Significance: Photoacoustic imaging (PAI) enables the detection of blood hemoglobin (HB) concentration and oxygenation (sO2) with high contrast and resolution. Despite the heavy use of photoacoustically determined total hemoglobin (THb) and oxygenation (sO2) biomarkers in PAI research, their relationship with underlying biochemical blood parameters and the impact of intra- and interspecies genetic variability have yet to be established. Aim: To explore the relationship between THb and sO2 photoacoustic biomarkers and the underlying biochemical blood parameters in a species-specific manner. Approach: Experiments were performed on blood in vitro using tissue-mimicking agar phantoms. Blood was extracted from mouse, rat, human, and naked mole-rat (Heterocephalus glaber), anticoagulated in ethylenediaminetetraacetic acid, and measured within 48 h. THb and sO2 were measured using a commercial photoacoustic tomography system (InVision 128, iThera Medical GmBH). Biochemical blood parameters such as HB concentration (g/dL), hematocrit (HCT, %), and red blood cell (RBC) count (μL − 1) were assessed using a hematology analyzer (Mythic 18 Vet, Woodley Equipment). Results: A significant correlation was observed between THb and biochemical HB, HCT, and RBC in mouse and rat blood. Moreover, PAI accurately recapitulated interspecies variations in HB and HCT between mouse and rat blood and resolved differences in the oxygen dissociation curves measured using sO2 between human, mouse, and rat. With these validation data in hand, we applied PAI to studies of blood obtained from naked mole-rats and could confirm the high oxygen affinity of this species in comparison to other rodents of similar size. Conclusions: Our results demonstrate the high sensitivity of photoacoustically determined hemoglobin biomarkers toward species-specific variations in vitro.

中文翻译：

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光声学解决了血红蛋白浓度和氧合作用的物种特异性差异。


意义：光声成像 (PAI) 能够以高对比度和分辨率检测血液血红蛋白 (HB) 浓度和氧合 (sO2)。尽管在 PAI 研究中大量使用光声测定的总血红蛋白 (THb) 和氧合 (sO2) 生物标志物，但它们与基础生化血液参数的关系以及种内和种间遗传变异的影响尚未确定。目的：以物种特异性的方式探讨 THb 和 sO2 光声生物标志物与潜在的生化血液参数之间的关系。方法：使用模拟组织的琼脂模型对体外血液进行实验。从小鼠、大鼠、人类和裸鼹鼠 (Heterocephalus glaber) 中提取血液，在乙二胺四乙酸中抗凝，并在 48 小时内进行测量。 THb 和 sO2 使用商用光声断层扫描系统（InVision 128，iThera Medical GmBH）进行测量。使用血液分析仪（Mythic 18 Vet，Woodley Equipment）评估血液生化参数，如 HB 浓度 (g/dL)、血细胞比容 (HCT, %) 和红细胞 (RBC) 计数 (μL − 1)。结果：小鼠和大鼠血液中的 THb 与生化 HB、HCT 和 RBC 之间存在显着相关性。此外，PAI 准确地再现了小鼠和大鼠血液之间 HB 和 HCT 的种间差异，并解决了使用 sO2 测量的人类、小鼠和大鼠之间氧解离曲线的差异。有了这些验证数据，我们将 PAI 应用于从裸鼹鼠身上获得的血液的研究，并且可以确认该物种与其他类似体型的啮齿动物相比具有高氧亲和力。 结论：我们的结果表明，光声测定的血红蛋白生物标志物对体外物种特异性变异具有高敏感性。