Dopamine In Brain Tissue Research Articles

Effect of arrhythmogenic doses of deslanoside on the uptake of monoamines in brain tissue and in cardiac tissue

The purpose of our study was to determine whether a toxic arrhythmogenic dose of digitalis administered to an in vivo preparation would affect the neuronal uptake of norepinephrine, serotonin and dopamine in brain tissue and norepinephrine in cardiac tissue. This was investigated by intoxicating anesthetized cats with deslanoside, removing cardiac and brain tissue at the onset of ventricular fibrillation, and examining the ability of brain tissue to accumulate [ 3H]-NE, [ 3H]-5-HT and [ 3H]-DA and cardiac tissue to accumulate [ 3H]-NE. It was found that deslanoside inhibited uptake of [ 3H]-NE into the left ventricle and [ 3H]5-HT into the area postrema. These selective effects may reflect greater blood flow to these regions or different sensitivities of the transport mechanisms for these amines. This inihibition of uptake into both left ventricular tissue and area postrema may contribute to some of the cardiovascular and emetic effects seen with digitalis drugs.

Dopaminergic mechanisms in schizophrenia: The antipsychotic effect and the disease process

A controlled trial of the isomers of flupenthixol in acute schizophrenia demonstrated that only the α-isomer possesses antipsychotic activity. The result is consistent with the hypothesis that dopamine receptor blockade is the only requirement for therapeutic activity. However, the onset of the therapeutic effect was slow, and delayed by at least two weeks by comparison with the establishment of receptor blockade as indicated by increased prolactin secretion. In post-mortem brain tissue dopamine turnover was found not to be increased in patients with schizophrenia. However, receptor density, assessed by the spiroperidol-binding technique, was significantly increased, and this increase was present in five patients who apparently had not received neuroleptic medication for at least one year before death.