Premium
An imaging apparatus for simultaneous measurement of isometric contraction and Ca 2+ fluorescence in large blood vessels of the rat
Author(s) -
Tykocki Nathan R.,
Wiseman Robert W.,
Jackson William F.,
Watts Stephanie W.
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.870.31
Subject(s) - contraction (grammar) , isometric exercise , chemistry , aorta , inferior vena cava , analytical chemistry (journal) , biomedical engineering , materials science , biophysics , chromatography , surgery , medicine , biology
While simultaneous measurement of contraction and Ca 2+ transients can be measured in small vessels (< 3 mm diameter), few strain gauges are available small and sensitive enough for concurrent measurement of Ca 2+ transients and contraction in large vessels (> 3 mm diameter). We constructed a highly sensitive low‐noise strain gauge for the simultaneous measurement of vessel tension development and Ca 2+ transients using fluorescent Ca 2+ indicators. The force transducer was fabricated from aluminum and produced a sensitivity of 0.26 μV/mg over a broad range of applied load (0.05 to 5 g) and a rapid (102.8 Hz) frequency response. Blood vessels mount to the transducer with two stainless steel pins submerged above a coverslip in a 5 ml preparation bath. We utilized this apparatus for concurrent measurement of global Ca 2+ and force production in rat aorta (RA) and vena cava (RVC) using the Ca 2+ indicator Fura‐2. ET‐1 (100 nM) caused a transient spike in global Ca 2+ that peaked when RA and RVC reached 25% of maximal contraction. After exposure to ET‐1, RVC Ca 2+ peaked within 76±9 sec and reached maximum contraction within 8±3 min. In RA, Ca 2+ peaked within 128±23 sec and reached maximum contraction within 18±4 min. These findings show that global Ca 2+ increases more rapidly in response to ET‐1 in RVC than in RA, and that this difference correlates to differences in the time to maximal force development. Supported by NIH P01HL70687.