Adrenomedullary hormonal and glycemic responses to high ambient temperature in the soft-shelled turtle, Lissemys punctata punctata

The aim of the investigation was to study the influence of high ambient tem perature on adrenomedullary activity and blood glucose levels in adult fema le soft-shelled turtles (Lissemys punctata punctata). Experiments were carr ied out at 25 degrees, 35 degrees, and 38 degrees, and one group was expose d to 38 degrees for 15 days and then maintained at 25 degrees for another 1 5 days. Exposure to a low ambient temperature of 25 degrees had no clear ef fect on adrenomedullary function with respect to histology (nuclear diamete r), epinephrine and norepinephrine concentrations, and blood glucose level of turtles, but higher temperatures of 35 degrees and 38 degrees stimulated adrenomedullary activity as well as blood glucose level in turtles compare d with controls (30 degrees). The extent of these changes was greater at 38 degrees than that at 35 degrees, and withdrawal from high ambient temperat ure reversed the effect in turtles. (C) 2001 Academic Press.