To establish a simple screening system for estimating efficacy of an agent for an oxidative-related lesion, we investigated the damage in isolated rat hepatocytes exposed to 75 microM tert-butyl hydroperoxide (t-BuOOH) and then subsequently incubated the cells in fresh medium. By electron spin resonance spectroscopy analysis using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), DMPO adducts of tert-butoxyl radicals and carbon center radicals were detected during the t-BuOOH exposure, and DMPO-OH formation was detected after t-BuOOH removal. In t-BuOOH-exposed cells, the level of phosphatidylcholine hydroperoxide (PCOOH), a peroxidative product of biomembranes in the hepatocytes, and the leakage of enzymes into the culture medium were significantly increased. An increase in acid phosphatase (AP) activity representing lysosome destabilization preceded the aspartate oxoglutarate aminotransferase (AST), alanine oxoglutarate aminotransferase (ALT) and lactate dehydrogenase (LDH) leakage. Ninjin-yoei-to added to the culture medium following the t-BuOOH exposure significantly inhibited the PCOOH formation and the leakage of AP, AST, ALT and LDH, concentration-dependently. Ninjin-yoei-to at 1 mg/ml in culture medium completely diminished these increases in enzyme activities down to the background levels found in control experiments and this reduction was greater than the most effective alpha-tocopherol concentration of 20 micromol/ml. Considering all of these results, it is likely Ninjin-yoei-to may exert its protective effect by antioxidative action and membrane stabilization.
From Volume 20 (2006), this title is published by Society of Integrated Sciences (International Medart, PO Box 37, 814 99 Bratislava 1, Slovak Republic, E-mail: publisher@nel.edu, Fax: +41 13553207).
Mice were made physically dependent on ethanol by a four-day period of ethanol inhalation. A single injection of L-dopa tended to enhance ethanol withdrawal reactions and 5HTP tended to suppress it. Daily treatment with PCPA and L-dopa or pretreatment with 60HDA tended to modify the severity of withdrawal reactions. PCPA slightly decreased the severity, 60 H DA tended to aggravate the severity, and L-dopa tended to decrease the severity. The simultaneous estimation of brain biogenic amine levels suggests that 5HT and DA may be involved in the development of physical dependence on ethanol. Treatment with neuropharmacological drugs during ethanol withdrawal modified the severity of ethanol withdrawal reactions. Pentobarbital and diazepam completely suppressed ethanol withdrawal reactions. GHBA and reserpine suppressed the severity and haloperidol, Imipramine, and methylphenidate aggravated it. The simultaneous estimation of brain catecholamine levels suggests that suppression of ethanol withdrawal reactions consistently results from the decreased activities of either noradrenergic or dopaminergic neurons. However, the effects of biogenic amines on ethanol withdrawal reactions may be different from those on the development of physical dependence on ethanol.
