M J Rand

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The amplifying effect of serotonin in subconstrictor concentrations on steady-state vasoconstrictor responses to norepinephrine (NE; 0.001-3 microM) and to stimulation of periarterial sympathetic nerves (SNS; 0.3-ms pulses, 0.1-3 Hz) has been studied in rabbit isolated ear artery. Ketanserin (30 nM by itself had no effect on responses to NE or SNS; however,(More)
In the rabbit ear artery both dopamine and noradrenaline inhibit stimulation-induced (S-I) transmitter noradrenaline efflux. Pimozide, which is reported to be a specific dopamine receptor antagonist, was used to further study the effects of dopamine on transmitter efflux. In a concentration of 0.2 micrometer pimozide blocked the inhibition of S-I efflux(More)
Nerve stimulation-induced contractions of the chick biventer cervicis muscle were slowly reduced by omega-conotoxin. However, omega-conotoxin had no effect on skeletal muscle function after i.v. injection in mice or on nerve stimulation-induced contractions of focally innervated muscle of the rat diaphragm or the rabbit proximal oesophagus, or the multiply(More)
1. The effects of endogenous and exogenous acetylcholine (ACh) on nitrergic relaxations elicited by electrical field stimulation (EFS) were studied in guinea-pig endothelium-denuded basilar artery preparations precontracted with 1 micromol/L prostaglandin F(2 alpha) and a possible role of K+ channels in mediating the effects was investigated. 2.(More)
1. The effects of omega-conotoxin GVIA (conotoxin), a potent inhibitor of neuronal N-type Ca2+ channels, have been examined on responses to stimulation of noradrenergic, cholinergic and non-adrenergic, non-cholinergic (NANC) nerves in a range of isolated tissues to investigate the role of conotoxin-sensitive Ca2+ channels in neurotransmission. 2.(More)
In the rabbit isolated and endothelium-denuded ear artery, endothelin-1 (1-10 nM) elicited concentration-dependent vasoconstrictor responses. Lower concentrations of endothelin-1 (0.1, 0.3 and 1 nM) with little or no direct vasoconstrictor action significantly enhanced responses to sympathetic nerve stimulation in both endothelium-denuded and(More)
Stimulation-induced increases in the efflux of radioactivity (S-I efflux) were measured in the bathing medium following labelling of the noradrenergic transmitter pools of rat atria and rabbit artery preparations with [3H]-noradrenaline. In atria stimulated with trains of 16 or 60 pulses at 2 Hz, phentolamine enhanced, whereas acetylcholine inhibited S-I(More)
The muscarinic agonist McN-A-343 did not affect the tone or nitroprusside-induced relaxations of the rat anococcygeus, but inhibited non-adrenergic non-cholinergic (NANC) relaxations. Atropine, pirenzepine and gallamine blocked the McN-A-343 inhibition of NANC relaxations. Agonists of alpha 1-(methoxamine) or alpha 2-adrenoceptors (clonidine, rilmenidine)(More)
The acute effects of a single capsule of each of two phenylpropanolamine-containing preparations were determined in a group of healthy young adults, by means of a double-blind comparison with matching placebo preparations. Supine diastolic blood-pressure rose to 100 mm Hg or more in 12 out of 37 subjects taking an anorectic preparation ('Trimolets'; 85 mg(More)