To study the therapeutic effect of Chinese herbal medicines (CHM) in treating ascites and to elucidate its mechanism in regulating the lymphatic stomata and promoting the absorption of ascites from the peritoneal cavity. Using scanning electron microscope ( SEM)

computerized image processing and quantitative analytic assay

the effect of CHM extract

consisting of Atractylodes macrocephala

Salvia miltiorrhiza

Codonopsis pilosula

Alismatis orientale and Leonurus heterophyllus

was studied. Intraperitoneal injection of nitric oxide

(NO) supplier (Sodium nitroprussiate) or CHM administration could cause the average area of lymphatic stomata obviously enlarged (P <0.05)

and the numbers of opening stomata significantly increased (P<0.01) in normal healthy mice. When L-notroarginine

a NO synthetase suppressor

was injected after CHM administration

the regulating effect of CHM on lymphatic stomata was inverted obviously

i.e. the average area and the density of lymphatic stomata were markedly reduced (P< 0.01). CHM might treat ascites through increasing the endogenous NO concentration to open the lymphatic stomata and in turn to conduct the peritoneal water through lymphatic path.