W J Zang

Learn More
1. High spatial resolution confocal imaging was used to investigate the fundamental nature of "Ca2+ sparks' in rat cardiac myocytes loaded with the fluorescent calcium indicator, fluo-3. 2. The sites at which calcium sparks occurred (Ca2+ release sites) were packed closely and irregularly in transverse planes along Z-lines (mean spacing between sites of(More)
1. The ACh-activated K+ current (IK,ACh) has been investigated in guinea-pig atrial cells at 36 degrees C using the whole-cell patch-clamp technique. 2. During an exposure to ACh, IK,ACh faded as a result of desensitization. Throughout the fade of the current, the current reversed at EK and showed inward-going rectification. The fade was, therefore, the(More)
L-type Ca2+ current, iCa, has been recorded in guinea-pig ventricular myocytes at 36 degrees C using the whole cell patch clamp technique. Intracellular Ca2+ was buffered with ethylenebis(oxonitrilo)tetraacetate (EGTA). An increase in the rate of stimulation from 0.5 to 3 Hz resulted in an abrupt decrease in iCa in the first beat at the high rate, followed(More)
Acetylcholine (ACh) released from parasympathetic nerves binds to muscarinic (M2) ACh receptor (mAChR) in the heart, which leads to activation of muscarinic K(+) channel via the betagamma subunit of a G protein. The effect of a general anaesthetic (halothane) on the muscarinic K(+) channel (i(K,Ach)) in guinea-pig atrial cells was investigated using the(More)
1. Activity of rat atrial muscarinic K+ channels has been measured in five configurations of the patch clamp technique. 2. In configurations in which the normal intracellular solution was lost, the slow phase of desensitization (a slow decline of channel activity during an exposure to ACh) was much reduced (or absent) and deactivation (on wash-off of ACh)(More)
The negative chronotropic effect of acetylcholine (ACh) on the sinoatrial node fades in the continuous presence of ACh as a result of desensitization. We have investigated the mechanism underlying desensitization in single rabbit sinoatrial node cells using the whole cell patch clamp technique. The negative chronotropic effect resulting from the injection(More)
The whole-cell patch clamp technique was used to investigate the effect of different charge carriers upon ultra-slow voltage-dependent inactivation of L-type Ca2+ channel current in ferret ventricular myocytes at 37 degrees C. Intracellular Ca2+ was buffered with 10 mM EGTA and the membrane potential held at -40 mV. With Ba2+ as the charge carrier, the(More)
1. Fast desensitization of the muscarinic K+ channel has been studied in excised patches from rat atrial cells. 2. In inside-out patches, ACh was present in the pipette and GTP was applied via the bath to activate the channel. In outside-out patches, GTP was present in the pipette and ACh was applied via the bath to activate the channel. In both cases,(More)
Block of the muscarinic K+ current (iK,ACh) by Ba2+ has been studied in guinea-pig atrial cells using the whole-cell patch-clamp technique. The dose-response curve for the block of iK,ACh can be fitted assuming that a muscarinic K+ channel is blocked when a single Ba2+ ion binds to it (apparent dissociation constant, Kd = 125 microM at 0 mV). Block was(More)
Confocal laser scanning microscopy and Fluo-4 were used to visualize Ca(2+) transients within individual smooth muscle cells (SMC) of rat resistance arteries during alpha(1)-adrenoceptor activation. The typical spatio-temporal pattern of [Ca(2+)] in an artery after exposure to a maximally effective concentration of phenylephrine (PE, 10.0 microM) was a(More)
  • 1