Hypertension in the recently weaned Dahl salt-sensitive rat despite a diet deficient in sodium chloride.
The Dahl rat is used as a model of hypertension that is "sensitive" to dietary salt (sodium chloride, NaCl). When dietary salt is supplemented in the Dahl rat, the arterial blood pressure of the "salt-sensitive" strain (S) becomes much greater than that of the "salt-resistant" strain (R). It has been widely reported that arterial blood pressure of the young Dahl S rat is not greater than that of the young Dahl R rat before dietary salt is supplemented. In the present study, however, mean arterial pressure directly measured in unanesthetized, unrestrained S rats was greater than in R rats, both when they had been recently weaned and for at least 10 weeks thereafter, despite their having been fed a diet frankly deficient in salt. In weanling S rats, the ratio of heart weight to body weight was also significantly greater than that in weanling R rats, suggesting that the greater blood pressure in the S rat causes cardiac hypertrophy. Thus, biologic differences demonstrated between the S rat and the R rat after weaning, including the phenomenon of salt-sensitivity, could be a consequence of, or be dependent on, an already extant difference in arterial blood pressure between the two strains.
D000818:Animals; D001794:Blood Pressure; D001795:Blood Pressure Determination; D004039:Diet, Sodium-Restricted; D005260:Female; D005263:Femoral Artery / Q000502:physiology; D006973:Hypertension / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains / Q000502:physiology*; D012965:Sodium Chloride / Q000378:metabolism; D014886:Weaning
D012965:Sodium Chloride