Mechanism of caffeine-induced corticosterone release in pregnant mice

ABSTRACT

The pituitary-adrenal axis of day 14 pregnancy was suppressed by parenteral administration of dexamethasone [0.4 mg/mouse, -20 h], pentobarbital [80 mg/kg, -0.75 h], pentobarbital [20 mg/kg, -0.75 h], intraperitoneally [100 mg/kg, 0 h] and plasma corticosterone and caffeine levels were determined 1.5 hours later. Plasma corticosterone of suppressed control animals was significantly decreased than that of unsuppressed controls at day 14 of gestation. Caffeine administration produced no change in plasma corticosterone level of 3 out of 7 animals and slightly increased the steroid level of the other 4 suppressed mice. In unsuppressed animals, however, a marked increase in plasma corticosterone level was observed. The low plasma corticosterone level in caffeine treated suppressed mice, compared with that of unsuppressed ones, indicated the high corticosterone level, and may indicate that the high corticosterone level induced by caffeine administration during pregnancy in mice could be mediated through release of adrenocorticotrophic hormone from the anterior pituitary gl and and not due to direct stimulation of the adrenal cortex