Abstract:

Objective To establish a mathematical model of the injection by dorsal motor nucleus of vagus(DMV), the dose of L-glutamic acid（L-Glu）and the duodenal myoelectric activity index of female rabbits was established to provide a theoretical basis for studying the mechanism of action of hormones, cytokines and other vagal activity. Methods In this experiment, we used microinjection technique to inject L-Glu to DMV by doses of 0 mol/L, 0.05 mol/L, 0.10 mol/L, 0.15 mol/L and 0.20 mol/L,monitoring the duodenal myoelectric activity of ovarian abducted rabbits,the number of samples per dose group was 5, and construct a mathematical model between the dose of L-Glu and the index of duodenal myoelectric activity. Results After t-test analysis, the amplitude of myoelectric activity increased gradually between adjacent dose groups, and the difference was extremely significant (P<0.01).The frequency was gradually strengthened, and the difference between 0 mol/L and 0.05 mol/L, 0.10 mol/L and 0.15 mol/L was significant (P<0.05).The index of myoelectric activity increased gradually, and the difference between groups was extremely significant (P<0.01). With L-Glu concentration as the independent variable x, the duodenal myoelectric activity index was the dependent variable y, the constructor relationship was y=13.71/1 + exp ［-22.35 × (x-0.082)］, function fitting accuracy was R²=0.9948，P<0.01，belonging to growth type S logic function. Function analysis showed that the L-Glu dose of 0.082 mol/L was the inflection point of the logic function. As the dose range of L-Glu was 0 mol/L 0.082 mol/L,duodenal myoelectric activity index showed an exponential growth pattern,as the L-Glu dose was greater than 0.082 mol/L,the duodenal myoelectric activity index showed a logarithmic growth pattern with a theoretical limit of 13.71. Conclusion L-Glu has a significant dose-effect relationship on the promotion of duodenal myoelectric activity in rabbits by DMV, and have the effect of interval,the mathematical model laid the theoretical foundation for further research on the role of hormones and cytokines on this basis.

Key words:  L-glutamic acid, Dorsal motor nucleus of the vagus, Myoelectric activity index, Mathematical model, Duodenum, Stereotactic method of brain, Female rabbit