Karri K. Bradley

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1. The molecular nature of the strong inward rectifier K+ channel in vascular smooth muscle was explored by using isolated cell RT-PCR, cDNA cloning and expression techniques. 2. RT-PCR of RNA from single smooth muscle cells of rat cerebral (basilar), coronary and mesenteric arteries revealed transcripts for Kir2.1. Transcripts for Kir2.2 and Kir2.3 were(More)
Swelling-activated or volume-sensitive Cl- currents are found in numerous cell types and play a variety of roles in their function; however, molecular characterization of the channels is generally lacking. Recently, the molecular entity responsible for swelling-activated Cl- current in cardiac myocytes has been identified as ClC-3. The goal of our study was(More)
The function and molecular expression of ATP-sensitive potassium (KATP) channels in murine colonic smooth muscle was investigated by intracellular electrical recording from intact muscles, patch-clamp techniques on isolated smooth muscle myocytes, and reverse transcription polymerase chain reaction (RT-PCR) on isolated cells. Lemakalim (1 microM) caused(More)
1. The membrane potential of gastrointestinal smooth muscles determines the open probability of ion channels involved in rhythmic electrical activity. The role of Ba2+-sensitive K+ conductances in the maintenance of membrane potential was examined in canine proximal colon circular muscle. 2. Application of Ba2+ (1-100 microM) to strips of tunica muscularis(More)
The role of intracellular guanosine 3',5'-cyclic monophosphate concentration ([cGMP]i) in nitric oxide (NO)-mediated relaxations in the uterus has become controversial. We found the NO donor S-nitroso-L-cysteine (CysNO) to potently (IC50 = 30 nM) inhibit spontaneous contractions in the nonpregnant human myometrium. CysNO treatment increased [cGMP]i(More)
Expression of the Kir3 channel subfamily in gastrointestinal (GI) myocytes was investigated. Members of this K(+) channel subfamily encode G protein-gated inwardly rectifying K(+) channels (I(KACh)) in other tissues, including the heart and brain. In the GI tract, I(KACh) could act as a negative feedback mechanism to temper the muscarinic response mediated(More)
Voltage-activated K(+) (K(V)) channels play an important role in regulating the membrane potential in excitable cells. In gastrointestinal (GI) smooth muscles, these channels are particularly important in modulating spontaneous electrical activities. The purpose of this study was to identify the molecular components that may be responsible for the K(V)(More)
We examined the effects of purines and the pyrimidine UTP on cellular proliferation in the human astrocytoma cell line 1321N1. Treatment of cultured cells with 100 microM ATP or 2-chloroadenosine (2-CA) resulted in significant reductions in cell numbers after 2 days, whereas adenosine (ADO) exhibited a slower time course of inhibition of cell growth.(More)
Epperson, Anne, Helena P. Bonner, Sean M. Ward, William J. Hatton, Karri K. Bradley, Michael E. Bradley, James S. Trimmer, and Burton Horowitz. Molecular diversity of KV aand b-subunit expression in canine gastrointestinal smooth muscles. Am. J. Physiol. 277 (Gastrointest. Liver Physiol. 40): G127–G136, 1999.—Voltage-activated K1 (KV) channels play an(More)
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