The sympatho-adrenergic response in hyperthermia.

The sympatho-adrenergic reaction was investigated in heated rats under the influence of a ganglioblocking agent--hexamethonium. The overheating at a 40 degrees environmental temperature produced in a relatively short interval (after 157 min on an average) the death of the animals. An initial bradycardia was followed by a tachycardic phase.

Effects of mild hypoxia (2200 m) on catecholamine and corticosterone secretion.

In experiments carried out in male Wistar rats submitted in laboratory to a 2200-m depressurization the urinary noradrenaline and adrenaline elimination, as well as the plasma corticosterone level were investigated. In rats previously submitted 12 days only to the environmental stress the true depressurization (7 days) produced a relatively increased noradrenaline and adrenaline elimination. A similar increased catecholamine output was observed in rats submitted directly to hypoxia.