Long-term portocaval shunt and changes in rat brain amine systems.
Brain amine system parameters were investigated in Wistar rats sacrificed 7 months following portocaval shunt or sham operation. After removal of the cerebellum and pons, the hypothalamus and remaining parts of the brain were examined. Histamine was assayed radioenzymatically; indoles and catechols by HPLC with electrochemical detection; spermidine and spermine by HPLC with fluorometry. MAO-A and MAO-B activities were estimated with radioassays employing serotonin and beta-phenylethylamine, respectively and specific inhibitors, clorgyline and deprenyl. Long-term portocaval shunt did not significantly alter cerebral catecholamines, serotonin, spermidine or spermine concentrations. However, brain histamine and 5-hydroxyindoleactic acid were significantly raised. Of the MAO enzymes only MAO-B activity was elevated (ca. 25%, p < 0.05) in the hypothalamus but not in the rest of the brain. The kinetic measurements suggest an adaptive change in MAO-B protein synthesis. The data suggest changes evoked by portocaval shunt in brain amine systems are permanent and there are species differences in MAO enzymes' response to higher substrate supply.
Fogel
W A
WA
Institute of Biogenic Amines, Polish Academy of Sciences, Lodz, Poland.
Andrzejewski
W
W
Sasiak
K
K
D000818:Animals; D001284:Atrophy; D015306:Biogenic Monoamines / Q000378:metabolism*; D001921:Brain / Q000201:enzymology; D001923:Brain Chemistry / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism; D006501:Hepatic Encephalopathy / Q000378:metabolism* / Q000473:pathology; D006632:Histamine / Q000378:metabolism; D008099:Liver / Q000098:blood supply / Q000473:pathology; D008297:Male; D008995:Monoamine Oxidase / Q000032:analysis; D011170:Portasystemic Shunt, Surgical / Q000009:adverse effects*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism; D013095:Spermidine / Q000378:metabolism; D013096:Spermine / Q000378:metabolism
D015306:Biogenic Monoamines; D013096:Spermine; D012701:Serotonin; D006632:Histamine; D008995:Monoamine Oxidase; D013095:Spermidine; D004298:Dopamine