Fluctuations of succinic dehydrogenase during morphine tolerance, dependence and withdrawals in the spinal cord and medulla oblongata of mice.
Changes in succinic dehydrogenase (SDH), during morphine dependence development, normal and antagonists (naloxone and naltrexone) precipitated withdrawals, have been analysed in the spinal cord and medulla oblongata of mice. The study reveals the following highlights. 1. There is a progressive inhibition of SDH upto six days of morphine treatment. However, the physically dependent animals demonstrate a significant recovery of the enzyme suggesting that steady-state level of the enzyme is achieved. 2. Antagonists application to morphine treated animals significantly reverted the enzyme, but the control level is achieved only with naloxone in single dose treated animals. 3. The abstinence of drug for two days not only recovered but also significantly raised the enzyme level both in spinal cord and in medulla oblongata. The antagonists treatment to these animals are insignificant. 4. A further withdrawal of the drug recovered the enzyme towards the control level, and on 15th day SDH is completely recovered. The antagonist treatments in withdrawal groups demonstrated insignificant changes. Overall data clearly show that enzymatic changes are morphine mediated, and at least 15 days of drug abstinence is needed for a complete recovery of the enzyme (Acta neurol. belg., 1988, 88, 281-289).
Josephjohn
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K
Department of Biosciences, Saurashtra University, Rajkot, India.
Sood
P P
PP
D000818:Animals; D004361:Drug Tolerance; D008526:Medulla Oblongata / Q000201:enzymology*; D051379:Mice; D008815:Mice, Inbred Strains; D009020:Morphine / Q000008:administration & dosage; D009021:Morphine Dependence / Q000201:enzymology*; D009270:Naloxone / Q000494:pharmacology; D009271:Naltrexone / Q000494:pharmacology; D013116:Spinal Cord / Q000201:enzymology*; D013375:Substance Withdrawal Syndrome / Q000201:enzymology*; D013385:Succinate Dehydrogenase / Q000032:analysis*; D013997:Time Factors
D009270:Naloxone; D009271:Naltrexone; D009020:Morphine; D013385:Succinate Dehydrogenase