Immunoassayable adrenocorticotropin in peripheral organs: concentrations during early development.

Although many have identified immunoassayable adrenocorticotropin (ACTH) in sites outside the pituitary (brain, gastrointestinal tract), there is relatively little information regarding immunoassayable ACTH in other major peripheral organs. Several major peripheral organs (pancreas, liver, kidney, heart) of rats were found to contain variable amounts of immunoreactive (IR-) ACTH which appeared to be authentic IR-ACTH on the basis of parallelism to ACTH1-39 upon serial dilution of extracts and gel filtration chromatography. Concentrations of IR-ACTH in peripheral organs were also studied to determine if changes occur during early development. Concentrations of IR-ACTH did not show significant changes in liver and heart at various ages between 10 and 80 days, but IR-ACTH in pancreas and kidney (day 10 vs. 80) did show significant decrements with aging.