Low doses of ethanol reduce neurotensin levels in discrete brain regions from LS/Ibg and SS/Ibg mice.
Studies were designed to examine the previously proposed hypothesis that some of the pharmacological actions of ethanol are mediated by neurotensinergic processes. Neurotensin-immunoreactivity (NT-ir) was extracted from various brain regions and shown by high performance liquid chromatography to possess the same retention time as authentic bovine NT1-13. The highest levels of NT-ir were observed in the hypothalamus with intermediate levels in the midbrain and striatum and lowest levels in the frontal cortex. Levels of NT-ir were higher in hypothalamus and midbrain from long-sleep (LS) than from short-sleep (SS) mice. Ethanol, in vivo, produced a dose-dependent decrease in NT-ir in several brain regions; low doses, 1.5 to 3.0 g/kg, but not high doses, 4.1 g/kg, of ethanol significantly decreased NT-ir in hypothalamus, midbrain, and striatum of LS and SS mice. Levels of NT-ir in the frontal cortex were not altered by ethanol administration. Ethanol-induced decreases in NT-ir were of rapid onset with a maximum decrease in 5 min after intraperitoneal (i.p.) injection, and they were of long duration with levels remaining depressed for 4 hr. These findings show that subhypnotic, intoxicating doses of ethanol enhance NT release, in vivo, and support the hypothesis that some of ethanol's actions are mediated by neurotensinergic systems.
Erwin
V G
VG
Alcohol Research Center, School of Pharmacy, University of Colorado, Boulder 80309.
Jones
B C
BC
Radcliffe
R
R
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000097:blood / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009496:Neurotensin / Q000378:metabolism*; D011863:Radioimmunoassay; D014020:Tissue Extracts / Q000032:analysis
D014020:Tissue Extracts; D009496:Neurotensin; D000431:Ethanol