Polarized FT-IR microscopy of calcified turkey leg tendon
Polarized FT-IR microscopy of calcified turkey leg tendon
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DOI：
10.3109/03008209609000699
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发表时间：
1996-01-01
影响因子：
2.9
通讯作者：
Mendelsohn, R
中科院分区：
文献类型：
--
作者：
Gadaleta, SJ;Landis, WJ;Mendelsohn, R
使用偏光傅立叶变换红外显微镜 (FT-IRM) 评估正常钙化火鸡腿腱的矿物质和基质成分的方向。对两组 60 周龄（老）肌腱进行了分析，检查了肌腱钙化、非钙化和过渡区域的线性序列。以“平行偏振”模式收集的光谱是用平行于胶原纤维轴的红外辐射的电矢量获取的，而以“垂直偏振”模式收集的光谱是用垂直于该轴的红外辐射的电矢量获取的。肌腱矿物质的nu(2)碳酸盐(850-890 cm(-1))和nu(1)、nu(3)磷酸盐(900-1180 cm(-1))轮廓以及细胞外基质的胶原酰胺I、II和III带均显示出明显的二色性。腱矿物中CO32-离子取代PO43-（878 cm(-1)，B型取代）表现出平行二色性，而腱矿物中CO32-离子取代OH（871 cm(-1)，A型取代）表现出垂直二色性。这些碳酸盐取代位点的定向效应在老年动物中更大。使用经验各向异性参数 (A) 分析 nu(1)、nu(3) 磷酸盐轮廓的偏振特性，该参数的值监控取向程度。该指数在其他动物中显着增加，表明衰老产生了更高定向的矿物质。胶原细胞外基质的酰胺I、II和III轮廓也表现出明显的二色性，酰胺I组分表现出垂直二色性，而酰胺II和III组分表现出平行二色性。目前的研究证明了偏振 FT-IRM 在微观水平上评估钙化组织的矿物质和基质成分的方向的能力。
Polarized Fourier transform infrared microscopy (FT-IRM) was used to assess the orientation of mineral and matrix components of the normally calcified turkey leg tendon. Two groups of tendon, 60 weeks of age (old), were analyzed, Linear sequences from calcified, non-calcified, and transitional regions of the tendons were examined. Spectra collected in the ''parallel polarization'' mode were acquired with the electric vector of the infrared radiation parallel to the collagen fiber axis whereas spectra collected in the ''perpendicular polarization'' mode were acquired with the electric vector of the infrared radiation perpendicular to this axis. The nu(2) carbonate (850-890 cm(-1)) and nu(1), nu(3) phosphate (900-1180 cm(-1)) contours of the tendon mineral as well as the collagen amide I, II, and III bands of the extracellular matrix all displayed marked dichroism. The CO32- ions substituted for PO43- (878 cm(-1), type B substitution) in the tendon mineral displayed parallel dichroism while the CO32- ions substituted for OH (871 cm(-1), type A substitution) in the tendon mineral displayed perpendicular dichroism. These orientational effects for both sites of carbonate substitution were greater in the older animals. The polarization properties of the nu(1), nu(3) phosphate contour were analyzed by use of an empirical anisotropy parameter (A), the value of which monitors the degree of orientation. This index significantly increased in the other animals indicating that aging produces a more highly oriented mineral. The amide I, II, and III contours of the collagen extracellular matrix also exhibited marked dichroism, The amide I component exhibits perpendicular dichroism while the amide II and III components exhibit parallel dichroism. The current study demonstrates the ability of polarized FT-IRM to assess the orientation of the mineral and matrix components of calcified tissue at the microscopic level.