Effect of lithium treatment on blood pressure and angiotensin-converting enzyme activity in normotensive Wistar-Kyoto and spontaneously hypertensive rats.
Short-term administration of LiCl (4 mEq/kg) reduced blood pressure of SH rats but had no effect on WKY animals. Lower doses of lithium, however, did not alter blood pressure in the SH or WKY rats. Acute and chronic administration of lithium had no appreciable effect on heart rate. Although all rats gained weight during the treatment period, the per cent increase in body weight of LiCl (4 mEq/kg) treated SH and WKY rats was significantly lower than the corresponding vehicle treated animals. Angiotensin converting enzyme (ACE) activity of anterior pituitary of WKY rats was significantly higher than that of SH rats. ACE activity of neurohypophysis, instead was lower in WKY rats than in SH rats. ACE activities in plasma, striatum and hypothalamus of SH and WKY rats did not differ. After short-term lithium treatment (4 mEq/kg), plasma ACE activity was significantly reduced only in the SH animals although ACE activities in pituitary, striatum or hypothalamus remained unaffected in the SH animals. The results suggest that the antihypertensive effect of lithium in SH animals may be related to decreased plasma ACE activity.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D008094:Lithium / Q000494:pharmacology*; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D008094:Lithium; D007703:Peptidyl-Dipeptidase A