[Testicular aging and its consequences].

Testicular aging is of concern at the same time to the individual and to his lineage. In the individual, vascular changes which come about because of age lead to diminished oxygenation of the tissues; modifications occurring in the endocrine cells lead to a lowering in androgen production; modifications in the enzymes lead to a lowering of the efficiency of the blood-testis barrier; modifications in Sertoli cells lead to a lowering of production of androgen binding protein. Parallel with the diminished number of spermatozoids and the alteration in their form and mobility is a lowering in fertility. As far as the offspring of these men is concerned, paternal aging is responsible for new dominant autosomic mutations which themselves cause numerous malformations and also of chromosome X linked recessive mutations, and of haemophilia A and Duchenne's muscular dystrophy. Experimentally, paternal aging has been shown in the rat to be responsible for a lowering in the level of learning capacity in the offspring. The possible mechanism by which genetic alterations occur has been briefly considered. Certain authors believe that gonadal aging and its consequences for the offspring start in men as in women about the age of 35-40.