These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Cell-attached measurements of attofarad capacitance steps in rat melanotrophs.
    Author: Kreft M, Zorec R.
    Journal: Pflugers Arch; 1997 Jun; 434(2):212-4. PubMed ID: 9136678.
    Abstract:
    Capacitance changes in cell-attached patches of rat melanotrophs were measured by a high-frequency lock-in amplifier. The background noise of around 30 aF allowed the detection of discrete steps due to fission (endocytosis) and fusion (exocytosis) of vesicles with diameters as small as 60 nm. The amplitude of both types of steps was similar with a modal value of around 300 aF. The frequency of these steps was not changed, if secretagougues such as ionomycin and/or dibutyril cAMP, were applied to the bathing solution. Moreover, this treatment did not result in an increased appearance of expected 2000 to 3000 aF steps due to exocytosis of secretory granules. We conclude that the likely explanation for recorded capacitance steps is that they represent the constitutive vesicle traffic. From the typical frequency and amplitude of these events (around 1 min-1, 300 aF) in a membrane patch (26 fF) it is estimated that the whole membrane of a rat melanotroph may be ingested under our conditions in 1 to 2 h.
    [Abstract] [Full Text] [Related] [New Search]