scholarly journals Stimulation of In Vitro Angiogenesis by Tetrahydrobiopterin in Bovine Aortic Endothelial Cells

1999 ◽  
Vol 80 (2) ◽  
pp. 177-180 ◽  
Author(s):  
Shunichi Shimizu ◽  
Masako Yasuda ◽  
Masakazu Ishii ◽  
Tsutomu Nagai ◽  
Yuji Kiuchi ◽  
...  
1983 ◽  
Vol 49 (02) ◽  
pp. 132-137 ◽  
Author(s):  
A Eldor ◽  
G Polliack ◽  
I Vlodavsky ◽  
M Levy

SummaryDipyrone and its metabolites 4-methylaminoantipyrine, 4-aminoantipyrine, 4-acetylaminoantipyrine and 4-formylaminoan- tipyrine inhibited the formation of thromboxane A2 (TXA2) during in vitro platelet aggregation induced by ADP, epinephrine, collagen, ionophore A23187 and arachidonic acid. Inhibition occurred after a short incubation (30–40 sec) and depended on the concentration of the drug or its metabolites and the aggregating agents. The minimal inhibitory concentration of dipyrone needed to completely block aggregation varied between individual donors, and related directly to the inherent capacity of their platelets to synthesize TXA2.Incubation of dipyrone with cultured bovine aortic endothelial cells resulted in a time and dose dependent inhibition of the release of prostacyclin (PGI2) into the culture medium. However, inhibition was abolished when the drug was removed from the culture, or when the cells were stimulated to produce PGI2 with either arachidonic acid or ionophore A23187.These results indicate that dipyrone exerts its inhibitory effect on prostaglandins synthesis by platelets or endothelial cells through a competitive inhibition of the cyclooxygenase system.


2006 ◽  
Vol 128 (3) ◽  
pp. 329-334 ◽  
Author(s):  
Michael B. Dancu ◽  
John M. Tarbell

Hemodynamics plays an important role in cardiovascular physiology and pathology. Pulsatile flow (Q), pressure (P), and diameter (D) waveforms exert wall shear stress (WSS), normal stress, and circumferential strain (CS) on blood vessels. Most in vitro studies to date have focused on either WSS or CS but not their interaction. Recently, we have shown that concomitant WSS and CS affect EC biochemical response modulated by the temporal phase angle between WSS and CS (stress phase angle, SPA). Large negative SPA has been shown to occur in regions of the circulation where atherosclerosis and intimal hyperplasia are prevalent. Here, we report that nitric oxide (NO) biochemical secretion was significantly decreased in response to a large negative SPA of −180 deg with respect to an SPA of 0° in bovine aortic endothelial cells (BAEC) at 5 h. A new hemodynamic simulator for the study of the physiologic SPA was used to provide the hemodynamic conditions of pro-atherogenic (SPA=−180 deg) and normopathic (SPA=0 deg) states. The role of complex hemodynamics in vascular remodeling, homeostasis, and pathogenesis can be advanced by further assessment of the hypothesis that a large negative SPA is pro-atherogenic.


Sign in / Sign up

Export Citation Format

Share Document