Adrenomedullin gene expression and levels in the cardiovascular system after treatment with lipopolysaccharide.
To study the effect of septicaemia, the temporal changes in tissue adrenomedullin (AM) and preproAM mRNA levels were studied in the heart and blood vessels after lipopolysaccharide (LPS) injection. Radioimmunoassay and solution hybridization-RNase protection assays were used to follow the changes in AM and its mRNA levels respectively after intraperitoneal injection of 10 mg/kg LPS in rats. The preproAM mRNA levels increased at 1 h in the right atrium after LPS injection, while the AM contents decreased at 1 h in the left atrium. The preproAM mRNA levels increased at 3 and 6 h in the left ventricle, whereas it increased at 6 h in the right ventricles after LPS injection. There was an increase in preproAM mRNA levels at 1 and 3 h in the mesenteric artery, while AM levels were increased at 1, 3 and 6 h. However, there were no such changes in the thoracic aorta. There were also increases in tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta and IL-6 in the heart, and in the mesenteric artery (TNF-alpha and IL-1beta) and in thoracic aorta (IL-1beta and IL-6). The present results suggest that the biosynthesis and secretion of AM may be increased in cardiovascular tissues of rats injected with LPS, and that AM may play multiple roles in inflammation.
Li
Yuk-Yin
YY
Department of Physiology, Faculty of Medicine, The University of Hong Kong, Hong Kong, PR China.
Cheung
Bernard M Y
BM
Wong
Louisa Y F
LY
Hwang
Isabel S S
IS
Kumana
Cyrus R
CR
Tang
Fai
F
D053607:Adrenomedullin; D000818:Animals; D001013:Aorta, Thoracic / Q000737:chemistry; D002319:Cardiovascular System / Q000737:chemistry* / Q000187:drug effects*; D015870:Gene Expression; D007375:Interleukin-1 / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D008070:Lipopolysaccharides / Q000633:toxicity*; D008297:Male; D008638:Mesenteric Arteries / Q000737:chemistry; D009206:Myocardium / Q000737:chemistry; D010455:Peptides / Q000032:analysis* / Q000235:genetics*; D011498:Protein Precursors / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D007375:Interleukin-1; D015850:Interleukin-6; D008070:Lipopolysaccharides; D010455:Peptides; D011498:Protein Precursors; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D053607:Adrenomedullin