Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of glucagon and secretin on food- or morphine-induced motor activity of the distal colon, rectum, and internal anal sphincter were investigated in 12 healthy subjects. Intraluminal pressure changes were measured using a triple-lumen polyvinyl tube assembly with 3 side orifices. Glucagon, administered intravenously, caused significant inhibition of food- or morphine-induced motor activity of both the distal colon and rectum. In contrast, secretin did not suppress morphine-induced motor activity but did significantly inhibit food-stimulated motor activity of the distal colon. The inhibitory effect of secretin on motor activity of the rectum was insignificant. Morphine, but not food, elevated the pressure of the anal sphincter which was not effected by glucagon or secretin. Hyperglycemia, produced by the infusion of 5% glucose, had no effect on motor activity. These studies demonstrate that glucagon but not secretin, in the doses employed, inhibits morphine-induced motor wave activity of both the distal colon and rectum and that this inhibitory effect is not secondary to hyperglycemia. Furthermore, the rise in anal sphincter pressure is not affected by glucagon or secretin.
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PMID:Effects of glucagon and secretin on food- or morphine-induced motor activity of the distal colon, rectum, and anal sphincter. 90 92

The sphincter of Oddi is the smooth muscle connection between the bile duct and the duodenum. Its physiological function is associated with a regular motility characterized by phasic contractions superimposed on the sphincter of Oddi baseline pressure. Recently introduced ERCP-manometry permits further studies of sphincter of Oddi pharmacology. A number of drugs have so far been studied. Sedatives of the diazepam type had no effect on the sphincter, while butylscopolaminium bromide, a typical neurotropic agent, brings about cessation of the sphincter motility for 3-8 minutes. Hymecromon lowered the sphincter baseline pressure from 9.8 to 7.8 mmHg. A 1.2 mg sublingual dose of nitroglycerin, a typical musculotropic agent, caused significant relaxation of the sphincter, and decreased baseline pressure from 8.9 mmHg to 2.9 mmHg; Sphincter motility was not affected. Morphine-like analgetics, in particular pentazocine, elevated sphincter baseline pressure, but buprenorphine and tramadol did not. Pharmacological doses of gastrointestinal hormones also affect the sphincter; CCK octapeptide, glucagon and secretin are able to decrease sphincter of Oddi baseline pressure, and CCK octapeptide abolishes sphincter motility. Sphincter of Oddi pharmacology is of clinical interest. The administration of sphincter-relaxing agents, in particular nitroglycerin and butylscopolaminium bromide, enables the endoscopist to extract small common bile duct stones without previous papillotomy. Analgetics that induce sphincter contraction and thus hinder the flow of bile and pancreatic juice, may be helpful for the treatment of pain in patients with pancreatico-biliary disease. Investigations into the effect of CCK on the healthy and diseased sphincter permit us to identify patients with sphincter dysfunction using a special CCK-provocation test.
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PMID:Pharmacology of the sphincter of Oddi. 304 55

This study was designed to assess the effects of morphine sulfate on glucose kinetics and on glucoregulatory hormones in conscious overnight fasted dogs. One group of experiments established a dose-response range. We studied the mechanisms of morphine-induced hyperglycemia in a second group. We also examined the effect of low dose morphine on glucose kinetics independent of changes in the endocrine pancreas by the use of somatostatin plus intraportal replacement of basal insulin and glucagon. In the dose-response group, morphine at 2 mg/h did not change plasma glucose, while morphine at 8 and 16 mg/h caused a hyperglycemic response. In the second group of experiments, morphine (16 mg/h) caused an increase in plasma glucose from a basal 99 +/- 3 to 154 +/- 13 mg/dl (P less than 0.05). Glucose production peaked at 3.9 +/- 0.7 vs. 2.5 +/- 0.2 mg/kg per min basally, while glucose clearance declined to 1.7 +/- 0.2 from 2.5 +/- 0.1 ml/kg per min (both P less than 0.05). Morphine increased epinephrine (1400 +/- 300 vs. 62 +/- 8 pg/ml), norepinephrine (335 +/- 66 vs. 113 +/- 10 pg/ml), glucagon (242 +/- 53 vs. 74 +/- 14 pg/ml), insulin (30 +/- 9 vs. 10 +/- 2 microU/ml), cortisol (11.1 +/- 3.3 vs. 0.9 +/- 0.2 micrograms/dl), and plasma beta-endorphin (88 +/- 27 vs. 23 +/- 6 pg/ml); all values P less than 0.05 compared with basal. These results show that morphine-induced hyperglycemia results from both stimulation of glucose production as well as inhibition of glucose clearance. These changes can be explained by rises in epinephrine, glucagon, and cortisol. These in turn are part of a widespread catabolic response initiated by high dose morphine that involves activation of the sympathetic nervous system, the endocrine pancreas, and the pituitary-adrenal axis. Also, we report the effect of a 2 mg/h infusion of morphine on glucose kinetics when the endocrine pancreas is clamped at basal levels. Under these conditions, morphine exerts a hypoglycemic effect (25% fall in plasma glucose, P less than 0.05) that is due to inhibition of glucose production (by 25-43%, P less than 0.05). The hypoglycemia was independent of detectable changes in insulin, glucagon, epinephrine and cortisol, and was not reversed by concurrent infusion of a slight molar excess of naloxone. Therefore, we postulate that the hypoglycemic effect of morphine results from the interaction of the opiate with non-mu receptors either in the liver or the central nervous system.
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PMID:Effects of morphine on glucose homeostasis in the conscious dog. 614 57

Insulin and glucagon release from monolayer pancreatic islet cell cultures were inhibited in a dose-response fashion by various enkephalins. Morphine, however, stimulated insulin and glucagon release. Both effects were blocked by naloxone, while naloxone alone had no effect. In isolated and denervated islet cells, opiates directly influence secretion from islet cells.
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PMID:Disparate effects of enkephalin and morphine upon insulin and glucagon secretion by islet cell cultures. 699 19

In rats weighing 200-250 g catheters were placed in the internal jugular vein and carotid artery. After 1 week of accommodation the training for the experimental situation, morphine (10 mg kg-1) was injected intravenously alone or in combination with naloxone (0.04 mg ml-1, 0.8 ml h-1). Otherwise no form of anaesthesia was used during the experiments. In control fed and fasted rats, there were no significant differences in blood glucose. In fed rats, morphine increased blood glucose as compared to control rats (p < 0.001). This was not seen in the fasted rats. The morphine induced increase in blood glucose in the fed rats was abolished by naloxone (p < 0.001). Glucagon was significantly higher in fasted than in fed control rats (p < 0.01). It was significantly increased after morphine in fed (p < 0.05), but not in fasted rats. The morphine induced increase in glucagon in fed rats was abolished by naloxone (p < 0.01). Insulin was significantly higher in fed than in fasted control rats (p < 0.05). Morphine increased insulin levels significantly in fed and fasted rats (p < 0.001), p < 0.01). The morphine induced increase in insulin in the fed rats was abolished by naloxone treatment. It is concluded that morphine stimulates glucose and glucagon release in fed but not fasted rats, and that these increases are caused by opioid action. Insulin increases after morphine were proved to be opioid-mediated only in the fed state.
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PMID:Morphine and morphine/naloxone modification of glucose, glucagon and insulin levels in fasted and fed rats. 814 Mar 90

Modification of pharmacological effects of morphine by its glucuronides has been recently reported. Morphine-6-glucuronide (M6G) is a more potent opioid agonist than morphine, whereas morphine-3-glucuronide (M3G) has no opioid effects and has been suggested to be an antagonist of morphine's antinociceptive and respiratory depressive effects. This study addressed the metabolic effects of direct central nervous system administration of M3G and its interaction with the hyperglycemic effects of M6G. Hormonal and whole body glucose metabolic effects of M3G, M6G, and M3G + M6G ICV administration were studied in conscious unrestrained chronically catheterized rats. Whole body glucose kinetics were assessed with a primed constant intravenous infusion of 3[3H]glucose in rats injected intracerebroventricularly (ICV) with H2O (5 microliters), M3G (1 microgram), M6G (1 microgram), or M3G (1 microgram) + M6G (1 microgram). A significant rise in plasma glucose level was observed after ICV injection of M6G (28%), and M3G + M6G (41%), but not after M3G as compared to time-matched H2O control. Early increases in the rate of glucose appearance (Ra) and whole body glucose utilization (Rd) were observed (58% and 48%, respectively) 30 min after M3G + M6G administration, whereas the increases after M6G injection were progressive and reached values 47% higher than basal 180 min after injection. M3G administration enhanced the M6G induced increase in plasma glucose level (+21%), Ra (+29%), Rd (+26%), and plasma lactate level (+21%). Though no significant hormonal change was observed in H2O, M3G, and M6G injected animals, the combination of M3G + M6G resulted in a significant increase in circulating catecholamine levels with no alterations in plasma corticosterone, insulin, and glucagon.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Modulation of metabolic effects of morphine-6-glucuronide by morphine-3-glucuronide. 853 54

Previous studies have indicated that excitatory amino acids are involved in the analgesic and addictive properties of morphine. However, their role in the morphine-induced alterations in glucose metabolism is not known. This study assessed the contribution of NMDA receptor activation to the morphine-induced hormonal and metabolic alterations in conscious unrestrained chronically catheterized rats. Whole body glucose flux was assessed with a primed constant intravenous infusion of [3-3H]glucose in rats pretreated with the NMDA-receptor antagonist MK-801 (0.25 mg/kg, intraarterial) or an equal volume (1.5 ml) of sterile saline (0.9%) administered 15 min prior to i.c.v. injection of H2O (Con; 5 microliters) or morphine sulfate (80 micrograms). No significant alterations were noted in metabolic and hormonal parameters of H2O injected rats. i.c.v. morphine increased the plasma glucose concentration (60%), hepatic glucose production (Ra; 60%) and whole body glucose utilization (Rd; 53%), but did not alter the glucose metabolic clearance rate (MCR). MK-801 alone resulted in transient hyperglycemia (25%), stimulation of glucose Ra (60%) and glucose Rd (53%), and a significant (30%) increase in MCR. MK-801 pretreatment blunted the morphine-induced hyperglycemia and the increased glucose Ra and Rd. Morphine increased the plasma concentration of epinephrine (4-fold), norepinephrine (2-fold) and corticosterone (67%); however, no alterations in plasma insulin and glucagon were detected. MK-801 pretreatment, blunted the morphine-induced increase in corticosterone and norepinephrine, and elicited a significant rise in insulin concentrations. These results indicate that activation of the NMDA receptors contributes to the morphine-induced hyperglycemia and hormonal alterations. Furthermore, this response appears partially mediated by activation of sympathetic outflow and suppression of insulin release, which is blunted by inhibition of NMDA receptors.
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PMID:Contribution of excitatory amino acids to morphine-induced metabolic alterations. 872 Apr 99

The effects of intrathecal (i.t.) morphine (25-100 micrograms) and of the intraperitoneal (i.p.) xanthan gum (30, 60 micrograms/kg) on blood glucose were studied in nonfasted rats. Morphine produced a time and dose-dependent hypoglycemia, whereas xanthan caused moderate decrease effect on blood glucose. Morphine and xanthan appears to be acting by different mechanisms, although the hypoglycemic effects of morphine appear to be due largely to an increased glucose uptake by skeletal muscle. Xanthan has a slow onset of hypoglycemic action which may allow homeostatic mechanisms to intervene. On the other hand, glucagon was increased significantly after i.t. morphine (50 micrograms) both at 30 and 60 min. The hyperglucagonaemic response after morphine may be due to a direct opioid effect on pancreas. The i.t. administration of morphine (50 micrograms) caused time-dependent decrease in liver and muscle glycogen levels in morphine-treated rats compared with saline-controlled rats. The data obtained point to the occurrence of active utilization of liver and muscle glycogen (glycogenolysis) in morphinized animals which is in concomitant with hypoglycemia and increased glucagon level recorded during the present work.
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PMID:Effect of intrathecal morphine on blood glucose, glucagon and tissue glycogen in rat: comparison with the effect of xanthan gum on blood glucose. 883 Nov 83