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Muramyl dipeptide β-heptylglycoside (C7MDP) was administered to non-pregnant CBA female mice and pregnant mice after non-abortion-prone mating (CBA×BALB/c) and mating associated with a high rate of spontaneous abortion (CBA×DBA/2). In non-pregnant females, C7MDP increased the production of IL-2, IL-4, IL-5, IL-6, IL-17, IFNγ, TNFα, and GM-CSF at constant production of IL-1α and IL-10. C7MDP increased the production of IL-10 and IL-17 and suppressed the production of IFNγ on day 8 of gestation in non-abortion-prone mouse couples and stimulated the synthesis of IL-4 and IFNγ, reduced IL-5 production, and slightly increased IL-1α secretion after abortion-prone mating. On day 14 of gestation, C7MDP elevated the yield of IL-2, IL-4, IFNγ, TNFα, and GM-CSF in CBA×BALB/c and CBA×DBA/2 couples and IL-17 in the fi rst variant of mating.

Rats were adapted to the continuous action of moderate immobilization stress for 1, 5, and 15 days. Thereafter the threshold of ventricular fibrillation and the heart rate were compared with biochemical indexes of adrenergic and cholinergic regulation of the heart, namely, catecholamine, cAMP, and cGMP content, acetylcholinesterase and choline acetyltransferase activity, the number and affinity of cardiac muscarinic receptors, and the catecholamine content in the adrenals. The threshold of ventricular fibrillation fell on the 1st day due to a predominance of the adrenergic regulatory effect over the cholinergic. Adaptation for 5 days is attended by a rise of the threshold of ventricular fibrillation to the norm and by marked bradycardia, both these shifts being abolished by atropine. Elevation of the heart's resistance to arrhythmias stems from the prevalence of cholinergic regulation. Equilibrium between the cholinergic and adrenergic effects on the heart was found as a results of 15-day adaptation. The normal threshold of ventricular fibrillation and the increased cardiac resistance to arrhythmia were preserved and dictated largely by adaptive changes at the cardiomycyte level.

The effects of single 1-hour immobilization stress exposure and of long-term (40 days) adaptation to intermittent high altitude hypoxia (in hypobaric chamber at "altitude" 4000 m, 4 hr, a day) on serum myoglobin content were studied in Wistar rats. It has been shown that such stress exposure induced the 2.5 fold increase in the serum myoglobin content. The adaptation did not change the myoglobin content, but effectively limited mentioned above stress-induced increase in the serum myoglobin level. These data suggest that serum myoglobin content can be used as a criterion for stress damage and efficiency of factors protecting against stress damage.

Experiments on rabbits have shown hyperlipidemia to develop within the first 48 h after a single intravenous injection of bovine serum albumin (BSA, fraction V). The mean concentration of blood plasma triglycerides (TG) was considerably higher than normal (by 262% after 24 and by 625% after 48 h). The cholesterol content was also elevated (by 80 and 270%, respectively). Following 7 and 14 days the lipid concentration returned to normal. The plasma post-heparin lipoprotein lipase activity (PHP-LPL) was lower 24 h and 7 days after BSA injection and the hypotriglyceridemic effect of heparin was less pronounced. The data obtained support the hypothesis that hyperlipidemia provoked by a single intravenous injection of BSA to rabbits results from low PHP-LPL activity and possible changes in TG-rich lipoprotein substrate affinity for the enzyme.