1. We have measured intracellular calcium concentrations in basal conditions and in response to cholecystokinin-octapeptide and acetylcholine in pancreatic acini isolated from rats with caerulein-induced acute pancreatitis and compared them with those in control rats. 2. We also measured amylase secretion in basal conditions and in response to cholecystokinin-octapeptide in both groups. 3. In p...

Ciliary ganglion neurons, half of which normally suffer developmental death in the embryo, will survive in culture in medium supplemented with depolarizing concentrations of potassium. It is not known how elevated potassium acts inside the cell to promote survival. We report here that depolarizing concentrations of extracellular potassium promote neuronal survival by causing a sustained increas...

background: oligodendrocytes, the myelinating glial cells of central nervous system, are highly vulnerable to ischemic‑induced excitotoxic insult, a phenomenon in which calcium overload triggers cell death. berberine is an alkaloid extracted from medicinal herbs as coptidis rhizoma with several pharmacological effects like inhibition of neuronal apoptosis in cerebral ischemia. methods: we exami...

RT112 cells, a line derived from a human bladder carcinoma, produce epitectin at very low levels in standard culture media; but production and secretion of this mucin are greatly increased when the cells are exposed to hyperosmotic conditions. It appears that hyperosmolarity, by inducing an increase in intracellular sodium, entrains an increase in intracellular free calcium. Evidence is present...

It is proposed that the basic mechanism of vasospasm which sometimes follows subarachnoid hemorrhage is dependent on increased free intracellular calcium ion produced by spasmogens from closely applied extravasated blood. Relaxation of this spasm occurs when the intracellular cyclic AMP levels are raised, resulting in sequestration of calcium ion by the vascular smooth muscle cell sarcoplasmic ...

In Alzheimer's disease (AD), abnormal accumulations of beta-amyloid are present in the brain and degenerating neurons exhibit cytoskeletal aberrations (neurofibrillary tangles). Roles for beta-amyloid in the neuronal degeneration of AD have been suggested based on recent data obtained in rodent studies demonstrating neurotoxic actions of beta-amyloid. However, the cellular mechanism of action o...

Extracellular calcium concentrations (Cao) > 0.1 mM are required for the differentiation of normal human keratinocytes in culture. Increments in Cao result in acute and sustained increases in the intracellular calcium level (Cai), postulated to involve both a release of calcium from intracellular stores and a subsequent increase in calcium influx through nonspecific cation channels. The sustain...

Angiotensin II stimulated the breakdown of phosphatidylinositol-4,5-bisphosphate (PIP2) and the generation of inositol trisphosphate (IP,) in cultured rat aortic smooth muscle cells. The decrease in PIP2 and increase in IP, levels were rapid (measurable at 5 seconds; maximum IP, levels at 15 seconds). The time course of these changes was comparable to that of angiotensin Il-induced increases in...

BACKGROUND The role of platelet activating factor (PAF) in asthma remains controversial. The priming effect of PAF on leukotriene B4 (LTB4) release, 5-lipoxygenase activity, and intracellular calcium levels in asthmatic neutrophils was examined. METHODS LTB4 and other lipoxygenase metabolites in neutrophils obtained from 17 asthmatic patients and 15 control subjects were measured by reverse p...

Neuritic regression and cell death (neurodegeneration) are common features of both normal nervous system development and neurodegenerative disorders. Growth factors and excitatory amino acid neurotransmitters have been suggested independently to play roles in neurodegenerative processes. The present study investigated the combined effects of fibroblast growth factor (FGF) and glutamate on the d...