Although it plays a major inhibitory role in the adult mammalian CNS, gamma-aminobutyric acid (GABA) may have an excitatory function in developing neurons. The present study focuses on the dependence of glutamate on GABA to generate action potentials in developing hypothalamic neurons. Under conditions where glutamate by itself could not evoke an action potential, GABA facilitated glutamate-med...

Double- and triple-barreled ion-sensitive microelectrodes were used to measure changes in extracellular K+ and Na+ concentrations ([K+]o, [Na+]o) in brown fat. Redox states of different respiratory enzymes were measured simultaneously in order to correlate ion movements with metabolic activity. Trains of stimuli applied to the efferent nerves evoked two distinct increases in [K+]o. A first, sma...

Doubleand triple-barreled ion-sensitive microelectrodes were used to measure changes in extracellular K+ and Na' concentrations ([K+]o, [Na'].) in brown fat . Redox states of different respiratory enzymes were measured simultaneously in order to correlate ion movements with metabolic activity . Trains of stimuli applied to the efferent nerves evoked two distinct increases in [K']o . A first, sm...

Differentiated glial fibrillary acidic protein-positive astrocytes in homogeneous cultures of early postnatal rat cerebral hemispheres respond by membrane depolarization to gamma-aminobutyric acid (GABA), glutamate, and aspartate with a threshold concentration of approximately 10(-5) M. The GABA-induced depolarization is antagonized by two blockers of the neuronal GABAA receptor, picrotoxin and...

We examined how monocrotaline (MCT), which impairs the endothelium and causes pulmonary hypertension, altered the endothelial regulation of pulmonary artery functions. Rats were given a single injection of MCT (60 mg/kg sc). Pulmonary arteries were depolarized to -48.3 +/- 2.6 and -39.8 +/- 2.2 mV at 2 and 3 wk after treatment with MCT, respectively (control arteries -59.9 +/- 1.9 mV). The basa...

Ischemic preconditioning models have been characterized in brain, heart, and other tissues, and previous pharmacologic studies have suggested an involvement of adenosine and ATP dependent potassium (KATP) channels in such tolerance phenomena. This question was reexamined in a reproducible gerbil model in which the duration of ischemic depolarization defined the severity of preconditioning and t...

The late receptor potential (LRP) recorded in barnacle photoreceptor cells exhibits, at high light levels, a strong dependence on the color of the stimulus and of the preceding adaptation. Most strikingly, red illumination of a cell previously adapted to blue light results in a depolarization which may last for up to 30 min after the light goes off, while blue illumination of a cell previously ...

The action potential of guinea pig papillary muscle exposed to the ceveratrum alkaloid germitrine (2 mugM) is followed by a long-lasting after-depolarization (maximal amplitude, 8 mV; half-time of decay, 32 seconds; total duration, approximately 75 seconds). This after-depolarization interrupts the terminal phase of repolarization. During repetitive stimulation (0.1-1.0 Hz; 80 nM germitrine) th...

Relevance. Alcoholic cardiomyopathy (ACMP) is the leading cause of mortality in chronic disease, which largely associated with an increased risk developing malignant diseases cardiovascular disease. Search for new drugs, including those exhibiting pronounced antiarrhythmic activity, supposed relevance. Objective. To study effect combination therapy fabomotizole and ALM-802 on atrial depolarizat...