Role of HTK cardioplegic solution in reducing inflammatory response during cardiac arrest: a rat model with a right thoracotomy

Abstract Objective: The aim of this research was to develop a rat model for CPB that was both elementary and cost-effective while also being characterized by minimal inter-individual variability. Materials and methods: Thirty rats were randomly assigned to three groups: the HTK, 4:1 blood cardioplegia (BC) and del Nido cardioplegia (DN) groups. The CPB procedure was established and post-CPB was persevered for a period of 2 hours and then samples of heart and blood were collected for analysis. Results: During CPB, the average hematocrit level was significantly below the typical physiological range (P<0.001). Histopathological scores were notably reduced in the HTK group in contrast to the BC group (P<0.001) or the DN group (P<0.001). At 2 hours after CPB, the levels of CK and CKMB in the DN and BC groups were notably elevated compared to the HTK group (P < 0.001). The levels of IL-6 and TNF-α proteins were notably increased in all three groups (P<0.001), with the BC and DN groups showing higher increases compared to the HTK group (P<0.001). Conclusions: The rat model was capable of reflecting the real organ injury of patients undergoing cardiac surgery and HTK was more beneficial in reducing inflammatory response.