Neurally-mediated vasodilatation in normal and portal hypertensive rats: role of nitric oxide and calcitonin gene-related peptide

• Published in: Journal of hepatology 1998-06, Vol.28 (6), p.1031-1036
• Main Authors: Moll-Kaufmann, Christine, Sumanovski, Lazar T., Sieber, Cornel C.
• Format: Article
• Language: English
• Subjects: Animal; Animals; Biological and medical sciences; Calcitonin Gene-Related Peptide - pharmacology; Calcitonin Gene-Related Peptide - physiology; Electric Stimulation; Hypertension, Portal - physiopathology; In vitro; Male; Medical sciences; Mesenteric Artery, Superior - innervation; Mesenteric Artery, Superior - physiology; Mesenteric Artery, Superior - physiopathology; Miscellaneous; Muscle, Smooth, Vascular - innervation; Muscle, Smooth, Vascular - physiology; Muscle, Smooth, Vascular - physiopathology; Neuropharmacology; Neurotransmitters. Neurotransmission. Receptors; Nitric Oxide - physiology; Nitroarginine - pharmacology; Non-adrenergic non-cholinergic; Peptide Fragments - pharmacology; Periarterial nerve stimulation; Pharmacology. Drug treatments; Portal hypertension; Rats; Rats, Sprague-Dawley; Reference Values; Sensory nerves; Sympathetic Nervous System - physiology; Vascular reactivity; Vasodilation - drug effects; Vasodilation - physiology
• ISSN: 0168-8278; 1600-0641
• DOI: 10.1016/S0168-8278(98)80353-X

Background/Aims: Portal hypertension is associated with systemic vasodilatation and vascular hyporeactivity, and is reversed by inhibiting nitric oxide biosynthesis. Nitric oxide and calcitonin gene-related peptide are neurotransmitters of non-adrenergic non-cholinergic nerves. The role of nitric oxide and calcitonin gene-related peptide in nerve-stimulated vasodilatation in portal hypertension is unknown. Methods: We tested (i) if in vitro perfused superior mesenteric arterial vascular beds of portal hypertensive rats (induced by partial portal vein ligation) showed an increased vasodilatation to periarterial nerve stimulation compared to normal controls, and (ii) if this vasodilatation was modulated by nitric oxide and calcitonin gene-related peptide antagonism. Results: Vasodilatatory responses to periarterial nerve stimulation (10 V, 1 ms) with increasing frequencies (Hertz, 2–12) in preconstricted vessels (methoxamine and guanethidine) were significantly smaller in vessel preparations of control ( n=8) compared to portal hypertensive ( n=7) rats, values with 8 Hertz being 32.3±3.6% and 44.9±3.6%, respectively ( p