The expression of cytoplasmic beta-actin and cardiac, skeletal, and smooth muscle alpha-actins during early avian cardiogenesis was analyzed by in situ hybridization with mRNA-specific single-stranded DNA probes. The cytoplasmic beta-actin gene was ubiquitously expressed in the early chicken embryo. In contrast, the alpha-actin genes were sequentially activated in avian cardiac tissue during th...

A monoclonal antibody (anti-ctsm-1) recognizing exclusively a-smooth muscle actin was selected and characterized after immunization of BALB/c mice with the NH2-terminal synthetic decapeptide of a-smooth muscle actin coupled to keyhole limpet hemocyanin. Anti-ctsm-1 helped in distinguishing smooth muscle cells from fibroblasts in mixed cultures such as rat dermal fibroblasts and chicken embryo f...

Goldsmith AM, Hershenson MB, Wolbert MP, Bentley JK. Regulation of airway smooth muscle -actin expression by glucocorticoids. Am J Physiol Lung Cell Mol Physiol 292: L99–L106, 2007. First published September 15, 2006; doi:10.1152/ajplung.00269.2006.—Airway smooth muscle hypertrophy appears to be present in severe asthma. However, the effect of corticosteroids on airway smooth muscle cell size o...

A monoclonal antibody (anti-alpha sm-1) recognizing exclusively alpha-smooth muscle actin was selected and characterized after immunization of BALB/c mice with the NH2-terminal synthetic decapeptide of alpha-smooth muscle actin coupled to keyhole limpet hemocyanin. Anti-alpha sm-1 helped in distinguishing smooth muscle cells from fibroblasts in mixed cultures such as rat dermal fibroblasts and ...

Previous studies from this laboratory have demonstrated that angiotensin II (Ang II) and arginine vasopressin (AVP) are potent hypertrophic agents in cultured rat aortic smooth muscle cells. The present study identified major proteins that accumulate in Ang H-induced and AVP-induced hypertrophic cells and initiated studies of the mechanisms that contribute to their accumulation. Smooth muscle c...

Thiosphosphorylated smooth muscle myosin and skeletal muscle myosin, both of which express Ca(2+)-independent actin-activated MgATPase activity, were used to examine the functional effects of calponin and caldesmon separately and together. Separately, calponin and caldesmon inhibited the actin-activated MgATPase activities of thiophosphorylated smooth muscle myosin and skeletal muscle myosin, c...

Dynamic remodeling of the actin cytoskeleton plays an essential role in the migration and proliferation of vascular smooth muscle cells. It has been suggested that actin remodeling may also play an important functional role in nonmigrating, nonproliferating differentiated vascular smooth muscle (dVSM). In the present study, we show that contractile agonists increase the net polymerization of ac...

The cellular distribution of the alpha-vascular and gamma-enteric smooth muscle actin isoforms was analyzed in rat embryos from gestational day (gd) 8 through the first neonatal week by in situ antigen localization using isoactin specific monoclonal antibodies. The alpha-vascular actin isoform was first detected on gd 10 in discrete cells lining the embryonic vasculature. By gd 14, this isoform...

Background and aims: Chronic idiopathic intestinal pseudo-obstruction (CIIP) is a severe motility disorder associated with significant morbidity. Several histopathological (neuropathic and myopathic) phenotypes have been described but only a single adult with jejunal smooth (circular) muscle a-actin deficiency. We present a prospective multinational case series investigating smooth muscle a-act...