Role of nitric oxide in salt and water excretion in experimental hypertension in hooded (Aguti) rats.
Autor: | Mojiminiyi FB; College of Health Sciences, Usman DanFodio University Sokoto College of Medicine, University of Lagos, Nigeria., Anigbogu CN, Sofola OA, Adigun SA |
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Jazyk: | angličtina |
Zdroj: | The Nigerian postgraduate medical journal [Niger Postgrad Med J] 2007 Jun; Vol. 14 (2), pp. 99-104. |
Abstrakt: | Objectives: The present study was designed to investigate the suitability of the hooded rat in experimental hypertension studies and to investigate some mechanisms underlying the development of hypertension. Methods: Hooded rats were randomly divided into 4 groups: control, Salt, L-NAME (N' -Nitro-L-Arginine Methyl Ester) and salt+L-NAME. Control rats received a normal rat chow. Hypertension was induced in the test groups by giving 8% salt and/or 100mg/kg/day L-NAME for 6 and/or 4 weeks respectively. Urine and serum samples were collected from the rats and analysed for their cation contents. The blood pressure of the rats was measured. Results: The mean arterial pressure (mean +/- SEM; mm Hg) increased significantly in the test groups of rats (salt: 138.3+/-4.0; L-NAME: 165.7+/-6.0; salt+L-NAME: 133.35.2) when compared with control (88.42.7; P<0.05). Water consumption, urine volume and Na+ excretion increased significantly in salt-loaded and salt+L-NAME groups compared with control (P<0.05) but remained similar in L-NAME rats. These values were however significantly less in salt+L-NAME rats compared with salt loaded rats (P<0.05). Urinary K+ excretion, serum Na+ and K+ concentrations remained similar in all groups. Conclusions: These results suggest that the hooded rat may be useful for experimental hypertension studies. Attenuation of the diuretic and natriuretic responses to salt loading in the presence of L-NAME suggests that nitric oxide is involved in the mechanisms involved in these responses. It is concluded that nitric oxide deficiency may exacerbate salt and volume retention in salt-loaded rats and possibly play a role in the subtle renal defect underlying salt sensitive hypertension. |
Databáze: | MEDLINE |
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