The mechanism of cerebrovascular vasoconstriction in response to locus coeruleus stimulation.
Stimulation of the locus coeruleus in 11 Macaca nemestrina monkeys resulted in a frequency-dependent increase in internal carotid resistance (vasoconstriction) and a frequency-dependent decrease in external carotid resistance (vasodilation). The internal carotid constrictor response is maximal at low frequency stimulation (5 s-1), and decreases as frequency of stimulation is increased or decreased. It is blocked by the non-specific alpha-adrenoceptor blocker phentolamine and the alpha-2 adrenoceptor blocker yohimbine, but is unaffected by the alpha-1 adrenoceptor blocker prazosin. It is concluded that the cerebral vasoconstrictor response to locus coeruleus stimulation is mediated by alpha-2 adrenoceptors.
Goadsby
P J
PJ
Lambert
G A
GA
Lance
J W
JW
D000818:Animals; D001921:Brain / Q000098:blood supply*; D002339:Carotid Arteries / Q000294:innervation*; D007275:Injections, Intravenous; D008125:Locus Coeruleus / Q000502:physiology*; D008254:Macaca nemestrina; D010646:Phentolamine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D014661:Vasoconstriction; D014666:Vasomotor System / Q000502:physiology; D015016:Yohimbine / Q000494:pharmacology
D011942:Receptors, Adrenergic, alpha; D015016:Yohimbine; D011224:Prazosin; D010646:Phentolamine