[The reflex and direct actions of novocaine on the rhythm of the heart beats in rats in early postnatal ontogeny]. / Reflektornoe i priamoe deistvie novokaina na ritm sertsebienii krys v rannem postnatal'nom ontogeneze.

In experiments on newborn rats it was shown that heart beating frequency depended on the intensity of interoceptive afferentation. Partial shutdown of the afferentation by means of intraperitoneal injection of novocaine in the dose of 25 mg/kg of body weight caused the increase of heart beating and the more complete one at higher doses (100 mg/kg of body weight) led to its decrease. The injection of 2% novocaine (150-200 mg/kg of body weight) into the peritoneum of rat puppies on the first week of life caused the transition of bradycardia into temporary or permanent stop of heart beating. The same effect was observed for isolated atrium of rat puppies on the first week of life after the addition of 0.1% novocaine to feeding solution. This effect disappeared in older animals. It was concluded that resorptive effect of novocaine on heart structures causing the disturbance of heart automatism in newborn rats occurred along with the reflex one.

[The effect of changes in the level of interoceptive afferentation on the spontaneous periodic motor activity of rat pups]. / Vliianie izmeneniia urovnia interotseptivnoi afferentatsii na spontannuiu periodicheskuiu motornuiu aktivnost' krysiat.

The effect of intraperitoneally injected (25 mg/kg) novocaine (procaine) on the spontaneous periodic motor activity was investigated in rat puppies ageing from 1 to 14 days. It was shown that reactions were phasic: initial continuous and then elevated activity was followed by depression and recovery. The duration and intensity of stimulation and depression decrease with age. It was concluded that in newborn animals an excitability of motor centers depends on the level of interoceptive afferentation. The last may be one of the motor activity regulation mechanisms. The role of this mechanism decreases with age in favour of extero- and proprioception mechanisms of motor control.

[Water metabolism in monkeys during 14-day anti-orthostatic hypokinesia]. / Vodnyi obmen u obez'ian v protsesse 2-nedel'nogo prebyvaniia v usloviiakh antiortostaticheskoi gipokinezii.

Water balance parameters were measured in hypokinetic rhesus monkeys using tritiated water. During exposure the water content decreased by 18.4%, with 11.3% lost within the first 7 days. The rate of water renovation measured with respect to H3 half-life was decreased by a factor of 1.5 during the first week and increased by 10% during the second week, as compared to the pretest value. Daily water losses diminished by 30% during the first week and approached the pretest level during the second week. These findings are indicative of three phases in the time-course variations of water balance during head-down tilt.