Learn More
Puzzled by recent reports of differences in specific ligand binding to muscle Ca2+ channels, we quantitatively compared the flux of Ca2+ release from the sarcoplasmic reticulum (SR) in skeletal muscle fibers of an amphibian (frog) and a mammal (rat), voltage clamped in a double Vaseline gap chamber. The determinations of release flux were carried out by the(More)
1. Fluo-3 fluorescence associated with Ca2+ release was recorded with confocal microscopy in single muscle fibres mechanically dissected from fast twitch muscle of rats or frogs, voltage clamped in a two Vaseline-gap chamber. 2. Interventions that elicited Ca2+ sparks in frog skeletal muscle (low voltage depolarizations, application of caffeine) generated(More)
In both skeletal and cardiac muscle, the dihydropyridine (DHP) receptor is a critical element in excitation-contraction (e-c) coupling. However, the mechanism for calcium release is completely different in these muscles. In cardiac muscle the DHP receptor functions as a rapidly-activated calcium channel and the influx of calcium through this channel induces(More)
We had previously described the leucine-rich acidic nuclear protein (LANP) as a candidate mediator of toxicity in the polyglutamine disease, spinocerebellar ataxia type 1 (SCA1). This was based on the observation that LANP binds ataxin-1, the protein involved in this disease, in a glutamine repeat-dependent manner. Furthermore, LANP is expressed abundantly(More)
The purpose of this study was to characterize excitation-contraction (e-c) coupling in myotubes for comparison with e-c coupling of adult skeletal muscle. The whole cell configuration of the patch clamp technique was used in conjunction with the calcium indicator dye Fluo-3 to study the calcium transients and slow calcium currents elicited by voltage clamp(More)
1. The Vaseline-gap voltage clamp technique was used to record dihydropyridine (DHP)-sensitive Ca2+ currents (ICa) and charge movement in single cut fibres from the rat extensor digitorum longus (EDL) muscle. Amyotrophic lateral sclerosis (ALS) immunoglobulin G (IgG) action on ICa and charge movement has been characterized. 2. ALS IgG reduced ICa amplitude.(More)
Ca2+ currents (ICa) and myoplasmic Ca2+ transients were simultaneously recorded in single muscle fibers from the semitendinosus muscle of Rana pipiens. The vaseline-gap voltage-clamp technique was used. Ca2+ transients were recorded with the metallochromic indicator dye antipyrylazo III. Ca2+ transients consisted of an early fast rising phase followed by a(More)
Differential effects of n-3 and n-6 polyunsaturated fatty acids (PUFAs) have been demonstrated on adipose tissue physiology. Facing to the widely recognized beneficial effects of n-3 PUFAs, the n-6 PUFA effects remain controversial. Thus, we further analyzed the linoleic acid (LA) influence on adipocyte functions. To this aim, we treated by LA(More)
1. Charge movement and myoplasmic calcium transients were simultaneously recorded from frog skeletal muscle fibres by using the double-seal Vaseline-gap technique. Calcium transients were monitored with the fluorescent indicator Rhod-2. 2. Ryanodine modified the kinetics and the total amount of charge moved during depolarizing pulses (Q(on)), while it did(More)
Proneural factors represent <10 transcriptional regulators required for specifying all of the different neurons of the mammalian nervous system. The mechanisms by which such a small number of factors creates this diversity are still unknown. We propose that proteins interacting with proneural factors confer such specificity. To test this hypothesis we(More)