Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1994 Dec;67(6):2546-57.
doi: 10.1016/S0006-3495(94)80744-1.

Kinetics of the secretory response in bovine chromaffin cells following flash photolysis of caged Ca2+

C Heinemann  1 , R H Chow, E Neher, R S Zucker
Affiliations

Kinetics of the secretory response in bovine chromaffin cells following flash photolysis of caged Ca2+

C Heinemann et al. Biophys J. 1994 Dec.

Abstract

The kinetics of the secretory response in bovine chromaffin cells following flash photolysis of caged Ca2+ were studied by capacitance (Cm) measurements with millisecond time resolution. After elevation of the internal Ca2+ concentration ([Ca2+]i), Cm rises rapidly with one or more exponentials. The time constant of the fastest component decreases for higher [Ca2+]i (range 3-600 microM) over three orders of magnitude before it saturates at approximately 1 ms. The corresponding maximal rates of secretion can be as fast as 100,000 fF/s or 40,000 vesicles/s. There is a Ca(2+)-dependent delay before Cm rises, which may reflect the kinetics of multiple Ca2+ ions binding to the secretory apparatus. The initial rise in Cm is described by models containing a sequence of two to four single Ca(2+)-binding steps followed by a rate-limiting exocytosis step. The predicted Ca2+ dissociation constant (Kd) of a single Ca(2+)-binding site is between 7 and 21 microM. At [Ca2+]i > 30 microM clear indications of a fast endocytotic process complicate the analysis of the secretory response.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Pflugers Arch. 1993 Jul;424(2):105-12 - PubMed
    1. J Neurosci Methods. 1993 Jul;48(3):225-40 - PubMed
    1. J Biol Chem. 1993 Dec 15;268(35):26386-90 - PubMed
    1. J Physiol. 1993 Sep;469:245-73 - PubMed
    1. Trends Neurosci. 1993 Nov;16(11):466-72 - PubMed

Publication types

LinkOut - more resources

-