ObjectiveTo investigate the application significance of serum histidine decarboxylase (HDC) and D-lactate for early-stage of strangulated intestinal obstruction in rats. MethodsThirty male Wistar rats were randomly divided into two groups:blank control group (n=10) and experimental group (n=20). Rats of experimental group were established to be strangulated intestinal obstruction model by ligating 4 cm-long ileum, and were divided into obstruction-1 hour group (n=10) and obstruction-3 hour group (n=10) according to the time of intestinal obstruction. Rats of blank control group only underwent sham operation. When intestinal obstruction models were built, the change of pathology in ileum tissue was observed by light microscope. The Park/Chiu scale was used to evaluate the severity of intestinal lesion. At the same time, blood was drawn from the heart to measure the concentration of serum HDC and D-lactate by ELISA method. Real time quantitative PCR was used to detect the expression of HDC mRNA in ileum tissues. ResultsThe median injury score of ileum tissues of rats in blank control group, obstruction-1 hour group, and obstruction-3 hour group were 0 (0-1), 2 (2-3), and 5 (4-5) respectively, and increased in blank control group, obstruction-1 hour group, and obstruction-3 hour group one by one (P<0.01). The median concentrations of serum HDC of rats in blank control group, obstruction-1 hour group, and obstruction-3 hour group were 10.5 pg/mL (4.60-17.18 pg/mL), 87.93 pg/mL (41.33-119.03 pg/mL), and 150.67 pg/mL (67.33-198.14 pg/mL) respectively, and increased in blank control group, obstruc-tion-1 hour group, and obstruction-3 hour group one by one (P<0.05). The median concentrations of serum D-lactate in rats of blank control group, obstruction-1 hour group, and obstruction-3 hour group were 0 ng/mL (0-3.90 ng/mL), 0 ng/mL (0-15.63 ng/mL), and 4.92 ng/mL (0-48.13 ng/mL) respectively, and there was no significant difference among the 3 groups (P>0.05). The median expression levels of HDC mRNA in ileum tissue of rats in obstruction-3 hour group was 7.81 (7.05-8.39), which was significantly higher than those of the obstruction-1 hour group[1.77 (1.74-1.94)] and blank control group[0.97 (0.88-1.15)], P<0.01, but there was no significant difference between obstruction-1 hour group and blank control group (P>0.05). ConclusionsConcentration of serum HDC can be used for early diagnosis of strangulated intestinal obstruction. Serum D-lactate has no significant change at early-stage of strangulated intestinal obstruction.