C. H. V. Hoyle

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Melatonin, a neurohormone secreted by the pineal gland, can stimulate three subtypes of receptors, namely: mt(1), MT(2) and MT(3). We examined the ability of melatonin and the selective MT(3) receptor agonist, 5-methoxycarbonylamino-N-acetyltryptamine (5-MCA-NAT), to modify intraocular pressure in rabbits. Both compounds significantly reduced intraocular(More)
In isolated strips of human urinary bladder detrusor muscle, ATP, alpha, beta-methylene ATP and P1,P6-diadenosine hexaphosphate caused concentration-dependent contractions. ATP was less potent than the two synthetic purine compounds and gave smaller maximum responses. Responses to ATP, P1,P6-diadenosine hexaphosphate and noncholinergic nerve stimulation(More)
The pattern of distribution and colocalization of nitric oxide-synthase (NOS) and NADPH-diaphorase in the myenteric plexus of whole-mount preparations of the antrum, duodenum, ileum, caecum, proximal colon and distal colon of the rat were investigated using immunohistochemical and histochemical staining techniques. Almost all the myenteric neurons that were(More)
1. Suramin, an inhibitor of several types of ATPase, was investigated for its ability to antagonize responses mediated via P2X-purinoceptors in the guinea-pig urinary bladder and P2Y-purinoceptors in the guinea-pig taenia coli. 2. In isolated strips of bladder detrusor muscle, suramin (100 microM-1 mM) caused a non-competitive antagonism of responses to(More)
1. Pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), an inhibitor of P2X-purinoceptor-mediated responses in rabbit vas deferens, was investigated for its ability to antagonize contractions evoked by alpha,beta-methylene ATP (alpha,beta-MeATP), carbachol and electrical field stimulation in the rabbit urinary bladder detrusor muscle. 2. PPADS.(More)
A newly identified myopathy of the internal anal sphincter is described. In the affected family, at least one member from each of five generations had severe proctalgia fugax; onset was usually in the third to fifth decades of life. Three members of the family have been studied in detail. Each had severe pain intermittently during the day and hourly during(More)
1. The isolated perfused rat mesenteric arterial bed was used to examine the activity of the adenine dinucleotides: beta-nicotinamide adenine dinucleotide (NAD); beta-nicotinamide adenine dinucleotide phosphate (NADP); flavin adenine dinucleotide (FAD); and of the alpha,omega-diadenosine polyphosphates: adenylyl adenosine (AP1A); P1,P2-diadenosine(More)
Examination of families of neuropeptides and their receptors can provide information about phyletic relationships and evolutionary processes. Within an individual a given signal molecule may serve many diverse functions, mediated via subtypes of the receptor which may be coupled to their transduction mechanisms in different ways. The rate of evolution of a(More)
Examination of neuropeptide families can provide information about phyletic relationships and evolutionary processes. In this article the oxytocin/vasopressin family, growth hormone releasing factor (GRF) superfamily and the substance P/tachykinin family have been considered in detail because they have been isolated from an extraordinarily diverse array of(More)
1. Pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), a P2-purinoceptor antagonist, was investigated for its ability to antagonize: (1) P2X-purinoceptor-mediated contractions of the rabbit central ear artery and saphenous artery evoked by either alpha,beta-methylene ATP (alpha,beta-MeATP) or electrical field stimulation (EFS); (2)(More)