Changes in the liver, kidney and heart fatty acid composition following administration of ibuprofen to mice

Suppression of constitutively expressed cyclooxygenase-2 in the epididymis of mice by nimesulide decreases sperm motility

Significant levels of constitutive cyclooxygenase-2 (COX-2) are present in the male reproductive organs of rodents, especially in the vas deferens and epididymis. In the epididymis, the sperm storehouse, COX-2 is thought to play a vital role in altering the membrane lipids of sperm. The present study aims at localizing COX-2 in the epididymis and analyzing the effects of the preferential COX-2 inhibitor nimesulide. COX-2 protein activity was nearly equal to that of COX-1 in the cauda epididymis. Immunohistochemical studies showed an intense staining for COX-2 in the cauda epididymis but not in the caput epididymis. Nimesulide administration induced a significant reduction in both COX-2 staining intensity and protein activity, followed by an initial decline in total prostaglandin levels but a reversible increase upon sustained COX-2 suppression. Sperm numbers and vitality showed no significant change, but motility decreased and total and free serum testosterone levels mildly increased.

Localization of cyclooxygenase-2 in mice testis and assessment of its possible role through suppressing its expression using nimesulide: a preferential cyclooxygenase-2 inhibitor

Present generation non-steroidal anti-inflammatory drugs (NSAID) are potent inhibitors of the enzyme cyclooxygenase-2 (COX-2). Even though they exhibit reduced incidence of gastrotoxicity, severe nephrotoxicity and other side effects have been widely reported with respect to usage of these drugs. Since COX-2 levels are not only upregulated by inflammation but also by other stimuli such as cytokines, growth factors, mitogens and steroid hormones, we investigated the localization of COX-2 and activity of both COX-1 and COX-2 in mice testis. To correlate the localization of COX-2 with its function we suppressed COX-2 expression with the aid of nimesulide a preferential COX-2 inhibitor. We found COX-2 was constitutively expressed in the Leydig cells of mice testis suggesting a role on testosterone synthesis. Suppression of COX-2 resulted in increased concentration of most of polyunsaturated fatty acids especially arachidonic acid (AA). Prostaglandin (PG) levels which showed an initial decline during nimesulide treatment had a reversible effect during prolonged treatment. These findings state that cyclooxygenase is constitutively expressed in mice testis and continuous inhibition of COX-2 interferes in maturation of sperm.

Treatment of hypertriglyceridemia with fenofibrate, fatty acid composition of plasma and LDL, and their relations to parameters of lipoperoxidation of LDL

The purpose of this study was to determine oxidation and oxidability of VLDL and LDL in connection with changes in their composition and content of FA in LDL after treatment with fenofibrate in patients with HTG.

Effects of selected anthropometric parameters on plasma lipoproteins, fatty acid composition, and lipoperoxidation

Four anthropometric parameters (body mass index, waist-to-hip circumference ratio, waist circumference, and ratio of subscapularis to triceps skinfold thickness), cutoff values being set according to the WHO guidelines, were compared as discriminative parameters for anthropometric, hemodynamic, and metabolic data relevant as risk factors of coronary heart disease. Waist circumference reflected differences between below and above cutoff values throughout all parameters, with the highest "effect size" values being for fat mass; blood pressure; glucose homeostasis parameters; plasma and LDL cholesterol; plasma, LDL, and VLDL apo B; and LDL oxidability (cumulative effect size value: 2777). Body mass index reflected most significantly plasma, LDL, and VLDL triglyceride; HDL and VLDL cholesterol; and content of linoleic acid in LDL phosphatidylcholine (cumulative effect size value: 2016). Waist-to-hip ratio dominated in effect size value only in VLDL oxidability (cumulative effect size value: 1497). Subscapularis to triceps skinfold thickness ratio had the lowest discriminating ability in all data.

Effects of fatty acids and fatty acyl CoA esters on Cu(2+)-induced conversion of xanthine dehydrogenase to oxidase in rabbit liver

Effects of various fatty acids and fatty acyl CoA esters on Cu(2+)-induced conversion of xanthine dehydrogenase to oxidase in rabbit liver were examined. Cu2+ (2-10 microM) brought about the conversion of xanthine dehydrogenase to oxidase in a dose-dependent manner. Oleic, arachidonic, eicosapentaenoic, and docosahexaenoic acids (50-200 microM) prevented the conversion of xanthine dehydrogenase to oxidase catalyzed by 6 microM-Cu2+. The effect of these four fatty acids was concentration-dependent, whereas palmitic, stearic, and linoleic acids had no effect on the conversion of xanthine dehydrogenase to oxidase at the same concentration range. On the other hand, palmitoyl, linoleoyl, and arachidonoyl CoAs elicited the inhibition of 6 microM-Cu(2+)-induced conversion of xanthine dehydrogenase to oxidase at concentrations of 50, 100, and 200 microM. These results suggest that oleic, arachidonic, eicosapentaenoic and docosahexaenoic acids, and fatty acyl CoAs have the potential to inhibit the conversion of xanthine dehydrogenase to oxidase in rabbit liver.