This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.107.119800v1 94/10/4095    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Kim, J. H. Articles by Kim, K.-W. PubMed PubMed Citation Articles by Kim, J. H. Articles by Kim, K.-W.

Label-Free Calcium Imaging in Ischemic Retinal Tissue by TOF-SIMS

Jin Hyoung Kim ^*, Jeong Hun Kim , Bum Ju Ahn ^*, Jae-Hwan Park ^*, Hyun Kyong Shon , Young Suk Yu , Dae Won Moon , Tae Geol Lee  and Kyu-Won Kim ^*

^* Neurovascular Coordination Research Center, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea; Department of Ophthalmology, Seoul National University College of Medicine & Seoul Artificial Eye Center, Clinical Research Institute, Seoul National University Hospital, Seoul, Korea; and NanoBio Fusion Research Center, Korea Research Institute of Standards and Science, Daejeon, Korea

Correspondence: Address reprint requests to Kyu-Won Kim, Tel.: 82-2-880-6988; E-mail: qwonkim{at}plaza.snu.ac.kr; or Tae Geol Lee, E-mail: tglee{at}kriss.re.kr.

The distribution and movement of elemental ions in biologic tissues is critical for many cellular processes. In contrast to chemical techniques for imaging the intracellular distribution of ions, however, techniques for imaging the distribution of ions across tissues are not well developed. We used time-of-flight secondary ion mass spectrometry (TOF-SIMS) to obtain nonlabeled high-resolution analytic images of ion distribution in ischemic retinal tissues. Marked changes in Ca²⁺ distribution, compared with other fundamental ions, such as Na⁺, K⁺, and Mg²⁺, were detected during the progression of ischemia. Furthermore, the Ca²⁺ redistribution pattern correlated closely with TUNEL-positive (positive for terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end-labeling) cell death in ischemic retinas. After treatment with a calcium chelator, Ca²⁺ ion redistribution was delayed, resulting in a decrease in TUNEL-positive cells. These results indicate that ischemia-induced Ca²⁺ redistribution within retinal tissues is associated with the order of apoptotic cell death, which possibly explains the different susceptibility of various types of retinal cells to ischemia. Thus, the TOF-SIMS technique provides a tool for the study of intercellular communication by Ca²⁺ ion movement.