[Effects of proadrenomedullin N-terminal 20 peptide on angiotensin II-induced NO production in rat cardiac fibroblasts].
OBJECTIVE
To explore the effects of proadrenomedullin N-terminal 20 peptide (PAMP) on nitric oxide (NO) production in rat cardiac fibroblasts (CFs) induced by angiotensin II (AngII) stimulation.


METHODS
Neonatal SD rat CFs isolated by trypsin digestion were cultured and stimulated with PAMP, AngII or their combination, and NO production in the CFs in response to the treatments was measured by nitric acid reductase method.


RESULTS
NO levels in the cell culture treated with 1x10(-9), 1x10(-8), 1x10(-7), and 1x10(-6) micromol/L AngII were 73.88-/+2.23, 64.34-/+3.02, 54.12-/+2.82, and 40.21-/+1.45 micromol/L, respectively, showing significant differences between the groups (P<0.01), whereas treatment of the cells with 1x10(-9), 1x10(-8), 1x10(-7), and 1x10(-6) micromol/L PAMP did not result in significant variation in NO production (74.40-/+3.42, 74.91-/+2.66, 75.77-/+3.31, and 74.23-/+2.43 micromol/L, respectively) in comparison with that of the blank control group (74.57-/+2.49 micromol/L, P>0.05). Combined treatments with 1x10(-7) micromol/L AngII and PAMP at 1x10(-9), 1x10(-8), 1x10(-7), and 1x10(-6) micromol/L PAMP caused significant increment of NO production (66.15-/+2.95, 80.58-/+3.77, 88.67-/+1.46, and 96.22-/+2.96 micromol/L, respectively, P<0.01) in a PAMP dose-dependent manner, suggesting the abolishment of AngII-induced enhancement of NO production in the CFs by PAMP.


CONCLUSIONS
PAMP increases NO production in the CFs in the presence of AngII but it does not induce significant changes in NO production when used alone.
Xue
Shi-rong
SR
Department of Cardiology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. xue9999@126.com
Li
Zhi-liang
ZL
Xu
Chun-sheng
CS
Yan
Quan-eng
QE
Jiang
Hai-long
HL
Wu
Hong-chao
HC
Tang
Chao-shu
CS
D053607:Adrenomedullin; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D010446:Peptide Fragments / Q000494:pharmacology*; D011498:Protein Precursors / Q000737:chemistry / Q000494:pharmacology*; D011506:Proteins / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D010446:Peptide Fragments; D011498:Protein Precursors; D011506:Proteins; C088633:proadrenomedullin; D000804:Angiotensin II; D053607:Adrenomedullin; D009569:Nitric Oxide