Changes in the concentration of endothelin-1 during development of hypertensive rats.
The concentration of endothelin-1 (ET-1) in the brain regions, heart, and throacic aorta of 1-, 4-, 6- and 8-week-old spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats was determined using radioimmunoassay. ET-1-like immunoreactivity in the brain regions of 1-week-old WKY and SHR rats was lower compared to older (6 and 8 weeks) rats. ET-1 levels in the central nervous system gradually increased with age in both SHR and WKY rats. However, the concentration of ET-1 in 8-week-old rats was lower in the brain regions of SHR compared to WKY rats. The concentration of ET-1 in the thoracic aorta of SHR (224 +/- 43 pg/g tissue) rats was lower than that of WKY (452 +/- 11 pg/g tissue) rats at 1 week of age. However, ET-1 levels gradually increased with age in SHR rats. By 8 weeks of age, levels of ET-1 in SHR (623 +/- 33 pg/g tissue) rats were higher compared to WKY (439 +/- 62 pg/g tissue) rats. In the heart, ET-1 levels were similar in WKY and SHR rats at 4 weeks of age, but at 8 weeks of age ET-1 levels were higher in SHR rats (364 +/- 33 pg/g tissue) compared to WKY rats (260 +/- 31 pg/g tissue). It appears that at 8 weeks of age when hypertension is fully expressed in rats, ET-1 levels are lower in the central nervous system and are higher in the thoracic aorta and heart of SHR compared to WKY rats.
Iyer
R S
RS
Department of Pharmaceutics and Pharmacodynamics, University of Illinois at Chicago 60612, USA.
Singh
G
G
Rebello
S
S
Roy
S
S
Bhat
R
R
Vidyasagar
D
D
Gulati
A
A
D000818:Animals; D001013:Aorta, Thoracic / Q000254:growth & development / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D001923:Brain Chemistry / Q000502:physiology; D016232:Endothelins / Q000378:metabolism*; D006321:Heart / Q000187:drug effects / Q000254:growth & development; D006339:Heart Rate / Q000502:physiology; D006973:Hypertension / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D016232:Endothelins