Cannabinoid system and cyclooxygenases inhibitors.

RATIONALE: The cannabinoid system consists of a complex array of receptors, substances with agonist/antagonist properties for those receptors, biosynthetic machineries and mechanisms for cellular uptake and degradation for endocannabinoids. This system is in interrelation with other systems that comprise lipid mediators like prostaglandins/leukotrienes systems. A clear antagonist, additive or synergic effect of nonsteroidal anti-inflammatory drugs (NSAIDs)-cannabinoid associations was not yet demonstrated. Aim. The present study tried to summarize the existent data on NSAIDS-cannabinoid system interactions. METHODS AND RESULTS: A bibliographic research in Medline, Scirus, Embase was made using as keywords cannabinoid, nonsteroidal anti-inflammatory drugs, aspirin, ibuprofen, flurbiprofen, diclofenac, indomethacin, acetaminophen, coxibs, antinociceptive, antinociception, analgesia DISCUSSIONS: A systematization of the results focusing on the NSAIDs drugs interaction with the cannabinoid system was presented. Out of all the substances analyzed in the present review, acetaminophen was studied the most regarding its interferences with the cannabinoid system, mainly due to contradictory results. CONCLUSIONS: Some NSAIDs have additional influences on the cannabinoid system either by inhibiting fatty acid amide hydrolase (FAAH) or by inhibiting a possible intracellular transporter of endocannabinoids. All the NSAIDs that inhibit COX2 can influence the cannabinoid system because a possible important degradative pathway for anandamide and 2-arachidonoyl glycerol might involve COX 2. One of the causes for the variety of experimental results presented might be due to pharmacokinetic mechanisms, depending on the route of administration and the dose

Electron microscopic study of the arterial wall in the cerebral aneurysms.

The ultrastructural modifications were observed in electron microscopy of the congenital aneurysm of the internal carotid artery with subarachnoid hemorrhage. The tunica intima very enlarged contains in the endothelial cells numerous microvesicles of pinocytosis, and rare cell organelles. The internal elastic lamina presented ruptured or absence zones. The luminal face of the cells appeared irregular with large evaginations and deep and narrow invaginations. Under the endothelial lining, large masses of extracellular matrix with different degrees of edema, and fragmented collagen fibrils realize a metabolic barrier between the tunica intima and media. The muscle fibers of the tunica media and the myofilaments in each myocyte are in reduced number.