Effect of chronic ANG I-converting enzyme inhibition on aging processes. V. Intracellular calcium-vasoreactivity coupling.
Age-related changes in intracellular calcium ([Ca2+]i)-vasoreactivity coupling efficiency (i.e., perfusion pressure divided by [Ca2+]i) were studied in vitro in tail arteries of male, normotensive, WAG/Rij rats aged 6, 12, 24, or 30 mo; one-half of these were chronically treated with the angiotensin I-converting enzyme inhibitor (ACEI) perindopril (1 mg.kg-1.day-1 orally) from 6 mo onward. Arterial segments were perfused at a constant flow rate (perfusion pressure taken as an index of arterial tone) and loaded with the acetoxymethyl ester of fluorescent dye fura 2 (fura 2-AM). Increases in [Ca2+]i were measured simultaneously with vasoconstriction after stimulation with a depolarizing hyperkalemic solution or the agonists norepinephrine or serotonin. Age had no effect on increases in [Ca2+]i vasoconstrictor responses, or electromechanical coupling efficiency (hyperkalemic solution). Increases in [Ca2+]i after agonists were similar in all groups, but vasoconstrictor responses and pharmacomechanical coupling efficiency decreased with age. ACEI had no effect on vasoconstriction or [Ca2+]i signals. In conclusion, coupling efficiency after agonist stimulation decreased with age; ACEI had no effect on coupling efficiency.
Capdeville-Atkinson
C
C
Laboratoire de Pharmacologie Cardiovasculaire, Faculté de Pharmacie, Université Henri Poincaré Nancy 1, France.
Oster
L
L
Thorin-Trescases
N
N
Robert
A
A
Corman
B
B
Atkinson
J
J
D000375:Aging / Q000187:drug effects / Q000502:physiology*; D000704:Analysis of Variance; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D001158:Arteries / Q000254:growth & development / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D007211:Indoles / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D024510:Muscle Development; D009131:Muscle, Smooth, Vascular / Q000254:growth & development / Q000502:physiology; D020913:Perindopril; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000494:pharmacology; D013623:Tail / Q000098:blood supply
D000806:Angiotensin-Converting Enzyme Inhibitors; D007211:Indoles; D012701:Serotonin; D002118:Calcium; D020913:Perindopril