Effects of NG-nitro-L-arginine on the blood pressure of spontaneously hypertensive rats with different degrees of hypertension.

Abstract

The effects of NG-nitro-L-arginine (L-NNA) on blood pressure of various strains of spontaneously hypertensive rats were studied. Blood pressure of the rats was higher in the order of WKY, SHR, SHRSP, M-SHRSP. L-NNA caused an elevation of the blood pressure, which was greatest in SHR and smallest in WKY and M-SHRSP. Endothelium-dependent relaxation of aortae by acetylcholine was greatest in preparations from WKY and it decreased as the blood pressure of rats increased. Phenylephrine (higher than 10(-6) mg/kg) caused an elevation of the blood pressure, which was greatest in SHR and smallest in M-SHRSP. It was suggested that L-NNA elevated blood pressure by inhibiting the basal or flow-induced release of nitric oxide from the endothelium that is causing a reduction in vascular smooth muscle tone. The smaller effect of L-NNA in WKY was due to weak smooth muscle tone, while the smaller effect in SHRSP and M-SHRSP is due to impaired function of endothelium.

• Authors: K Yamamoto, K Shimamura, F Sekiguchi, S Sunano
• Journal: Clinical and experimental hypertension (New York, N.Y. : 1993) (Clin Exp Hypertens) Vol. 23 Issue 7 Pg. 533-44 (Oct 2001) ISSN: 1064-1963 [Print] England
• PMID: 11710755 (Publication Type: Journal Article)

Chemical References

• Enzyme Inhibitors
• Vasoconstrictor Agents
• Phenylephrine
• Nitroarginine
• Nitric Oxide

Topics

• Animals
• Blood Pressure (drug effects)
• Body Weight
• Endothelium, Vascular (drug effects, physiology)
• Enzyme Inhibitors (pharmacology)
• Heart Rate (drug effects)
• Nitric Oxide (metabolism)
• Nitroarginine (pharmacology)
• Phenylephrine (pharmacology)
• Rats
• Rats, Inbred SHR
• Rats, Inbred WKY
• Species Specificity
• Vasoconstrictor Agents (pharmacology)