Opiate-induced inhibition of the visceral distension reflex by peripheral and central mechanisms

  title={Opiate-induced inhibition of the visceral distension reflex by peripheral and central mechanisms},
  author={S. J. Clark and T. W. Smith},
  journal={Naunyn-Schmiedeberg's Archives of Pharmacology},
Summary1.Distension of the proximal ileum by elevation of the intraluminal pressure, caused a transient, reflex fall in blood pressure of urethane-anaesthetised rats. The threshold intraluminal pressure required to evoke a reflex response was increased by codeine, but not by the quaternary opiate agonist N-methylmorphine.2.The magnitude of the reflex hypotension was decreased by codeine, morphine and N-methylmorphine. The quaternary opiate antagonist N-methylnalorphine reduced the effects of N… Expand
Peripheral κ-opioid receptors mediate the antinociceptive effect of fetodozine on the duodenal pain reflex in rat
Abstract Fedotozine has been shown to act on gastrointestinal sensitivity through peripheral κ-opioid receptors. The present study investigated the action of fedotozine and reference compounds,Expand
Peripheral analgesic blockade of hypernociception: activation of arginine/NO/cGMP/protein kinase G/ATP-sensitive K+ channel pathway.
Analgesic stimulators of the neuronal arginine/NO/cGMP/PKG/K(ATP)(+) pathway constitute a previously undescribed well defined class of peripheral analgesics with a mechanism of action different from either glucocorticoids or inhibitors of cyclooxygenases. Expand
Experimental colitis alters visceromotor response to colorectal distension in awake rats
The influence of intermittent colorectal distension (CRD) on proximal colonic motility and abdominal pain perception was investigated in awake rats equipped with intraparietal electrodes on theExpand
Physiological and behavioural responses to duodenal pain in freely moving rats
It is reported here that silicone balloon catheters implanted in the duodenum via the stomach have long patency without obvious tissue damage, which should make long-lasting studies of pharmacological and environmental effects on visceral sensitivity more feasible. Expand
Models of Visceral Nociception


Visceral pain reflex after pretreatment with capsaicin and morphine
The initial pressor response to intestinal distension or to afferent periaterial mesenteric nerve stimulation persists in capsaicin desensitized rats excluding the involvement of C fibre afferents and in spinal rats indicating that the reflex centre is within the spinal cord. Expand
An etorphine-evoked vagal reflex in rats is inhibited by naloxone, N-methylnaloxone, and SMS 201-995.
Results indicate that N-methylnaloxone and SMS 201-995 can block the peripheral receptors which mediate opiate-induced bradycardia and completely antagonizes the cardiovascular and respiratory effects of etorphine. Expand
Quaternary opiate antagonists lower blood pressure and inhibit leucine-enkephalin responses.
The decrease in mean pressure induced by these antagonists coupled with the inhibition of the intravenous [Leu5]enkephalin response suggests that peripheral enkephalins may play a role in blood pressure regulation. Expand
Cardiovascular effects of intravenous morphine in the anaesthetized rat.
With high doses, direct cardiodepressant actions of morphine may contribute to the fall in blood pressure and there is also evidence of direct peripheral release of catecholamines. Expand
III - Prostaglandin hyperalgesia: relevance of the peripheral effect for the analgesic action of opioid-antagonists.
It was concluded that the site of analgesic action of opioid-antagonists is peripheral rather than central, and agents derived from morphine, morphine-antagonist, enkephalins or cGMP devoid of central effect but having a strong peripheral effect may constitute a new class of safer analgesics. Expand
Inhibition of peristaltic activity in the guinea-pig ileum by specific stress stimulus; its reversal by naloxone and indomethacin.
The response of the guinea-pig ileum to stress stimulation could be profoundly modified by an interference with endorphin and prostaglandin systems. Expand
Antagonism of gut, but not central effects of morphine with quaternary narcotic antagonists.
Naltrexone methylbromide effectively antagonizes the acute gut stimulating effect, but not the chronic behavioral effect of morphine administration in dogs, and does not cross the blood-brain barrier in rats but may in mice. Expand
The analgesic effect of quaternary analogues of morphine and nalorphine.
  • B. B. Lorenzetti, S. Ferreira
  • Chemistry, Medicine
  • Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas
  • 1982
It is concluded that quaternary analogues of morphine and nalorphine, which do not have central effects because they do not cross the blood-brain barrier, retain the peripheral analgesic effects of the parent compounds. Expand
A comparison of the pharmacologic effects of morphine and N-methyl morphine.
It is concluded that the modification of the morphine molecule does not necessarily destroy its pharmacologic actions once it has access to its receptor sites but the profound differences reported previously are due mainly to the inability of the charged N-methyl molecule to enter the central nervous system. Expand
II - Prostaglandin hyperalgesia: the peripheral analgesic activity of morphine, enkephalins and opioid antagonists.
It was suggested that the peripheral analgesic effect of morphine is due to an inhibition of adenylate-cyclase activity. Expand