The present study was designed to investigate the electrophysiological properties of strial pericytes and the effect of aspirin on pericyte K+ channels. Pericytes were identified by determining their morphological characteristics and using pericyte‑associated immunofluorescence techniques. The electrophysiological properties of strial pericytes were observed with a whole‑cell patch‑clamp techni...

LDD175 (4-chloro-7-trifluoromethyl-10H-benzo[4,5]furo[3,2-b]indole-1-carboxylic acid) is a benzofuroindole compound characterized previously as a potent opener of the large conductance calcium activated (BK(Ca)) channels. Activators of the BK(Ca) channels are potential therapies for smooth muscle hyperactivity disorders. The present study investigates the influence of LDD175 on the mechanical a...

Raising extracellular K+ concentration ([K+](o)) around mesenteric resistance arteries reverses depolarization and contraction to phenylephrine. As smooth muscle depolarizes and intracellular Ca(2+) and tension increase, this effect of K+ is suppressed, whereas efflux of cellular K+ through Ca(2+)-activated K+ (K(Ca)) channels is increased. We investigated whether K+ efflux through K(Ca) suppre...

Stretch-induced relaxation has not been clearly identified in gastrointestinal tract. The present study is to explore the role of large conductance calcium-activated potassium channels (BKCa) in stretch-induced relaxation of colon. The expression and currents of BKCa were detected and the basal muscle tone and contraction amplitude of colonic smooth muscle strips were measured. The expression o...

Ionic mechanisms underlying low-threshold (LTO) and high-threshold (HTO) oscillations occurring in a class of spiny neurons within the basolateral amygdaloid complex (see companion paper) were investigated in slice preparations of the guinea pig amygdala in vitro. LTOs were abolished through local application of tetrodotoxin (TTX, 10-20 microM) or a decrease in the extracellular sodium concentr...

Docosahexaenoic acid (DHA) shows more pronounced relaxation when blood vessel is contracted with prostanoid receptor agonists than other stimulants. The present study was carried out to obtain information on the mechanisms underlying prostanoid receptor-selective relaxant action of DHA, particularly focusing on the possible roles for K(+) channels and its CYP epoxygenase (EOX) metabolites. In e...

High conductance calcium-activated potassium (BK(Ca)) channels can modulate cell excitability and neurotransmitter release at synaptic and afferent terminals. BK(Ca) channels are present in primary afferents of most, if not, all internal organs and are an intriguing target for pharmacological manipulation of visceral sensation. Our laboratory has a long-standing interest in the neurophysiologic...

Odor stimulation may excite or inhibit olfactory receptor neurons (ORNs). It is well established that the excitatory response involves a cAMP transduction mechanism that activates a non-selective cationic cyclic nucleotide-gated (CNG) conductance, accompanied by the activation of a Ca 2+-dependent Cl-conductance, both causing a depolarizing receptor potential. In contrast, odor inhibition is du...

In this study, we investigated the effects of bladder outlet obstruction (BOO) on the expression and function of large conductance (BK) and small conductance (SK) Ca(2+)-activated K(+) channels in detrusor smooth muscle. The bladder from adult female Sprague-Dawley rats with 6-wk BOO were used. The mRNA expression of the BK channel alpha-subunit, beta1-, beta2-, and beta4-subunits and SK1, SK2,...

The muscularis mucosae, a type of smooth muscle located between the urothelium and the urinary bladder detrusor, has been described, although its properties and role in bladder function have not been characterized. Here, using mucosal tissue strips isolated from guinea pig urinary bladders, we identified spontaneous phasic contractions (SPCs) that appear to originate in the muscularis mucosae. ...