Identification of morphine in the rat adrenal gland.

Morphine was identified in rat adrenal extracts by reverse-phase HPLC, following liquid and solid extraction. All experiments were carefully performed to prevent exogenous morphine contamination. The morphine extracted from adrenal tissue (105.31 ng/g of wet adrenal gland) was identical to that of a morphine internal standard. The morphine corresponding HPLC fractions were further analyzed by gas chromatography-mass spectrometry and found to be identical to synthetic morphine. The study conclusively proves morphine is endogenous to the rat adrenal gland.