The process of signal transduction across the lymphocyte plasma membrane is under investigation. Novel fluorescent probes of physiolobic parameters such as membrane potential, intracellular pH and intracellular calcium, in conjunction with the high sensitivity and single cell resolution of flow cytometry, are being utilized. We have found that positively charged cyanine dyes are not suitable for measuring membrane potential in cells containing mitochondria, but that negatively charged oxonol dyes are reliable indicators. Lymphocytes and moncytes, but not granulocytes, buffer membrane potential over more than the physiologic range of extracellular potassium ion. T lymphocytes, but not B lymphocytes, possess a calmodulin-dependent, calcium-densitive potassium channel. A new calcium probe, indo-1, is very useful for measuring intracellular free calcium ion. We find that blocking the IgG Fc receptor of B cells significantly prolongs the calcium transient induced by anti-immunoglobulin.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Intramural Research (Z01)
Project #
1Z01AI000425-02
Application #
3960603
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
2
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Niaid Extramural Activities
Department
Type
DUNS #
City
State
Country
United States
Zip Code