Role of plasma renin activity and the renal nerves in the natriuresis of l-NMMA infusion in rats
Autor: | A. A. Khraibi, Franklyn G. Knox, Carla R. Ramsey, Denise M. Heublein, Theresa J. Berndt |
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Rok vydání: | 2001 |
Předmět: |
Male
medicine.medical_specialty Fractional excretion of sodium Natriuresis Renal function Blood Pressure Kidney Nephrectomy Rats Inbred WKY Plasma renin activity General Biochemistry Genetics and Molecular Biology Nitric oxide chemistry.chemical_compound Bolus (medicine) Species Specificity Rats Inbred SHR Internal medicine Peripheral Nervous System Renin Animals Medicine Enzyme Inhibitors General Pharmacology Toxicology and Pharmaceutics Infusions Intravenous Denervation omega-N-Methylarginine business.industry General Medicine Rats medicine.anatomical_structure Endocrinology chemistry Hypertension cardiovascular system business Glomerular Filtration Rate circulatory and respiratory physiology |
Zdroj: | Life Sciences. 69:1123-1131 |
ISSN: | 0024-3205 |
Popis: | The objective of this study was to determine the effect of N(G)-monomethyl-L-arginine (L-NMMA) infusion on plasma renin activity (PRA) in the presence or absence of the renal nerves in normotensive Wistar-Kyoto (WKY) rats and Okamoto spontaneously hypertensive rats (SHR). All rats were unilaterally nephrectomized two weeks before the acute experiment. On the day of the experiment, acute renal denervation (Dnx) of the remaining kidney was performed in one group of WKY rats (Dnx-WKY; n= 10) and one group of SHRs (Dnx-SHR: n=7). The renal nerves were left intact in a group of WKY rats (Inn-WKY; n=8) and SHRs (Inn-SHR; n=9). After a control clearance period, L-NMMA was administered i.v. (15 mg/kg bolus followed by 500 microg/kg/min infusion) and another clearance period of 20 min was taken. In all experimental groups L-NMMA infusion resulted in a significant natriuresis. L-NMMA infusion increased fractional excretion of sodium (FE(Na)) to a greater extent in the Inn-SHR than in the Inn-WKY (delta FE(Na) = 5.23+/-0.87% vs delta FE(Na) = 2.87+/-0.73% respectively; P=0.05), PRA did not change in the SHR with the infusion of L-NMMA. However, in the Inn-WKY group, the natriuresis of L-NMMA infusion was associated with a tendency for lower PRA levels as compared to a group of time control Inn-WKY rats. In Dnx-WKY, the natriuresis of L-NMMA infusion (delta FE(Na) = 4.60+/-0.52%) was associated with a significantly lower level of PRA (4.26+/-1.18 ng AI/ml/hr) as compared to a group of time control Dnx-WKY rats (9.83+/-1.32 ng AI/ml/hr; P0.05). In the Dnx-SHR, the natriuretic response to L-NMMA infusion was significantly attenuated by renal denervation (delta FE(Na) = 2.36+/-0.34%) and PRA was unchanged. In conclusion, the natriuretic effect of systemic inhibition of nitric oxide (NO) synthesis was associated with decreased PRA in the Dnx-WKY suggesting that a potential interaction exists between NO and the renal nerves in the modulation of PRA in the normotensive WKY rat. Whereas, the natriuretic effect of L-NMMA infusion in the SHR in the presence and absence of the renal nerves, were independent of changes in PRA. |
Databáze: | OpenAIRE |
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