TY - JOUR
T1 - Where are the mu receptors that mediate opioid analgesia? an autoradiographical study in the har and lar selection lines
AU - Belknap, J. K.
AU - Laursen, S. E.
AU - Sampson, K. E.
AU - Wilkie, A.
PY - 1991/4/12
Y1 - 1991/4/12
N2 - One line (strain) of mouse has been selectively bred in our laboratory for 15 generations to exhibit a very high sensitivity to levorphanol-induced analgesia on the hot plate assay (HAR or high antinociceptive response line). Concurrently, a second line (LAR or low antinociceptive response line) has been bred in the opposite direction, i.e., to exhibit a very low sensitivity under the same conditions. This has resulted in a 7-fold difference in sensitivity between HAR and LAR mice as a result of changes in gene frequency. Receptor autoradiographic studies with 3H-DAGO were carried out in the central gray to find receptor populations differing greatly in density between HAR and LAR mice to parallel their in vivo sensitivity differences: such receptors would then be implicated in mediating in vivo analgesia. The caudal portions of the dorsal raphe nucleus (DRN) showed 1.5- to 2-fold differences in density of mu sites, while the periaqueductal grap (PAG) showed relatively small differences. These results strongly suggest that my receptors in a portion of the DRN are involved in mediating analgesia due to systematically administered opiods in this population of mice.
AB - One line (strain) of mouse has been selectively bred in our laboratory for 15 generations to exhibit a very high sensitivity to levorphanol-induced analgesia on the hot plate assay (HAR or high antinociceptive response line). Concurrently, a second line (LAR or low antinociceptive response line) has been bred in the opposite direction, i.e., to exhibit a very low sensitivity under the same conditions. This has resulted in a 7-fold difference in sensitivity between HAR and LAR mice as a result of changes in gene frequency. Receptor autoradiographic studies with 3H-DAGO were carried out in the central gray to find receptor populations differing greatly in density between HAR and LAR mice to parallel their in vivo sensitivity differences: such receptors would then be implicated in mediating in vivo analgesia. The caudal portions of the dorsal raphe nucleus (DRN) showed 1.5- to 2-fold differences in density of mu sites, while the periaqueductal grap (PAG) showed relatively small differences. These results strongly suggest that my receptors in a portion of the DRN are involved in mediating analgesia due to systematically administered opiods in this population of mice.
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U2 - 10.1300/J069v10n01_03
DO - 10.1300/J069v10n01_03
M3 - Article
C2 - 1648410
AN - SCOPUS:0025776168
SN - 1055-0887
VL - 10
SP - 29
EP - 44
JO - Journal of Addictive Diseases
JF - Journal of Addictive Diseases
IS - 1-2
ER -