B. H. Hoiting

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1. The effects of increased cellular cyclic AMP levels induced by isoprenaline, forskolin and 8-bromoadenosine 3':5'-cyclic monophosphate (8-Br-cyclic AMP) on phosphoinositide metabolism and changes in intracellular Ca2+ elicited by methacholine and histamine were examined in bovine isolated tracheal smooth muscle (BTSM) cells. 2. Isoprenaline (pD2 (-log10(More)
This study was carried out to determine the intracellular components responsible for the transmembrane current evoked by stimulation of H1-histaminergic receptors in DDT1 MF-2 smooth muscle cells. Histamine elicited an outward current that was reversed below the K+ equilibrium potential and passed voltage-independent K+ channels. A histamine(More)
1. The specificity of intracellular Ca2+ stores to Ca(2+)-mobilizing agonists was studied in DDT1 MF-2 vas deferens cells of the Syrian hamster. 2. Application of histamine (100 microM) or ATP (100 microM) to the DDT1 MF-2 cells caused an initial increase of intracellular Ca2+ followed by a lower phase as measured by using Indo-1 as fluorescent probe at 22(More)
In isolated bovine tracheal smooth muscle cells, the potent and specific protein kinase C inhibitor GF 109203X caused an inhibition of methacholine-and histamine-induced Ca2+ mobilization and influx, indicating for the first time that protein kinase C activation induced by contractile agonists exerts a positive feedforward control of Ca2+ signalling by(More)
Endotoxin plays an important role in the pathogenesis of septicaemia by activation of cellular and plasmatic systems. This study was performed to investigate the effects of infusion of endotoxin in rabbits by measuring the activation of cellular and plasma systems. Endotoxin was infused at a rate of 1 mg/kg body wt for 10 min, which caused death of all(More)
The effect of suramin on the ATP-induced response in vas deferens DDT1 MF-2 smooth muscle cells was studied. Stimulation of P2-purinoceptors by ATP caused a change in membrane currents, measured by using the whole-cell patch-clamp configuration, and enhanced the formation of inositol phosphates, as analysed by high performance liquid chromatography. The(More)
1. Stimulation of P2U-purinoceptors with UTP or histamine H1-receptors with histamine gave rise to the formation of inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) and inositol 1,3,4,5-tetrakisphosphate (Ins(1,3,4,5)P4) in DDT1 MF-2 smooth muscle cells. 2. Stimulation of P2U-purinoceptors or histamine H1-receptors caused an increase in cytoplasmic Ca2+,(More)
According to the two state receptor model, the beta(2)-adrenergic receptor (beta(2)-AR) isomerizes between an inactive state and a constitutively active state, which couples to the stimulatory G-protein in the absence of agonist. In bovine tracheal smooth muscle (BTSM), we investigated the effect of short and long term beta(2)-AR activation by fenoterol on(More)
The effect of alpha 1-adrenoceptor stimulation on inositol phosphates (InsPs), intracellular Ca2+ and membrane current was measured in vas deferens DDT1 MF-2 cells. The InsPs were analyzed after labelling the cells with [3H]myo-inositol using high performance liquid chromatography and the internal Ca2+ concentration was determined by measuring fluorescence(More)