Effect of DOCA-salt treatment duration and anteroventral third ventricle lesions on a plasma-borne sodium pump inhibitor in rats.
We determined the effect of plasma obtained from rats treated with DOCA-salt for 6 and 28 days on sodium pump activity, measured as ouabain-sensitive Rb+ uptake in tail arteries from these rats. The effect of an electrolytic lesion in the area of the anteroventral third cerebral ventricle (AV3V) before DOCA-salt treatment was investigated in relation to the ability of plasma to inhibit vascular Na+ pump activity. Systolic blood pressures, plasma sodium and potassium concentrations, body weights and haematocrit were also measured. Six days after DOCA-salt treatment, there was a 22% suppression of vascular Na+ pump activity in these rats. This suppression was due to a plasma factor since plasma from these rats produced a similar degree of suppression in arteries isolated from untreated control rats. Furthermore, tail arteries from DOCA-salt rats treated for 6 days displayed normal Na+ pump activity when incubated in plasma from control rats or in Krebs-Henseleit buffer. There was no elevation of systolic blood pressure at the end of 6 days of treatment with DOCA-salt. Placement of an electrolytic brain lesion in the AV3V area before treatment with DOCA-salt abolished the ability of plasma to inhibit the vascular Na+ pump. Treatment with DOCA-salt for 28 days resulted in a significant increase in systolic blood pressure, a decrease in plasma potassium concentration, and a significant increase in vascular Na+ pump activity (26%).(ABSTRACT TRUNCATED AT 250 WORDS)
Songu-Mize
E
E
Department of Pharmacology, University of Tennessee, Memphis 38163.
Bealer
S L
SL
Caldwell
R W
RW
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D001798:Blood Proteins / Q000187:drug effects / Q000378:metabolism*; D002552:Cerebral Ventricles / Q000502:physiology*; D003900:Desoxycorticosterone / Q000494:pharmacology*; D006973:Hypertension / Q000097:blood* / Q000139:chemically induced; D066298:In Vitro Techniques; D008297:Male; D010042:Ouabain / Q000493:pharmacokinetics; D011188:Potassium / Q000493:pharmacokinetics; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012414:Rubidium Radioisotopes; D012965:Sodium Chloride / Q000493:pharmacokinetics*; D000097795:ATPase Inhibitory Protein
D001798:Blood Proteins; D003900:Desoxycorticosterone; D010042:Ouabain; D011188:Potassium; D011506:Proteins; D012414:Rubidium Radioisotopes; D012965:Sodium Chloride; D000097795:ATPase Inhibitory Protein