Intracardiac expression of neutral endopeptidase.
Neutral endopeptidase (NEP), a proteolytic enzyme, is known to degrade several peptides which control cardiovascular homeostasis. This is a preliminary study of the pattern of the intracardiac regional expression of the NEP gene in the normal heart, and the age-related changes in this expression in the cardiac regions. The relative abundance of NEP mRNA was determined by RT-PCR in the right atrium (RA), right ventricle (RV), left atrium (LA), left ventricle (LV) and interventricular septum (IVS) in 2-month-old (young) and 12-month-old (advanced-age adult) Wistar Kyoto (WKY) rats. The NEP gene was expressed in all 5 cardiac regions in both age groups. In young rats, the NEP expression level was lowest in the RA; this level was significantly lower than in the septum (p < 0.05). In the advanced-age adult rats, the level was lowest in the LA; this level also was significantly lower than in the septum (p < 0.05). The level in the RA in advanced-age rats was higher than that in the young rats (p < 0.01), but the levels in other regions were not significantly different between the young rats and advanced-age adult rats. Our study showed that the NEP gene was expressed in all cardiac regions of both young rats and advanced-age adult rats. However, the regional distribution of the gene was different in each age group. The region-specific expression of the NEP gene and the age-related regional changes in the expression may be due to the structural and functional characteristics of the various regions.
Raizada
V
V
Department of Internal Medicine, University of New Mexico School of Medicine, Health Sciences Center, Albuquerque 87111, USA.
Luo
W
W
Skipper
B J
BJ
McGuire
P G
PG
D000375:Aging / Q000235:genetics*; D000818:Animals; D015971:Gene Expression Regulation, Enzymologic; D009206:Myocardium / Q000201:enzymology*; D015260:Neprilysin / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011921:Rats, Inbred WKY; D020133:Reverse Transcriptase Polymerase Chain Reaction
D012333:RNA, Messenger; D015260:Neprilysin