[Seasonal and circadian fluctuations in blood biochemical indicators in mice in natural conditions and exposed to constant light]. / Sezonnye i sutochnye kolebaniia biokhimicheskikh pokazatelei krovi u myshei v estestvennykh usloviiakh i pri postoiannom osveshchenii.

The fluctuations of activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and those of the levels of protein, glucose, cholesterol, bilirubin, creatinine, blood urea nitrogen, K+, Cl-, Na+ in blood plasma of mice in natural conditions (NC) and exposed to constant light (CL) were studied in different seasons of the year (in January, April, July, October) on days 18, 24, 6 (at 12 o'clock). Most indices both in NC and CL animals had seasonal rhythm similar for each of them. This proves a primary effect of environmental geoclimatic factors of formation of circadian periodicals as compared to desynchronization in constant light revealed by Kosinor analysis in winter (acrophase from 14.16 till 16.32 o'clock) and autumn (acrophase from 23.03 til 4.40 o'clock). During the same seasons one can observe the maximum desynchronization influences of constant light, which leads to abrupt falling (to the 10-fold and more) of the fluctuations amplitude and in some cases to stabilization of circadian rhythm.

[Chronosensitivity to absolute hypercapnia in various light regimens]. / Khronochuvstvitel'nost' k absoliutnoi giperkapnii pri razlichnom svetovom rezhime.

The studies of mice on the natural regimen of day and night alterations have revealed a daily rhythm of hypercapnia toxicity, with the maximum sensitivity observed at 6 a.m. and the minimum sensitivity at 6 p.m.-2 a.m. and 2 p.m.-6 p.m. The experiments on animals kept for 2 weeks-1 month on the constant light regimen have demonstrated the shift in sensitivity acrophase to 10 a.m.-4 p.m. and the prolongation of the daily period of increased sensitivity. With the animals' return to the natural regimen, a two-peak rhythm with the maximum sensitivity at 2 a.m. and 10 a.m.-2 p.m. and the minimum sensitivity at 22 p.m. and 6 a.m. was observed during the first 2 weeks-1 month. 2 months later the rhythm curve flattening was recorded, with the initial daily sensitivity rhythm to absolute hypercapnia recovering in 2 1/2 months.