy-like in testes of mice with hyperlipidaemia, and vacuolar degeneration of mitochondria and dilation of endoplasmic reticulum were identified as well as the number of mitochondria and lipid droplets decreased significantly in Leydig cells and Sertoli cells. Electrondense deposits were observed in cytoplasms of germ cells. The testicular histostructure in group B treated with melatonin was similar to that of control. Apoptosis was determined by terminal-deoxynucleotidyl-transferase-mediated dUTP nick end labelling. Apoptotic germ cells were significantly more numerous in group A than in group B and controls. The results suggest that melatonin may be potential to attenuate testicular damage by improving histopathological changes and reducing germ cell apoptosis in hyperlipidaemic mice.