[Effect of sodium nitroprusside on Na+, K+-ATPase of rat myocardium and renal cortex].
The influence of NO donor, sodium nitroprusside (SNP) in concentrations of 10(-5)-10(-3) M, on the Na-pump activity in membrane preparations (microsomes) of rat miocardium and renal cortex was studied. A correlation has been observed between Na-pump activation by 31.4% and 73.6% and increase in thiol group content by 45.0% and 94.0% in native microsomes of myocardium and renal cortex by low concentrations of SNP (10(-5)-10(-4) M). The Na-pump activation as well as the increase in the number of DTNB-reactive thiol groups was abolished after the detergent treatment (0.025% sodium dodecylsulphate); however, the detergent by itself exerted similar influence on Na-pump activity and thiol group content in microsomes. A comparable effect of other oxidants (hydrogen peroxide and nitroglycerine) on SH-group content in microsomes of renal cortex was also shown. A conclusion was made that non-specific oxidative action of SNP on some membrane structures in microsome preparations led to their exposure and activation of the Na-pump by demasking of its latent activity.
Akopova
O V
OV
Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv.
Vavilova
G L
GL
Kharlamova
O N
ON
Sagach
V F
VF
D000818:Animals; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology; D009206:Myocardium / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000378:metabolism
D020030:Nitric Oxide Donors; D013438:Sulfhydryl Compounds; D009599:Nitroprusside; D000254:Sodium-Potassium-Exchanging ATPase