Central effects of leukotriene C4 and D4 in rats and mice.

Leukotrienes (LTs) C4 or D4 in a dose of 12 nmoles were administered into the lateral ventricle (i.c.v.) of the rat brain under urethane anaesthesia, and the changes in the blood pressure, heart and respiratory rate were investigated. In other animals the behaviour was evaluated by means of the open field test, and the rectal body temperature was measured. Besides, the content of noradrenaline, 5-hydroxytryptamine and 5-hydroxyindole acetic acid was estimated in different parts of the brain following i.c.v. application of LTs. In mice the antinociceptive effect of LTs in a dose of 1.5 nmoles was examined in the hot plate test; furthermore, the effect of LTs on chlorpromazine catalepsy was measured. Only LTC4 caused a slight rise of the peripheral blood pressure, a decreased respiratory rate and affected the behaviour of rats. Both LTs decreased the rectal body temperature but did not alter the content of biogenic amines in the brain of rats. In mice both LTs did not change the reactivity to thermic pain stimulus; only LTC4 intensified chlorpromazine catalepsy. The results indicate that both LTs exert slight biological effects upon the central nervous system; however, it should be emphasized that LTC4 has a stronger effect.