Cardiac puncture as a survival and multiple blood collection method in laboratory rats

Abstract

Blood collection is a vital tool for diagnosis and treatment. Cardiac puncture is considered a suitable terminal technique to attain a single large and good quality blood sample at the end of an experimental period. The present study aimed to modify the cardiac puncture technique to make it a non-terminal multiple blood sampling method. Forty-eight adult Wistar rats of both sexes were randomly divided into four equal groups, each containing six animals for each sex. Cardiac puncture blood sampling, under anesthesia by 3–5% isoflurane, was executed once (group I), twice (group II), three times (group III), and four times (group IV), with a week interval from the first, second, third, and fourth groups, respectively, throughout five weeks. By the end of each group, rats were euthanized under anesthesia with a ketamine/xylazine cocktail to get the heart tissue samples. The hematological parameters, including red blood cell (RBC) and platelet (PLT) counts, hemoglobin (Hb) content, packed cell volume (PCV), and blood indices were investigated. Serum activities of lactate dehydrogenase (LDH), creatine kinase (CK), and aspartate aminotransferase (AST) were estimated. The cardiac levels of malondialdehyde (MDA), glutathione (GSH), and nitric oxide (NO) were reported. Histopathological examination of the cardiac tissue was conducted. We found no significant differences in any of hematological, biochemical, or oxidative stress parameters. Histopathological analysis demonstrated relatively moderate, non-progressive cardiac alterations following repeated sampling, suggesting minimal tissue injury. The 3Rs principle for animal welfare is implemented through the use of the heart puncture technique, which can be modified to serve as a non-terminal approach for collecting multiple blood samples.