[Plasma concentration curves of catecholamines and corticosteroids as well as PBI in swine kept under various conditions and acutely exposed to cold].

The response to acute cold (-5 degrees C) of swine kept single was found to differ from that of animals kept in groups. Such difference in reaction was reflected in significant variation of plasma concentration curves in catechol amines and 11-OHKS during and after acute exposure to cold. The response to cold stimulation of animals kept single was primarily and pronouncedly via the sympathicoadrenal system, whereas animals kept in groups responded to acute cold exposure, with the hypothalamic-adrenocortico-pituitary system playing the major role. Significant rise in PBJ in response to 30 and 90 minutes of exposure to cold was recorded only from animals kept single and interpreted as an expression of strong adrenergic reaction of such probands. Such difference in response to one and the same acute stimulus supported the conclusion that there was a difference in adaptation capacity between animals in those two keeping conditions. The results also suggested that type and degree of organic response to a specific stimulus were likely to depend not only on the intensity of the given stimulus, but also on the control potential produced by all closely interconnected control circuits at the time of stimulation.