الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
Opioid analgesics are used widely to control various types of pain. Several studies reported that they may produce lowering of plasma glucose. The present work aims to study the effect of both tramadol and fentanyl on the plasma glucose and liver glycogen of STZinduced diabetic rats and uncover the possible mechanism of this effect. Experimental diabetes was induced by single I.P injection of STZ in a dose of 45 mg/ kg in albino rats. All animals were subjected to assessment of pain tolerance using Basile AnalgesyMeter apparatus, detection of plasma glucose with glucoxidase test, and glycogen detection using anthrone reagent. I.V injection of either tramadol or fentanyl produced significant increase in pain tolerance. I.V naloxone partially block analgesic effect of tramadol while, analgesic effect of fentanyl was completely blocked by naloxone. I.V administration of either tramadol or fentanyl for 4 successive days in STZinduced diabetic rats produced significant reduction in fasting and random plasma glucose on comparison with non treated STZinduced diabetic rats. Naloxone blocks the effect of both tramadol and fentanyl on fasting and random plasma glucose. I.V injection of either tramadol or fentanyl in STZinduced diabetic rats for 4 successive days produced significant recovery of glycogen content of the liver in diabetic rats compared with diabetic non treated group. This effect was also blocked by I.V naloxone administration 30 min before administration of either tramadol or fentanyl. The histochemical examination of PAS stained sections of the liver, prepared from rats used during this work, confirmed the results obtained by chemical detection of glycogen content of the liver homogenate. Finally, these data suggested that both tramadol and fentanyl have a significant anti hyperglycemic effect. This effect is through activation of MOP receptors which may be mediated through increased glycogen deposition in the liver. Furthermore, these data confirmed pervious report which stated that analgesic effect of tramadol is mediated through opioid and non opioid mechanisms.