High-K diets reduce brain haemorrhage and infarcts, death rate and mesenteric arteriolar hypertrophy in stroke-prone spontaneously hypertensive rats.
Male stroke-prone spontaneously hypertensive rats (SHRSP) were fed 4% NaCl diets containing either 0.75% normal K or 2.11% high K, starting at 6 weeks of age. After 8 months on these diets 69% of 58 SHRSP rats on 0.75% K had died, whereas 2% of 95 rats of 2.11% K died, a 98% reduction in mortality, P less than 0.000 001. After 20 weeks the daytime and night-time blood pressure (BP) of each rat were measured intra-arterially. We selected two groups precisely matched for BP. One matched SHRSP group (BP 182 mmHg) ate the 0.75% K diet and 30 of 47 rats died (64% mortality). The other matched SHRSP group (BP 182 mmHg) ate the 2.11% K diet, and two of 35 died (6% mortality, a 91% reduction of mortality, P less than 0.0001). Seemingly, the striking reduction in mortality rate with the 2.11% hig-K diet does not depend on a lowering of BP. High-K diets do not change body Na or K. The dry weight of mesenteric arterioles was reduced by 22% on 2.11% K diet versus 75% K (7.5 versus 9.7 mg) (P less than 0.001), indicating a greatly reduced hypertensive hypertrophy. In nine surviving SHRSP on 0.75% K, 13 of 36 brain hemisphere slides (four slides per rat) showed infarcts (36%). In 11 surviving SHRSP on 2.11% K, one of 44 brain slides showed infarcts (2%, a 94.5% reduction, P less than 0.0001). Brain haemorrhage was reduced by 92% on the 2.11% K diet. High-K diets allow cerebral arteries to carry very high BPs without sustaining damage to the artery wall, thereby drastically reducing brain infarcts and lowering the death rate.
Tobian
L
L
Lange
J M
JM
Johnson
M A
MA
MacNeill
D A
DA
Wilke
T J
TJ
Ulm
K M
KM
Wold
L J
LJ
D000818:Animals; D002543:Cerebral Hemorrhage / Q000517:prevention & control*; D002544:Cerebral Infarction / Q000517:prevention & control*; D004032:Diet; D006973:Hypertension / Q000178:diet therapy* / Q000235:genetics / Q000401:mortality; D006984:Hypertrophy / Q000517:prevention & control; D008297:Male; D008638:Mesenteric Arteries / Q000473:pathology*; D011188:Potassium / Q000008:administration & dosage*; D051381:Rats; D011918:Rats, Inbred SHR
D011188:Potassium