Quantitative autoradiographic mapping of μ-, δ- and κ-opioid receptors in knockout mice lacking the μ-opioid receptor gene

Content Provider	Semantic Scholar
Author	Kitchen, I. Slowe, Susan J. Matthes, Hans W. D. Kieffer, Brigitte Lina
Copyright Year	1997
Abstract	Abstract Mice lacking the μ-opioid receptor ( MOR ) gene have been successfully developed by homologous recombination and these animals show complete loss of analgesic responses to morphine as well as loss of place-preference activity and physical dependence on this opioid. We report here quantitative autoradiographic mapping of opioid receptor subtypes in the brains of wild-type, heterozygous and homozygous mutant mice to demonstrate the deletion of the MOR gene, to investigate the possible existence of any μ-receptor subtypes derived from a different gene and to determine any modification in the expression of other opioid receptors. μ-, δ-, κ 1 - and total κ-receptors, in adjacent coronal sections in fore- and midbrain and in sagittal sections, were labelled with [ 3 H]DAMGO ( d -Ala 2 -MePhe 4 -Gly-ol 5 enkephalin), [ 3 H]DELT I ( d -Ala 2 deltorphin I), [ 3 H]CI-977 and [ 3 H]bremazocine (in the presence of DAMGO and DPDPE) respectively. In heterozygous mice, deficient in one copy of the MOR gene, μ-receptors were detectable throughout the brain at about 50% compared to wild-type. In brains from μ-knockout mice there were no detectable μ-receptors in any brain regions and no evidence for μ-receptors derived from another gene. δ-, κ 1 - and total κ-receptor binding was present in all brain regions in mutant mice where binding was detected in wild-type animals. There were no major quantitative differences in κ- or δ-binding in mutant mice although there were some small regional decreases. The results indicate only subtle changes in δ- and κ-receptors throughout the brains of animals deficient in μ-receptors.
Starting Page	73
Ending Page	88
Page Count	16
File Format	PDF HTM / HTML
DOI	10.1016/S0006-8993(97)00988-8
Volume Number	778
Alternate Webpage(s)	https://api.elsevier.com/content/article/pii/S0006899397009888
Alternate Webpage(s)	https://www.sciencedirect.com/science/article/pii/S0006899397009888?dgcid=api_sd_search-api-endpoint
Alternate Webpage(s)	https://doi.org/10.1016/S0006-8993%2897%2900988-8
Journal	Brain Research
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article