Extracellular calcium transients at single excitations in rabbit atrium measured with tetramethylmurexide.
نویسندگان
چکیده
منابع مشابه
Extracellular calcium transients at single excitations in rabbit atrium measured with tetramethylmurexide
Extracellular calcium transients were resolved within the time course of single contraction cycles in rabbit left atrium using tetramethylmurexide (2 mM) as the calcium-sensitive dye (150-250 microM total calcium, 80-150 microM free calcium). Net extracellular calcium depletion began within 2-4 ms upon excitation; over the following 5-20 ms, depletion continued steeply and amounted to 0.2 mumol...
متن کاملActivation-dependent cumulative depletions of extracellular free calcium in guinea pig atrium measured with antipyrylazo III and tetramethylmurexide.
We have used a spectrophotometric method to monitor mean free extracellular calcium concentrations in isolated left atria of guinea pigs via extracellular application of the calcium-sensitive absorption dyes, antipyrylazo III and tetramethylmurexide. Exchange of extracellular free calcium with the bathing medium takes several minutes and closely parallels contractile response in this preparatio...
متن کاملExtracellular calcium transients and action potential configuration changes related to post-stimulatory potentiation in rabbit atrium
Extracellular calcium transients were monitored with 2 mM tetramethylmurexide at low calcium (250 microM total, 130 microM free), and action potentials were monitored together with developed tension at normal calcium (1.3 mM) during the production and decay of post-stimulatory potentiation in rabbit left atrial strips. At normal calcium, the contractile potentiation produced by a brief burst of...
متن کاملRate-dependent changes in extracellular potassium in the rabbit atrium.
We measured levels of potassium ion in the extracellular space of isolated superfused rabbit atria continuously with double-barreled microelectrodes of which on barrel was a K+ liquid ion-exchanger microelectrode and the other a potential-sensing micropipette. Increases in heart rate resulted in transient increases in extracellular potassium ([K+]0). When the quiescent atrium was stimulated the...
متن کاملMechanical transients of single toad stomach smooth muscle cells. Effects of lowering temperature and extracellular calcium
Smooth muscle's slow, economical contractions may relate to the kinetics of the crossbridge cycle. We characterized the crossbridge cycle in smooth muscle by studying tension recovery in response to a small, rapid length change (i.e., tension transients) in single smooth muscle cells from the toad stomach (Bufo marinus). To confirm that these tension transients reflect crossbridge kinetics, we ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of General Physiology
سال: 1986
ISSN: 0022-1295,1540-7748
DOI: 10.1085/jgp.87.5.707