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[Biological model of the accelerated aging. I. Dynamics of spontaneous mutation in spermatogenesis in SAM mice (senescence-accelerated mouse)].

We studied the dynamics of age-related cytogenetic changes in the developing male germ cells of mice prone to accelerated senescence (strain SAMP1) and mice resistant to accelerated senescence (strain SAMR1) by counting the spermatogonial and meiotic micronuclei and testing the defects of the spermatozoon head shape. In these animals, the accumulation of germinative mutations has a nonlinear pattern. During the entire ontogenesis of SAMP1 mice, the frequency of circular spermatids with micronuclei corresponded to the level observed upon induced mutagenesis.

Aging↗
PubMedDate not supplied

[A biological model of accelerated aging. III. Histological characteristics of age-related changes of spermatogenic epithelium in mice SAM (senescence-accelerated mouse)].

The data characterizing the age-related morphological changes in the spermatogenic epithelium of SAMP1 (senescence-accelerated prone) and SDAMR1 (senescence-accelerated resistant) mice are presented. In many tubules, "early spermatogenesis" was accompanied by the formation of many morphologically abnormal germ cells on histological sections of the gonads of sexually immature (three-four weeks) mice of both strains. At this stage, destructive processes in the spermatogenic epithelium were more pronounced in SAMR1 mice. In sexually mature (two-three months) SAMP1 and SAMR1 mice, spermatogenesis as a whole proceeded normally. The first signs of regressive changes in the inner structure of most tubules (disintegration, detachment of spermatogenic epithelium from basal membrane) and morphology of germ cells (pycnosis, nuclear and cytoplasmic vacuolization) were found in SAMP1 mice at the age of six-seven months. In the older age groups (9-10 and 12-15 months), all types of spermatogenic cells were represented in both SAMP1 and SAMR1 mice, but most of these cells were atypical. Mitotic figures were recorded in a population of highly differentiated Sertoli cells.

Aging↗