Previous results have suggested that orexins causes a rise of intracellular free calcium ([Ca(2+)](i)) in cultured rat dorsal root ganglion (DRG) neurons, implicating a role in nociception, but the underlying mechanism is unknown. Hence, the aim of the present study was to investigate whether the orexins-mediated signaling involves the PKC pathways in these sensory neurons. Cultured DRG neurons...

Neuronostatin, a newly identified peptide hormone sharing the same precursor with somatostatin, exerts multiple pharmacological effects in gastrointestinal tract, hypothalamus, and cerebellum. However, the cardiovascular effect of neuronostatin is unknown. The aim of this study was to elucidate the impact of neuronostatin on cardiac contractile function in murine hearts and isolated cardiomyocy...

The stimulant drug amphetamine is postulated to enhance dopamine release through the plasmalemmal dopamine transporter by an exchange diffusion with synaptosomal dopamine. Because protein kinase C has been shown to have an effect on dopamine transporter activity, we examined the effect of protein kinase C inhibitors on endogenous dopamine release stimulated by amphetamine in perfused rat striat...

The relative roles of mitochondrial (mito) ATP-sensitive K(+) (mitoK(ATP)) channels, protein kinase C (PKC), and adenosine kinase (AK) in adenosine-mediated protection were assessed in Langendorff-perfused mouse hearts subjected to 20-min ischemia and 45-min reperfusion. Control hearts recovered 72 +/- 3 mmHg of ventricular pressure (50% preischemia) and released 23 +/- 2 IU/g lactate dehydroge...

CD3 antigen is a crucial molecule in T cell signal transduction. Although its expression on cell surface is constitutive, dynamic regulation of TCR-CD3 level is probably the most important mechanism allowing T cells to calibrate their response to different levels of stimuli. In our study we examined the role of two main T cell signal transduction pathways in controlling the surface level of CD3...

A current hypothesis states that tolerance to nitroglycerin (GTN) involves increased formation of superoxide (O2*-). Studies showing that inhibitors of protein kinase C (PKC) prevent tolerance to GTN suggest the involvement of PKC activation, which can also increase O2*-. We examined the roles of O2*-, peroxynitrite (ONOO-), and PKC activation in GTN tolerance. Pre-exposure of rat aortic rings ...

In evaluating mechanisms of trimethyltin (TMT)-initiated neuronal damage, the present study focused on involvement of reactive oxygen species, protein kinase C (PKC), and glutamate receptors. Exposure of cerebellar granule cells to TMT (0.01-0.1 microM) produced primarily apoptosis, but higher concentrations were associated with cellular lactate dehydrogenase efflux and necrosis. TMT increased ...

BACKGROUND Sanguinarine (SG) has been reported to form DNA adducts in vitro and increase the levels of DNA single strand breaks in the blood and bone marrow of mice treated intraperitoneally with SG. Recently, we showed no genotoxic effects of orally administrated 120 mg/kg feed Macleaya cordata extract (a mixture of sanguinarine and chelerythrine) in pigs or rats in 90-day studies. The goal of...

Signaling mechanisms for muscarinic receptor-mediated vasoconstriction in coronary resistance arteries were studied in potassium-arrested isolated rat hearts perfused at a constant flow rate. The cholinergic agonist bethanechol was given by bolus injection or constant infusion. Perfusion pressure was monitored as an indicator of coronary vascular resistance. Bolus injection of bethanechol evoke...

Nakamura, Tomoe Y., William A. Coetzee, Eleazar Vega-Saenz De Miera, Michael Artman, and Bernardo Rudy. Modulation of Kv4 channels, key components of rat ventricular transient outward K1 current, by PKC. Am. J. Physiol. 273 (Heart Circ. Physiol. 42): H1775–H1786, 1997.— Current evidence suggests that members of the Kv4 subfamily may encode native cardiac transient outward current (Ito). Antisen...