Michael K Herbert

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The effect of histamine on the sensory activity of primary afferents was studied in normal and acutely inflamed cat knee joints. A subpopulation of groups III and IV articular afferents could be activated by close-arterial bolus injections of histamine: units with a high resting activity (about 100/min) were particular sensitive to histamine and were(More)
Primary afferent neurons, originating from the dorsal root ganglia, provide a perivascular network of fibres around the arterial system throughout the body. When stimulated, these fibres cause a nonadrenergic noncholinergic (NANC) vasodilatation by release of calcitonin gene-related peptide (CGRP). This peptide is a potent vasodilator and, in this action,(More)
Inhibition of gastrointestinal motility is a major problem in critically ill patients. Motor stasis gives rise to subsequent complications including intolerance to enteral feeding, enhanced permeability of the atrophic intestinal mucosa and conditions as severe as systemic inflammatory response syndrome, sepsis and multiple organ failure. Although the(More)
Activation of sensory unmyelinated neurons by noxious stimuli evokes the release of neuropeptides, such as substance P and calcitonin gene-related peptide (CGRP) from peripheral nerve endings. These neuropeptides and subsequently released mediators cause a local oedema, hyperaemia and an erythema which extends beyond the site of stimulation (so-called flare(More)
Calcitonin gene related peptide (CGRP) is the major mediator of afferent nerve mediated vasodilatation in the gastric mucosa and skin of the rat. Since receptors for CGRP occur on both the vascular endothelium and smooth muscle, it is conceivable that the vascular actions of CGRP involve multiple mechanisms. The vasodilator effect of rat CGRP-alpha in the(More)
1. This study examined the effect of interleukin-1 beta (IL-1 beta) on the capsaicin-induced increase in cutaneous blood flow of anaesthetized rats as measured by laser Doppler flowmetry. 2. The substances were administered by intraplantar subcutaneous injection of 10 microliters-volumes, saline being injected into one hindpaw and IL-1 beta into the other.(More)
Inhibition of intestinal peristalsis is a major side effect of opioid analgesics. It is unknown whether non-opioid analgesics, such as acetaminophen, acetylsalicylic acid, and dipyrone, exert any effect on intestinal motility. In the current in vitro study we examined the effect of these analgesics on intestinal peristalsis and analyzed some of their(More)
In cats anesthetized with alpha-chloralose, extracellular recordings were made from fine afferent units belonging to the medial articular nerve (MAN) of the knee joint. The excitatory and sensitizing effects on articular afferents of serotonin (5-HT) applied intra-arterially close to the joint were examined. The joints were either normal or an experimental(More)
BACKGROUND Inhibition of intestinal peristalsis is a major side effect of opioid analgesics. Although tramadol is an opioid-like analgesic, its effect on gut motility is little known. Therefore, the effect of (+)-tramadol, (-)-tramadol and the major metabolite O-desmethyltramadol on intestinal peristalsis in vitro and their mechanisms of action were(More)
The undecapeptide substance P is expressed by primary afferent neurons where it is considered to be a cotransmitter of other peptides and glutamate. Since it is predominantly found in sensory neurons with unmyelinated fibres (C-fibres), substance P has long been thought to be a "pain transmitter". Following stimulation of nociceptive afferents, substance P(More)