Increased plasma level of endothelin-1 in the Okamoto spontaneously hypertensive rat.
The objectives of this study were to determine plasma levels of endothelin (ET) in a genetic model of hypertension and in control rats during control conditions and in response to short-term volume expansion with saline. Okamoto spontaneously hypertensive rats (SHR) and control Wistar-Kyoto (WKY) rats were used in this study. One group of each strain served as control animals, and another group of each strain underwent volume expansion with saline (5% of body weight infused during a period of 30 minutes). The levels of ET-1 and ET-3 were measured in plasma by using a double-antibody radioimmunoassay. In the control groups of SHR and WKY rats, plasma ET-1 levels were 72.5 +/- 14.9 pg/ml (N = 8) and 40.2 +/- 7.5 pg/ml (N = 12), respectively (P < 0.05). In the volume-expanded SHR group (N = 8), the plasma ET-1 level was 45.5 +/- 11.1 pg/ml (approximately 37% less than that of the control SHR group), whereas it was 40.6 +/- 10.2 pg/ml in the volume-expanded group of WKY rats (N = 10) (almost identical to that of the control WKY group). Plasma levels of ET-3 were similar in control and in volume-expanded groups of SHR and WKY rats. These data show that basal levels of plasma ET-1 are significantly higher in the SHR than in the WKY rat.(ABSTRACT TRUNCATED AT 250 WORDS)
Khraibi
A A
AA
Department of Physiology and Biophysics, Mayo Clinic, Rochester, MN 55905.
Heublein
D M
DM
Knox
F G
FG
Burnett
J C
JC
D000818:Animals; D016232:Endothelins / Q000097:blood*; D008297:Male; D010952:Plasma Substitutes; D051381:Rats; D011918:Rats, Inbred SHR / Q000097:blood*; D011921:Rats, Inbred WKY / Q000097:blood; D012965:Sodium Chloride
D016232:Endothelins; D010952:Plasma Substitutes; D012965:Sodium Chloride