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The great majority of the sustained secretory response of adrenal chromaffin cells to histamine is due to extracellular Ca(2+) influx through voltage-operated Ca(2+) channels (VOCCs). This is likely to be true also for other G protein-coupled receptor (GPCR) agonists that evoke catecholamine secretion from these cells. However, the mechanism by which these(More)
The current study has investigated the electrophysiological responses evoked by histamine in bovine adrenal chromaffin cells using perforated-patch techniques. Histamine caused a transient hyperpolarization followed by a sustained depolarization of 7.2 +/- 1.4 mV associated with an increase in spontaneous action potential frequency. The hyperpolarization(More)
The ability of a number of drugs and neuropeptides to stimulate phosphoinositide metabolism in cultured bovine adrenal medullary cells has been assessed. Low concentrations (10 nM) of angiotensin II, bradykinin, histamine, arginine-vasopressin, and bombesin, and high (10 microM) concentrations of oxytocin, prostaglandins E1, and E2, beta-endorphin, and(More)
Angiotensin II binding sites have been localized in sections of bovine adrenal glands and on living cultured bovine adrenal medullary cells using [125I]-[Sar1,Ile8]-angiotensin II and autoradiographic techniques. Binding sites were observed over both adrenaline and noradrenaline chromaffin cells. However, they were present in higher density over adrenaline(More)
Samples of rat striatum and synthetic sulphated cholecystokinin octapeptide were extracted by different procedures and the solubilised cholecystokinin-like immunoreactivity analysed by gel filtration and ion-exchange chromatography. Ice-cold 90% methanol extraction gave the greatest recovery of tissue immunoreactivity without any major modification of the(More)
Both nicotine and histamine have been reported to increase cyclic AMP levels in chromaffin cells by Ca(2+)-dependent mechanisms. The present study investigated whether Ca2+ was an adequate and sufficient signal for increasing cyclic AMP in cultured bovine adrenal medullary cells. Depolarization with 50 mM K+ caused a two- to three-fold increase in cellular(More)
Tyrosine hydroxylase (TOH) activity is regulated acutely by phosphorylation of serines 8, 19, 31 and 40. The only kinases known to phosphorylate Ser31 are the mitogen-activated protein kinases MAPK-1 and 2. The involvement of these kinases in TOH activation in situ was therefore investigated using intact bovine chromaffin cells. Nicotine, K+ and A23187(More)
Phosphatidylinositol 3-kinase (PI3K) can activate endothelial nitric oxide synthase (eNOS), leading to production of the vasodilator NO. In contrast, vascular smooth muscle (VSM) PI3K may partially mediate vascular contraction, particularly during hypertension. We tested whether endothelial and VSM PI3K may have opposing functional roles in regulating(More)
Primary cultures of bovine adrenal medullary cells have been used to study the effects of angiotensin II on catecholamine secretion and inositol phosphate accumulation. Angiotensin II induced a weak secretion of both adrenaline and noradrenaline, with a threshold of 10-100 pM and a shallow concentration-dependence up to 10 microM. The response was fully(More)
Two tissue extraction techniques and two radioimmunoassays were used to study the distribution of gastrin and cholecystokinin in rat brain. Small amounts of gastrin were found in extracts of neurohypophysis, but in neither ice-cold 90% methanol nor in boiling water-acetic acid extracts of the other 33 brain areas studied. Cholecystokinin was found in(More)