The catecholamine content of the perinatal rat adrenal gland.

1. High performance liquid chromatography combined with electro-chemical detection (HPLC/ECD) has been used to measure the noradrenaline, adrenaline and dopamine content of individual adrenal glands from adult rats and from rats aged between day 16 of gestation and day 12 after birth. 2. At all ages studied, the dopamine content of the rat adrenal was significantly lower than the noradrenaline or adrenaline content. 3. Noradrenaline was detected at day 16 of gestation (7.58 ng/gland) and there was a 26 fold increase in the noradrenaline content of the rat adrenal by day 10 after birth (201.67 +/- 51.01 ng/gland). 4. Adrenaline was also detected at day 16 of gestation (2.19 ng/gland) and there was a 700 fold increase in adrenaline content of the rat adrenal by day 10 after birth (1408.62 +/- 473.00 ng/gland). 5. The adrenaline: noradrenaline ratio exceeded one by day 18 of gestation (1.60:1) and had increased to (3.05:1) at birth. 6. This ratio at day 10 after birth (7.43:1) was significantly greater than the ratio at or before birth, and also in the adult (4.20:1).