title: Aortic reactivity and electrophysiology in normotensive rats, spontaneously hypertensive rats and rats made hypertensive with desoxycorticosterone plus salt.
abstract: The mechanical and electrophysiological activity of rings and strips of thoracic aortic smooth muscle taken from normotensive, DOCA-hypertensive and New Zealand spontaneously hypertensive (A.S. strain) rats have been compared. Aortae from A.S.-hypertensive rats developed less tension in the presence of noradrenaline and K+ than those isolated from normotensive and DOCA-hypertensive rats. Aortae from DOCA-hypertensive rats developed the same tension in response to K+ as normotensive rats but were less reactive to noradrenaline. Measurements of resting membrane potentials from the three groups of rats demonstrated that whereas normotensive and DOCA-hypertensive rats had similar resting membrane potentials, those from A.S.-hypertensive rats were significantly lower (P<0.001). It is suggested that the enhanced responsiveness of intact vascular beds in A.S.-hypertensive rats is a consequence of a change in the geometry of the blood vessels rather than an increase in the contractor response of the smooth muscle cells.
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000503:physiopathology*; D003900:Desoxycorticosterone; D004558:Electric Stimulation; D004594:Electrophysiology; D005260:Female; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology*; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D012965:Sodium Chloride
chemical_list: D003900:Desoxycorticosterone; D012965:Sodium Chloride; D009638:Norepinephrine