eCite Digital Repository
Profiling the effects of repetitive morphine administration on motor behavior in rats
Citation
Paul, AK and Gueven, N and Dietis, N, Profiling the effects of repetitive morphine administration on motor behavior in rats, Molecules, 26, (4) pp. 1-14. ISSN 1420-3049 (2021) [Refereed Article]
 | PDF 1Mb |
Copyright Statement
Copyright 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).
DOI: doi:10.3390/molecules26144355
Abstract
Efficient repetitive clinical use of morphine is limited by its numerous side effects, whereas
analgesic tolerance necessitates subsequent increases in morphine dose to achieve adequate levels
of analgesia. While many studies focused on analgesic tolerance, the effect of morphine dosing on
non-analgesic effects has been overlooked. This study aimed to characterize morphine-induced
behavior and the development and progression of morphine-induced behavioral tolerance. Adult
male Sprague–Dawley rats were repetitively treated with subcutaneous morphine for 14 days in two
dose groups (A: 5 mg/kg/day (b.i.d.) → 10 mg/kg/day; B: 10 mg/kg/day (b.i.d.) → 20 mg/kg/day).
Motor behavior was assessed daily (distance traveled, speed, moving time, rearing, rotation) in an
open-field arena, before and 30 min post-injections. Antinociception was measured using tail-flick
and hot-plate assays. All measured parameters were highly suppressed in both dosing groups on
the first treatment day, followed by a gradual manifestation of behavioral tolerance as the treatment
progressed. Animals in the high-dose group showed increased locomotor activity after 10 days of
morphine treatment. This excitatory phase converted to an inhibition of behavior when a higher
morphine dose was introduced. We suggest that the excitatory locomotor effects of repetitive high dose morphine exposure represent a signature of its behavioral and antinociceptive tolerance.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | morphine dosing, behavior, locomotor activity, tolerance |
| Research Division: | Biomedical and Clinical Sciences |
| Research Group: | Pharmacology and pharmaceutical sciences |
| Research Field: | Basic pharmacology |
| Objective Division: | Health |
| Objective Group: | Public health (excl. specific population health) |
| Objective Field: | Behaviour and health |
| UTAS Author: | Paul, AK (Dr Alok Paul) |
| UTAS Author: | Gueven, N (Dr Nuri Guven) |
| ID Code: | 147581 |
| Year Published: | 2021 |
| Web of Science® Times Cited: | 10 |
| Deposited By: | Pharmacy |
| Deposited On: | 2021-11-09 |
| Last Modified: | 2021-12-16 |
| Downloads: | 10 View Download Statistics |
Repository Staff Only: item control page