title: Altered cardiac beta-adrenoreceptors in spontaneously hypertensive rats receiving salt excess.
abstract: 1. Altered adrenergic responsiveness of hearts and blood vessels occurs in both experimental and clinical hypertension. 2. Since salt excess aggravates both types of hypertension, we investigated beta-adrenoreceptor properties in the hearts of spontaneously hypertensive and normotensive rats drinking 1% NaCl or tap water for 3 weeks. 3. Sodium loading increased heart weight in both spontaneously hypertensive and normotensive rats. 4. In spontaneously hypertensive rats excess salt attenuated the age-related decrease in beta-adrenoreceptor number observed in spontaneously hypertensive and normotensive rats drinking tap water and in normotensive rats drinking 1% NaCl. 5. Unlike the normotensive rats, which did not show a relationship between beta-adrenoreceptor number and blood pressure, spontaneously hypertensive rats on tap water and 1% NaCl showed a significant negative logarithmic relationship between these two variables. These data provide further evidence implicating sodium excess as an aggravating factor in this model of experimental hypertension.
mesh_terms: D000375:Aging; D000818:Animals; D001794:Blood Pressure; D006321:Heart / Q000503:physiopathology*; D006973:Hypertension / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D009929:Organ Size; D051381:Rats; D011941:Receptors, Adrenergic / Q000502:physiology*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism / Q000502:physiology*; D012964:Sodium / Q000378:metabolism*
chemical_list: D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; D012964:Sodium