3H-Spiroperidol (Spiperone) Binding Sites in Rat Adrenal Glomerulosa Cells

3H-spiperone, a dopaminergic antagonist, was used to study binding sites in rat adrenal glomerulosa membrane. The equilibrium dissociation constant (Kd) and binding capacity for 3H-spiperone binding were 2.2 nM and 268 fmol/mg protein, respectively. Determination of the Kd by kinetic studies provided a value of 2.6 nM, which corresponded closely to the Kd estimated by equilibrium studies. In a study of the subcellular distribution of dopamine receptors in adrenal glomerulosa cells, 3H-spiperone binding activity at the interface of density 1.14 to 1.16 accounted for 60% of the total activity in all fractions. These dopaminergic binding sites in adrenal glomerulosa cells may modulate aldosterone secretion induced by antidopaminergic agents

Effects of Treatments for Experimental Bone Tumor on Prostaglandin E Level and Bone Scintigrams

The role of Prostaglandin E (PgE) level was studied experimentally as follows: 1) intrahepatic implantation of VX-2, 2) intravenous injection of VX-2, 3) effect of treatments on intramedullary implanted VX-2. The levels of PgE in intrahepatic and intravenous transplantation were not higher than that of intramedullary transplantation. Mitomycin C (MMC) did not reduce the PgE level and appearance time of bone scan abnormality was the same as that of untreated animals. A combination of indomethacin and MMC caused a delay in appearance time of bone scan abnormalities

Therapeutic regimen of l-arginine for MELAS: 9-year, prospective, multicenter, clinical research

ObjectiveTo examine the efficacy and safety of the therapeutic regimen using oral and intravenous l-arginine for pediatric and adult patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS).MethodsIn the presence and absence of an ictus of stroke-like episodes within 6 h prior to efficacy assessment, we correspondingly conducted the systematic administration of oral and intravenous l-arginine to 15 and 10 patients with MELAS in two, 2-year, prospective, multicenter clinical trials at 10 medical institutions in Japan. Subsequently, patients were followed up for 7 years. The primary endpoint in the clinical trial of oral l-arginine was the MELAS scale, while that for intravenous l-arginine was the improvement rates of headache and nausea/vomiting at 2 h after completion of the initial intravenous administration. The relationships between the ictuses of stroke-like episodes and plasma arginine concentrations were examined.ResultsOral l-arginine extended the interictal phase (p = 0.0625) and decreased the incidence and severity of ictuses. Intravenous l-arginine improved the rates of four major symptoms—headache, nausea/vomiting, impaired consciousness, and visual disturbance. The maximal plasma arginine concentration was 167 μmol/L when an ictus developed. Neither death nor bedriddenness occurred during the 2-year clinical trials, and the latter did not develop during the 7-year follow-up despite the progressively neurodegenerative and eventually life-threatening nature of MELAS. No treatment-related adverse events occurred, and the formulations of l-arginine were well tolerated.ConclusionsThe systematic administration of oral and intravenous l-arginine may be therapeutically beneficial and clinically useful for patients with MELAS