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The effects of catecholamines on spinal motoneurones and spinal reflex discharges were investigated in the isolated spinal cord of newborn rat. Noradrenaline (NA), adrenaline (Adr), dopamine (DA) and isoproterenol (Iso) caused depolarization of the motoneurones in a dose-dependent manner. The depolarizing action persisted in Ca2+-deficient Krebs solution.(More)
1. The onset and development of functional innervation of intramural neurones were examined by transmural nerve stimulation in circular muscle strips isolated from the rat stomach during the period from embryonic day (ED) 15 to 7-days postnatal. 2. At ED 15, transmural stimulation elicited an atropine-sensitive contraction in about half of the preparations.(More)
1. The effect of ouabain on the noradrenaline output from peripheral adrenergic neurones has been studied using isolated guinea-pig vasa deferentia.2. Exposure to ouabain (10(-4)M) causes a gradual increase in the noradrenaline output. The effect occurs after a delay of 20 min and reaches a maximum during the period from 40-60 min.3. In the absence of(More)
1. Gastric vasodilatation, relaxation, and vasoactive intestinal peptide (VIP) output in response to vagal stimulation were studied in anaesthetized dogs. 2. Stimulation of the peripheral end of the vagus nerve (10 Hz, 40 V, 0.5 ms) normally evoked a gastric contraction, but caused relaxation in atropinized dogs. There was no detectable difference between(More)
1. The effects of compound 48/80 on cholinergic nerve transmission and on the liberation of histamine in the isolated chick oesophagus were investigated. 2. Compound 48/80 (0.2-1 microgram ml-1) potentiated the cholinergic nerve-induced contraction and caused the contraction of the oesophagus itself. The latter response was prevented by atropine,(More)
The effects of ryanodine, a selective inhibitor of the Ca(2+)-induced Ca2+ release mechanism, on caffeine-evoked changes in cytosolic Ca2+ concentration ([Ca2+]i) and catecholamine secretion were investigated using cultured bovine adrenal chromaffin cells. Caffeine (5-40 mM) caused a concentration-dependent transient rise in [Ca2+]i and catecholamine(More)
1. The effects of vasoactive intestinal peptide (VIP) on contractile responses to carbachol (CCh), KCl and caffeine of the circular smooth muscle in rat stomach were examined by the isometric tension recording method and by measurement of the intracellular Ca level, [Ca]i, with fura 2. 2. Removal of extracellular Ca or nifedipine (0.1 microM) inhibited(More)
1 Transmural electrical stimulation (TMS) of longitudinal smooth muscle strips taken from the cardiac portion of the pig stomach produced biphasic responses consisting of initial contractions followed by relaxations. The excitatory component was enhanced by neostigmine and abolished by atropine. After atropine treatment, TMS and nicotine or(More)
Experiments were conducted on uteri excised from 44 gilts to clarify the autonomic innervation of the longitudinal (LM) and circular muscle (CM) layers of the myometrium. Functionally and biochemically, the two layers differed markedly in their reaction to transmitters. On transmural nerve stimulation (TMS) of isolated LM strips, relaxation was elicited and(More)
1. The effects of cyclic AMP on contraction and Ca(2+)-activated K+ currents induced by carbachol (CCh), caffeine and inositol 1,4,5-trisphosphate (InsP3) were examined in intact and skinned smooth muscle fibres and in whole-cell voltage-clamped smooth muscle cells of the rat stomach. Intracellular Ca2+ level, [Ca2+]i, was monitored in intact muscle fibres(More)