Voltage-sensitive elevation of cytosolic [Ca2+] in guinea-pig cardiac myocytes elicited by calcitonin gene-related peptide.
We have studied the effect of the 37-amino acid cardioactive peptide, calcitonin gene-related peptide (CGRP) on cytosolic [Ca2+] in guinea-pig ventricular myocytes following depolarization. Cytosolic [Ca2+] was measured in single myocytes using fura-2. The application of 20 mM K+ led to a transient rise of cytosolic [Ca2+] followed by an exponential decline. The subsequent application of 2 nM CGRP resulted in a marked increase in cytosolic [Ca2+]. In contrast, no such response was obtained without prior depolarization. The results suggest a basis for the cardiotropic effects of CGRP through an influence on cytosolic [Ca2+].
Gill
J S
JS
Department of Cardiological Sciences, St George's Hospital Medical School, London.
Moonga
B S
BS
Huang
C L
CL
Lu
F
F
Zaidi
M
M
Camm
A J
AJ
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism*; D004594:Electrophysiology; D005110:Extracellular Space / Q000378:metabolism; D005260:Female; D006168:Guinea Pigs; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D009994:Osmolar Concentration; D011189:Potassium Chloride / Q000378:metabolism
D011189:Potassium Chloride; D015740:Calcitonin Gene-Related Peptide; D002118:Calcium