Increased immunoreactive dynorphin and leu-enkephalin in posterior pituitary of obese mice (ob/ob) and super-sensitivity to drugs that act at kappa receptors.

Abstract

Posterior pituitaries of obese mice (ob/ob) contained significantly more immunoreactive dynorphin (P less than .01) and leu-enkephalin (P less than .01) than their lean littermates. Drinking in obese mice was stimulated by 0.3%, and feeding by 10%, of the dose of ethylketocyclazocine, a kappa receptor agonist, needed to produce extra feeding and drinking in lean mice. Obese mice also showed greater and longer lasting suppression of ingestion after MR-2266, a kappa antagonist, than did lean mice. MR-2266 was much more effective than naloxone in suppressing schedule-induced polydipsia in rats. These results indicate that kappa receptors are involved in feeding and drinking and that obesity is associated with changes in these receptors and their ligands.

• Authors: M Ferguson-Segall, J J Flynn, J Walker, D L Margules
• Journal: Life sciences (Life Sci) 1982 Nov 15-22 Vol. 31 Issue 20-21 Pg. 2233-6 ISSN: 0024-3205 [Print] Netherlands
• PMID: 6131356 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Analgesics, Opioid
• Benzomorphans
• Endorphins
• Morphinans
• Receptors, Opioid
• Receptors, Opioid, kappa
• MR 2266
• Ethylketocyclazocine
• Enkephalin, Leucine
• Dynorphins
• Cyclazocine

Topics

• Analgesics, Opioid (pharmacology)
• Animals
• Benzomorphans (analogs & derivatives, pharmacology)
• Cyclazocine (analogs & derivatives, pharmacology)
• Drinking (drug effects)
• Dynorphins
• Eating (drug effects)
• Endorphins (metabolism)
• Enkephalin, Leucine (metabolism)
• Ethylketocyclazocine
• Female
• Mice
• Mice, Obese
• Morphinans (pharmacology)
• Obesity (physiopathology)
• Pituitary Gland, Posterior (drug effects, metabolism)
• Receptors, Opioid (drug effects, physiology)
• Receptors, Opioid, kappa