Fischer W, Pfitzer G
II. Physiologisches Institut, Universität Heidelberg, FRG.
FEBS Lett. 1989 Nov 20;258(1):59-62. doi: 10.1016/0014-5793(89)81615-1.
In intact smooth muscle strips from chicken gizzard, electrical stimulation and carbachol elicited brief, phasic contractions which were associated with a very rapid, transient phosphorylation of the 20 kDa myosin light chains. The phosphorylation transients reached their peak after 3 s and 6 s and preceded that of force. Phosphorylation was not significantly different from basal levels after 10 s and 30 s while force still amounted to 50% of the peak value. The rate of tension decline could be increased by cessation of stimulation or by addition of atropine, even at apparently basal phosphorylation levels suggesting a phosphorylation independent regulation.
