Subject smooth muscle cells

Elastogenesis occurs primarily during late fetal and early neonatal periods. Elastin is synthesized and secreted from several cell types including smooth muscle cells, fibroblasts, endothelial cells, chondroblasts, and mesothelial cells (Uitto et al, 1991) with tissue-specific induction of elastin expression during development (Swee et al, 1995). After elastin has been deposited, its synthesis ceases and very little turnover of elastin is seen during adult life, unless the elastic fibers are subject to injury. In this case,... 

Airway smooth muscle cells isolated from canine tracheae and bronchi subjected to cyclic strain exhibit increased cell number and DNA synthesis in cell culture. The content of total cellular protein, especially contractile proteins including myosin, myosin light chain kinase, and desmin, was increased compared to cells cultured under static conditions. 

In particular, Aviptadil was shown to reduce the proliferation of pulmonary artery vascular smooth muscle cells. A high rate of Aviptadil receptor expression was found in the lungs, but this reflected the high lung uptake of radiolabeled Aviptadil in normal subjects [26]. 

It is not clear whether L-type Ca + channels in other tissues such as smooth muscle are also affected by conditions in which cAMP is elevated. Other modulatory pathways that have been proposed are (1) both activation and inhibition of the L-type Ca2+ channel in cardiac and smooth muscle cells by protein kinase C (PKC) and (2) direct activation of the skeletal muscle and cardiac L-type Ca2+ channel by a GTP binding protein (Gg-a). The smooth muscle L-type Ca2+ channel can be modulated by agonists such as in bronchial and vascular smooth muscle (Nelson et al., 1988 Worley et al., 1991 Kamishima et al., 1992). Modulation of the smooth muscle L-type Ca + channel remains an important subject of future research. 

The role of NO and cGMP in the hyperpolarization of the smooth muscle cell membrane has been the subject of much scrutiny and controversy in the last few years. On the one hand, there is a wealth of evidence that supports the notion that in some smooth muscle cell preparations, NO or cGMP activates BK channels. However, in a few of these instances, NO has been found to activate BK channels independent of cGMP elevations. And then there are some smooth muscle cell types where BK channels appear to play no role in NO- or cGMP-mediated relaxation. These findings have led to the realization that there appears to be cell-specific effects for NO and cGMP for the activation of BK channels. These findings are summarized here. 

Biochemical and physiological data have shown that both smooth muscle MLCK and MLCP activities are subject to modulation. MLCK can be phosphory-lated at a regulatory site A near the CaM-binding domain, which densitizes its activation by Ca +/CaM (Conti and Adelstein, 1981). MLCK site A phosphorylation in smooth muscle cells desensitizes RLC phosphorylation to Ca2+ (Tansey etal., 1994). MLCP activity is diminished following dissociation of the catalytic subunit from its targeting subunit in vitro (Alessi etal.,... 

FIGURE 4 Effects of candidate cytostatic agents on DNA synthesis by rat aorta smooth muscle cells in culture. (A) The diethylamine/nitric oxide adduct (DEA/NO), whose half-life for NO release is 2.1 min under the conditions used (B) The diethylenetriamine/nitric oxide adduct (DETA/NO), with a half-life of 20 hr. Cells were incubated at 37°C for 22 hr after addition of the given drug at the indicated concentrations, whereupon [ H]thymidine was added. After an additional 2-hr incubation DNA was isolated from the cells and subjected to scintillation counting to provide a quantitative measure of DNA synthesis by these cells. [Adapted from Mooradian et al. (1995) with permission.]... 

Smooth muscle tissues occur ubiquitously throughout the body and are present in almost every organ, where they are subjected to varied mechanical, hormonal and neural stimuli. Although generalizations can be made regarding many features of smooth muscle, it should be recognized that great diversity exists in the structure and properties of smooth muscle cells and tissues. This diversity enables the functional properties of... 

Inasmuch as cardiovascular research is concerned, the contribution of 5-HTj receptors to blood pressure through contraction of smooth muscle cells, seems firmly established. 5-HT-stimulated rise in blood pressure or in vitro arterial contractions, is subject to ketanserin and spiperone [75, 48, 49]. However, it was also shown that a close correlation exists with aj-antagonist properties, also exerted by ketanserin. Furthermore, the mixed 5HT2A/2C antagonist ritanserine was much less effective in mimicking the vascular relaxing properties of ketanserin... 

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