33 Result(s)
within
Article
J. Hescheler
-
Article
Injection of isolated subunits of cAMP-dependent protein kinase II into single adult cardiac myocytes modulates the slow Ca++ inward current
-
Article
Does the organic calcium channel blocker D600 act from inside or outside on the cardiac cell membrane?
The effects of extra- and intracellularly applied D600 (methoxyverapamil) and D890 (a quarternary derivative) on the action potentials of isolated guinea pig myocytes were compared. We also studied the extrace...
-
Article
Injection of subunits of cyclic AMP-dependent protein kinase into cardiac myocytes modulates Ca2+ current
β-Adrenergic stimulation of the heart is thought to increase cardiac muscle contractility by activation of cyclic AMP-dependent protein kinase and concomitant increase in the phosphorylation of certain proteins.....
-
Article
Inward-rectifying channels in isolated patches of the heart cell membrane: ATP-dependence and comparison with cell-attached patches
Inward rectifying potassium single-channel currents were studied in the membrane of guinea pig cardiac myocytes. In isolated inside-out patches two different channels were observed: a channel of 25 pS conducta...
-
Article
Modulation of Ca current during the phosphorylation cycle in the guinea pig heart
The calcium current (I Ca) in the heart is increased by phosphorylation of a protein which is part of, or close to, the Ca channel. The phosphorylation is catalysed by cAMP-dependent protein kinase (cAMP-PK). The...
-
Article
On the mechanism of muscarinic inhibition of the cardiac Ca current
The mechanism of muscarinic inhibition of the Ca-current (I Ca) was studied in ventricular myocytes of guinea pig hearts and the following results were obtained. 1. Acetylcholine (ACh) in concentrations up to 10−...
-
Article
The protein-specific phosphatase 1 antagonizes the β-adrenergic increase of the cardiac Ca current
In isolated ventricular cells from the adult guinea pig heart the slow Ca current was recorded during β-adrenergic stimulation and during cell dialysis with a protein-specific phosphatase-1 (PPase-1).
-
Article
The GTP-binding protein, Go9 regulates neuronal calcium channels
In neuronal cells, opioid peptides and opiates inhibit neuro-transmitter release, which is a calcium-dependent process1. They also inhibit adenylyl cyclase2, presumably via the membrane signal-transducing compone...
-
Article
Changes of membrane currents in cardiac cells induced by long whole-cell recordings and tolbutamide
Single isolated myocytes were obtained from the ventricles of adult guinea pig hearts. The whole-cell recording configuration of the patch-clamp technique was used to measure membrane currents. A decrease (run...
-
Article
On the mechanism of histamine induced enhancement of the cardiac Ca2+ current
In guinea pig ventricular myocytes, the effect of histamine on the slow Ca2+ current (ICa) was studied and the following results were obtained: (1) Superfusion of cells with histamine resulted in a dose-dependent...
-
Article
“Run-down” of the Ca current during long whole-cell recordings in guinea pig heart cells: role of phosphorylation and intracellular calcium
We examined by a statistical approach the decrease of the Ca current (“run-down”) during long-lasting recordings with the whole-cell patch-clamp technique in guinea pig ventricular myocytes. The results are as...
-
Article
Effects of a protein phosphatase inhibitor, okadaic acid, on membrane currents of isolated guinea-pig cardiac myocytes
The effects of a protein phosphatase inhibitor, okadaic acid (OA), were studied on membrane currents of isolated myocytes from guinea-pig cardiac ventricle. The whole-cell Ca2+ current (I Ca) was recorded as peak...
-
Article
A possible physiological role of the Ca-dependent protease calpain and its inhibitor calpastatin on the Ca current in guinea pig myocytes
The decrease (‘run-down’) of the L-type Ca2+-current during long-lasting recordings with the whole-cell patch-clamp technique was examined in guinea pig ventricular myocytes. We have tested whether proteolysis is...
-
Article
Regular and chaotic behaviour of cardiac cells stimulated at frequencies between 2 and 20 Hz
We measured the non-linear dynamics of cardiac action potentials by varying the stimulation frequency from 2 to 20 Hz and obtained the following results: (i) When the fast Na+ current initiated the action potenti...
-
Article
Calcium currents of neuroblastoma × glioma hybrid cells after cultivation with dibutyryl cyclic AMP and nickel
The long-term modulation of calcium (Ca2+) currents (I Ca) was studied in 108CC15 neuroblastoma × glioma hybrid (N×G) cells grown under various culture conditions. The following results were obtained:
-
Article
Abstract of the 68th Meeting (Spring Meeting) 6–9 March 1990, Heidelberg
-
Article
Assignment of G-protein subtypes to specific receptors inducing inhibition of calcium currents
The inhibition of voltage-dependent Ca2+ channels in secretory cells by plasma membrane receptors is mediated by pertussis toxin-sensitive G proteins. Multiple forms of G proteins have been described, differing p...
-
Article
Different β-subunits determine G-protein interaction with transmembrane receptors
REGULATORY GTP-binding proteins (G proteins) are membrane-attached heterotrimers (α, β, γ) that mediate cellular responses to a wide variety of extracellular stimuli1,2. They undergo a cycle of guanine-nucleotide...
-
Article
The isoquinoline derivative LOE 908 selectively blocks vasopressin-activated nonselective cation currents in A7r5 aortic smooth muscle cells
The effect of (R,S)-(3,4-dihydro6,7-dimethoxyisoquinoline-1-yl)-2-phenyl-N,N-di- [2- (2, 3,4-trimethoxyphenyl)ethyl]-acetamide (LOE 908), a cation channel blocker in HL-60 promyeloblasts, was studied in the A7r5 ...
-
Article
DC electrical field-induced c-fos expression and growth stimulation in multicellular prostate cancer spheroids
The effects of electrical direct current (DC) field pulses on c-fos expression, growth kinetics and vitality patterns of multicellular tumour spheroids (MCSs) were studied. Monitoring the membrane potential of...
