Levels of homoiothermy and homoioosmy and probable reasons determining them

V. V. Khlebovich

Zoological Institute, RAS 199034 Universitetskaya, 1, St.-Petersburg
e-mail: sult@zin.ru

Temperature of independently evolved homoiothermic animals (birds and animals) is maintained on the same level of 37—40°C. Flying or preparing to fly insects is heated to the same temperature. This temperature is close to the lethal temperatures resulting in denaturation of proteins (Dolnik, 2003). Freshwater homoioosmy animals (annelids, mollusks, various groups of crustaceous, Cyclostomata and fishes) which independently occupied continental waters maintain internal salinity around 5-8%_o. The same level is retained in terrestrial and secondary marine animals (Khlebovich, 1974). In the case of decline in internal salinity below 5-8%₀ the optical density of soluble tissue extracts increased, that could be explained by coagulation of tissue proteins. Therefore in the cases of homoiothermy and homoioosmy the values of regulated parameter are close to the parameters of protein complexes stability. It may be suggested that there are definitive advantages of governing regulated parameters exactly near boundaries of stability, out of which the process is terminated. Analogy could be found in control of reactions of nuclear synthesis and disintegration which are conducted under conditions which are close to the critical point of explosion. This statement can be regarded as a particular case of the Mopertui principle of the least operation.