Effect of substance P on intravenous self-administration of morphine in different rat strains.
We studied the effects of substance P on intravenous self-administration of morphine in WAG/G and Fischer-344 rats. By the end of week 2 the daily amount of self-administered morphine in WAG/G rats was higher than in Fischer-344 rats. Treatment with substance P markedly suppressed self-injection of morphine, particularly in low doses. The most pronounced effects were observed in Fischer-344 rats. Substance P did not change food-procuring behavior of animals in the same experimental chambers. Since the content of substance P in the hippocampus, hypothalamus, and midbrain of Fischer-344 rats is much lower than in WAG/G rats, and morphine addiction in Fischer-344 rats is less pronounced than in WAG/G rats, the degree of opiate addiction is not determined by the content of substance P in rat brain. However, in our experiments treatment with substance P abolished morphine addiction, particularly in animals with low content of this compound in the brain.
Sudakov
S K
SK
Laboratory of Attraction Neurobiology, Institute of Drug Abuse, Russian Ministry of Health, Moscow. ssudakov@mtu-net.ru
Figurina
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Medvedeva
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Rusakova
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D000818:Animals; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D007275:Injections, Intravenous; D008297:Male; D008636:Mesencephalon / Q000187:drug effects / Q000378:metabolism; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D013045:Species Specificity; D013373:Substance P / Q000494:pharmacology*; D019966:Substance-Related Disorders; D013997:Time Factors
D013373:Substance P; D009020:Morphine