Stimulation of growth and calcium influx in cultured, bovine, aortic endothelial cells by platelets and vasoactive substances

While cigarette smoking has beenimplicated in the development of cardiovascular diseases, it has been reported to increase fibrinolytic activity in vivo. However, no data is available regarding the underlying mechanism of action. The present investigation was carried out to evaluate the effects of nicotine and its major metabolite, cotinine, on the seretion of plasminogen activator (PA) and PA inhibitor (PAI) by cultured bovine aortic endothelial cells. PA activity was determined by the fibrin plate method, and individual molecular species with PA and PAI activities were separated and visualized using SDS-PAGE with zymography and reverse fibrin autography. Both nicotine and cotinine increased PA secretion in a time- and dose-dependent manner. A maximum stimulation in PA secretion after 24-hour incubation was observed for nicotine at 10-8 M and for cotinine at 10-7> M, which corresponded to 2.5- and 2.7-foldincreases over control, respectively. These concentrations are in the range observed after cigarette smoking. The pharmacological stimulation of PA activity required both RNA and protein synthesis, as evidencedby its inhibition by cycloheximide and actinomycin D. Both control cells and cells treated with nicotine and cotinine produced multiple forms of PA and a single form of PAI. The PAI was mainly of the latent form as no quenching effect was observed on standard tissue plasminogen activator (tPA) and urokinase (UK) after they were mixed with the conditioned culture medium. The PAs werefound to consist of both tPA and UK,and the corresponding complexes with PAI, however, the UK bands were wider than the tPA bands. Both species were enhanced by nicotine and cotinine. Although activities of all species of PA were enhanced by nicotine and cotinine, these compounds had no apparent quantitative or qualitative effects on the release ofPAI. These results thus suggest that the mechanism underlying the enhanced fibrinolytic activity after cigarette smoking may be due to nicotine- and cotinine-induced stimulation of PA synthesis and subsequent release.

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Bradykinin-stimulated calcium influx in cultured bovine aortic endothelial cells

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1988.255.2.h219 ◽

1988 ◽

Vol 255 (2) ◽

pp. H219-H227 ◽

Cited By ~ 5

Author(s):

W. P. Schilling ◽

A. K. Ritchie ◽

L. T. Navarro ◽

S. G. Eskin

Keyword(s):

Endothelial Cells ◽

Calcium Influx ◽

Peak Level ◽

Fold Increase ◽

Aortic Endothelial Cells ◽

Fourfold Increase ◽

Bovine Aortic Endothelial Cells ◽

Induced Changes ◽

K Permeability ◽

Aortic Endothelial

Bradykinin (BK)-stimulated release of endothelium-derived relaxing factor has been linked to a rise in cytosolic Ca2+ concentration and a change of K+ permeability of the endothelial cell. In the present study, measurement of BK-induced changes in fura-2 fluorescence and 86Rb+ efflux were used to monitor changes in cytosolic Ca2+ and K+ permeability in cultured bovine aortic endothelial cells. In the presence of normal extracellular Ca2+, BK induced a fourfold increase in cytosolic Ca2+, which peaked at 20 s and declined within 1 min to a value that was 50% of the peak level. Subsequently, cytosolic Ca2+ decreased and approached basal levels within 8 min. In the absence of Ca2+, BK produced a 1.5- to 2-fold increase in cytosolic Ca2+ that peaked within 20 s and declined to basal levels within 2 min. Addition of Ca2+ to the Ca-free reaction buffer 3-5 min after addition of BK resulted in a two-to threefold increase in cytosolic Ca2+ that declined slowly back to basal levels. Thus Ca2+ influx can occur in response to BK at a time when there is minimal elevation of cytosolic Ca2+ above the resting level. Under all conditions tested, 86Rb+ efflux paralleled changes in the cytosolic Ca2+, suggesting that efflux occurred through Ca2+-activated K+ channels. Isosmotic substitution of Na+ with N-methyl-D-glucamine did not affect the BK-stimulated changes in cytosolic Ca2+ or 86Rb+ efflux, suggesting that Na+-Ca2+ exchange plays little role in the BK response. These results suggest that BK stimulates Ca2+ influx via a BK receptor-operated channel or a channel activated by some internal messenger other than Ca2+.

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Correlation of HSP70 Expression and Cell Viability Following Thermal Stimulation of Bovine Aortic Endothelial Cells

Journal of Biomechanical Engineering ◽

10.1115/1.1993661 ◽

2005 ◽

Vol 127 (5) ◽

pp. 751-757 ◽

Cited By ~ 26

Author(s):

Marissa Nichole Rylander ◽

Kenneth R. Diller ◽

Sihong Wang ◽

Shanti J. Aggarwal

Keyword(s):

Endothelial Cells ◽

Cell Viability ◽

Guideline Development ◽

Cardiac Cells ◽

Thermal Stimulation ◽

Hsp70 Expression ◽

Aortic Endothelial Cells ◽

Bovine Aortic Endothelial Cells ◽

Stimulation Of ◽

Aortic Endothelial

Thermal preconditioning protocols for cardiac cells were identified which produce elevated HSP70 levels while maintaining high cell viability. Bovine aortic endothelial cells were heated with a water bath at temperatures ranging from 44to50°C for periods of 1-30min. Thermal stimulation protocols were determined which induce HSP70 expression levels ranging from 2.3 to 3.6 times the control while maintaining cell viabilities greater than 90%. An Arrhenius injury model fit to the cell damage data yielded values of A=1.4×1066s−1 and Ea=4.1×105J∕mol. Knowledge of the injury parameters and HSP70 kinetics will enhance dosimetry guideline development for thermal stimulation of heat shock proteins expression in cardiac tissue.

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