Mt Garcia

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Calciseptine is a natural peptide consisting of 60 amino acids with four disulfide bonds. The peptide is a natural L-type Ca2+-channel blocker in heart and other systems, but its actions in skeletal muscle have not been previously described. The aim of this study is to characterize the effects of calciseptine on L-type Ca2+ channels of skeletal muscle and(More)
1. Modulation of fast and slow Ca2+ channels of frog skeletal muscle by adrenaline (10(-6) to 10(-5) M) and cyclic AMP was investigated using intracellular voltage recordings in intact fibres and a voltage-clamp technique in cut fibres. 2. In tetraethylammonium (TEA), Cl(-)-free Ringer solution, adrenaline increased the maximum rate of rise of Ca2+ spikes(More)
1. L-type Ca2+ channels play an important role in vital cell functions such as muscle contraction and hormone secretion. Both a voltage-dependent and a Ca2+-dependent process inactivate these channels. Here we present evidence that inhibition of the mitochondrial Ca2+ import mechanism in rat (Sprague-Dawley) ventricular myocytes by ruthenium red (RR), by(More)
The voltage-gated K+ channel Kv3.1 is expressed in skeletal muscle and in GABAergic interneurons in the central nervous system. Hence, the absence of Kv3.1 K+ channels may lead to a phenotype of myogenic or neurogenic origin, or both. Kv3.1-deficient (Kv3.1-/-) 129/Sv mice display altered contractile properties of their skeletal muscles and show poor(More)
A case of an unusual congenital intramedullary tumor of the spinal cord is reported. A paraplegic 11-day-old boy with hypotonia and atrophy of the abdominal and lower-extremity muscles showed a complete myelographic block between T-5 and T-8. Surgical exploration disclosed an elongated tumor mass within the spinal cord, that blended with the surrounding(More)
The effects of a long-term blockade of L-type Ca2+ channels on membrane currents and on the number of dihydropyridine binding sites were investigated in skeletal muscle fibers. Ca2+ currents (ICa) and intramembrane charge movement were monitored using a voltage-clamp technique. The peak amplitude of ICa increased by more than 40% in fibers that were(More)
A second-generation surveillance system of people infected with human immunodeficiency virus (HIV) has been implemented in Spain. Behavioural and clinical data were collected between 2002 and 2011 through an annual one-day, cross-sectional survey in public hospitals, including all in- and outpatients receiving HIVrelated care on the survey day. Mean age(More)
The effects of long-term depolarization on the level of alpha1s and on L-type Ca2+ currents of skeletal muscle were investigated. Long-term depolarization (14 h) caused a 50% decrease of alpha1s, revealed with the Western blot technique. This decline was prevented by preincubation with the Ca2+ channel blocker nifedipine. Electrophysiological experiments(More)
Voltage-clamp experiments using the three-microelectrode voltage clamp technique were performed on ventroabdominal flexor muscles of the crustacean Atya lanipes. Potassium and chloride currents were found to underlie the normal, passive response of the muscle. Blocking potassium currents with tetraethylammonium and replacing chloride ions with(More)
This study is an investigation into the modulatory effects of heparin, a component of the extracellular matrix that binds to dihydropyridine receptors, on contraction and Ca2+ channels in frog skeletal muscle. Using tension and Ca2+ signal measurements in single intact skeletal muscle cells we have found that heparin (100-200 micrograms ml-1) substantially(More)