Manidipine 10 to 40 mg once daily for 4 weeks

GH3 cells were used for activity evaluation. the cells grown on glass coverslips were loaded with 5 mM 1-[2-(5-carboxyoxazol-2-yl)- 6-aminobenzofuran- 5-oxyx-2(-21-amino-51-methylphenoxy)-ethane-N,N,N1,N1-tetraace-tic acid pentaacetoxymethyl ester (fura-2AM) in Krebs–Ringer saline solution (5.5 mM KCl, 160 mM NaCl, 1.2 mM MgCl , 1.5 mM CaCl , 10 mM glucose, and 10 mM Hepes-NaOH, pH 7.4) for 1 h at room temperature. At the end of fura-2AM loading, the coverslip was introduced into a microscope chamber (Medical System, Greenvale, NY) on an inverted Nikon Diaphot fluorescence microscope. The cells were kept in Krebs–Ringer saline solution throughout the experiment. All the drugs tested were introduced into the microscope chamber by fast injection. When the depolarizing extracellular Kq solution (55 mM) was used, the osmolarity of the solution was kept constant by accordingly reducing the extracellular Naq concentration. A 100-W Xenon Lamp (Osram, Germany) with a computer-operated filter wheel bearing two different interference filters (340 and 380 nm) illuminated the microscopic field with UV light, alternating the wavelength at an interval of 500 ms. The interval between each pair of illuminations was 2 s, and the interval between filter movements was 1 s. Consequently, [Ca2++] was measured every 3 s. Emitted light was passed through a 400-nm dichroic mirror, filtered at 510 nm, and collected by a CCD camera connected to a light amplifier. Images were digitized and analyzed with a Magiscan image processor. Using a calibration curve, the Tardis software calculated the [Ca2++] corresponding to each pair of images from the ratio between the intensity of the light emitted when the cells were illuminated at both 340 and 380 nm.