To observe the regulating effects of vascular endothelial growth factor （VEGF） and angiotensinⅡ （ANG II） on the frog’s pericardium

lymphatic stomata and angiogenesis so as to reveal their effects and mechanism on the mesothelial permeability

lymphatic stoma regulation and myocardial hypertrophy. Methods. VEGF and ANGⅡ were injected into the frog’s peritoneal cavity so as to examine the changes of the pericardial stromata by using transmission electron microscopy

scanning electron microscopy and computerized imaging analysis. Results. Scattered distributed pericardial stomata were found on the parietal pericardium of the frog with a few sinusoid mesothelial cells

whose blood supply was directly from the cardiac chambers flowing into the trabecular spaces of the myocardium （because there are no blood vessels in the myocardium of the frog）. The average diameters of the pericardial stomata in VEGF and ANGⅡ groups were 1.50μ m and 1.79μ m respectively

which were much larger than those in the control group (0.72μ m

P Conclusions. VEGF and ANGⅡ could strongly regulate the pericardial stomata by increasing their numbers and openings with larger diameters and higher distribution density. They could also increase the sinusoid areas with the result of the higher permeability of the pericardium

which clearly indicated that VEGF and ANGⅡ could speed up the material transfer of the pericardial cavity and play an important role in preventing myocardial interstitial edema. Yet there was no strong evidence to show the angiogenesis in the myocardium.