Martin Johannes Bek

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Dopamine is an important transmitter in the CNS and PNS, critically regulating numerous neuropsychiatric and physiological functions. These actions of dopamine are mediated by five distinct receptor subtypes. Of these receptors, probably the least understood in terms of physiological functions is the D5 receptor subtype. To better understand the role of the(More)
Podocyte injury is a central mechanism in the pathogenesis of proteinuria. Prostaglandin E 2 (PGE 2) has been suggested to protect podocytes from cellular injury. Here we investigated whether PGE 2-induced gene expression accounts for the protective role of PGE 2 in podocytes. Using a suppressive-subtractive hybridization method, we isolated a(More)
Experimental and clinical studies impressively demonstrate that angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) significantly reduce proteinuria and retard progression of glomerular disease. The underlying intraglomerular mechanisms are not yet fully elucidated. As podocyte injury constitutes a critical step in the(More)
The effect of neuropeptide Y [NPY(1-36)] and related peptides on the voltage-dependent currents and the nicotinic acetylcholine receptor (nAChR) currents (IACh) of bovine adrenal chromaffin cells was investigated using the whole-cell patch clamp technique. Catecholamine release from single chromaffin cells was measured by means of fast cyclic voltammetry.(More)
Podocytes are the most differentiated cell types in the glomerulus, which have been assumed to participate in the regulation of the ultrafiltration coefficient K(f). In podocytes in vivo and in vitro vasoactive agonists, such as angiotensin II and acetylcholine, increase the free cytosolic Ca(2+) concentration via a release of Ca(2+) from intracellular(More)
The effects of acetylcholine (ACh) on the free intracellular calcium concentration ([Ca2+](i)) of microdissected glomeruli were investigated using fura-2 fluorescence digital imaging and two-photon confocal microscopy. ACh caused a concentration-dependent [Ca2+](i) increases with an initial peak followed by a sustained plateau, which was suppressed by(More)
BACKGROUND Dopamine influences glomerular haemodynamics and dopamine receptors have been demonstrated in the glomerulus, but little is known about the cellular effects of dopamine in glomerular cells. The aim of this study was to investigate the influence of dopamine on the cellular functions of podocytes. METHODS The effect of dopamine on membrane(More)
INTRODUCTION To evaluate the cause of methemoglobinemia in patients undergoing extended daily hemodialysis/hemodiafiltration we analyzed the relationship between methemoglobinemia and the water disinfection schedule of the hospital. METHODS We reviewed all arterial blood gas analyses, obtained over a one-year period, in patients undergoing extended(More)
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