Effect of acute temperature stress on the plasma catecholamine, corticosterone and metabolite levels in the pigeon

1. Adult pigeons of both sexes were exposed to either +2°C or +32°C for 5, 15, 30 or 60 min. Furthermore, 2 groups of pigeons were housed at these temperatures for 3 weeks. 2. Acute cold or heat stress produced biphasic changes in the blood NA, A and corticosterone concentrations. Both at cold and heat an immediate rise in A level was seen, but corticosterone level increased only at cold, which was followed by a fall at 30 min. Thereafter the corticosterone levels were recovered and at 60 min even exceeded the initial values. In NA level an immediate and controversial fall both at cold and heat was seen. However, at cold, an unexpected and significant elevation above the pre-exposure level was seen at 30 min. 3. In FFA, glycerol and glucose levels an immediate fall at heat but a controversial elevation at cold was observed. 4. Our findings show that there are increased plasma glycerol, FFA, A and NA levels in cold-acclimated pigeon compared with heat-acclimated pigeon.