Long-term regulation of contractility and calcium current in smooth muscle
Författare
Summary, in English
Longitudinal smooth muscle strips from guinea pig ileum were cultured in vitro for 5 days, and the relationship between extracellular Ca2+ and force in high-K+ medium was evaluated. In strips cultured with 10% fetal calf serum (FCS), this relationship was shifted to the right (50% effective concentration changed by 2-3 mM) compared with strips cultured without FCS. The shift was prevented by inclusion of verapamil (1 microM) during culture and mimicked by ionomycin in the absence of FCS. The intracellular Ca2+ concentration ([Ca2+]i) during stimulation with high-K+ solution or carbachol was reduced after culture with FCS, whereas the [Ca2+]i-force relationship was unaffected. Cells were isolated from cultured strips, and whole cell voltage-clamp experiments were performed. Maximum inward Ca2+ current (10 mM Ba2+), normalized to cell capacitance, was almost three times smaller in cells isolated from strips cultured with FCS. Culture with 1 microM verapamil prevented this reduction. These results suggest that increased [Ca2+]i during culture downregulates Ca2+ current density, with associated effects on contractility.
Avdelning/ar
Publiceringsår
1997
Språk
Engelska
Sidor
1714-1720
Publikation/Tidskrift/Serie
American Journal of Physiology: Cell Physiology
Volym
273
Issue
5
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
American Physiological Society
Ämne
- Physiology
Nyckelord
- fura 2
- verapamil
- patch clamp
- ionomycin
- tissue culture
Status
Published
Forskningsgrupp
- Vascular Physiology
ISBN/ISSN/Övrigt
- ISSN: 1522-1563