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The report attempts to give a synthesis of special realizations and limited experiences in the field of automatic control of thermal power plants. The functions ensured by the automatic control are examined under the aspect of performances and behaviour expected of the generating units in the overall power system operation, including normal operation, shut-down, start-up and their behaviour during incidents.

Hypothalamic slices of the rabbit brain were incubated with 10-7 M of 3H-serotonin (3H-5HT). After the incubation and an initial washout period, a nearly constant basal efflux of tritium was detected. This basal efflux was not significantly altered by Ca2+-free solution or by the 5HT-antagonist metitepin (10-5 M), but was augmented by chlorimipramine (10-5 M) and by unlabelled 5HT (10-6 M); the acceleration caused by unlabelled 5HT was absent in presence of chlorimipramine (10-5 M). Both electrical stimulation (4 Hz, 50 mA, 2 min) and high K+ (50 mM) induced an overflow of 3H. This overflow was nearly abolished in Ca2+-free solution. In presence of chlorimipramine (10-5 M) both the tritium overflow evoked by electrical stimulation and that evoked by high K+ were augmented by metitepin (10-5 M) and decreased in a concentration dependent manner by unlabelled serotonin (10-8–10-6 M); the latter effect was antagonized by metitepin (10-6 M and 10-5 M). These experiments suggest that in rabbit hypothalamic slices, the release of 3H-5HT is controlled by a negative feedback mechanism acting via presynaptic serotonin receptors.

Cisapride (R 51 619) is a newly synthesized compound, which facilitates the release of acetylcholine in the myenteric plexus of the gut. Its effect on gastric emptying of a barium meal was evaluated in 84 patients under randomized, double-blind conditions. Two oral doses (5 mg and 10 mg) of cisapride were compared with a placebo, and two intravenous doses (4 mg and 8 mg) with a placebo and with 10 mg metoclopramide. All doses of cisapride and metoclopramide were significantly superior to placebo in accelerating gastric emptying, intensifying antral contractions and shortening the mouth-to-caecum transit time. The effects of 8 mg cisapride and 10 mg metoclopramide given intravenously were comparable.