CASTELLANO OROZCO , Antonio Gonzalo

El presente trabajo continua con una de las líneas de investigación de nuestro grupo que trata del estudio de las propiedades electrofisiológicas de neuronas del sistema nervioso central de mamíferos. Este estudio se inició en diferentes estructuras cerebrales, entre ellas el área septal, mediante la técnica de registro intracelular in vitro,...

Voltage-gated Na+ and Ca2+ conductances of freshly dissociated septal neurons were studied in the whole-cell configuration of the patch-clamp technique. All cells exhibited a large Na+ current with characteristic fast activation and inactivation time courses. Half-time to peak current at -20 mV was 0.44 +/- 0.18 ms and maximal activation of Na+...

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The interaction of thyrotropin-releasing hormone (TRH) and its physiological metabolite TRH-OH with Na+ channels was studied in enzymatically dissociated guinea pig septal neurons by using the whole-cell variant of the patch-clamp technique. In about 60% of the cells tested, the neuropeptides at concentrations between 0.01 and 2.5 ,uM produced...

Voltage-dependent K 1 channel gating is influenced by the permeating ions. Extracellular K 1 determines the occupation of sites in the channels where the cation interferes with the motion of the gates. When external [K 1] decreases, some K 1 channels open too briefly to allow the conduction of measurable current. Given that extracellular K 1 is...

Recent work has demonstrated the existence of regulatory K1 channel a-subunits that are electrically silent but capable of forming heterotetramers with other pore-forming subunits to modify their function. We have investigated the molecular determinant of the modulatory effects of Kv2.3, a silent K1 channel a-subunit specific of brain. This...

Early adaptive responses to hypoxia are essential for cell survival, but their nature and underlying mechanisms are poorly known. We have studied the post-transcriptional changes in the proteome of mammalian cells elicited by acute hypoxia and found that phosphorylation of eukaryotic elongation factor 2 (eEF2), a ribosomal translocase whose...

The physiological diversity of K1 channels mainly depends on the expression of several genes encoding different a-subunits. We have cloned a new K1 channel a-subunit (Kv2.3r) that is unable to form functional channels on its own but that has a major regulatory function. Kv2.3r can coassemble selectively with other a-subunits to form functional...

Background/Aims: Protein kinase C (PKC)- and RhoA/Rho-associated kinase (ROCK) play important roles in arterial sustained contraction. Although depolarization-elicited RhoA/ROCK activation is accepted, the role of PKC in depolarized vascular smooth muscle cells (VSMCs) is a subject of controversy. Our aim was to study the role of PKC in...

Background: Since 1994, over 50 families affected by the episodic ataxia type 1 disease spectrum have been described with mutations in KCNA1, encoding the voltage-gated K+ channel subunit Kv1.1. All of these mutations are either transmitted in an autosomal-dominant mode or found as de novo events. Methods: A patient presenting with a severe...

Voltage-dependent CaV1.2 L-type Ca2 channels (LTCC) are the main route for calcium entry in vascular smooth muscle cells (VSMC). Several studies have also determined the relevant role of store-operated Ca2 channels (SOCC) in vascular tone regulation. Nevertheless, the role of Orai1- and TRPC1-dependent SOCC in vascular tone regulation and...

SCN5A gene variants are associated with both Brugada syndrome and conduction disturbances, sometimes expressing an overlapping phenotype. Functional consequences of SCN5A variants assessed by patch‐clamp electrophysiology are particularly beneficial for correct pathogenic classification and are related to disease penetrance and severity. Here,...

Aneurysmal subarachnoid hemorrhage (aSAH) is a neurovascular disease produced by extravasation of blood to the subarachnoid space after rupture of the cerebral vessels. After bleeding, the immune response is activated. The role of peripheral blood mononuclear cells (PBMCs) in this response is a current subject of research. We have analysed the...

Aims: Urocortin-2 (Ucn-2) is a potent cardioprotector against Ischemia and Reperfusion (I/R) injuries. However, little is known about its role in the regulation of intracellular Ca2+ concentration ([Ca2+]i) under I/R. Here, we examined whether the addition of Ucn-2 in reperfusion promotes cardioprotection focusing on ([Ca2+]i handling. Methods...