| Abstrakt: |
The transport of nitrites and nitrates in the kidney has been studied on the background of single and prolonged injection of thyroxine. The function of kidneys and the state of renal transport of endogenous nitrites and nitrates were studied depending on the duration of thyroxin administration alone and in combination with an unspecific inhibitor of NO-synthases (Nomega-NLA) or sodium nitrite. It was established that thyroxin injection results in a decrease in the glomerular filtration rate, increase of proteinuria, and enhanced excretion of nitrite and nitrates via kidneys already in 2 h after hormone administration. After a 7-day injection of the hormone, the rate of glomerular filtration was retained on a reduced level, and the excretion of protein by the kidneys exceeded the control values. At the same time, on the background of increased concentration of nitrites in the blood plasma, the excretion of nitrites via kidneys (per 1 ml glomerular filtrate) was lower and the excretion of nitrates was substantially higher than in the control. In an acute period, the injection of thyroxine stimulated the production of nitrites and nitrates in the organism, which was accompanied by an increase in their concentration in the plasma and by enhanced excretion of these substances via kidneys. In the case of long-term injection of thyroxine, a decrease in the clearance of nitrites is among the basic mechanisms that provide the retention of nitrites in the extracellular liquid. |
