Morphological, functional, and psychological development of children living permanently in the Tyva Republic.

For estimation of national-ethnic features of the development of young school-children, 1,928 children 8-11 years old of the Russian and Tuvinian ethnicity permanently living in urban and rural areas of the Tyva Republic were studied. The level of physical development, parameters of cardio-respiratory system, psycho-physiological status, functional asymmetry of brain, memory and attention were estimated. It was established that despite accelerated development of all children, Tyvinian schoolboys have lower parameters of physical and mental development, but a higher level of functional condition of cardiovascular and respiratory systems in comparison with Russian children.

[Characteristics of the K(+)-ion transport in the rat intestine following the use of natural zeolites as food additives].

Effects of zeolites as a food supplement have been studied on Wistar rats both in vivo perfusion experiments in the jejunum and distal colon and Rb fluxes through intestinal wall in the Ussing chamber. It has been found that zeolites decrease the K+ absorption and stimulate K+ secretion in the gut. This effect was due to inhibition of the apical N(+)-K(+)-ATPase and ouabain-sensitive Na(+)-independent K(+)-ATPase as well as the activation of the basolateral N(+)-K(+)-ATPase.

[Effect of natural zeolites on renal functions and water-salt metabolism in rats].

In vivo experiments on adult Wistar rats, it has been found that intake of natural zeolites resulted in temporary decrease of renal water, sodium and potassium excretion. At the same time, reabsorption of water and electrolytes increased. This effect was due to the stimulation of Na+, K(+)-ATPase activity in thick ascending limb of Henle loop and hormonal changes: increase of insulin, thyroxin and aldosterone concentration in plasma.

[Age characteristics of K(+) transport in the rat distal colon].

In vitro and in vivo experiments with perfusion in 20- and 60-day old rats revealed that K+ absorption in the gut as well as 86Rb uptake in the distal colon was significantly higher in younger rats due probable, to the higher activity of the apex-located K+-dependent ATPase and lower activity of the basolateral K+-carriers. The luminal blockade of K+ absorbing pumps with ouabain or omeprazole resulted in a decrease of the K+ absorption and K2 accumulation in skeletal muscles. The higher K+-absorbing/K_ secreting mechanisms ratio in younger rats contributes to the positive potassium balance.