Figure 5.
Effect of β-adrenergic stimulation and β1 blockade on cerebral vascular smooth muscle cell membrane potential. (A and B) Recordings of artery diameter and membrane potential (Em) in rat superior cerebellar artery (SCA) exposed to 1 μmol/L isoproterenol (ISO), 30 nmol/L CGP20712 (CGP) and 1 μmol/L isoproterenol added to CGP. After recording baseline Em, ISO was added to the bath (1). After washout, CGP was added to the bath followed by ISO (2). (C) Average Em values before any addition of drugs (Control), after ISO alone, multiple washouts (Wash), CGP, and ISO in the presence of CGP (ISO+CGP), n=5 arteries each. *Significant difference from Control, P<0.05.