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Releases of Norepinephrine and Dopamine in Ventriculocisternal Perfusions in Hepatectomized and Laparotomized Rats
Author(s) -
McKinzie Sanna L.,
Hammond Donna L.,
Grabau Curtis,
Tyce Gertrude M.
Publication year - 1996
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1996.66020569.x
Subject(s) - medicine , dopamine , endocrinology , hepatectomy , norepinephrine , basal (medicine) , hepatic encephalopathy , perfusion , chemistry , biology , cirrhosis , surgery , resection , insulin
The completely hepatectomized rat has frequently been used as a model to study changes in the economy of norepinephrine (NE) and dopamine (DA) in hepatic coma. Hypothermia characteristically develops in hepatectomized rats and also occurs in patients in hepatic coma and is associated with improved survival in both. The aims of the present study were to measure both release and uptake of NE and release of DA in brain in warm (37°C) and cool (30–32°C) rats at 3–5 h after laparotomy or hepatectomy. Ventriculocisternal perfusions of the brain were performed on rats under basal conditions and during releases evoked by 40 m M K + . Basal releases of NE and DA and evoked release of DA were greater in the warm hepatectomized rats than in all other groups. In some studies, 10 −5 M amitriptyline was added to the perfusates to assess whether neuronal uptake was changed after hepatectomy. Uptake of released NE was equally robust in cool hepatectomized as in cool laparotomized rats but could not be measured in warm hepatectomized rats because of amitriptyline toxicity in these rats. Decreases in NE and increases in DA content were found in most areas of the brain after perfusion. Increased releases of NE and DA may contribute to the pathogenesis of hepatic encephalopathy.