[Modulation of the contractile activity of the fast and slow twitch rat muscle during continuous stimulation]. / Modifikatsiia sokratitel'nykh svoistv bystroi i medlennoi myshts krys v usloviiakh nepreryvnoi stimuliatsii.

The fast- and slow-twitch muscles were tested with single pulses in the course of unfused tetanus formation. The tetanus decreased differences in contractile parameters of the test-twitch contractions and, after continuous stimulation, eliminated them altogether.

[The effect of temperature and cold adaptation on slow-muscle contractile activity in rats]. / Vliianie temperatury i adaptatsii k kholodu na sokratitel'nuiu aktivnost' medlennoi myshtsy krys.

Temperature dependence of single twitches as well as tetanic twitches was revealed. The adaptation changes were found to occur in single twitches alone. A distinction between slow twitch and fast twitch muscle contractions decreased after cold adaptation.

[The characteristics of long-term dentate tetanus of the skeletal muscle in the rat after cold adaptation]. / Kharakteristika dlitel'nogo zubchatogo tetanusa skeletnoi myshtsy krysy posle adaptatsii k kholodu.

Prolonged unfused tetanuses of control and cold-adapted rats' m. gastrocnemius at different muscle temperature (29-30 and 24-25 degrees C) were studied. The time of achievement of the maximum level increased, the phase of higher thermogenesis became longer and the third economic phase was delayed after cold adaptation (both at 29-30 degrees C and 24-25 degrees C).

[The effect of cooling on the characteristics of a single skeletal muscle contraction in cold-adapted rats]. / Vliianie okhlazhdeniia na kharakteristiku odinochnogo sokrashcheniia skeletnoi myshtsy u adaptirovannykh k kholodu krys.

The time parameters and amplitude of the m. gastrocnemius twitch contractions were studied in control and in cold-adapted rats at optimal muscle temperature (29-30 degrees C) and after cooling the muscle to 24-25 degrees C. A decrease of the twitch contraction force and an increase of the time of the contraction to the maximum, occurred in cold-adapted rats. The cooling of muscle decreased the velocity of the twitch contraction in both groups of animals.

[Characteristics of lengthy spiked tetanus of rat skeletal muscle]. / Kharakteristika dlitel'nogo zubchatogo tetanusa skeletnoi myshtsy krysy.

Prolonged unfused tetanuses of the rat m. gastrocnemius were investigated. An increase in the stimulation frequency raised the tension of unfused tetanuses, shortened the time of achievement of the maximum level, and accelerated the beginning of the third (economic) phase. After cooling the muscle to 24-25 degrees C, the unfused tetanuses developed yet during low frequency stimulation and the economic phase began sooner.

[Classes of rat lymphocyte surface immunoglobulins detected by enzymatic radioiodination]. / Klassy immunoglobulinov poverkhnosti limfotsitov krys, vyiavliaemye metodom énzimaticheskogo radioiodirovaniia

By means of enzymatic radioiodination, immunopre-cipitation and acrylamide gel electrophoresis in sodium dodecyl sulfate it was found that on the surface of normal rat splenocytes there were two main immunoglobulin classes--monomeric IgM and Ig (H2L2) which had a heavy chain larger than they phi, yet smallerthan the micron chain, differing from them by the antigenic properties. It is possible that this Ig class corresponds to the human IgD and the mouse IgD-like cell surface molecules. Small amounts of thedetected cell surface IgG may indicate both its cytophilic properties and the immunological status of the experimental animals.