Human β-defensin 2 (HBD2) is a cysteine-rich cationic antimicrobial peptide known for its important role in innate immune system. Intensive studies have demonstrated its antimicrobial and chemotactic activities in vitro. In this study, ELISA analysis showed that HBD2 was significantly downregulated in sera of patients with hypertension. It relaxed vessel smooth muscle by acting on the major reg...

Mitochondria have been suggested as a potential target for cytoprotective strategies. It has been shown that increased K+ uptake mediate by mitochondrial ATP-regulated potassium channels (mitoKATP channel) or large-conductance Ca2+-activated potassium channels (mitoBKCa channel) may provide protection in different models of cell death. Since recent findings demonstrated the presence of BKCa cha...

Astrocyte signals can modulate arteriolar tone, contributing to regulation of cerebral blood flow, but specific intercellular communication mechanisms are unclear. Here we used isolated cerebral arteriole myocytes, astrocytes, and brain slices to investigate whether carbon monoxide (CO) generated by the enzyme heme oxygenase (HO) acts as an astrocyte-to-myocyte gasotransmitter in the brain. Glu...

We investigated the role of K(+) channels in the attenuated pulmonary artery (PA) contractility characteristic of acute Pseudomonas pneumonia. Contractility of PA rings from the lungs of control or pneumonia rats was assessed in vitro by obtaining cumulative concentration-response curves to the contractile agonists KCl, phenylephrine, or PGF(2 alpha) on PA rings before and after treatment with ...

Zonisamide (ZNS; 3-sulfamoylmethyl-1,2-benzisoxazole), as one of the newer antiepileptic drugs, has been demonstrated its broad-spectrum clinical efficacy on various neuropsychiatric disorders. However, little is known regarding the mechanism of ZNS actions on ion currents in neurons. We thus investigated its effect on ion currents in differentiated hippocampal 19-7 cells. In whole-cell configu...

Gliomas are morbid brain tumors that are extremely resistant to available chemotherapy and radiology treatments. Some studies have suggested that calcium-activated potassium channels contribute to the high proliferative potential of tumor cells, including gliomas. However, other publications demonstrated no role for these channels or even assigned them antitumorogenic properties. In this work w...

BACKGROUND Depolarization-induced suppression of excitation (DSE) at parallel fiber-Purkinje cell synapse is an endocannabinoid-mediated short-term retrograde plasticity. Intracellular Ca(2+) elevation is critical for the endocannabinoid production and DSE. Nevertheless, how elevated Ca(2+) leads to DSE is unclear. METHODOLOGY/PRINCIPAL FINDINGS We utilized cytosolic phospholipase A(2) alpha ...

In depolarized smooth muscle cells of pressurized cerebral arteries, ryanodine receptors (RyRs) generate "Ca2+ sparks" that activate large-conductance, Ca2+ -, and voltage-sensitive potassium (BK) channels to oppose pressure-induced (myogenic) constriction. Here, we show that BK channels and RyRs have opposing roles in the regulation of arterial tone in response to sympathetic nerve activation ...

Ohya, Susumu, Yukiko Kuwata, Kazuho Sakamoto, Katsuhiko Muraki, and Yuji Imaizumi. Cardioprotective effects of estradiol include the activation of large-conductance Ca -activated K channels in cardiac mitochondria. Am J Physiol Heart Circ Physiol 289: H1635–H1642, 2005; doi:10.1152/ajpheart.00016.2005.—The molecular components of the large-conductance Ca -activated K channels that are functiona...

The present study was designed to investigate whether large conductance Ca2+ -activated K+ (BK) channels were regulated by epidermal growth factor (EGF) receptor (EGFR) tyrosine kinase. BK current and channel tyrosine phosphorylation level were measured in BK-HEK 293 cells expressing both functional α-subunits and the auxiliary β1-subunits using electrophysiology, immunoprecipitation and Wester...