[Seasonal changes in the testes of the silver fox].

In 14 mature male silver foxes in spring and autumn by means of counting dots and transsections, relative and absolute summational volumes and areas of the seminiferous tubule surfaces, interstitial glandulocytes (Leydig's cells) and stroma have been calculated. Average diameter and total length of the tubules have been determined. Increased mass of the testes in spring is the result of a proportional enlargement of the total volume of the seminiferous tubules and stroma, while the total volume of the endocrinic part in the organ changes insignificantly.

[Relative hypertrophy of the right ventricle in silver foxes selected for domestication behavior].

Silver foxes selected for domestication behavior were found to have relative hypertrophy of the right heart ventricle, which was 21% as enlarged in males and 18% as enlarged in females as compared with non-domesticated animals. It was established by stereological methods that hypertrophy occurs mainly at the expense of an increase in the absolute and relative content of myofibrils in cardiomyocytes, with the absolute total volume of the mitochondria being equal both in domesticated and non-domesticated animals. It was shown by means of dissociated cell counts that in both animal groups, the absolute number of cardiomyocytes and their nuclei in the right ventricles is approximately similar.

[Adrenaline-induced damage to the myocardium in rats with genetically determined arterial hypertension].

Genetically hypertensive and normotensive rats were subjected to acute myocardial injury by a single subcutaneous injection of adrenaline (0.5 mg/100 g bw). The animals were sacrificed one day later.

[Ratio of spontaneous and o-aminoazotoluene-induced hepatocarcinogenesis in mice].

No correlation was found between the frequency of spontaneous and o-aminoazotoluene (o-AAT)-induced hepatic tumours in mice. High susceptibility to tumour induction with o-AAT in mice both genetically susceptible (strains CBA and A/He) and resistant (strains DBA/2J and DD) to spontaneous hepatocarcinogenesis was detected. The CC57BR mice predisposed to spontaneous hepatomas were insensitive to their induction with o-AAT.