Effects of salbutamol and sodium cromoglicate on phospholipase D activity during the degranulation of rat peritoneal mast cell
LU Yun-Bi, JIANG Bo, ZHOU Han-Liang (Department of Pharmacology, School of Medical Science, Zhejiang University, Hangzhou 310031, China)
Peritoneal mast cells were obtained from actively sensitized rats. Degranulation of rat peritoneal mast cell (RPMC) was determined by measurement of the release of β-hexosaminidase, a granule marker. Phospholipase D (PLD) activity assay of RPMC was carried out by a high sensitive method of the chemiluminescent oxidation of luminol. The method relies on the measurement of PLD product, choline. When challenged with ovalbumin(4 mg·L -1) for 120 s, PLD activity of sensitized RPMC was increased to more than 2-fold and the release of β-hexosaminidase was elevated to more than 8-fold. 1% butanol and 10 mmol·L -1 2,3-DPG produced an inhibition of PLD activity and a reduction of degranulation to control level. Wortmannin (300 nmol·L -1) decreased both PLD activity and β-hexosaminidase release. Salbutamol (1, 10 μmol·L -1) and sodium cromoglicate (1, 10 μmol·L -1) reduced PLD activity and β-hexosaminidase release in challenged mast cell but did not reach to the control level of them. These results indicate that PLD play a role in the regulation of β-hexosaminidase release in challenged sensitized RPMC, and the mechanism by which salbutamol (1, 10 μmol·L -1) and sodium cromoglicate (1, 10 μmol·L -1) inhibit degranulation in challenged sensitized RPMC is involved in reduction of PLD activity.