Antinociceptive Effect of Morphine Microinjections into the Dorsal Hippocampus in the Formalin-Induced Orofacial Pain in Rats
Journal Title: Veterinary Research Forum - Year 2010, Vol 1, Issue 2
Abstract
In the present study, the effects of intra-hippocampal microinjections of morphine (an opioid agonist) and naloxone (an opioid antagonist) were investigated in the formalin-induced orofacial pain in rats. Orofacial pain was induced by subcutaneous injection of formalin (1 %, 50 μl) in the upper lip region and the time spent of face rubbing was measured in 3-min blocks for 45 min. Formalin induced a biphasic (first phase: 0-3 min; second phase: 15-33 min) pain response. Intra-hippocampal microinjections of morphine at doses of 2 and 4 μg significantly ([i]P[/i] < 0.05) attenuated the first phase, and at doses of 1, 2 and 4 μg, morphine significantly ([i]P[/i] < 0.05) suppressed both phases of formalin-induced orofacial pain response. Intra-hippocampal microinjections of naloxone (1 and 4 μg) non-significantly increased pain when used alone, and in pretreatment microinjection, naloxone (4 μg) reversed morphine (2 μg)-induced antinociception. These results indicate that at the level of hippocampus of the brain, morphine through a naloxone-reversible mechanism produced an antinociceptive effect confronting the pain induced by formalin in the orofacial region in rats.
Authors and Affiliations
Amir Erfanparast , Esmaeal Tamaddonfard , Amir Abbas Farshid , Emad Khalilzadeh
Keywords
Related Articles
- EP ID EP119781
- DOI -
- Views 128
- Downloads 0
Histomorphometric study of on blood cells in male adult ostrich
In order to perform a histomorphometric study of blood cells in male adult ostrich, blood samples were obtained from jugular vein of 10 clinically healthy male adult ostriches (2 - 3 years old). The slides were stained w...
Effect of a phytogenic feed additive on performance, ovarian morphology, serum lipid parameters and egg sensory quality in laying hen
This present study was conducted to evaluate the effects of dietary inclusion of 4, 8 and 12 g kg-1 phytogenic feed additives mixture on performance, egg quality, ovary parameters, serum biochemical parameters and yolk t...
PCR detection of Campylobacter fetus subspecies venerealis in smegma samples collected from dairy cattle in Fars, Iran
Bovine venereal campylobacteriosis, caused by Campylobacter fetus subsp. venerealis (Cfv), is regarded as one of the major threats to the cattle industry around the world. Abortion and infertility are two important repro...
Modeling the growth of Staphylococcus aureus as affected by black zira (Bunium persicum) essential oil, temperature, pH and inoculum levels
Black zira (Bunium persicum) is a medicinal plant and spice, naturally grows in Iran. The aim of this study was to investigate the combined effects of different concentrations of Bunium persicum essential oil (EO; includ...
Study on the Use of Dried Poultry Litter in the Camel's Ration
A feeding trial of 120 days duration was conducted to study the effect of replacing 20 and 25 % of camel ration by poultry litter (PL) on the performance and some blood biochemical parameters. Fifteen healthy one–humped...