Effect of hypophysectomy and adrenalectomy on 5-hydroxytryptamine uptake by rat hypothalamic synaptosomes and blood platelets.

The effect of adrenalectomy and hypophysectomy on 5-HT uptake by rat platelets and hypothalamic synaptosomes taken from the same animal was studies. The experiments were performed 1-2 weeks after the operations of the shamoperations. After adrenalectomy a significant decrease of 25% in 5-HT uptake by platelets was noted. In synaptosomes there was a similar trend, but the decrease was not significant. After hypophysectomy a significant 25% decrease in 5-HT uptake was observed both in platelets and in synaptosomes. These results suggest that corticosteroid hormones might mediate adaptive changes of 5-HT uptake both in synaptosomes and in blood platelets. Blood platelets have been used as a peripheral model of serotoninergic nerve terminal in studies concerning physiology of monoamines systems. But the present results suggest that also in some pathological conditions changes in platelet biochemistry could reflect those in the CNS neurones.