Cyclical coronary flow reductions in conscious dogs equipped with ameroid constrictors to produce severe coronary narrowing

In conscious dogs equipped with ameroid constrictors to produce gradual coronary occlusion, coronary flow velocity was monitored prior to complete occlusion when coronary constriction was severe (resting flow velocity reduced by 10–50% from control recordings made 7–10 days after ameroid implantation). In six of the ten dogs, we observed spontaneous cyclical variations in coronary flow velocity, characterized by gradual reduction in flow followed by very abrupt restoration of flow. The cyclic coronary flow reductions were observed between 20 and 31 days after ameroid implantation. These changes in flow bear striking similarity to those observed by previous investigators using anesthetized, open-chest canine preparations, in which the role of platelets was clearly demonstrated. Consequently, we hypothesize that spontaneous platelet aggregation and de-aggregation within the severely narrowed coronary lumen (enclosed by the ameroid constrictors) could account for our observations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41746/1/395_2005_Article_BF01906748.pd

Carnitine reduces the lipoperoxidative damage of the membrane and apoptosis after induction of cell stress in experimental glaucoma

The pathological damage caused by glaucoma is associated to a high intraocular pressure. The ocular hypertone is most likely due to a defective efflux of aqueous humor from the anterior chamber of the eye. Ocular hypertension causes apoptotic death of retinal ganglion cells and overexpression of molecular markers typical of cell stress response and apoptosis. In this work, we report on the neuroprotective, antiapoptotic and antioxidant action of a natural substance, -carnitine. This compound is known for its ability to improve the mitochondrial performance. We analyze a number of cellular and molecular markers, typical of ocular hypertension and, in general, of the cell stress response. In particular, -carnitine reduces the expression of glial fibrillary acidic protein, inducible nitric oxide synthase, ubiquitin and caspase 3 typical markers of cell stress. In addition, the morphological analysis of the optic nerve evidenced a reduction of the pathological excavation of the optic disk. This experimental hypertone protocol induces a severe lipoperoxidation, which is significantly reduced by -carnitine. The overall interpretation is that mortality of the retinal cells is due to membrane damage

Metabolic constituents of grapevine and grape-derived products

The numerous uses of the grapevine fruit, especially for wine and beverages, have made it one of the most important plants worldwide. The phytochemistry of grapevine is rich in a wide range of compounds. Many of them are renowned for their numerous medicinal uses. The production of grapevine metabolites is highly conditioned by many factors like environment or pathogen attack. Some grapevine phytoalexins have gained a great deal of attention due to their antimicrobial activities, being also involved in the induction of resistance in grapevine against those pathogens. Meanwhile grapevine biotechnology is still evolving, thanks to the technological advance of modern science, and biotechnologists are making huge efforts to produce grapevine cultivars of desired characteristics. In this paper, important metabolites from grapevine and grape derived products like wine will be reviewed with their health promoting effects and their role against certain stress factors in grapevine physiology