Length-dependent regulation of basal myosin phosphorylation and force in detrusor smooth muscle.

Content Provider	Semantic Scholar
Author	Ratz, Paul H. Miner, Amy S.
Copyright Year	2003
Abstract	Urinary bladder (detrusor) smooth muscle is active in the absence of an external stimulus. Tone occurs even "at rest" during the filling phase, and it is elevated in patients with overactive bladder. This study examined the role of muscle length on tone and the level of basal myosin light chain phosphorylation (MLC(20P)). MLC(20P) was 23.9 +/- 1% (n = 58) at short lengths (zero preload; L(z)). An increase in length from L(z) to the optimal length for contraction (L(o)) caused a reduction in MLC(20P) to 15.8 +/- 1% (n = 49). Whereas 10 microM staurosporine reduced MLC(20P) at L(z), 1 microM staurosporine, a Ca(2+)-free solution, and inhibitors of MLC kinase, protein kinase C (PKC) and RhoA kinase (ROK) did not. However, 1 microM staurosporine and inhibitors of ROK inhibited MLC(20P) and tone at L(o). These data support the hypothesis that a Ca(2+)-independent kinase, possibly ZIP-like kinase, regulates MLC(20P) at L(z), whereas in detrusor stretched to L(o), additional kinases, such as ROK, participate.
Starting Page	1321
Ending Page	1333
Page Count	13
File Format	PDF HTM / HTML
DOI	10.1152/ajpregu.00596.2002
Alternate Webpage(s)	http://ajpregu.physiology.org/content/ajpregu/284/4/R1063.full.pdf
PubMed reference number	12626367
Alternate Webpage(s)	https://doi.org/10.1152/ajpregu.00596.2002
Journal	Medline
Volume Number	284
Issue Number	4
Journal	American journal of physiology. Regulatory, integrative and comparative physiology
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article