The role of Na,K-ATPase inhibitor on pressor responsiveness in patients with benign essential hypertension.
To clarify the role of Na,K-ATPase inhibitor in the enhanced pressor response to infused noradrenaline (NA-R) in patients with benign essential hypertension (EHT), NA-R, plasma noradrenaline concentration (PNA), and blood ionized calcium (Ca2+) were investigated before and after intravenous injection of ouabain in 15 normotensive subjects (NT) and 13 EHT. NA-R was enhanced by ouabain in both NT and EHT. The augmentation of NA-R following ouabain injection (delta NA-R) and % delta NA-R were significantly lower in EHT than in NT. Following ouabain injection, no significant change in PNA and blood Ca2+ was observed in both NT and EHT. NA-R negatively correlated with PNA and blood Ca2+, which were estimated just prior to noradrenaline infusion, before ouabain injection as well as after. After ouabain, the regression line between NA-R and PNA or blood Ca2+ shifted toward higher NA-R level in NT, unlike in EHT. These results suggest that an exogenous Na,K-ATPase inhibitor brings about a blunted enhancement of NA-R in EHT consistent with the presence of an endogenous Na,K-ATPase inhibitor in EHT.
Yamaji
I
I
Second Department of Internal Medicine, Sapporo Medical College, Japan.
Kikuchi
K
K
Nishimura
M
M
Nozawa
A
A
Hasegawa
T
T
Kobayakawa
H
H
Komura
H
H
Iimura
O
O
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D002118:Calcium / Q000097:blood; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000503:physiopathology*; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D010042:Ouabain / Q000008:administration & dosage / Q000494:pharmacology*; D011311:Pressoreceptors / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism
D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium; D009638:Norepinephrine