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H Kurose

Publications and source records attributed to H Kurose.

61 records · Page 4Linked to original sources

Effect of dibutyryl adenosine 3',5'-monophosphate administration on plasma concentrations of 1,25-dihydroxyvitamin D in pseudohypoparathyroidism type I.

The effect of dibutyryl cAMP on plasma concentrations of 1,25-dihydroxyvitamin D [1,25-(OH)2D] was studied in two patients with pseudohypoparathyroidism (PHP) type I, five normal adults, and three normal children as controls. In normal adults, plasma 1,25-(OH)2D tended to increase 3 h after the infusion of 2.5 mg/kg dbcAMP and was significantly increased after 6 h. In normal children, plasma 1,25-(OH)2D increased 3 h after the infusion, then gradually decreased; in the patients with PHP type I, it increased greatly from 6.8 and 11.2 pg/ml to 264.6 and 128.2 pg/ml 3 h after the infusion. These results suggest that the renal mechanism for the response to parathyroid hormone is intact distal to the renal adenylate cyclase in patients with PHP type I.

24,25-Dihydroxyvitamin D 3↗

Functional reconstitution of purified muscarinic receptors and inhibitory guanine nucleotide regulatory protein.

Muscarinic receptors trigger several different responses including an increase in concentration of cyclic GMP, a decrease in cyclic AMP concentration, breakdown of polyphosphoinositides and changes in ion permeability. It is not yet clear whether these reactions occur sequentially or independently and which directly coupled to the muscarinic receptor. Several lines of evidence indicate that muscarinic receptors in many, if not all, cell types are coupled to the inhibitory guanine nucleotide regulatory protein (Ni or Gi) of adenylate cyclase. To provide direct evidence for this coupling, we have reconstituted muscarinic receptors purified from porcine brain with Ni purified from rat brain in a phospholipid vesicle. Here, we report that the GTPase activity of Ni is stimulated by carbachol. This action is blocked by the simultaneous addition of atropine and is not observed when the Ni protein is ADP-ribosylated. We conclude that one function of the muscarinic receptor is the activation of Ni.

Adenosine Diphosphate Ribose↗

Cellular and subcellular sites for noradrenergic action in the monkey dorsolateral prefrontal cortex as revealed by the immunocytochemical localization of noradrenergic receptors and axons.

A series of electron microscopic immunocytochemical studies was performed to analyze subcellular sites for noradrenergic modulation in monkey prefrontal cortex. One out of 12 noradrenergic varicosities, identified by dopamine beta-hydroxylase immunocytochemistry within single ultrathin sections, forms morphologically identifiable junctions with small dendrites and spines. Accordingly, alpha2-adrenergic receptors, almost all of which are of the A-subtype, that occur in spines are localized discretely over postsynaptic membranes. alpha2-Adrenergic receptors are also found at sites along axons, dendritic shafts and astrocytic processes lacking morphologically identifiable synaptic junctions, suggesting that these receptors are activated by volume transmission. In particular, axonal alpha2-adrenergic receptors occur mostly at pre-terminal regions, suggesting that axo-axonic interactions may mediate reduction of neurotransmitter release at sites other than axo-spinous junctions by closing voltage-dependent calcium channels. These results indicate that noradrenergic modulation of prefrontal cortex involves synaptic interactions at spines of pyramidal neurons and nonsynaptic volume transmission to glia, dendritic shafts and axons.

Animals↗