Holarctic Marmots as a factor of Biodiversity.
Rumiantsev V.Yu;, Nikol'skii A.A. & Brandler O.V. eds.,
Abstracts, 3d Conference on Marmots (Cheboksary, Russia, 25-30 August 1997),
Moscow ABF 1997, 216p. : 192-193.


PHENOMENON OF ENDOCRINE AND GERMINATIVE COMPOSITION OF MARMOTS' TESTICLES BEFORE HIBERNATION AND ITS BIOLOGICAL IMPORTANCE


N.N. Shevljuk

Department of Histology and Embriology, State Medicine Academy, Orenburg, Russia


Activating of endocrine and germinative functions in testicles before hibernation were described for some animals. Two peaks of endocrine and germinative testicle activity (one is directly connected with breeding season, the other is before hibernation) were described. for several amphibians (Ruzen-Range, 1980; Rastogi et al., 1989; Fasano et al., 1989) and reptiles (Saint Hirons, 1980; Ivanova, 1993). Testicle activating before hibernation was shown in marmots by Spivakova, Kapitonov (1992). Our analysis of testicles of 41 marmot individuals, trapped in July-August, revealed, that in marmot testicles endocrinocytes and their nuclei extensively grew up in July. Nucleus-cytoplasm ratio in most Leydig's cells fluctuated between 0.15-0.30. Vesicles of smooth endoplasmic reticulum occupied almost all cytoplasm with many mitochondrions and lipid drops. After endocrinocyte activating spermatogenesis also activizes in tubules. By August diameter of curved tubules increases twice. Spermatogenic epithelium again appears as multilayer, meiosis takes place in many tubules. Interesting, that activating of endocrine and germinative functions in testicles is observed almost in all mature animals., and only 58.3 4.9% individuals breed in spring. High functional activity of endocrinocytes both in breeding in spring season and in non-breeding needs to be explained.

Biological importance of reported phenomenon, probably, is connected with morpho-physiological grounds, which are set before hibernation for prompt activating of full spermatogenesis just after animal arousal. Before hibernation the longest stages of spermatogenesis take place in curved tubules of testicles, such as meiosis. Although final stages of meiosis are short-tern, prophase of the first meiosis fission is very long-term.

Morpho-physiological signs of high secretory activity in interstitial endocrinocytes of testicles keeping after breeding and observed in non-breeding animals may show that testicle endocrinocytes provide not only reproduction, but also control other functions of organism. Perhaps, endocrinocyte activity supports homeostasis maintenance, providing mechanisms of adaptations in marmots.

Increasing of number of argentaffin granules in testicle endocrinocytes before hibernation may indirectly show their role in control mechanisms initiating hibernation, particularly in processes providing drop of body temperature.

The results indicate complex character of interactions between inter- and infra-system mechanisms of control of testicle histo-physiology. Clear explanation of obtained results is hardly possible now. So, the study of endocrine and germinative structures of testicles in hibernating animals is challenging.


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