Inhibitory Effect and Mechanism upon Glucose-Insulin-Potassium Administration on Postpartum Mice with Uterine Cramping Pain.

This study aimed to explore the effect of glucose-insulin-potassium (GIK) on postpartum uterine cramping pain(UCP) in mice and the possible underlying mechanisms. Thirty full-term pregnancy C57BL/6 mice, within 6 h after spontaneous labor, the mice were randomly assigned into the following three groups: the control group (group C), the oxytocin group (group O), and the GIK plus oxytocin group (group G). Group G and group O were administered GIK and normal saline, respectively, and 10 min later, oxytocin was injected intraperitoneally; group C received normal saline twice. The pain scores of the mice were assessed after establishment of the postpartum UCP model. The differential expressions of energy metabolism and oxidized lipid metabolites in the uterus were analyzed. The behavioral scores in group G were significantly lower than those in group O (P < 0.05).When compared to group O, group G showed a significant increase in ATP levels (P = 0.046), and group G exhibited elevated levels of amino acids, including L-glutamine, L-aspartic acid, and ornithine. Additionally, phosphate compounds (2-phosphoglyceric acid and 3-phosphoglyceric acid) showed elevated levels. When compared to group O, group G exhibited a decrease in 19R-hydroxy PGF, an increase in 9,10-EpOME and 12,13-EpOME, and a decrease in trans-EKODE-E-Ib. Additionally, group G showed an elevation in 16,17-EpDPE and 8-HDoHE. This study confirms the analgesic effect of GIK during postpartum oxytocin infusion. Metabolomics and glycolysis product analysis suggest that GIK's alleviation of UCP is associated with its enhancement of glycolysis and the influence of phenylalanine synthesis, aspartate metabolism, and arginine synthesis pathways. Additionally, the effects of GIK appears to be linked to its influence on the linoleic acid metabolic pathway.