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Effects of multiple intracerebroventricular injections of [D-Pen2,D-Pen5]enkephalin and [D-Ala2,Glu4]deltorphin II on tolerance to their analgesic action and on brain delta-opioid receptors.
Brain Res. 1997 Jan 16; 745(1-2):243-7.BR

Abstract

Male Swiss-Webster mice were injected intracerebroventricularly (i.c.v.) with [D-Pen2,D-Pen5]enkephalin (DPDPE), a delta 1-opioid receptor agonist (20 micrograms per mouse) twice a day for either 2 or 4 days. Vehicle injected mice served as controls. Treatment of mice with DPDPE for 2 or 4 days decreased its analgesic response by 44 and 76%, respectively in comparison to vehicle injected mice. Treatment of mice with DPDPE for 2 or 4 days decreased density (Bmax) of [3H]DPDPE to bind to brain homogenates by 77 and 76%, respectively, in comparison to vehicle injected controls but the apparent dissociation constant (kd) values were not altered. The effects of i.c.v. injections of [D-Ala2,Glu4]deltorphin II (deltorphin II), a delta 2-opioid receptor agonist (20 micrograms per mouse) twice a day for either 2 or 4 days on its analgesic response as well as on brain receptors for [3H]DPDPE were also determined. The analgesic response to deltorphin II decreased by 51 and 78%, respectively in mice treated with deltorphin II for 2 or 4 days, respectively. Two or four days treatment with deltorphin II decreased the Bmax of [3H]DPDPE by 76 and 87%, respectively. The 2-day treatment also increased the Kd value by 58%, but the 4-day treatment with deltorphin II had no effect on the Kd of [3H]DPDPE to bind to brain membranes. Thus, multiple injections of delta 1- or delta 2-opioid receptor agonists results in the development of tolerance to their analgesic action and the intensity of tolerance increases with the duration of treatment. Both delta 1- and delta 2-opioid receptor agonist, on chronic administration, result in the down-regulation of delta 1-opioid receptors labeled with [3H]DPDPE.

Authors+Show Affiliations

Department of Pharmaceutics and Pharmacodynamics (M/C865), University of Illinois at Chicago 60612, USA.No affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

9037415

Citation

Zhao, G M., and H N. Bhargava. "Effects of Multiple Intracerebroventricular Injections of [D-Pen2,D-Pen5]enkephalin and [D-Ala2,Glu4]deltorphin II On Tolerance to Their Analgesic Action and On Brain Delta-opioid Receptors." Brain Research, vol. 745, no. 1-2, 1997, pp. 243-7.
Zhao GM, Bhargava HN. Effects of multiple intracerebroventricular injections of [D-Pen2,D-Pen5]enkephalin and [D-Ala2,Glu4]deltorphin II on tolerance to their analgesic action and on brain delta-opioid receptors. Brain Res. 1997;745(1-2):243-7.
Zhao, G. M., & Bhargava, H. N. (1997). Effects of multiple intracerebroventricular injections of [D-Pen2,D-Pen5]enkephalin and [D-Ala2,Glu4]deltorphin II on tolerance to their analgesic action and on brain delta-opioid receptors. Brain Research, 745(1-2), 243-7.
Zhao GM, Bhargava HN. Effects of Multiple Intracerebroventricular Injections of [D-Pen2,D-Pen5]enkephalin and [D-Ala2,Glu4]deltorphin II On Tolerance to Their Analgesic Action and On Brain Delta-opioid Receptors. Brain Res. 1997 Jan 16;745(1-2):243-7. PubMed PMID: 9037415.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of multiple intracerebroventricular injections of [D-Pen2,D-Pen5]enkephalin and [D-Ala2,Glu4]deltorphin II on tolerance to their analgesic action and on brain delta-opioid receptors. AU - Zhao,G M, AU - Bhargava,H N, PY - 1997/1/16/pubmed PY - 1997/1/16/medline PY - 1997/1/16/entrez SP - 243 EP - 7 JF - Brain research JO - Brain Res VL - 745 IS - 1-2 N2 - Male Swiss-Webster mice were injected intracerebroventricularly (i.c.v.) with [D-Pen2,D-Pen5]enkephalin (DPDPE), a delta 1-opioid receptor agonist (20 micrograms per mouse) twice a day for either 2 or 4 days. Vehicle injected mice served as controls. Treatment of mice with DPDPE for 2 or 4 days decreased its analgesic response by 44 and 76%, respectively in comparison to vehicle injected mice. Treatment of mice with DPDPE for 2 or 4 days decreased density (Bmax) of [3H]DPDPE to bind to brain homogenates by 77 and 76%, respectively, in comparison to vehicle injected controls but the apparent dissociation constant (kd) values were not altered. The effects of i.c.v. injections of [D-Ala2,Glu4]deltorphin II (deltorphin II), a delta 2-opioid receptor agonist (20 micrograms per mouse) twice a day for either 2 or 4 days on its analgesic response as well as on brain receptors for [3H]DPDPE were also determined. The analgesic response to deltorphin II decreased by 51 and 78%, respectively in mice treated with deltorphin II for 2 or 4 days, respectively. Two or four days treatment with deltorphin II decreased the Bmax of [3H]DPDPE by 76 and 87%, respectively. The 2-day treatment also increased the Kd value by 58%, but the 4-day treatment with deltorphin II had no effect on the Kd of [3H]DPDPE to bind to brain membranes. Thus, multiple injections of delta 1- or delta 2-opioid receptor agonists results in the development of tolerance to their analgesic action and the intensity of tolerance increases with the duration of treatment. Both delta 1- and delta 2-opioid receptor agonist, on chronic administration, result in the down-regulation of delta 1-opioid receptors labeled with [3H]DPDPE. SN - 0006-8993 UR - https://www.unboundmedicine.com/medline/citation/9037415/Effects_of_multiple_intracerebroventricular_injections_of_[D_Pen2D_Pen5]enkephalin_and_[D_Ala2Glu4]deltorphin_II_on_tolerance_to_their_analgesic_action_and_on_brain_delta_opioid_receptors_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0006-8993(96)01156-0 DB - PRIME DP - Unbound Medicine ER -