Quantitative assessment of [Ca2+]i levels in rat skeletal muscle in vivo.
Am J Physiol
; 275(5): H1652-62, 1998 11.
Article
de En
| MEDLINE
| ID: mdl-9815073
ABSTRACT
Intracellular free Ca2+ concentration ([Ca2+]i) plays an essential role in physiological regulatory processes and common pathological conditions. Better understanding of these phenomena is still hampered by problems encountered in the quantitative assessment of [Ca2+]i changes, especially in blood-perfused organs. This study demonstrates that the ratiometric fluorescence technique can be adapted for quantitative in vivo [Ca2+]i determinations. The rat spinotrapezius muscle was topically loaded with indo 1-AM and imaged by a cooled digital camera. Ratio images were calculated in small regions (100 micrometers x 100 micrometers) practically devoid of large vessels in the resting state, after 30 min of ischemia, 20 min of reperfusion, or ionomycin or manganate treatments. When we assumed an average [Ca2+]i of 100 nM in the resting blood-perfused muscle, ischemia increased [Ca2+]i to approximately 200 nM. During reperfusion [Ca2+]i decreased to approximately 140 nM. Ionomycin induced an increase in [Ca2+]i to well above 750 nM. Manganate reduced Ca2+-dependent fluorescence to virtually zero. Our main conclusion is that changes in [Ca2+]i can be monitored and quantitatively determined in vivo.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Calcium
/
Muscles squelettiques
Limites:
Animals
Langue:
En
Journal:
Am J Physiol
Année:
1998
Type de document:
Article
Pays d'affiliation:
Hongrie