We studied functional and intracellular calcium responses to treppe and extracellular calcium in spontaneously hypertensive rat (SHR) hearts during the transition from compensated pressure overload to failure. Intracellular calcium was measured using aequorin, a bioluminescent Ca2+ indicator. Experiments were performed with intact, isovolumically contracting, buffer-perfused hearts from three r...

Intranigral injection of the transient receptor potential vanilloid subtype 1 (TRPV1; also known as VR1) agonist capsaicin (CAP) into the rat brain, or treatment of rat mesencephalic cultures with CAP, resulted in cell death of dopaminergic (DA) neurons, as visualized by immunocytochemistry. This in vivo and in vitro effect was ameliorated by the TRPV1 antagonist capsazepine (CZP) or iodo-resin...

In bovine tracheal smooth muscle, carbachol (CCh, 1 microM) and high K+ (72.7 mM) induced sustained increases in cytosolic Ca2+ level ([Ca2+]i), myosin light chain (MLC) phosphorylation and force of contraction. Forskolin (FK, 1-10 microM) inhibited the CCh-induced increase in [Ca2+]i, MLC phosphorylation and force in parallel. In contrast, FK inhibited the high K(+)-induced contraction and MLC...

We analysed the roles of orexin receptors in the effects of orexin-A on KCl-induced increases in intracellular calcium ion levels ([Ca2+]i) in C-fiber-like small neurons of rats with inflammation induced by intraplantar injection of carrageenan into the hind paw. Controls were treated with saline. Paw withdrawal and threshold forces in response to tactile stimuli were determined using von Frey ...

The presence and functional significance of the extracellular calcium-sensing receptor (CaR) on human pancreatic beta-cells were investigated. Reverse transcriptase-polymerase chain reaction with primers for the extracellular domain of the CaR expressed in human parathyroid-secreting cells identified a product of the expected size in human pancreatic mRNA. Immunocytochemistry using an antibody ...

Although it is known that there are some pharmacological differences between the structurally similar barbiturates, the underlying mechanism of action remains unclear. We have compared the effects of thiopental, thiamylal and phenobarbital on both voltage-gated calcium channels (VGCC) and N-methyl-D-aspartate (NMDA) receptors in rat hippocampal slices by determining changes in intracellular cal...

The effects of raising cyclic AMP levels, by forskolin stimulation, ,f-adrenoceptor activation or cyclic AMP phosphodiesterase inhibition, on inositol phospholipid hydrolysis and increases in intracellular free [Ca2+] ([Ca2+]i) elicited by a range of agonists have been investigated in the hamster vas deferens smoothmuscle cell line DDT1MF-2. Isoprenaline {log [EC50 (M)] = -7.7+ 0.2}, forskolin ...

Ischemia, and subsequent acidosis, induces neuronal death following brain injury. Oxidative stress is believed to be a key component of this neuronal degeneration. Acute chemical ischemia (azide in the absence of external glucose) and acidosis (external media buffered to pH 6.0) produce increases in intracellular calcium concentration ([Ca2+]i) and inward membrane currents in cultured rat corti...

Previously, it was shown that glycine prevented increases in intracellular calcium ([Ca2+]i) in Kupffer cells. Since Kupffer cells and T lymphocytes are derived from the same pluripotent stem cell, it was hypothesized that glycine would prevent increases in [Ca2+]i in lymphocytes and inhibit cell proliferation. Lymphocyte proliferation was measured in one-way MLC with spleen cells from DA and L...