Effect of Central Losartan on DOCA-Salt Hypertension Rats
Korean Circulation Journal
;
: 84-91, 2004.
Article
in English
| WPRIM
| ID: wpr-82004
ABSTRACT
BACKGROUND:
The purpose of this study was to investigate whether brain AT1 receptor stimulation contributes as a hypertensive mechanism to deoxycorticosterone acetate (DOCA)-salt hypertension.METHODS:
1) Acute injectionLosartan (1 mg/4 uL) or artificial cerebrospinal fluid (aCSF) was injected into the lateral cerebral ventricle (icv) of conscious control uninephrectomized Wistar rats or rats with DOCA-salt at 2 or 4 weeks, and mean arterial pressure (MAP) and heart rates (HR) were recorded. 2) Chronic injectionUsing osmotic minipump, losartan (1 mg/kg/d) or aCSF was injected to a sham group or three DOCA-salt rat groups [icv-aCSF, icv-losartan, sc-losartan (subcutaneous) groups] for 4 weeks, after which the MAP and HR were recorded in addition to the weights of the left (LV) and right ventricles (RV) and kidneys.RESULTS:
1) Acute injection In rats treated with DOCA-salt, resting MAP significantly increased compared to the control group [144+/-6 mmHg (2 weeks), 170+/-5 mmHg (4 weeks) vs 115-120 mmHg (controls)]. MAP decreased significantly (2 weeks, 4 weeks) at 4, 8, 24 hours after icv injection of losartan to the level of the control group. 2) Chronic injection The general trend showed that MAP decreased more in the icv-losartan group than in the icv-aCSF group (127+/-15.2 mmHg vs 141.1+/-5.5 mmHg, p=0.0578). In all DOCA-salt groups, no differences in RV weight were found. In the icv-aCSF and sclosartan groups, the kidney weight increased compared to the control group, but there was no difference in LV and kidney weight between the icv-losartan group and the control group.CONCLUSION:
Normalization of MAP after acute or chronic icv administration of the AT1 receptor antagonist suggests that the stimulation of the brain AT1 receptor plays a significant role in the development and maintenance of hypertension in the DOCA-salt hypertensive rat model. Losartan icv injection appeared to have a protective effect on the heart and kidney.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Weights and Measures
/
Brain
/
Angiotensin II
/
Cerebral Ventricles
/
Cerebrospinal Fluid
/
Rats, Wistar
/
Losartan
/
Models, Animal
/
Receptor, Angiotensin, Type 1
/
Desoxycorticosterone
Limits:
Animals
Language:
English
Journal:
Korean Circulation Journal
Year:
2004
Type:
Article
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