Abstract

The ileal longitudinal smooth muscle developed a transient contraction on cooling from 37 degrees C to 1 degree C in normal Ca2+ (2.5 mM) medium. The transient contraction was not inhibited by pretreatment with the Ca2+ antagonist, D-600 (1 X 10(-6)M). The contractions were sustained by cooling to 1 degree C in the presence of added Ca2+ greater than 10 mM. After the pretreatment with D-600, when the muscle incubated in normal medium with added 20 mM Ca2+ had been cooled to 1 degree C, a phasic response was only seen. However, D-600 did not inhibit the sustained contraction at 1 degree C after incubation in the presence of added 20 mM Ca2+. It is suggested that the transient and sustained contraction at 1 degree C is maintained by Ca2+ release from a cellular site, probably the cell membrane and it requires more calcium for the sustained tension.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.