Articles: histamine.
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Acta Anaesthesiol Scand · Aug 1998
Inhibited hypothalamic histamine metabolism during isoflurane and sevoflurane anesthesia in rats.
Histamine is most densely distributed in the hypothalamus and has an important effect on consciousness or wakefulness. It has been little considered whether general anesthetics could exert their effects on hypothalamic histamine metabolism. The present study was conducted to investigate the effects of isoflurane and sevoflurane anesthesia on hypothalamic histamine metabolism. ⋯ Histamine metabolism was inhibited during both isoflurane and sevoflurane anesthesia and accelerated only in the posterior hypothalamus during the emergence from these anesthetics.
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Arch. Dermatol. Res. · Jun 1998
Randomized Controlled Trial Clinical TrialEffect of topical capsaicin on the cutaneous reactions and itching to histamine in atopic eczema compared to healthy skin.
Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide) is thought to produce analgesic and possibly also antipruritic effects when applied topically. Capsaicin 0.05% was applied three times daily over a 5-day period to the same infrascapular region. The effects of the pretreatment upon the pruritogenic and wheal and flare reactions to subsequent histamine iontophoresis (20 mC) were evaluated on the following day. ⋯ Itch sensations in capsaicin-pretreated skin were significantly lower in control subjects than in AE patients. We conclude that capsaicin does effectively suppress histamine-induced itching in healthy skin but has less effect in AE. The diminished itch sensations and the absence of alloknesis in atopic individuals indicate that histamine is not the key factor in itching in AE.
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Anasthesiol Intensivmed Notfallmed Schmerzther · Jun 1998
Randomized Controlled Trial Comparative Study Clinical Trial[Histamine plasma concentration and cardiovascular effects of non-depolarizing muscle relaxants: comparison of atracurium, vecuronium, pancuronium and pipecuronium in coronary surgical patients at risk].
Cardiovascular effects of four commonly used non-depolarising muscle relaxants and their ability to increase histamine plasma concentrations were studied in patients scheduled for coronary artery bypass grafting. ⋯ All investigated neuromuscular blocking agents exhibited marked cardiovascular stability which permits their use, being based exclusively on pharmacodynamic and pharmakokinetic considerations even in patients with coronary heart disease. If an increase in heart rate appears beneficial Pancuronium may be advantageous.
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Acta Derm. Venereol. · Mar 1998
Histamine and cutaneous nociception: histamine-induced responses in patients with atopic eczema, psoriasis and urticaria.
Having observed altered itch and flare reactions after histamine application in patients with atopic eczema, we tried to determine these reactions in patients with urticaria and psoriasis. We investigated 16 healthy non-atopic subjects, 16 atopics in an eczema-free interval, 16 with acute atopic eczema, 16 with urticaria and 16 with psoriasis. Histamine was iontophoretically applied. ⋯ However, flares were "normal" in symptom-free atopics and were not significantly different from controls. In conclusion, all "acute" patients showed a diminished axon-reflex function, possibly due to a downregulation of C-fiber responsiveness to histamine or an increased turnover rate of inflammatory mediators. Both atopic groups reported weaker itching, suggesting altered central nervous processing of itch.
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J. Invest. Dermatol. · Feb 1998
Randomized Controlled Trial Clinical TrialCutaneous responses to endothelin-1 and histamine in patients with vibration white finger.
Vibration white finger (VWF) is the episodic blanching of the fingers that occurs in response to cold in those who work with hand-held vibrating tools. Clinically the condition differs from primary Raynaud's phenomenon as persistent pain and paresthesia are common in the hands and arms and occur independently of the "white attacks." We have previously reported a decrease in protein gene product 9.5 and calcitonin gene-related peptide-immunoreactive nerve fibers in the digital skin of individuals with VWF. In this study, we have sought to determine whether this deficit of immunoreactive sensory-motor nerves has a functional counterpart in vivo. ⋯ In contrast, the area of erythema induced by intradermal injection of calcitonin gene-related peptide at both 21 degrees C and 4 degrees C was of a similar size in patients with VWF and in heavy manual workers. These results indicate that the neuroneal deficit identified by immunohistochemistry in the digital skin of patients with VWF has a functional counterpart in vivo and is evident as a reduced ability to propagate an axon-reflex vasodilator response when challenged with histamine and ET-1. Furthermore, these results enable patients with VWF to be differentiated from both asymptomatic vibration-exposed workers, in whom the histamine- and ET-1-induced flares are normal, and those with primary Raynaud's disease, in whom the ET-1 flare is reduced and the histamine-induced flare is normal.