There is strong evidence supporting the hypothesis of an electrogenic Na-K pump in the basolateral membrane of several epithelia. Thermodynamic considerations and results in nonepithelial cells indicate that the current carried by the pump could be voltage dependent. In order to measure the pump current and to determine its voltage dependence in a tight epithelium, we have used the isolated per...

Macrophage migration inhibitory factor (MIF) has widespread actions in the immune, endocrine, and nervous systems. Previously, we reported that increases in the intracellular levels of MIF depress the firing of hypothalamus/brain stem neurons in culture, including the chronotropic actions of angiotensin II. The objective of this study was to investigate the effects of MIF on delayed rectifier K...

We investigated the features of the inward-rectifier K channel Kir1.1 (ROMK) that underlie the saturation of currents through these channels as a function of permeant ion concentration. We compared values of maximal currents and apparent K(m) for three permeant ions: K(+), Rb(+), and NH(4)(+). Compared with K(+) (i(max) = 4.6 pA and K(m) = 10 mM at -100 mV), Rb(+) had a lower permeability, a lo...

Hoesch, Robert E., Daniel Weinreich, and Joseph P. Y. Kao. Localized IP3-evoked Ca 2 release activates a K current in primary vagal sensory neurons. J Neurophysiol 91: 2344–2352, 2004. First published December 10, 2003; 10.1152/jn.01008.2003. Electrophysiological and microfluorimetric techniques were used to determine whether intracellular photorelease of caged IP3, and the consequent release o...

Acetylcholine (ACh) rapidly increases cardiac K(+) currents (IKACh) by activating muscarinic K(+) (KACh) channels followed by a gradual amplitude decrease within seconds. This phenomenon is called short-term desensitization and its precise mechanism and physiological role are still unclear. We constructed a mathematical model for IKACh to examine the conditions required to reconstitute short-te...

The tonic electroreceptors of the marine catfish Plotosus consist of a cluster of ampullae of sensory epithelia, each of which is an isolated receptor unit that is attached to the distant skin with only a long duct. The single-cell layered sensory epithelium has pear-shaped receptor cells interspersed with thin processes of supporting cells. The apical border of the receptor cells is joined to ...

In this lecture I will give a brief review of the experimental progress in the study of CP violation in the neutral K meson system. We will speak exclusively of the measurement of ~noo~2/~n+-~2 for which two new experimental results have been announced. A more complete discussion of other relevant experiments has been given in the lectures of Stan Wojcicki in this volume. A thorough discussion ...

We characterized a voltage-dependent ionic current in dental pulp cells on dental pulp slices using a nystatin perforated-patch recording configuration. The outward currents in dental pulp cells were inhibited by the following channel blockers: 1) Ca(2+)-free extracellular solution containing 10 mM Ba2+, 2) extracellular 400 nM apamin and 3) extracellular 300 nM 4,4'-diisothiocyanatostilbene-2,...

The GABA-B receptor is densely expressed throughout the brain and has been implicated in many CNS functions and disorders, including addiction, epilepsy, spasticity, schizophrenia, anxiety, cognitive deficits, and depression, as well as various aspects of nervous system development. How one GABA-B receptor is involved in so many aspects of CNS function remains unanswered. Activation of GABA-B r...