Objective:To study the effect of Tangweian decoction on gastric emptying in diabetic rats with gastrointestinal diseases

so as to explore its mechanism. Method:Fifty 2-3-month-old male Wistar rats were collected as subjects. Ten of them were randomly selected as normal control group (CON)

and the other 40 were made diabetic through intraperitoneal injection with streptozotocin(STZ

50 mg·kg). Diabetes was verified after 1 week

and the animals with a blood sugar level higher than 16.9 mmol·L-1 were considered as diabetic for the experiments. The 40 rats were randomly divided into diabetic control group (DM)

high-dose Tangweian decoction group (T1)

middle-dose group (T2)

and low-dose group (T3)(15

10

5 g·kg-1). CON group and DM group were treated with distilled water by gavage. After 8 weeks

the gastric emptying rate was determined by single photon emission computed tomography (SPECT). The immunohistochemistry was used to observe the changes of Cajal interstitial cells in the gastric myenteric layer. The hypothalamus substance P protein expression was detected by Western blot. Result:Compared with the CON group

the gastric emptying rate in DM group

T1 group

T2 group and T3 group decreased significantly (P<0.01); the Cajal interstitial cells in gastric myenteric layer decreased significantly (P<0.05

P<0.01); the hypothalamus protein expression substance P decreased significantly (P<0.05

P<0.01). Compared with DM group

the gastric emptying rate and the Cajal interstitial cells in T1 and T2 groups were increased significantly (P<0.05

P<0.01)

while the expression of P substance in hypothalamus increased significantly(P<0.05

P<0.01). For T3 group

the gastric emptying rate

Cajal interstitial cells and the expression of P substance in hypothalamus were increased

but with no statistically significant difference. Conclusion:Gastric emptying rate

Cajal interstitial cells in gastric myenteric layer

and the expression of substance P in hypothalamus were decreased in rats with gastrointestinal disease. Tangweian decoction has the effect in promoting the gastric emptying rate of diabetic rats with gastrointestinal diseases rats and improving gastrointestinal motility by increasing Cajal interstitial cells in gastric myenteric layer and substance P levels.