Influence of age on diurnal rhythms of adrenal norepinephrine, epinephrine, and corticosterone levels in soft-shelled turtles (Lissemys punctata punctata).

An investigation was made of what role aging plays on diurnal rhythms of norepinephrine, epinephrine, and corticosterone contents in the adrenal gland of soft-shelled turtles. To resolve this problem, juvenile and adult soft-shelled turtles were sacrificed at four different time intervals (0600, 1200, 1800, and 2400 hr) and adrenal hormonal levels were measured by spectrofluorometer. The findings revealed that peak norepinephrine, epinephrine, and corticosterone values were observed at 2400, 0600, and 2400 hr, respectively, and trough values for all the hormones were found at 1200 hr in both juvenile and adult animals. Thus, diurnal rhythms for all the hormones studied exist in both juvenile and adult animals. It is suggested that aging apparently has no influence on diurnal variations of adrenal hormones in turtles.