Dietary sodium restriction and blood pressure response to alpha-receptor blockade in young spontaneously hypertensive rats.
Dietary sodium restriction (9 mumol/g food) was started in 4-week-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY), and was continued for 3 or 6 weeks. Low sodium intake for 3 weeks prevented the development of hypertension in SHR. More prolonged restriction caused hypotensive blood pressure levels in both SHR and WKY. At 7 weeks of age, SHR and WKY on a control diet showed similar blood pressure decreases after prazosin; at 10 weeks the response was significantly larger in SHR. Sodium restriction from 4 to 7 weeks of age did not inhibit the prazosin effect, whereas after more prolonged restriction the response was significantly inhibited in SHR compared with control SHR as well as with sodium-restricted WKY. These results indicate that sodium restriction may affect blood pressure in several ways, and that inhibition of the alpha 1-receptor mediated pressor effect is specific to SHR.
Leenen
F H
FH
Hypertension Unit, Toronto Western Hospital, Ontario, Canada.
Klement
G
G
D000367:Age Factors; D000818:Animals; D001794:Blood Pressure; D006973:Hypertension / Q000503:physiopathology*; D011224:Prazosin / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR / Q000502:physiology*; D011919:Rats, Inbred Strains / Q000502:physiology*; D011921:Rats, Inbred WKY; D011942:Receptors, Adrenergic, alpha / Q000502:physiology; D012982:Sodium, Dietary / Q000502:physiology*
D011942:Receptors, Adrenergic, alpha; D012982:Sodium, Dietary; D011224:Prazosin