Objective:To observe the responses of small mesenteric arteries to vasoconstrictors in diabetic patients.
Methods:The small mesenteric arteries in patients with diabetes undergoing abdominal surgeries were obtained and used as the observation group, and the corresponding small mesenteric arteries of nondiabetic patients were  obtained and used as control group. The dose-effect curves of small mesenteric arteries response to vasoconstrictors including K+, NA, 5-HT, S6c and ET-1 were recorded using BL-420 tension trace system.
Results:The vascular tension induced by K+ in the observation group and the control group was (5.39±1.19) mN and (2.92±0.78) mN, respectively (P＜0.01); Maximal contraction (Emax) and pEC50 induced by NA in observation group was (162±10)% and (6.57±0.14), and in control group was (97±19)% and 5.94±0.17 (P＜0.01), respectively. Emax and pEC50 induced by 5-HT in observation group and control group was (41±14)%, (6.21±0.19) mN,and (3±1)%,  (7.49±0.21) mN respectively (P＜0.01); Emax and pEC50 of observation group induced by S6c was (60±14)% and (7.81±0.76) mN; no response to S6c was noted in the control group (P＜0.01). The response of the observation group to lower concentration ET-1 (<10-11 mmol/L) was higher than that of the control group  (P＜0.01), and to higher concentration ET-1 was lower than that of the control group (P>0.05).
Conclusions:The response of small mesenteric arteries to vasoconstrictors in diabetic patients is higher than that in the nondiabetic individuals, which is probably due to increased receptor-binding affinity of the α-receptor, 5-HT and ETB.