Involvement of delta 2 opioid receptors in acute dependence on morphine in mice.

Abstract

The effects that naltriben (NTB) and naltrindole 5'-isothiocyanate (5'-NTII) have on acute morphine dependence were investigated in mice. The degree of acute dependence was estimated by the ED50 value of s.c.-administered naloxone that was required to precipitate withdrawal jumping 4 hr after s.c. injection of 100 mg/kg of morphine sulfate (MS-100). Pretreatments with NTB (10 mumol/kg, s.c., 30 min before MS-100) and 5'-NTII (10 mumol/kg, s.c., 24 hr before MS-100) increased the ED50 values of naloxone compared to those of the respective saline-treated control mice. Although NTB itself (up to 10 mumol/kg s.c.) did not precipitate jumping 4 hr after MS-100, small doses of NTB (1 and 2 mumol/kg, s.c.) administered 30 min before the challenge doses of naloxone increased substantially the ED50 value of naloxone. These results suggest that delta 2 opioid receptors are involved in acute dependence on morphine in mice.

• Authors: Y Miyamoto, P S Portoghese, A E Takemori
• Journal: The Journal of pharmacology and experimental therapeutics (J Pharmacol Exp Ther) Vol. 265 Issue 3 Pg. 1325-7 (Jun 1993) ISSN: 0022-3565 [Print] United States
• PMID: 8389861 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Isothiocyanates
• Receptors, Opioid, delta
• Thiocyanates
• naltrindole benzofuran
• naltrindole 5'-isothiocyanate
• Enkephalin, Leucine
• Naltrexone
• enkephalin, Ser(2), Leu(5), Thr(6)-
• Morphine

Topics

• Animals
• Drug Interactions
• Enkephalin, Leucine (analogs & derivatives, antagonists & inhibitors, pharmacology)
• Isothiocyanates
• Male
• Mice
• Morphine
• Naltrexone (analogs & derivatives, pharmacology)
• Receptors, Opioid, delta (antagonists & inhibitors, metabolism)
• Substance-Related Disorders
• Thiocyanates (pharmacology)