flunarizine and dipfluzine

To investigate the effects of dipfluzine (Dip), a new derivative of cinnarizine (Cin), first developed by China, upon 5-hydroxytryptamine (5-HT)-induced contractions in cerebral arteries.. Compared Dip, flunarizine (Flu), and Cin antagonistic effects and actions on 2-component contractions evoked by 5-HT in isolated pig basilar artery.. Dip showed a greater concentration-dependent antagonistic effect on 5-HT-evoked contraction than Cin and Flu in pig basilar artery rings. The order of potency (IC50) was Dip (4.0 mumol.L-1) > Flu (15.6 mumol.L-1) > Cin (25.2 mumol.L-1). All the Dip, Flu, and Cin inhibited 2-components of 5-HT-induced contraction. The antagonistic effects of Dip and Cin on the initial fast-phase contraction (FPC) were greater than that on the sustained tonic-phase contraction (STC), but Flu showed no difference between inhibiting effects on 2-component contractions.. Dip was more potent than both of Flu and Cin on cerebrovascular dilation, associated mainly with the inhibition of intracellular calcium release.

Topics: Animals; Basilar Artery; Calcium Channel Blockers; Cinnarizine; Flunarizine; In Vitro Techniques; Muscle Contraction; Muscle, Smooth, Vascular; Serotonin Antagonists