著者

Masashi Takemura Kentaro Mochizuki Yoshinori Harada Akira Okajima Michiyo Hayakawa Ping Dai Yoshito Itoh Hideo Tanaka

出版者

JAPAN SOCIETY OF HISTOCHEMISTRY AND CYTOCHEMISTRY

雑誌

ACTA HISTOCHEMICA ET CYTOCHEMICA (ISSN:00445991)

巻号頁・発行日

vol.55, no.2, pp.57-66, 2022-04-27 (Released:2022-04-27)

参考文献数

37

被引用文献数

5

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Spontaneous Raman microscopy, which can detect molecular vibrations in cells and tissues, could be a useful tool for the label-free assessment of non-alcoholic fatty liver disease (NAFLD). However, it is unclear whether it can be used to evaluate the nascent state of NAFLD. To address this, we analyzed the Raman spectra of rat liver tissues in the nascent state of NAFLD upon excitation at 532 nm. Raman and histochemical analyses were performed of liver tissues from rats fed a high-fat, high-cholesterol diet (HFHCD). Raman microscopic imaging analysis of formalin-fixed thin tissue slices showed hepatic steatosis, as revealed by the Raman band at 2,854 cm−1, whereas lipid droplets were not detectable by hematoxylin-eosin staining of images until 3 days after feeding a HFHCD. Raman signals of retinol at 1,588 cm−1 emitted from hepatic stellate cells were distributed alongside hepatic cords; the retinol content rapidly decreased after feeding a HFHCD, whereas hepatic lipid content increased inversely. Raman microscopic analysis of the surface of fresh ex vivo livers enabled early detection of lipid accumulation after a 1-day feeding a HFHCD. In conclusion, spontaneous Raman microscopy can be applied to the label-free evaluation of the nascent state of NAFLD liver tissues.

著者

Koki Ikemoto Kosuke Hashimoto Yoshinori Harada Yasuaki Kumamoto Michiyo Hayakawa Kentaro Mochizuki Kazuhiko Matsuo Kenta Yashiro Hitoshi Yaku Tetsuro Takamatsu Hideo Tanaka

出版者

JAPAN SOCIETY OF HISTOCHEMISTRY AND CYTOCHEMISTRY

雑誌

ACTA HISTOCHEMICA ET CYTOCHEMICA (ISSN:00445991)

巻号頁・発行日

pp.21-00016, (Released:2021-04-17)

被引用文献数

5

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Spontaneous Raman spectroscopy, which senses changes in cellular contents of reduced cytochrome c, could be a powerful tool for label-free evaluation of ischemic hearts. However, undetermined is whether it is applicable to evaluation of myocardial viability in ischemic hearts. To address this issue, we investigated sequential changes in Raman spectra of the subepicardial myocardium in the Langendorff-perfused rat heart before and during ligation of the left coronary artery and its subsequent release and re-ligation. Under 532-nm wavelength excitation, the Raman peak intensity of reduced cytochrome c at 747 cm−1 increased quickly after the coronary ligation, and reached a quasi-steady state within 30 min. Subsequent reperfusion of the heart after a short-term (30-min) ligation that simulates reversible conditions resulted in quick recovery of the peak intensity to the baseline. Further re-ligation resulted in resurgence of the peak intensity to nearly the identical value to the first ischemia value. In contrast, reperfusion after prolonged (120-min) ligation that assumes irreversible states resulted in incomplete recovery of the peak intensity, and re-ligation resulted in inadequate resurgence. Electron microscopic observations confirmed the spectral findings. Together, the Raman spectroscopic measurement for cytochrome c could be applicable to evaluation of viability of the ischemic myocardium without labeling.