High NaCl predisposes Dahl rats to cerebral infarction after middle cerebral artery occlusion.
High (8%) and low (0.3%) NaCl diets were administered for 3 weeks before testing inbred Dahl salt-sensitive (SS/Jr) or salt-resistant rats (SR/Jr) for altered susceptibility to cerebral infarction after occlusion of the middle cerebral artery. At occlusion time, mean systolic blood pressure (BP) was 201 +/- 7 mm Hg in SS/Jr fed a high NaCl diet. Two weeks later an atrophied infarct was present in the territory of the occluded artery of all (n = 10) hypertensive SS/Jr, and infarct size was correlated with BP at occlusion time (p less than 0.01). In normotensive control SS/Jr fed a low NaCl diet (n = 11), BP (118 +/- 3 mm Hg), frequency of infarction (18%), and infarct size were all significantly less (p less than 0.05) than in the hypertensive rats. In SR/Jr fed a high (n = 11) or low (n = 10) NaCl diet, BP was not statistically different (112 +/- 4 vs 116 +/- 4 mm Hg). Cerebral infarction frequency was significantly (p less than 0.05) greater in SR/Jr fed a high NaCl diet (73%) than in SR/Jr receiving a low NaCl diet (20%), but infarct size was not correlated with BP in SR/Jr (p greater than 0.05). Thus, elevated NaCl intake in SS/Jr and SR/Jr before middle cerebral artery occlusion predisposes to cerebral infarction, but differences in infarct size and its correlation with BP suggest the controlling factors are not identical in the two strains.
Coyle
P
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Department of Anatomy and Cell Biology, University of Michigan, Ann Arbor 48109.
D000818:Animals; D001794:Blood Pressure; D002536:Cerebral Arteries / Q000502:physiology*; D002544:Cerebral Infarction / Q000209:etiology*; D003250:Constriction; D005260:Female; D006973:Hypertension / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012307:Risk Factors; D012965:Sodium Chloride / Q000494:pharmacology*; D012982:Sodium, Dietary / Q000008:administration & dosage*
D012982:Sodium, Dietary; D012965:Sodium Chloride