Manipulation of serotonin protects against an hypoxia-induced deficit of a passive avoidance response in rats

The vasoconstrictor actions of 5-hydroxytryptamine (5-HT) were investigated in the isolated helical strips of the pulmonary artery and vein of the adult bovine and calf. Agonist-antagonist interactions were studied by pretreating the vessels with methysergide, ketanserin and phentolamine and then establishing the dose-response curves to 5-HT or noradrenaline (NA). Methysergide significantly (p less than 0.05) inhibited 5-HT-induced contractions in the vessels. Ketanserin antagonized the vasoconstrictor actions of 5-HT but inhibition was not dose-related. NA-induced contractions of the vessels from the adult bovine were non-competitively inhibited by ketanserin. Phentolamine (PH) competitively antagonized contractions induced by 5-HT and NE in the tissues. The results suggest that 1. ketanserin is a potent, competitive antagonist of 5-HT but a weak antagonist of NE and 2. 5-HT-induced contractions in the bovine pulmonary vessels are mediated via specific tryptamine receptors (5-HT2) and alpha-adrenergic receptors.

Ketanserin

Methysergide

Phentolamine

Phenoxybenzamine

Source

Cite

Citations (4)

The vascular interaction of noradrenaline and 5-hydroxytryptamine

European Journal of Pharmacology (1983)

Jennifer M. Seabrook Peter L. Nolan

Methysergide

Ketanserin

Cyproheptadine

Serotonin Antagonists

Metergoline

Mesenteric arteries

10.1016/0014-2999(83)90617-9

Cite

Citations (22)

Evaluation of the cytotoxicity of dihydroxytryptamines and 5-hydroxytryptamine antagonists as cytotoxic agents in dimethylhydrazine-induced adenocarcinomata

Cancer Chemotherapy and Pharmacology (1978)

P. J. M. Tutton David H. Barkla

Cyproheptadine

Methysergide

10.1007/bf00257151

Cite

Citations (9)

The effects of cyproheptadine, methysergide, BC 105 and reserpine on brain 5-hydroxytryptamine and brain growth

European Journal of Pharmacology (1972)

Kjell Hole

Cyproheptadine

Methysergide

Reserpine

10.1016/0014-2999(72)90003-9

Cite

Citations (18)

Neuronal involvement in type 1 hypersensitivity reactions in gut epithelia

British Journal of Pharmacology (1987)

Alan W. Baird A. W. Cuthbert

1 Using a number of 5-hydroxytryptamine (5-HT)-antagonists we have compared their activity against the chloride-secretory response in guinea-pig ileal and colonic epithelia when challenged with 5-HT or antigen. Guinea-pigs sensitized to β-lactoglobulin (βLG) were used throughout; these were obtained by providing animals with cows' milk for drinking. 2 Of methysergide, ketanserin, cyproheptadine and ICS 205–930, only the latter inhibited both the response to 5-HT and to antigen challenge. Methysergide caused a minor, significant effect on 5-HT but not on βLG responses. Ketanserin had no effect on the responses to 5-HT, but both ketanserin and cyproheptadine inhibited the challenge to βLG. 3 The data are considered in relation to the current views of receptor subtypes for 5-HT. Some of the reported inhibitors may be non-specific, while we consider there is evidence to support the view that 5-HT3-receptors (neuronal receptors) are involved both in the responses to 5-HT and to antigen challenge. 4 Tetrodotoxin mimicked the effect of ICS 205–930 on both the response to 5-HT and to antigen challenge in sensitized tissues, confirming a neuronal involvement for both types of stimuli.

Methysergide

Cyproheptadine

Ketanserin

Serotonin Antagonists

10.1111/j.1476-5381.1987.tb11368.x

Cite

Citations (90)

On the central anti-serotoninergic actions of cyproheptadine and methysergide☆

Neuropharmacology (1978)

Jacob H. Jacoby Jennifer J. Poulakos Graeme F. Bryce

Cyproheptadine

Methysergide