“3) The inhibition of VIP action by epinephrine is reversed by the alpha antagonists dihydroergotamine , phentolamine and the alpha 2 antagonist yohimbine, while unaffected by the beta antagonist propranolol and the alpha 1 antagonist prazosin, (4) Epinephrine inhibits VIP-stimulated adenylate cyclase activity in preparations of colonic plasma membranes.”