Hiroshi Fujimiya

Antigen-induced biphasic diacylglycerol formation in RBL-2H3 cells: The late sustained phase due to phosphatidylcholine hydrolysis is dependent on protein kinase C

Exposure to antigen (Ag) caused a biphasic 1,2-diacylglycerol (DG) production in [3H]myristic acid-labeled RBL-2H3 cells; the early, small transient phase and the second large sustained phase. The accumulation of phosphatidic acid (PA) or phosphatidylethanol (PEt) in the presence of ethanol was paralleled by the second-phase DG generation. Ag-induced formation of phosphocholine and choline in [3H]choline-labeled cells suggested the hydrolysis of phosphatidylcholine (PC) by phospholipases C and D. Treatment with phorbol myristate (PMA) or A23187 caused increases in [3H]DG and water-soluble [3H]choline metabolites. In protein kinase C (PKC) down-regulated cells, PEt formation was markedly reduced. In these cells DG production induced by Ag and A23187 was largely suppressed, thus indicating that PKC would play an important regulatory role for PC hydrolysis. However, because the A23187 treatment showed significant accumulation of water-soluble choline metabolites in PKC down-regulated cells, an increase in intracellular Ca2+ is another factor regulating PC hydrolysis. Taken together, these results may indicate that PC hydrolysis in response to Ag is dependent on PKC and Ca2+.

Effect of a Novel Antiallergic Drug, Pemirolast, on Activation of Rat Peritoneal Mast Cells: Inhibition of Exocytotic Response and Membrane Phospholipid Turnover

The effects of a potent antiallergic drug, pemirolast (TBX), on activation of signal-transducing phospholipase C and A2, were examined in rat peritoneal mast cells. TBX at concentrations between 10(-7) and 10(-5) g/ml effectively inhibited degranulation in response to both antigen and compound 48/80. At the same concentrations the drug markedly suppressed the formation of 1,2-diacylglycerol and phosphatidic acid, and the decrease in phosphatidylinositol, suggesting the prevention of phospholipase C activation. The blockade of phospholipase A2 was suggested by the decrease in agonists-induced arachidonic acid liberation. These results indicate that TBX may exert its inhibitory effects on mast cells, at least in part, by preventing the activation of signal-transducing phospholipases.

Actual situation of balance disordered persons recognized in the Law for the Welfare of Physically Disabled Persons

1) The data published by the Welfare Ministry and the Gifu prefectural office were analyzed with respect to persons with balance disorders. Balance disorders account for only 0.1 percent to 0.2 percent of all physical disabilities.2) The number of, persons with balance disorders living in Gifu prefecture is 81.3) The causes of the balance disorder in these 81 persons were : labyrinth or eighth cranial nerve damage (31), CNS disturbance (42), combined disturbance of the labyrinth and CNS (4), and unknown (4).4) Persons under 18 years or 60 years of age had mainly CNS disturbances.5) The incidence of multiple handicaps, especially balance disorder plus deafness, was higher in the labyrinth and the eighth cranial nerve damage group than in the CNS disturbance group.6) Grade 5 balance disorder was more common than grade 3 in the labyrinth and the eighth cranial nerve damage group. The number of grade 3 and grade 5 balance disorders was approximately equal in the CNS disturbance group.