[Changes in the opioid peptide content of the adrenals of rats during immobilization stress].

Radioimmunoassay was used to study variation in the content of opioid peptides (leu- and met-enkephalins) in rat adrenal glands at different stages of immobilization stress. The data obtained were correlated to the content of catecholamines (CA). It was discovered that during stress, the content of peptides noticeably increased, being independent of the main pool of CA in adrenal tissue.