1. Previous studies have indicated that increases in dietary K+ promote diuresis and retard
stroke development in
stroke-prone spontaneously hypertensive rats (spSHR) fed a Japanese-style diet containing 4% NaCl. 2. It is possible that elevations in dietary K+ retard
stroke development by inducing natriuresis and facilitating the clearance of Na+, and that
diuretics associated with natriuresis might also be capable of retarding
stroke development in spSHR. To test if this was the case, the onset of
stroke development in spSHR fed a low (0.75%) K+ diet containing 4% NaCl (controls) was monitored and compared with that in spSHR treated with (a)
frusemide, (b)
chlorothiazide, (c)
amiloride or (d)
acetazolamide, and with (e) untreated spSHR fed a high (2.11%) K+ diet. 3. The onset of
stroke, as well as death resulting from
stroke, occurred at a significantly later age in spSHR fed a high K+ diet than in spSHR fed a low-K+ diet, despite the fact that both groups of spSHR rats had comparable blood pressures. 4. Treatment of spSHR with the above-named
diuretics before
stroke development did not alter the blood pressure of the rats. The onset of
stroke development and death in spSHR treated with
chlorothiazide,
amiloride or
acetazolamide was comparable with that observed in untreated control spSHR. In spSHR treated with
frusemide, the onset of
stroke was comparable with that of untreated control spSHR, whereas the onset of death after
stroke development was accelerated. 5. Post mortems performed on spSHR that developed
stroke indicated the presence of haemorrhagic
stroke of comparable severity in the six groups of spSHR studied.(ABSTRACT TRUNCATED AT 250 WORDS)