Sustained smooth muscle contraction is mediated by protein kinase C (PKC) through a signal transduction cascade leading to contraction. Heat-shock protein 27 (HSP27) appears to be the link between these two major events, i.e., signal transduction and sustained smooth muscle contraction. We have investigated the involvement of HSP27 in signal transduction and HSP27 association with contractile p...

PURPOSE To enhance our understanding of sonographically visible alterations in bladder wall thickness, we delineated phenotypic changes occurring in developing smooth muscle cells of the fetal and postnatal bladder with respect to gender specific differences. MATERIALS AND METHODS Bladders of 30 male and 18 female fetuses and 4 stillborn infants were immunostained with an alpha-smooth muscle ...

Mature airway smooth muscle cells are characterized by a low proliferative index and expression of contractile marker proteins such as smooth muscle alpha-actin (sm-alpha-actin), calponin, and smooth muscle myosin heavy chain (sm-MHC). In the present study, defined extracellular matrix (ECM) components were examined on the proliferative and phenotypic status of mitogen-stimulated, cultured huma...

Relaxation of both smooth and skeletal muscles appears to be caused primarily by inhibition of the step associated with Pi release in the actomyosin ATPase cycle, rather than by a block in the binding of the myosin X ATP and myosin X ADP X Pi complexes to actin. In skeletal muscle, troponin-tropomyosin not only causes marked inhibition of Pi release, but it also markedly inhibits the binding of...

background: the process of wound healing involves integrated events including inflammation, granulation tissue formation, matrix deposition and remodeling. growth factors play a key role in the process. among them transforming growth factor-ß1 (tgf-ß1) is known to accelerate tissue repair by promoting the synthesis and deposition of extracellular matrix proteins. however, persistence or overact...

Caldesmon is known to inhibit actomyosin ATPase and filament sliding in vitro, and may play a role in modulating smooth muscle contraction as well as in diverse cellular processes including cytokinesis and exocytosis. However, the structural basis of caldesmon action has not previously been apparent. We have recorded electron microscope images of negatively stained thin filaments containing cal...

OBJECTIVE To study the healing process of the myocardium in hypertensive rats undergoing inhibition of nitric oxide synthesis. METHODS Two groups of animals were studied: one received L-NAME, 12 mg/kg/day, and the other was a control group. The presence of type III collagen, fibronectin, and alpha-smooth muscle actin-positive cells was assessed by immunohistochemistry. RESULTS Fibronectin w...

We studied product inhibition of the actin-activated ATPase of myosin subfragment-1 (S-1) from the three types of muscle tissue: skeletal, cardiac, and smooth. Increasing levels of [MgADP] in the 0-1-mM range caused significant inhibition of the actin-activated MgATPase activity of cardiac and gizzard but not skeletal muscle S-1. When total nucleotide concentration ([ATP] + [ADP]) was kept cons...

The interactions of vascular smooth muscle caldesmon with actin, tropomyosin, and calmodulin were determined under conditions in which the four proteins can form reconstituted Ca2+-sensitive smooth muscle thin filaments. Caldesmon bound to actin in a complex fashion with high affinity sites (K = 10(7) M-1) saturating at a stoichiometry of 1 per 28 actins, and lower affinity sites at 1 per 7 act...

We estimated the cellular myosin, actin, and tropomyosin contents of vascular smooth muscle from (1) seven major arteries, (2) seven large veins, and (3) the first through third order branches of the uterine vasculature to determine whether variations in the contractile apparatus contribute to the functional diversity of vascular smooth muscle. We obtained the estimates by quantitative densitom...