▁pe pt ides , ▁including ▁an ▁in active ▁ 5 3 - am ino ▁acid ▁AM , ▁e ▁PA MP , ▁ad ren ot ens in ▁and ▁AM 9 5 - 1 4 6 . ▁ ▁M ature ▁human ▁AM ▁is ▁activ ated ▁to ▁form ▁a ▁ 5 2 ▁am ino ▁acid , ▁ 6 - am ino ▁acid ▁ring , ▁that ▁shares ▁moder ate ▁struct ural ▁similarity ▁to ▁the ▁cal cit on in ▁family ▁of ▁regul atory ▁pe pt ides ▁( cal cit on in , ▁CG R P ▁and ▁am y lin ). ▁ ▁Cir cul ating ▁AM ▁consists ▁of ▁both ▁amid ated ▁active ▁form ▁( 1 5 %) ▁and ▁the ▁g ly c ated ▁in active ▁form ▁( 8 5 %). ▁ ▁It ▁has ▁a ▁pl asma ▁half - life ▁of ▁ 2 2 min , ▁mean ▁clear ance ▁rate ▁of ▁ 2 7 4 ▁m L / kg / min , ▁and ▁apparent ▁volume ▁of ▁distribution ▁of ▁ 8 8 0 ▁ ± ▁ 1 5 0 ▁m L / kg . ▁ ▁Re cept ors ▁▁ ▁Ad ren omed ull in ▁( AM ) ▁ex ert s ▁its ▁actions ▁through ▁combinations ▁of ▁the ▁cal cit on in ▁re ceptor ▁like ▁re ceptor ▁( C AL C RL ) ▁or ▁CL R ; ▁and ▁either ▁( Re ceptor ▁activity - mod ifying ▁protein ) ▁▁ 2 ▁( RA MP 2 ) ▁or ▁RA MP 3 , ▁( known ▁as ▁AM 1 ▁and ▁AM 2 ▁re cept ors ▁respectively ).