Ariel Margulis

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Zinc maintains a diverse array of functions in the mammalian central nervous system as a key component of numerous enzymes, via its role in the activation of transcription factors, and as a neuroregulator, modulating neuronal receptors such as N-methyl-D-aspartate and gamma-aminobutyric acid. Zinc has a dark side, however, with massive influx of Zn(2+) to(More)
Cyclic-GMP, which plays a pivotal role in visual transduction in the vertebrate retina, is synthesized by guanylate cyclase. The purpose of this study was to localize a rod outer segment-derived particulate guanylate cyclase (ROS-GC) to the retina of several species that have different populations of rods and cones. A rabbit antibody was raised against a(More)
BACKGROUND The clinical usefulness of intravenous thrombolytic therapy in unstable angina is currently unknown, despite the pathogenetic similarity of this entity to acute myocardial infarction, for which thrombolysis has enjoyed great success. To compare the clinical benefit of intravenous urokinase with that of conventional antithrombotic therapy in(More)
Cyclic GMP has been shown in recent years to directly activate ion channels in bipolar and ganglion cells, and to indirectly regulate coupling between horizontal cells, and between bipolar and amacrine cells. In all of these cases, the effects of cyclic GMP are mimicked by nitric oxide. An increase in calcium concentration stimulates the production of(More)
Dopamine is a major neurotransmitter and neuromodulator in vertebrate retina. Although its pharmacological and physiological actions are well understood, the biochemical mechanisms of its signal transduction are less clear. Acting via D1 receptors, dopamine was shown to increase cyclic AMP levels in intact retina and to activate adenylate cyclase in retinal(More)
1. Lithium was known to inhibit both adrenergic and cholinergic agonist-induced activation of G-proteins in cerebral cortex. 2. Doly et al (1989) observed that lithium reduced the b-wave of the electroretinogram and suggested that the effect was due to inhibition of G-protein in photoreceptor cells. 3. This study was undertaken to test this hypothesis(More)
A large amount of information regarding the kinetics of biochemical reactions involved in visual transduction was derived from electrophysiological studies on dark-adapted rod outer segments. Hodgkin et al. [(1985) J. Physiol. 358, 447-468] observed that when Na was replaced with Li in the perfusion solution bathing the rod outer segment, the dark current(More)
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