Vasoconstriction mediated by the highly selective alpha-2 adrenoceptor agonist dexmedetomidine leads to transiently increased blood pressure and severe hypertension. The dexmedetomidine-induced contraction involves the protein kinase C (PKC)-mediated pathway. However, the main PKC isoform involved in the dexmedetomidine-induced contraction remains unknown. The goal of this in vitro study was to...

The renal dopamine system plays an important role in sodium homeostasis and a defect in dopamine D1 receptor (D1R) function is present in hypertension, diabetes, and aging. Our previous studies in hyperinsulinemic animals and in renal cell cultures treated with insulin showed decrease in D1R number and defective coupling to G proteins; however, the exact mechanisms remained unknown. Therefore, ...

Previous studies have demonstrated that the benzo[c]phenanthridine alkaloid chelerythrine chloride (CC) has inhibitory effects on various tumors. However, the anticancer activity of CC and its underlying mechanisms have not been elucidated in renal cancer cells. The present study examined the effects of CC on growth inhibition and apoptosis of renal cancer cells in vitro and in vivo. Flow cytom...

Serotonin (5-HT) mediates learning-related facilitation of sensorimotor synapses in Aplysia californica. Under some circumstances 5-HT-dependent facilitation requires the activity of protein kinase C (PKC). One critical site of PKC's contribution to 5-HT-dependent synaptic facilitation is the presynaptic sensory neuron. Here, we provide evidence that postsynaptic PKC also contributes to synapti...

Prophylactic treatment with D-myo-inositol 1,4,5-trisphosphate hexasodium [D-myo-Ins(1,4,5)P3], the sodium salt of the endogenous second messenger Ins(1,4,5)P3, triggers a reduction of infarct size comparable in magnitude to that seen with ischemic preconditioning (PC). However, the mechanisms underlying D-myo-Ins(1,4,5)P3-induced protection are unknown. Accordingly, our aim was to investigate ...

Fleegal, Melissa A., and Colin Sumners. Drinking behavior elicited by central injection of angiotensin II: roles for protein kinase C and Ca2 /calmodulin-dependent protein kinase II. Am J Physiol Regul Integr Comp Physiol 285: R632–R640, 2003. First published May 8, 2003; 10.1152/ ajpregu.00151.2003.—Prior studies utilizing neurons cultured from the hypothalamus and brain stem of newborn rats h...

We examined the role of protein kinase C (PKC) in the cardioprotective mechanism induced by long-term adaptation to chronic intermittent hypoxia. Adult male Wistar rats were exposed to hypobaric hypoxia of 7,000 m for 8 h/day, 5 days/wk; the total number of exposures was 24-32. A control group was kept under normoxic conditions. Western blot analysis of PKC isoforms-delta and -epsilon was perfo...

In the present study the effect of phosphatidylinositol 4,5-bisphosphate (PIP(2)) was studied on a native TRPC1 store-operated channel (SOC) in freshly dispersed rabbit portal vein myocytes. Application of diC8-PIP(2), a water soluble form of PIP(2), to quiescent inside-out patches evoked single channel currents with a unitary conductance of 1.9 pS. DiC8-PIP(2)-evoked channel currents were inhi...

Our previous studies indicated that opioid-induced cardioprotection occurs via activation of mitochondrial ATP-sensitive K(+) (K(ATP)) channels. However, other elements of the Met(5)-enkephalin (ME) cardioprotection pathway are not fully characterized. In the present study, we investigated the role of tyrosine kinase, MAPK, and phosphatidylinositol 3-kinase (PI3K) signaling in ME-induced protec...

Opioids generate free radicals that mediate protection in isolated cultured cardiomyocytes. We hypothesize that the nature of these radicals is nitric oxide, and that nitric oxide activates the protein kinase C (PKC) delta isoform. Through this signal transduction pathway, opiates protect cardiomyocytes during hypoxia and reoxygenation. Cell viability was quantified in chick embryonic ventricul...