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Biomedical subjects

O P Petrova

Publications and source records attributed to O P Petrova.

At least 19 recordsLinked to original sources
PubMed2005

Fluorescent microscopic study of epithalon binding in maternal and fetal rabbit tissues in health and under conditions of placental insufficiency.

Epithalon (regulatory tetrapeptide) labeled with dansil (fluorescent stain) easily penetrates into all tissues and organs of pregnant rabbit females and through the placenta into fetal organs. Incorporation of labeled epithalon in placental tissues is more often observed in fetuses developing under conditions of placental insufficiency than in normal fetuses.

Animals↗
PubMed2005

[Compensatory-adaptive responses of the rabbit fetuses developed under different intrauterine conditions, to noradrenaline administration].

In 9 experimental rabbit fetuses (with reduced uterine-placental blood frow), noradrenaline administration led to an obvious thermogenic response and heart rate increase, but not in intact rabbits. Obviously the noradrenaline dosage corresponds to the range of adaptive capacities of the functional systems in intact fetuses and so does not induce any shifts of the homeostasis parameters in them. The experimental fetuses prove to be more vulnerable to stresses, and homeostasis parameter shifts in them are statistically significant.

Adaptation, Physiological↗
PubMed2002

[Adaptive thermoregulatory reactions of the rabbit fetus at the end of the intrauterine development].

The data of permanent simultaneous registration of electrocardiogram, rectal & brown adipose tissue temperatures of the rabbit foetus have been obtained in chronic experiments. The haemodynamic shift in intensity of maternal-placental and foeto-placental blood flow (by female trental injection) led to a decrease in the foetus rectal temperature (0.33 +/- 0.09 degree C in intact foetus and 0.58 +/- 0.27 degree C in retarded foetus, p < 0.05). Both foetuses reacted by rectal temperature decrease (0.65 +/- 0.28 & 0.68 +/- 0.31 degree C, respectively) during immobilisation (by foetus arduan injection). Thus in both series of experimental cooling of foetus, brown fat activation was similar in intact foetus (approximately 53%), but did not change in growth retardation foetus--as a result of its tissue functional immaturity, probably.

Adaptation, Physiological↗
PubMed2001

[Cold-induced paralysis and recovery of lung respiration and heart contractions in newborn rats (inversion of Arrhenius law for physiological functions)].

Arrest of respiration and heart activity in new-born rats aged 3-4 days and 10-11 days was shown to occur at a body temperature 6-7 degrees C and 2-3 degrees C lower than in adult rats, resp. At room temperature the body temperature of profoundly cooled rat's litter gradually increases and the functions are restored. In 3-4-day old rats, at the body temperature rising from profound cooling to 15-18 degrees C, the respiration and heart rates are 2-4-fold more than at the same temperature attained from the normal body temperature. These differences in the respiration and heart rates at the same body temperature suggest an inversion of the Arrhenius law (the Q10 coefficient) for physiological functions in early ontogenesis. This effect completely disappears in 10-11-day old rats.

Animals↗
PubMed1999

[Thermoregulatory reaction in the rabbit fetuses developing under the reduced utero-placental blood flow].

Rectal temperature, temperature of the brown adipose tissue, and the heart rate were studied in the rabbit foetus under intact and reduced utero-placenta blood flow in the end of the intrauterine development. With the reduced utero-placenta blood flow, bradycardia and a drop in the brown fat metabolism due, probably, to an insufficient development and functional immaturity of this tissue, were revealed.

Adipose Tissue, Brown↗
PubMed1992

[The value and comparative analysis of the energy expenditures of newborn animals and children].

As opposed to adults, infants were found to have 5-fold differences in values of heat production per unit of mass and unit of body surface. Animals of the same age have these differences not over 20-50%. Newborn mature infants could have these differences to reach 50-60%. The data obtained suggest significant differences in the efficiency coefficient values for muscles contractile activity to play the role of the mechanism of heat production control in chemical thermoregulation and postnatal formation of the constancy of main (standard) metabolism.

Animals↗
PubMed1990

[Sarcoidosis and sarcoid-like granulomas in the liver].

Based on examination of 2450 liver biopsy specimens it has been shown that different granulomas occur in 4% of all the biopsy specimens. Of these, sarcoid-like granulomas are detectable in 13.5% of cases. Diagnosis of liver sarcoidosis is always based on the clinicomorphological findings with regard to an injury to at least of one more organ or tissue characteristic for such a disease. Sarcoid impairment of the liver is not infrequently coupled with chronic liver disease. The greatest difficulties may occur in differential diagnosis between primary biliary cirrhosis and sarcoidosis.

Adult↗
PubMed1986

[Mechanisms of chemical thermoregulation in mature and immature-born animals at an early postnatal age].

The energy contribution of motor activity and gray fat to the total heat production was studied in 3-4-day old mice Acomys cochirinus and Wistar rats at ambient temperatures 37 degrees C, 34 degrees C and 30 degrees C. At lower ambient temperature, the motor activity and the total heat production were found to increase. A significant positive correlation was found among the motor activity, total heat production and temperature of the gray fat tissue. The latter exceeded the rectal temperature by 0.6-1.0 degrees C in all animals in all conditions. The 3-4-day old animals produce more heat per unit of motor activity than the 8-10-day old animals.

Adipose Tissue, Brown↗
PubMed1985

[Features of thermogenesis in newborn rats].

The millicalorimetry technique with simultaneous recording of the EMG and of the rectal and brown fat tissue temperatures revealed the energy contributions of motor activity and of brown fat to total heat production in newborn rats of 3-4 and 8-9-day age. In absence of motor activity no increase of heat production occurs. In 3-4-day old rats, the heat production per unit of motor activity in greater than in 8-9-day old rats. Nevertheless, as the result of more intense movements, the 8-9-day old rats handle better a moderate cold stress: their rectal temperature proved higher by 1.3 degrees than in the 3-4-day old rats.

Adipose Tissue, Brown↗