Comparative investigation of the delayed effects of prenatal hypoxia in the period of progestation and organogenesis

The aim of the present study was to compare the survival, physical development and spontaneous behavior of rat pups born from white rats subjected to acute hypobaric hypoxia on the 3rd-5th days of gestation (progestation) period or on the 9-10th day of gestation (period of early organogenesis). It was shown that the delayed effects of progestation hypoxia were less expressed than those following acute hypoxia modeled in the early organogenesis. In latter case, hypoxia led to the increased mortality among rat pups of both sexes while hypoxia-induced delay in physical development and changes in spontaneous behavior and anxiety level were registered up to the 57th day of postnatal period.     

Erythrocyte ion transport in rats subjected to acute and chronic hypobaric hypoxia

Our study addresses selected parameters of rat erythrocyte ion transport (Na(+)-K(+) pump, Na(+)-K(+)-2Cl- cotransport, and passive cation fluxes) after acute or chronic hypoxia exposure. We did not find any significant change of ion transport after acute hypoxia. However, chronic hypoxia could modify ion transport because the affinity of Na(+)-K(+) pump for intracellular Na(+) seems to be decreased.     

Characteristics of the function of the higher portions of the central nervous system of rats subjected to acute hypoxia in the antenatal period]

A reduction of motor activity, and of the orientative reflex, its more rapid extinction in comparison with control were seen in the sexually mature rats which sustained acute hypoxia during the antenatal period. The experimental animals displayed disturbances of the conditioned reflex activity indicating a worse fixation of the temporary association, weakening of the inhibitory process and reduction of the nervous process mobility. Epileptiform convulsions occurred in presentation of "difficult" experimental tasks. There was also noted an increase in convulsioness after the administration of threshold doses of carasol.     

Intestinal iron absorption and mucosal transferrin in rats subjected to hypoxia

Three days hypoxia (0.5 atm) increased the haemoglobin and haematocrit values in rats paralleled by enhanced intestinal iron absorption. The destination of recently-absorbed iron was primarily the erythropoietic system, viz. bone marrow, spleen and red cells. Total plasma transferrin, was increased by 30%, but no significant changes in mucosal transferrin were found. No increase in labelling of mucosal transferrin by absorbed iron was observed. These results suggest that mucosal transferrin does not play a major role in the regulation of intestinal iron absorption in hypoxia.     

Effect of prenatal hypoxia during organogenesis on albino rat behavior during postnatal period

The survival rate, physical development, and spontaneous behavior has been evaluated in pups of albino rats exposed to acute hypobaric hypoxia on the 9–10th day of gestation corresponding to the onset of organogenesis. Prenatal hypoxia increased the mortality among the offspring, delayed their physical development, and affected their spontaneous behavior up to the age of 2 months. The females exposed to intrauterine hypoxia proved to be more sensitive to hypoxia than males.     

Ultrastructural characteristics of the cerebral capillaries of aging animals subjected to hypoxic hypoxia

The ultrastructure of capillary walls of the mamillary bodies was studied in rats distributed in two age groups: adult (6-8-month-old) and old (28-30-month-old) animals under hypoxic hypoxia. It was found that age-related differences in the response of brain capillary walls to the injuring agent were reduced to a rapid increase in dystrophic phenomena and less conspicuous compensatory processes seen in the old animals. More profound injuries to other brain tissues adjacent to the vessels were also indicative of less efficacy of the adaptive reactions in the old animals.     

低压低氧大鼠摄氧量测定装置

目的：设计并制作一种用于测定模拟不同海拔低压低氧环境中大鼠摄氧量的装置。方法：该装置容积约为0．01m3。它包括动物舱、参照舱、高度表、高度升降速率表、动物舱与参照舱间气压差感应和氧气自动补偿装置、低范围气压计、钠石灰和氯化钙、小风扇、温度湿度表、循环水温度控制装置、真空泵。利用该装置检测大鼠在平原（50m）、4000m和6000m模拟海拔环境中的摄氧量。结果：大鼠在平原（50m,北京）、4000m和6000m模拟海拔环境中的摄氧量分别为（24．4±2．1）、（10．8±2．0）和（8．8±1．6）ml／（kg·min）（x±s,n=10）,随着海拔高度的升高其摄氧量逐渐降低。结论：本文制作的低压低氧动物摄氧量测定装置可用于测定不同海拔环境中大鼠的摄氧量。     

Pulmonary vascular resistance in adult rats exposed to hypoxia in the neonatal period

Newborn rats were exposed to hypoxia (10% O2 + N2) from 24 h to day 6 of neonatal life and then returned to room air until 45 days of age (experimental). The rats were anaesthetized, heparinized, and exsanguinated. The chest was opened and the lungs were perfused with diluted autologous blood at a constant flow rate (Q). The pulmonary arterial pressure (Pa) and venous pressure (Pv) were monitored. The properties of the pulmonary vasculature were assessed by measuring baseline vascular resistance, PVR = (Pa-Pv)/Q, segmental pressure gradients (double occlusion technique), pressure-flow relationship, hypoxic pressor response (HPR, 3% O2), and the response to 0.5 microgram bolus of angiotensin II (AII). These were compared with similar measurements on age-matched control animals never exposed to hypoxia. The perfusate hematocrit and gases were not significantly different between the two groups. The PVR normalized to body weight was 30% higher in the experimental groups (p less than 0.005). The double occlusion results (obtained at a flow rate of 13 mL/min) revealed that this increase in resistance was primarily due to the increase in the postcapillary resistance. HPR was primarily in the upstream segment in both groups but was larger in the experimental group. In contrast, the response to AII occurred in both the upstream as well as in the downstream vascular segments and did not differ between the two groups. We conclude that adult rats exposed to hypoxia in the neonatal period have elevated pulmonary vascular resistance and increased vascular reactivity to hypoxia.     

The characteristics of higher nervous activity and of the brain benzodiazepine system in rats subjected to ethanol exposure in the prenatal period

Exposure to ethanol during pregnancy results in the alternation of 3H-diazepam binding to synaptosomal neocortical membranes from the rat offspring. In male experimental rats, 14 days of age, binding level diminished to 11%. In two-month-old control rats Scatchard plot was biphasic. It has been shown that prenatal exposure to ethanol leads to changes in the nature of binding in two-month-age experimental animals, as compared with the control ones. 3H-diazepam binding changes went along with behavioural deviations. In experimental rats locomotor activity was increased in the "open field" test, passive avoidance conditioned reflex retention was decreased and elaboration parameters of active avoidance conditioned reflex were changed, as compared with the control ones. The data obtained show that higher integrative functions were disturbed by prenatal alcoholization. Correlations between benzodiazepine receptor state and behaviour were studied.     

The characteristics of glutathione reductase distribution and activity in the liver of adult rats subjected to paraquat action in the embryonic period

Paraquat action on glutathione reductase activity and intratissue distribution in the liver of intact rats and also in the animals antenatally treated with the given herbicide was studied by some biochemical and histochemical methods. It has been ascertained that paraquat injection into intact animals promotes the increase in the intracellular enzyme level, development of glutathione reductase staining of hepatocyte nuclei, diffuse distribution of the staining along the lobe. In rats antenatally treated with paraquat acute priming does not induce glutathione reductase. In these conditions a mosaic distribution of this enzyme is observed in the hepatic tissue.     

Lymphopoietic characteristics in acute hypobaric hypoxia

10 healthy men were examined, that underwent a 48 hours hypobaric (acute) hypoxia in the climate chamber "Taba?", with conditions corresponding to those at an altitude of 4,000 m. The "ascent" and "descent" were performed correspondingly within 30 minutes. Increased share of dying lymphocytes and frequency of chromosomal aberrations in these were found in addition to an elevated activity of nucleolar organizers and to changed morphological patterns of argentophilic nucleoli. T- and B-lymphocyte contents remained unchanged. The role of the lymphopoietic alterations in autoimmune complications and of hemopoietic disorders in the mountains is discussed.     

Influence of intermittent normobaric hypoxia during early organogenesis on the development of white rats

The influence of antenatal intermittent normobaric hypoxia during early organogenesis (days 9–10 of intrauterine development) on the physical development, vegetative balance, and antioxidant defense system of 60-day-old rats was studied. Antenatal exposure to intermittent hypoxia resulted in the impaired physical development of all offspring during the early 15-day postnatal period and caused changes in the vegetative balance of heart regulation, which were differently directed in males and females. Moreover, females that survived antenatal hypoxia had a decreased superoxide dismutase activity in the brain, compared to that in the control rats.     

The effect of acute progestational hypoxia on ECG parameters and contractility of lymphatic vessels in mature white rats

Acute progestational hypoxia induced hyperactivity with low anxiety level and bradycardia in female descendants only. The experimental males demonstrated a significant increase in the duration and frequency of contractions of lymphatic vessels following NE application, while females showed no difference compared to the control.     

Postnatal behavioral consequences of antenatal intermittent hypoxia experienced during early organogenesis in mature rats

This study analyses the spontaneous behavior and anxiety-phobic status of mature rats that were subjected to antenatal intermittent hypoxia during the early stages of organogenesis. Antenatal intermittent hypoxia caused a decrease of motor activity as well as an enhanced anxiety level in rats of both sexes, while males appeared to be more sensitive to hypoxic influence. The effects of single antenatal intermittent hypoxia were more expressed than those of double exposure.     

Sexual cycle period and resistance of mice to acute experimental hypoxia]

Variations of survival to an acute hypoxia (nitrogen) were studied, in 200 females, OF1, SPF mice, 72 days old, in groups of 10, at different periods of their estrus cycle, which were evidenced by vaginal smears. In mice which were in diestrus since 3-4 following days, the hypoxic survival (27.27%) was statistically less than in mice which were in estrus (58.00 %) or at the beginning of the diestrus (53.85 %).     

Morphofunctional characteristics of the venous bed of the myocardium in response to acute hypoxia

Anatomical redistribution of blood outflow between the superficial and deep pathways is motivated, changes in microvessels under a circular hypoxia are presented. General peculiarities in structure of the sources for both pathways are ascertained, as well as specific differences stipulated by the physiological role of the cardiac venous sinusis.