The paper deals with capacity of tissues of the bull and rat auricle and of the rat deferent duct for trapping L-[3H] noradrenaline and [3H] adrenaline under different conditions of cooling. It is established that at the preliminary incubation temperature of 20 degrees C the intensity of tissues trapping both the hormone and mediator is essentially decreased and [3H] noradrenaline does not inhibit the adrenaline trapping. When the bull auricle tissue is cooled down to 4 and 0 degrees C its capacity for the [3H]-noradrenaline trapping is restored. The rat deferent duct tissue recover its capacity to the [3H] adrenaline trapping after cooling down to 0 degrees C. Freezing down to -20 and 196 degrees C has a pronounced inhibitory effect on the [3H] adrenaline and [3H] noradrenaline trapping by all the tissues under study. Possible thermodependence mechanisms of the adrenergic mediator-hormones trapping are explained.