Adrenomedullin Intestinal Microvascular Endothelial Cell Injury In Septic Rats

Objective: Adrenomedullin (ADM), a novel peptide consisting of 52 amino acids. ADM seems to be a very relevant peptide with respect to the protection of the vascular wall during various disorders of the cardiovascular system, as regulator of endothelial permeability. However increasing evidencesuggests an important role of AM in inflammatory reactions and in particular, in the regulation of endothelial barrier function. To investigate the possible protective effect of adrenomedullin on the expression of vascular cell adhesion molecule (VCAM-1) of rat intestinal mucosa microvascular endothelial cells,and to confirm adrenomedullin can decrease released inflammatory factors to slow down or inhibite occurrence and development of sepsis.Method: 1. The rat intestinal mucosa microvascular endothelial cells were isolated and cultured in vitro,and were divided into sham operated (sham operated serum),sepsis serum(with addition of sepsis serum) and ADM serum (with 0.1ng/kg adrenomedullin 6h after sepsis treatment) groups. 2. The expression of VCAM-1 on RIMMVECs surface and the soluble VCAM-1 (sVCAM-1)content in RIMMVECs culture supernatant were measured by ELISA at 24 hours after the serum stimulation. 3. mRNA expression of VCAM-1 in RIMMVECs was measured by reverse transcription polymerase chain reaction(RT-PCR) after difference groups serum stimulation. 4. The VCAM-1 expression on the membrane in RIMMVECs was measured by flow cytometry.Result: 1. The rat intestinal mucosa microvascular endothelial cells were isolated and cultured in vitro,and were divided into sham operated (sham operated serum),sepsis serum(with addition of sepsis serum) and ADM serum (with 0.1ng/kg adrenomedullin 6h after sepsis treatment) groups.2. The VCAM-1 content in the supernatant of sepsis group (0.63±0.13 ng/ml) was obviously higher than that in sham operated (0.09±0.02 ng/ml) and ADM (0.21±0.06 ng/ml) groups. 3. The expression of VCAM-1 mRNA increased obviously in sepsis group after the sepsis serum stimulation,The above expression was significantly decreased in ADM groups at 24 hours,but there was no difference compared with sham operated groups(P<0.05). 4. The VCAM-1 expression on the membrane of RIMMVECs was evidently higher in sepsis group (202.75±57.21) than that in sham operated group (112.95±47.39,P<0.05) at 24 hours, but it was decreased significantly in ADM groups (124.63±54.32),and there was no significantly difference compared with sham operated group(P>0.05),and which was evidently lower than that in sepsis group (P<0.05).Conclusion:ADM serum can decrease the expression of VCAM-1 in RIMMVECs,and the decreased VCAM-1 can decrease the followed inflammation factors,inhibit the occurrence and development of sepsis.