Effect of chronic hypertension on acute hypertensive disruption of the blood-brain barrier in rats.
The effect of chronic hypertension on acute hypertensive disruption of the blood-brain barrier has been studied in only two models of hypertension, with inconsistent results. The purpose of this study was to reinvestigate whether chronic hypertension has a consistent effect on acute hypertensive disruption of the blood-brain barrier and to determine whether one of the previously studied models has an unusual response to chronic hypertension. We studied four rat models of chronic hypertension: spontaneously hypertensive rats (SHR), two-kidney, 1 clip Goldblatt rats (2K1C), rats treated with deoxycorticosterone acetate (DOCA) and NaCl, Dahl salt-sensitive rats fed a high salt diet, and two groups of normotensive controls: Wistar-Kyoto rats (WKY) and Dahl salt-sensitive rats fed a low salt diet. We caused acute hypertension in some rats with the use of bicuculline (1.2 mg/kg) and aortic occlusion. Rats without acute hypertension served as controls. Blood-brain barrier disruption was quantitated using the brain/blood ratio of 125I-labeled albumin. Acute hypertensive disruption was less in SHR, rats treated with DOCA-NaCl, and Dahl salt-sensitive rats fed a high salt diet, but not in 2K1C rats, as compared with normotensive controls. Acute hypertensive disruption was greater in Dahl salt-sensitive rats fed a low salt diet than in WKY. A series of control WKY, SHR, rats treated with DOCA-NaCl, 2K1C rats, and Dahl salt-sensitive rats fed low or high salt diets, but not subjected to acute hypertension, were also studied. Brain/blood 125I-albumin ratios were significantly less in these control rats not subjected to acute hypertension than in rats subjected to acute hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)
Werber
A H
AH
Department of Pharmacology and Toxicology, Albany Medical College, New York 12208.
Fitch-Burke
M C
MC
D000818:Animals; D001812:Blood-Brain Barrier; D001927:Brain Diseases / Q000209:etiology; D002561:Cerebrovascular Disorders / Q000209:etiology; D002908:Chronic Disease; D004044:Dietary Proteins / Q000494:pharmacology; D006973:Hypertension / Q000150:complications / Q000503:physiopathology*; D008297:Male; D011188:Potassium / Q000008:administration & dosage; D051381:Rats; D011919:Rats, Inbred Strains; D011921:Rats, Inbred WKY
D004044:Dietary Proteins; D011188:Potassium