Among several lipolytic hormones tested, adrenocorticotropin (ACTH), epinephrine,
glucagon, thyroid-stimulating hormone, and luteinizing hormone stimulated adenyl cyclase
activity in a plasma membrane-rich fraction, termed" ghosts," isolated from rat fat cells. The
effects given by various combinations of these hormones, at maximally stimulating
concentrations, were not additive, indicating that a single enzyme was activated by all of
these hormones. Different effects of the combined hormones were found depending upon …