Enkephalin inhibits the release and action of secretin on pancreatic secretion in the dog.

Chey, William Y.; Coy, David H.; Konturek, S J; Tasler, J

doi:10.1113/jphysiol.1980.sp013092

Cited by 21 publications

(7 citation statements)

References 12 publications

(8 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With reference to previous studies in various mammals, the present study has indicated that interspecific differences in the expression of Leu-Enk in mammalian pancreas are present. Similar immunohistochemical studies have identified Leu-Enk-IR nerve fibres near the acini, ducts, intrapancreatic neurons, and blood vessels of the pancreas of a number of species, including pigs (ADEGHATE et al, 1996), rats (SCHULTZBERG et al, 1980), guinea pigs (YALCIN, 1990;SCHULTZBERG et al, 1980) and dogs (CHEY et al, 1980). The present study provides an analysis of the distribution of LeuEnk-IR structures in the pancreas of sheep, and revealed that SOM, SP and GAL are coexpressed with Leu-Enk.…”

Section: Discussionsupporting

confidence: 80%

“…It has been postulated that Leu-Enk plays a role in the modulation and regulation of pancreatic hormone secretion (MILLAN and HERZ, 1985). The expression of Leu-Enk has been shown in the endocrine pancreas of various species, such as rats (TIMMERS et al, 1989;KHAWAJA et al, 1990;ADEGHATE and PONERY, 2001), guinea pigs (CETIN, 1990), pigs (ADEGHATE et al, 1996), cats (LARSSON, 1979) and dogs (CHEY et al, 1980), but sheep so far have not attracted researchers' interest. Therefore, the aim of the present immunofluorescence study was to examine the distribution pattern of neuronal elements containing Leu-Enk in the ovine pancreas.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Leucine-enkephalin is co-expressed with substance P, galanin and somatostatin in the ovine pancreas

2017

View full text Add to dashboard Cite

Leucine-enkephalin (Leu-Enk) is an endogenous opioid peptide that binds to opioid receptors. Leu-Enk is widely distributed in the central and peripheral nervous system. The aim of the present immunofluorescence study was to examine the distribution of Leu-Enk-immunoreactive (IR) neuronal elements in the ovine pancreas. Using double immunohistochemical staining, the co-localization of Leu-Enk with galanin, somatostatin and substance P was also studied. In the intrapancreatic ganglia, immunoreactivity to Leu-Enk was found in 64.9 ± 1.7% of neurons. Small arterioles and the ductal system were innervated by numerous Leu-Enk-IR nerve terminals. Moderate Leu-Enk-IR nerve fibres surrounded the islets of Langerhans but none of them penetrated into spaces between endocrine cells. In 66.7 ± 4.3% of Leu-Enk-immunoreactive intrapancreatic neurons, expression of galanin was found. A statistically smaller subpopulation of Leu-Enk-IR intrapancreatic neurons (37.4 ± 6.2%) exhibited immunoreactivity to SP. The expression of somatostatin was detected in the relatively smallest group (21.2 ± 3.8%) of Leu-Enk-positive intrapancreatic neurons. Co-expression of Leu-Enk and SP was detected in nerve terminals encircling the pancreatic small arterioles, connective tissue and ducts. LeuEnk-positive nerve fibres around the islets of Langerhans were not immunoreactive for SP. None of the Leu-ENK-positive nerve fibres around the islets of Langerhans co-stored somatostatin. In general, there was also no co-localization between Leu-Enk and somatostatin in nerve terminals supplying small arterioles and veins. Coexpression of GAL and Leu-Enk was observed well in nerve fibres encircling the blood vessels, but not in nerve fibres of the connective tissue. We conclude that abundant immunoreactivity to Leu-Enk in the ovine pancreas and the co-localization of Leu-Enk with other regulatory neuropeptides may reflect the possible involvement of Leu-Enk as a regulator of the exocrine and endocrine pancreatic functions, as well as in regulation of pancreatic blood flow.

show abstract

Section: Discussionsupporting

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Leucine-enkephalin is co-expressed with substance P, galanin and somatostatin in the ovine pancreas

2017

View full text Add to dashboard Cite

show abstract

“…Loperamide significantly (P õ .05) not only interacts with peripheral opiate receptors in the colon but also with opiate receptors in the proximal part of attenuated maximum gallbladder contraction in response to AID Hepa 0032 / 5p24$$$621 07-10-97 11:52:27 hepa WBS: Hepatology of CCK. 40,41 According to our data, the evidence in humans is otherwise because the release of CCK in response to a meal is enhanced by loperamide. A prolonged contact time between stimulating nutrients and CCK-secreting cells may be responsible for this enhanced release of CCK by loperamide because loperamide delays the passage of fluid through the intestine.…”

Section: Pmol/l) Duringmentioning

confidence: 99%

Inhibition of pancreaticobiliary secretion by loperamide in humans

et al. 1997

View full text Add to dashboard Cite

effects of loperamide on pancreaticobiliary functions are Loperamide, a peripherally acting opiate receptor agonist poorly investigated. Inhibition of gallbladder emptying or with antidiarrheal action, inhibits ileal and colonic motor pancreatic enzyme secretion by loperamide may have imfunction. It was determined whether loperamide also affects portant clinical implications because stasis of bile is a major gallbladder emptying and pancreatic enzyme secretion in hufactor contributing to the formation of gallstones 6-10 and bemans. Plasma cholecystokinin (radioimmunoassay), gallbladcause impairment of pancreatic enzyme secretion may induce der volume (ultrasonography), and intraduodenal bilirubin or aggravate maldigestion. 11-13 and amylase output (spot sampling) were measured at regularThe aim of this study, therefore, was to determine the intervals before and during intraduodenal perfusion of an effect of loperamide on basal and meal-stimulated gallbladder amino acid meal in 8 healthy subjects: once without and once motility and pancreatic enzyme secretion in healthy volunwith pretreatment of 8 mg loperamide, ingested 13 and 4 teers. Gallbladder emptying and pancreatic enzyme secretion hours before the start of the meal. Loperamide decreased were studied in response to an intraduodenal amino acid basal amylase output from 3.2 { 0.5 to 1.0 { 0.5 kU/h meal to circumvent possible influences of loperamide on gas-(P õ .005) and abolished basal bilirubin output (21 { 5 vs.tric emptying or on the digestion of nutrients. 14 0 { 0 mmol/h; P õ .005) into the duodenum. Loperamide increased basal gallbladder volume from 28 { 4 to 39 { 4 PATIENTS AND METHODS mL (P õ .0001) but was without effect on basal plasma cholecystokinin (2.7 { 0.3 vs. 3.0 { 0.3 pmol/L). During Subjects. Eight healthy volunteers (3 women and 5 men; age the amino acid meal, pretreatment with loperamide inhibited range, 19-27 years) participated in the studies. None of the volunamylase output from 5.1 { 0.8 to 1.6 { 0.4 kU/h (P õ .001), teers was taking any medication or had a history of gastrointestinal bilirubin output from 39 { 6 to 18 { 6 mmol/h (P õ .0005) symptoms or surgery. The study protocol was approved by the and gallbladder contraction from 47% { 3% to 26% { 6% ethical committee of the University Hospital Nijmegen, and all sub-(P õ .05), whereas loperamide enhanced amino acid-stimu-jects gave their written informed consent before entering the study.

show abstract

“…It has a powerful opiate-like effect and participates in the control of a wide variety of motor and secretory functions in the gastrointestinal tract (21). MEK has been shown to exert an inhibitory action on pancreatic exocrine secretion stimulated by duodenal acidification, exogenous secretin, and CCK in the dog (4). The inhibition by MEK appears to be caused, at least in part, by a direct effect on the exocrine pancreas.…”

mentioning

confidence: 99%

“…The inhibition by MEK appears to be caused, at least in part, by a direct effect on the exocrine pancreas. In addition, the release of secretin, and perhaps CCK, was also reduced by MEK in the dog (4). Konturek et al (12) reported that MEK inhibited pancreatic secretion elicited by sham feeding or exogenous secretin and CCK in humans that was reversed by naloxone.…”

mentioning

confidence: 99%

MEK inhibits secretin release and pancreatic secretion: roles of secretin-releasing peptide and somatostatin

Lee

Chang

et al. 2001

American Journal of Physiology-Gastrointestinal and Liver Physi

View full text Add to dashboard Cite

We investigated the mechanism of action of methionine enkephalin (MEK) on HCl-stimulated secretin release and pancreatic exocrine secretion. Anesthetized rats with pancreatobiliary cannulas and isolated upper small intestinal loops were perfused intraduodenally with 0.01 N HCl while bile and pancreatic juice were diverted. The effect of intravenous MEK on acid-stimulated secretin release and pancreatic exocrine secretion was then studied with or without coinfusion of naloxone, an anti-somatostatin (SS) serum, or normal rabbit serum. Duodenal acid perfusate, which contains secretin-releasing peptide (SRP) activity, was collected from donor rats with or without pretreatment with MEK, MEK + naloxone, or MEK + anti-SS serum, concentrated by ultrafiltration, and neutralized. The concentrated acid perfusate (CAP), which contains SRP bioactivity, was infused intraduodenally into recipient rats. MEK increased plasma SS concentration and inhibited secretin release and pancreatic fluid and bicarbonate secretion dose-dependently. The inhibition was partially reversed by naloxone and anti-SS serum but not by normal rabbit serum. In recipient rats, CAP increased plasma secretin level and pancreatic secretion. CAP SRP bioactivity decreased when it was collected from MEK-treated donor rats; this was partially reversed by coinfusion with naloxone or anti-SS serum. These results suggest that in the rat, MEK inhibition of acid-stimulated pancreatic secretion and secretin release involves suppression of SRP activity release. Thus the MEK inhibitory effect appears to be mediated in part by endogenous SS.

show abstract

Enkephalin inhibits the release and action of secretin on pancreatic secretion in the dog.

Cited by 21 publications

References 12 publications

Leucine-enkephalin is co-expressed with substance P, galanin and somatostatin in the ovine pancreas

Leucine-enkephalin is co-expressed with substance P, galanin and somatostatin in the ovine pancreas

Inhibition of pancreaticobiliary secretion by loperamide in humans

MEK inhibits secretin release and pancreatic secretion: roles of secretin-releasing peptide and somatostatin

Contact Info

Product

Resources

About