[Effects of exogenic noradrenaline and melatonin on the neurogenic vasoreactivity].

The effect of 0.1 microM noradrenaline and melatonin on the response to electrical field stimulation (EFS) of the juvenile rat artery segment was studied. Noradrenaline like melatonin was shown to potentiate the EFS-evoked constriction decreased in the course of experiments or in the acidic solution (pH 6.6), and this potentiation was proportional to the extent of the preceding decrease of the constriction. The effect of these substances was additive. The results suggest that noradrenaline as well as melatonin can serve as a means to restore the diminished neurogenic reactivity of blood vessels.