Tissue-dependent VEGF and GLUT1 induction in a rat hemorrhage model: With regard to diagnostic application of mRNA quantification in forensic pathology

• Animal studies were performed to reinforce the human autopsy findings.
• Heart, brain, kidney, liver, lung and skeletal muscle were investigated.
• VEGF and GLUT1 mRNAs showed significant inductions under hemorrhage.
• Tissue-dependent induction patterns of mRNAs were revealed in the rat model.
• This study guides the selection of markers and tissue samples in forensic practice.

Systemic hypoxia is inevitably involved in the death process to a varying extent. Hypoxia-response factors proved useful in forensic pathology in previous studies; however, fundamental investigations using animal models are expected to reinforce the findings from autopsy practice. An animal experiment using a rat model of fixed-volume hemorrhage was performed to apply basic insight into quantitative mRNA analyses in forensic pathology. Male Sprague–Dawley rats (n = 5) were anesthetized, bled from the femoral artery (24 ml/kg; about 30% of total circulating blood volume), and decapitated after 1 or 2 h. Tissue samples of the heart, brain (hippocampus), kidney, liver, lung and skeletal muscle were collected for RNA and protein analyses. Quantitative analyses of VEGF, GLUT1 and GAPDH mRNAs were performed with TaqMan real-time RT-PCR assay. In the sham control without bleeding, mRNA quantification revealed the tissue-dependent mRNA levels in physiological condition. Relative quantification of VEGF and GLUT1 showed significant inductions under hemorrhage at the mRNA level, using GAPDH as endogenous reference. In conclusion, tissue-dependent induction patterns of VEGF and GLUT1 were revealed in the volume-fixed hemorrhage rat model. This study could practically guide the selection of mRNA markers and tissue samples in forensic pathology related to tissue ischemia and cellular hypoxia for autopsy cases.