Effects of peptide fragments from the proadrenomedullin on cAMP——"The intramolecular regulation" of signal transduction pathway in cells / 中国药理学通报

ABSTRACT

Aim To study the effect of Peptide fragments that originate from the same proadrenomedullin on cAMP in rat aorta.Methods Isolated aortic tissues were exposed to ADM,PAMP and ADT for 2 h.The content of cAMP in the incubated media was assayed by radioimmunoassay.Results ① The content of cAMP in the aortic tissues that were exposed to ADM (10~(-7) and 10~(-8) mol·L~(-1)) was significantly increased. The content of cAMP in the aortic tissues stimulated by PAMP (10~(-8) mol·L~(-1))or ADT (10~(-8) mol·L~(-1))alone was significantly increased, compared with the control.② The content of cAMP was not in-creased when the tissues were treated with ADM (10~(-8) mol·L~(-1)) and PAMP (10~(-8) mol·L~(-1)) or ADT (10~(-8) mol·L~(-1)) in combination, compared with that after the treatment with ADM(10~(-8) mol·L~(-1))alone, but was significantly decreased than that in PAMP(10~(-8) mol·L~(-1)) or ADT(10~(-8)mol·L~(-1)) groups. After incubation with ADM,PAMP and ADT at the same dose (10~(-8) mol·L~(-1)), the content of cAMP did not change as compared with that of the ADM group (10~(-8) mol·L~(-1),P>0.05), but was greatly reduced, compared with that of the PAMP or ADT groups(10~(-8) mol·L~(-1),P<0.01).Conclusion ADM, PAMP and ADT which originate from the proadrenomedullin have an antagonism on cAMP production in rat aorta.