Experiments were performed in C57BL/6J male mice to determine the effects of acetylcholinesterase (AChE) inhibitor pyridostigmine bromide (PB) and stress on cardiovascular function, structure, and apoptosis. Mice were studied for seven days under the following conditions: Controls (osmotic minipump with saline), PB (10 mg/kg/day, minipumps), shaker stress (45 stressors/day, minipump with saline) and PB+Stress combination. AChE activity was significantly reduced in all PB-treated mice. PB caused no changes in 24-h mean arterial pressure (MAP) or heart rate (HR). Stress
increased 24-h MAP on day 1 and 24-h HR on day 7 in both Stress and PB+Stress groups. A significant reduction in the aortic wall thickness/diameter ratio (P <0.05 vs. control) and slightly reduced relative heart weight were observed in the PB group. These effects were blunted by simultaneous stress exposure. Immunochemistry was used to stain for Bax and Bcl-2 (apoptosis markers). There was a four-fold increase in Bax/Bcl-2 ratio in the heart of PB and PB+Stress treated mice while an attenuation was observed in aortic endothelium. Results suggest that a relatively short-term continuous PB exposure may have adverse effects on the heart and blood vessels, independently of changes in MAP and HR.
Red wine polyphenols have been reported to exert beneficial effects in preventing cardiovascular diseases but their molecular mechanisms of hemodynamic effects on functional cardiovascular and renal changes were studied much less. The review is focused on in vitro as well as in
vivo effects of red wine extract containing polyphenolic compounds
(Provinols™) on cardiovascular systems and kidney in relation to the molecular and biochemical mechanisms of these compounds. This review provides the evidence that Provinols™ is able to produce ex vivo
endothelium-dependent relaxation as a result of enhanced NO synthesis. Administration of Provinols™ partially prevents the development of hypertension during NO deficiency and accelerates the decrease of blood pressure in already established hypertension. The effects of Provinols™ include prevention and/or attenuation of myocardial fibrosis, reduction of aortic wall thickening and improvement of vascular functions. These functional and structural alterations are associated with significant augmentation of NO production, seen as the increase of NO synthase activity and eNOS protein expression. Moreover, it has been documented that Provinols™ decreased the oxidative stress within the cardiovascular system and kidney.
Endothelial loss of isolated rabbit femoral artery and renal artery was evaluated during in vitro vessel perfusion. Desquamated endothelial cells were captured on millipore filters from the perfusion solution outflow of the vessel in 3 intervals lasting 5 minutes each. In the first 5 minutes of perfusion the endothelial loss was 1 289.2 ± 166.5 cells: in the interval after a 30 minute perfusion 4 967.9 ± 1 428.3 cells were caught on the filters, 3.9 times more than in the first interval. During and after the 2 minutes air bubble perfusion the endothelial catch was 5.5 times greater as compared to the second interval with the average of 27 473 ±6 209.6 cells. The present method of quantification of the endothelial cell loss in the in vitro vessel perfusion experiment makes it possible to obtain informations about the actual state of the endothelial lining and to contribute to more precise evaluation of the modulatory effect of the endothelium on vessel reactivity to pharmacological agents.
It became evident in the present study that carbon tetrachloride (CCl4), in addition to its known liver and renal toxicity, causes serious damage to endothelial cells. The preventive effect of red wine on cardiovascular diseases has been documented in a number of human population studies as well as in animal experimental models. In this study, the endothelium protective effect of polyphenolic compounds isolated from red wine was studied in rats administered 0.5 ml of CCl4/kg body weight intraperitoneally twice a week for 8 weeks. Endothelemia (endothelial cells/10 μl of plasma) was used as the marker of endothelial cell injury in vivo. Chronic CCl4 treatment for 8 weeks lead to a 3-fold increase of free endothelial cells circulating in the blood when compared to the baseline values (2.5±0.3). Parallel oral administration of polyphenols 40 mg/kg/day significantly decreased the endothelemia. Polyphenolic compounds alone did not produce significant changes. Three weeks of spontaneous recovery after the 8-week treatment with CCl4 did not lead to a marked decrease of endothelemia, but the administration of red wine polyphenols during the 3-week period significantly decreased free endothelial cells in the blood. It can be concluded that long-term administration of CCl4 may serve as a useful experimental model of endothelial damage. The red wine polyphenolic compounds exert a powerful protective effect on endothelial cells from the injury caused by CCl4. This effect was documented by decreased endothelemia that corresponded to diminished endothelial cell swelling and detachment evaluated by histology of the vascular intima. The endothelium protective effect may be one of the key factors that contribute to the preventive action of red wine on cardiovascular diseases.