Resistance of noradrenaline in blood vessels to depletion by 6-hydroxydopamine or immunosympathectomy.
1. The degree of the decrease in the noradrenaline concentrations caused by 6-hydroxydopamine or immunosympathectomy was different in different areas of the cardiovascular system.2. In rats or guinea-pigs 6-hydroxydopamine depleted the noradrenaline content of the heart by 90%, of the mesenteric vein by 80% and of the mesenteric artery and aorta by 30-60%. Immunosympathectomy elicited a 70% reduction in the cardiac noradrenaline but only a 50% reduction in the noradrenaline of the blood vessels of the rat.3. The tyrosine hydroxylase activity of the heart, blood vessels, or adrenal glands was not significantly altered 2 weeks after 6-hydroxydopamine. Nor was the monoamine oxidase activity in heart or blood vessels changed.4. The inconsistent ability of both 6-hydroxydopamine and immunosympathectomy to abolish experimental hypertension may be due to the partial persistence of noradrenaline and functional sympathetic nervous system activity in the blood vessels.
D000311:Adrenal Glands / Q000201:enzymology; D000818:Animals; D001011:Aorta / Q000032:analysis; D001808:Blood Vessels / Q000032:analysis / Q000187:drug effects* / Q000201:enzymology; D005260:Female; D006168:Guinea Pigs; D006973:Hypertension / Q000188:drug therapy; D007106:Immune Sera / Q000494:pharmacology*; D008297:Male; D008638:Mesenteric Arteries / Q000032:analysis; D008642:Mesenteric Veins / Q000032:analysis; D009206:Myocardium / Q000032:analysis / Q000201:enzymology; D009414:Nerve Growth Factors; D009638:Norepinephrine / Q000032:analysis*; D010627:Phenethylamines / Q000494:pharmacology*; D013562:Sympathectomy; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis
D007106:Immune Sera; D009414:Nerve Growth Factors; D010627:Phenethylamines; D014446:Tyrosine 3-Monooxygenase; D009638:Norepinephrine