Antidepressants alter cerebrovascular permeability and metabolic rate in primates.
External detection of the annihilation radiation produced by water labeled with oxygen-15 was used to measure cerebrovascular permeability and cerebral blood flow in six rhesus monkeys. Use of oxygen-15 also permitted assessment of cerebral metabolic rate in two of the monkeys. Amitriptyline produced a dose-dependent, reversible increase in permeability at plasma drug concentrations which are therapeutic for depressed patients. At the same concentrations the drug also produced a 20 to 30 percent reduction in cerebral metabolic rate. At higher doses normal autoregulation of cerebral blood flow was suspended, but responsivity to arterial carbon dioxide was normal.
D000639:Amitriptyline / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001812:Blood-Brain Barrier / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002196:Capillaries / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D007700:Kinetics; D008253:Macaca mulatta; D010539:Permeability; D012039:Regional Blood Flow / Q000187:drug effects
D000639:Amitriptyline