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Pitfalls using metalloporphyrins in carbon monoxide research
The proposal that endogenously produced carbon monoxide (CO) may act as a biological messenger has remained controversial. Carbon monoxide is generated by haem oxygenase isoenzymes in the degradation of haem-containing molecules. Certain metalloporphyrins, which are inhibitors of haem oxygenase, have been widely used as pharmacological tools in order to establish a messenger role for CO in the bra
Localization and activity of haem oxygenase and functional effects of carbon monoxide in the feline lower oesophageal sphincter
1. In the feline lower oesophageal sphincter (LOS), the distribution of the carbon monoxide (CO) producing enzymes haem oxygenase (HO)-1 and -2 was studied by immunohistochemistry and confocal microscopy, the HO activity was measured and the possible role for CO as a mediator of relaxation was investigated. 2. HO-2 immunoreactivity was abundant in nerve cell bodies of the submucosal and myenteric
Effects of the neuropeptide Y (NPY)-receptor antagonist BIBP3226 on vascular NPY-receptors with different ligand requirements
The aim was to examine effects of a newly developed neuropeptide Y (NPY)-receptor antagonist, BIBP3226 and to characterize NPY-receptors in the isolated guinea pig caval vein and human subcutaneous artery, respectively. BIBP3226 < or = 1 microM did not affect the basal tension. Pretreatment with increasing concentrations of BIBP3226 (10 nM-1 microM) resulted in a progressive rightward shift of the
Carbon monoxide as a putative messenger molecule in the feline lower oesophageal sphincter of the cat
The distribution of the carbon monoxide (CO) producing enzymes haem oxygenase (HO) type 1 and 2 were studied in the feline lower oesophageal sphincter (LOS), as were HO activity and functional effects of CO. HO-2 immunoreactivity was observed in nerve cell bodies in the submucosal and myenteric plexus, nerve fibres, non-neuronal cells surrounding smooth muscle bundles, and in arterial endothelium,
Ligand binding and functional effects of systematic double D-amino acid residue substituted neuropeptide Y analogs on Y1 and Y2 receptor types
In order to identify the signal epitopes of the neuropeptide Y (NPY) molecule, the conformation of the NPY molecule was pertubated by a systematic double D-amino acid replacement of neighbouring residues. These NPY-analogs were examined for receptor affinity and on biological activity. The rat cerebral cortex and hippocampus were used for binding characteristics on Y1 and Y2 binding sites, respect
Modulation of carbon monoxide production and enhanced spatial learning by tin protoporphyrin
Endogenous carbon monoxide (CO), produced by haem oxygenase (HO), may play a role in hippocampal long-term potentiation (LTP). Its role in learning and memory in intact animals is less well known. Tin protoporphyrin (Sn-PP; 25 mg kg-1, i.p.) effectively but transiently inhibited HO activity in brain homogenates, and improved acquisition in the Morris water maze. Locomotor activity was unaffected,
Haem oxygenase activity in blood vessel homogenates as measured by carbon monoxide production
Risks in combination therapy of antidepressant drugs
Quantitative SO2 Detection in Combustion Environments Using Broad Band Ultraviolet Absorption and Laser-Induced Fluorescence
Spectrally resolved ultraviolet (UV) absorption cross sections of SO2 in combustion environments at temperatures from 1120 to 1950 K were measured for the first time in well-controlled conditions through applying broad band UV absorption spectroscopy in specially designed one-dimensional laminar flat flames. The temperature was observed to have a significant effect on the absorption cross-section
Neuropeptide Y and truncated neuropeptide Y analogs evoke histamine release from rat peritoneal mast cells. A direct effect on G proteins?
Several regulatory peptides, including neuropeptide Y, can release histamine from mast cells. In the present study we investigated which parts of the neuropeptide Y molecule are required to evoke the release of histamine from isolated rat peritoneal mast cells. In addition, we examined whether the histamine release evoked by neuropeptide Y (and by compound 48/80) is sensitive to the G protein inhi
Neuropeptide Y effector systems : perspectives for drug development
Neuropeptide Y was isolated in 1982 and has since attracted considerable interest. It is widely distributed in central and peripheral neurones and can produce a multitude of biological effects in the brain and the periphery. For example, the peptide has been associated with stimulation of food and water intake, control of mood, and regulation of central autonomic functions. In the periphery, sympa
Inhibition by zinc protoporphyrin-IX of receptor-mediated relaxation of the rat aorta in a manner distinct from inhibition of haem oxygenase
1. Carbon monoxide (CO), produced by haem oxygenase through degradation of haem, has been claimed to be a neuromessenger and a possible regulator of vascular tone. We examined whether the haem oxygenase inhibitor, zinc protoporphyrin-IX (ZnPP) and other porphyrins affect the relaxation evoked by various agents in the rat isolated aorta. 2. Pretreatment with ZnPP (0.1 mM) virtually abolished the re
Functional effects and ligand binding of chimeric galanin-neuropeptide Y (NPY) peptides on NPY and galanin receptor types
1. The effects and binding characteristics of a series of chimeric galanin-neuropeptide Y (NPY) peptides were examined in various preparations known to contain a predominant population of either Y1 or Y2 receptors for NPY or galanin receptors. 2. NPY suppressed the electrically stimulated twitches of the rat vas deferens (Y2 receptors), while galanin enhanced the electrically stimulated twitches.
Synthesis and Applications of III-V Nanowires
Low-dimensional semiconductor materials structures, where nanowires are needle-like one-dimensional examples, have developed into one of the most intensely studied fields of science and technology. The subarea described in this review is compound semiconductor nanowires, with the materials covered limited to III-V materials (like GaAs, InAs, GaP, InP,...) and III-nitride materials (GaN, InGaN, AlG
Multiple neuropeptide Y receptors are involved in cardiovascular regulation. Peripheral and central mechanisms
1. Neuropeptide Y (NPY) occurs in both the central and peripheral nervous system. In the periphery, NPY coexists with noradrenaline (NA) in perivascular sympathetic fibers. 2. NPY has a vasopressor effect, reflecting direct vasoconstriction of blood vessels and potentiation of the NA-evoked response. NPY also suppresses the release of NA from sympathetic fibers. 3. The post- and pre-junctional NPY
Activation of neuropeptide Y1 and neuropeptide Y2 receptors by substituted and truncated neuropeptide Y analogs : identification of signal epitopes
Neuropeptide Y (NPY-(1-36)) acts on Y1 and Y2 receptors at the sympathetic neuroeffector junction. Various truncated NPY analogs were tested in the isolated guinea-pig caval vein where NPY is a vasoconstrictor (Y1 receptors) and in isolated rat vas deferens, by monitoring the suppression of electrically evoked contractions (Y2 receptors). The aim of this study was to define which parts of the NPY-
Neuropeptide Y suppresses the neurogenic inflammatory response in the rabbit eye; mode of action
Ocular injury in the rabbit causes miosis and breakdown of the blood aqueous barrier (aqueous flare response, AFR), reflecting a sensory nerve-mediated inflammatory response, elicited by the release of tachykinins and calcitonin gene-related peptide (CGRP) from C-fibers. Neuropeptide Y (NPY) occurs in sympathetic fibers in the eye. The study was designed to examine whether NPY and related peptides
Unmasking the vasoconstrictor response to neuropeptide Y and its interaction with vasodilating agents in vitro
Neuropeptide Y (NPY) is a powerful vasoconstrictor in vivo but is usually much less active on isolated blood vessels. The contractile effect of NPY was examined in the isolated rat femoral artery exposed to various degrees of vasoconstriction. The effects of NPY on the relaxation induced by vasodilator agents was also studied. NPY (< or = 1 microM) had no contractile effect. In vessels pretreated
Unlike VIP, the VIP-related peptides PACAP, helodermin and helospectin suppress electrically evoked contractions of rat vas deferens
We have compared the effects of vasoactive intestinal peptide (VIP) and of the VIP-related peptides pituitary adenylate cyclase activating peptide (PACAP) 1-27 and 1-38, helodermin, helospectin I and helospectin II, on the electrically evoked twitches in the isolated vas deferens of the rat. While VIP was virtually without effect, PACAP 1-38 suppressed the electrically evoked twitches effectively