Premium
INHIBITION BY APOMORPHINE OF THE METOCLOPRAMIDE‐INDUCED CATALEPSY AND INCREASE IN STRIATAL HOMOVANILLIC ACID CONTENT
Author(s) -
AHTEE LIISA
Publication year - 1975
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1975.tb06941.x
Subject(s) - metoclopramide , apomorphine , homovanillic acid , catalepsy , chemistry , endocrinology , medicine , dopamine , dopaminergic , atropine , pharmacology , haloperidol , receptor , serotonin , vomiting
1 The mechanism of the cataleptic effect of metoclopramide was analyzed by using drugs which alter the activity of dopaminergic or cholinergic neurones or the content of γ‐aminobutyric acid in the central nervous system of rats. 2 The cataleptic effect of metoclopramide (20 mg/kg) was antagonized by apomorphine (10 mg/kg) and by atropine (50 mg/kg). Aminooxyacetic acid (AOAA, 25–50 mg/kg) potentiated the catalepsy induced by metoclopramide (5 mg/kg). 3 Metoclopramide alone did not alter the rectal temperature of rats. It did not alter the AOAA‐induced hypothermia, but it partially antagonized apomorphine‐induced hypothermia. 4 Metoclopramide induced a six‐fold increase in striatal homovanillic acid (HVA) concentration, but it did not change the dopamine or noradrenaline content in the brain of rats. Apomorphine decreased the striatal HVA concentration in control and in metoclopramide‐treated rats. Atropine and AOAA did not alter the metoclopramide‐induced increase in striatal HVA concentration. 5 The results suggest that metoclopramide produces catalepsy by blocking striatal dopamine receptors.