Protective effects of a dual endothelin converting enzyme/neutral endopeptidase inhibitor on the development of pulmonary hypertension secondary to cardiac dysfunction in the rat.
Endothelium-derived nitric oxide (NO) and endothelin (ET)-1 interact to regulate the vascular tone in pulmonary hypertension (PH). We investigated the protective effects of an orally active, dual endothelin converting enzyme (ECE)/neutral endopeptidase (NEP) inhibitor/CGS 26393 on pulmonary vascular remodeling and pulmonary expressions of ET-1 and endothelial nitric oxide synthase (eNOS) during the development of PH secondary to cardiac dysfunction. Significant increases in the mean pulmonary arterial pressure, pulmonary arteriolar medial thickness, and pulmonary expression of ET-1 were seen in rats subjected to aortic banding for 4 weeks, compared with sham-operated rats. Treatment with CGS 26393 (30 mg/kg, twice daily, p.o.) began on 1 day after aortic banding. CGS 26393 treated rats had lower mean pulmonary arterial pressure (15 ± 1 mmHg, mean ± SEM, P < 0.05) compared to vehicle-treated rats (37 ± 1 mmHg). It also normalized pulmonary arteriolar medial thickness and reduced the levels of pulmonary ET-1 and big ET-1 by 55% (P < 0.05) and 28% (P < 0.01), respectively, when compared with vehicle-treated animals. Meanwhile, the expressions of eNOS mRNA and eNOS protein and cGMP levels in the lung of CGS 26393-treated rats were increased by 62% (P < 0.05), 100% (P < 0.05), and 32% (P < 0.01), respectively, compared to the vehicle-treated rats. These results suggest that CGS 26393 could offer preventive effects on the development of PH by ameliorating pulmonary remodeling, decreasing ET-1 production, and up-regulating eNOS and cGMP in aorta-banded rats. However, the molecular mechanisms by which treatment with CGS 26393 results in altered expressions of eNOS and cGMP awaits further investigation.
Dai
Zen-Kong
ZK
Department of Pediatrics, Faculty of Medicine, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
Hsieh
Chong-Chao
CC
Chai
Chee-Yin
CY
Wu
Jiunn-Ren
JR
Jeng
Arco Y
AY
Chou
Shah-Hwa
SH
Wu
Bin-Nan
BN
Yeh
Jwu-Lai
JL
Chen
Ing-Jun
IJ
Tan
Mian-Shin
MS
D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000037:antagonists & inhibitors*; D001794:Blood Pressure / Q000187:drug effects; D019332:Endothelin-1 / Q000032:analysis; D000072396:Endothelin-Converting Enzymes; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000201:enzymology; D008168:Lung / Q000187:drug effects / Q000201:enzymology / Q000503:physiopathology; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors*; D015260:Neprilysin / Q000037:antagonists & inhibitors*; D052250:Nitric Oxide Synthase Type III / Q000032:analysis; D063065:Organophosphonates / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use*; D011651:Pulmonary Artery / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar; D013777:Tetrazoles / Q000494:pharmacology*; D015854:Up-Regulation
D019332:Endothelin-1; D063065:Organophosphonates; D011480:Protease Inhibitors; D013777:Tetrazoles; C098285:CGS 26393; D052250:Nitric Oxide Synthase Type III; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; D015260:Neprilysin; D000072396:Endothelin-Converting Enzymes