Dexmedetomidine, a highly selective α-2 adrenoceptor agonist, produces vasoconstriction, which leads to transiently increased blood pressure. The goal of this study was to investigate specific protein kinases and the associated cellular signal pathways responsible for the increased calcium sensitization induced by dexmedetomidine in isolated rat aortas, with a particular focus on phosphorylatio...

It has been known for some time that agonist-induced contractions of vascular smooth muscle are often associated with a sensitization of the contractile apparatus to intracellular Ca2+. One mechanism that has been suggested to explain Ca2+ sensitization is inhibition of myosin phosphatase activity. In the present study, we tested the hypothesis that differential localization of the phosphatase ...

Recent evidence suggests that Rho/Rho kinase signaling plays an important role in the sustained vasoconstriction induced by many agonists and is involved in the pathogenesis of systemic vascular diseases. However, little is known about its role in increased vascular tone in hypoxic pulmonary hypertension (PH). The purpose of this study was to examine whether Rho/Rho kinase-mediated Ca2+ sensiti...

Repeated administration of nicotine causes incentive and behavioral sensitization in animals. Ascorbic acid administration inhibits some effects of nicotine. In the present study, the effect of ascorbic acid administration on nicotine-induced behavioral sensitization in Male Swiss-Webster mice (20-25 g) was investigated. Animals were injected with nicotine (0.25 mg/kg, i.p.) once daily for seve...

Proteases that are released during inflammation and injury cleave protease-activated receptor 2 (PAR2) on primary afferent neurons to cause neurogenic inflammation and hyperalgesia. PAR2-induced thermal hyperalgesia depends on sensitization of transient receptor potential vanilloid receptor 1 (TRPV1), which is gated by capsaicin, protons and noxious heat. However, the signalling mechanisms by w...

Type B gamma-aminobutyric acid receptor (GABABR) is a G protein-coupled receptor that regulates neurotransmitter release and neuronal excitability throughout the brain. In various neurons, GABABRs are concentrated at excitatory synapses. Although these receptors are assumed to respond to GABA spillover from neighboring inhibitory synapses, their function is not fully understood. Here we show a ...

Ca(2+) ion is a universal intracellular messenger that regulates numerous biological functions. In smooth muscle, Ca(2+) with calmodulin activates myosin light chain (MLC) kinase to initiate a rapid MLC phosphorylation and contraction. To test the hypothesis that regulation of MLC phosphatase is involved in the rapid development of MLC phosphorylation and contraction during Ca(2+) transient, we...

there is strong evidence demonstrating that nifedipine dissolved in ethanol selectively inhibits only l-type ca2+ current. in addition, acute ethanol exposure reduces voltage-dependent calcium currents. in the present study, we investigated the antagonistic effect of fixed concentration of nifedipine dissolved in different concentration of ethanol on l-type ca2+ current. in a na+-k+ free soluti...

Repeated administration of nicotine causes incentive and behavioral sensitization in animals. Ascorbic acid administration inhibits some effects of nicotine. In the present study, the effect of ascorbic acid administration on nicotine-induced behavioral sensitization in Male Swiss-Webster mice (20-25 g) was investigated. Animals were injected with nicotine (0.25 mg/kg, i.p.) once daily for seve...