Brian P Richardson

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We describe a new class of drugs that selectively block serotonin M-receptors on peripheral neurones. Because of their high affinity, some of these drugs are the most potent of any pharmacological class yet reported. They have allowed the identification of three M-receptor subtypes, one of which is responsible for mediating the painful effects of serotonin(More)
As a result of controversy in the literature regarding the classification and nomenclature of functional receptors for 5-hydroxytryptamine (5-HT), a framework for classification is proposed. The formulation of these proposals has only been made possible by the recent advent of new drug tools. It is considered that there are three main types of 5-HT(More)
The contractile effect of 5-HT in the isolated longitudinal ileal muscle of adult guinea-pigs was studied over a large concentration range. 5-HT produced a biphasic concentration-response curve indicative of an interaction with at least two independent populations of receptors. The concentrations which elicited half-maximal effects for the first and the(More)
1. The existence and functional significance of Na channels in pancreatic beta-cell membranes were investigated by studying the effects of the plant alkaloid veratridine on the temporal release of insulin from perfused isolated rat islets of Langerhans.2. 100 muM veratridine evoked a sustained threefold increase in insulin release which was almost(More)
The incidence of gastric carcinoma was studied in a series of 210 patients presenting with apparently benign gastric ulcer. In eight cases (3.9 per cent), carcinoma was diagnosed within 18 months and was almost certainly present from the outset; in 2.4 per cent the diagnosis was delayed for over three months, and the five-year death-rate due to gastric(More)
The results of ion flux measurements and insulin release studies performed on isolated rat islets of Langerhans using veratridine and tetrodotoxin show that Na+ channels exist in the outer membrane of pancreatic beta-cells. From a pharmacological point of view these channels appear very similar, if not identical, to those present in nerve. The consequences(More)
The effects of cyproheptadine on basal and glucose-induced insulin release by isolated rat islets was studied by use of a perifusion system. A forty-five minute preincubation of islets with a medium containing both 34.3 mug./ml. (10(-4) M) cyproheptadine and 1.0 mg./ml. glucose completely abolished the biphasic pattern of increased insulin secretion(More)