although the naturally-occurring catecholamines , and isoprenaline , are thought to act at the same pro-lipolytic beta-adrenoceptor antilipolytic agents , working through the alpha 2-adrenoceptor moiety of adenyl cyclase , appear to act at separate sites for : true alpha 2-agonists such as clonidine , for adenosine and for prostaglandins .
C0007412
catecholamines
C0022245
isoprenaline