β-adrenergic regulation of adenosine 3′,5′-monophosphate concentration in brain microvessels

Norepinephrine increases the concentration of adenosine 3′,5′-monophosphate (cyclic AMP) in an incubated suspension of brain microvessels. This response can be matched by other drugs that stimulate the β receptors, but the α-adrenergic agonist phenylephrine is without effect; β-adrenergic blockade abolishes the response while αa -adrenergic blockade produces no change. The data support the contention that cerebral capillary function is subject to adrenergic neural control.