| Abstract: | Cyclic 3', 5' AMP and cyclic 3', 5' GMP levels were determined in the plasma of male and female White Leghorn chickens of three age groups: 28 weeks, 12 weeks, and 3 days of age. Experimental birds were exposed to either thermoneutral or hyperthermic temperatures for 24 hours prior to blood sampling. The cyclic nucleotides were determined in the plasma using a modification of the enzymatic radioisotopic displacement method developed by Brooker et al. (1968). Cyclic AMP: Under thermoneutral conditions, individual cyclic AMP levels ranged from 1.00 to 8.25 micro moles per liter of plasma. These levels are in excess of the levels of 1.00 to 3.70e-2 micro moles per liter reported for mammals. Cyclic ucleotide levels in the plasma of three-day-old chicks were significantly higher than those found in either 12-week or 28-week-old chickens. No significant differences were found between sexes. |
|---|