Ibuprofen abolishes the increase in leucocyte chemiluminescence observed during ischemic myocardial failure, but fails to improve hemodynamic function

Ibuprofen inhibits adhesiveness of monocytes to endothelium and reduces cellular oxidative stress in smokers and non-smokers

BACKGROUND

Cigarette smoking is a major risk factor in atherosclerosis and a useful model from which to study chronic inflammation. We compared monocyte function, lipid profiles and inflammatory markers in smokers and non-smokers, before and after oral ibuprofen intake. The adhesion of freshly isolated monocytes to native and tumour necrosis factor alpha (TNFalpha) stimulated human umbilical vein endothelial cells (HUVEC), as well as superoxide anion (O2-) levels and hydrogen peroxide (H2O2) production in resting and phorbol myristate acetate (PMA) stimulated monocytes were determined.

MATERIALS AND METHODS

A group of nine smokers without any other coronary risk factor was compared with an age-matched group of 9 non-smokers. Tests were performed before and after a two-week course of oral ibuprofen (600 mg day-1).

RESULTS

In smokers before ibuprofen, monocyte adhesion to native and TNFalpha-stimulated HUVEC was increased (P < 0001 and P < 0.01, respectively), and so were O2- levels in native and PMA-stimulated monocytes (P < 0.01 and P < 0.001, respectively). Ibuprofen reduced the adhesion of monocytes to native and stimulated HUVEC (P < 0.001) and O2- generation by resting and PMA-stimulated cells (P < 0.01) in both groups. H2O2 production by resting and PMA-stimulated monocytes was reduced in smokers and non-smokers (P < 0.01). Interestingly, ibuprofen increased HDL cholesterol levels in smokers (P < 0.01) and non-smokers (P < 0.001), and reduced the level of triglycerides in smokers (P < 0.05).

CONCLUSION

Oral administration of ibuprofen reduced the adhesion of monocytes to HUVEC, suppressed oxidative stress and increased HDL cholesterol levels in smokers and non-smokers.

The ischemic heart--experimental models

Results obtained by experimental studies of the ischemic heart have been of tremendous importance for the understanding of physiology, biochemistry and lately also the molecular genetics of the heart. Experimental models in use for the study of the ischemic heart involve studies on the integrated organism, experiments with isolated hearts or multicellular preparation, and also studies of cells isolated from the heart. Regional ischemia in the anaesthetized animal has been a standard model. Knowledge about infarct size limitation as well as heart function in acute and chronic ischemia has been obtained based on experiments in a wide variety of species. The isolated perfused heart has been subjected to extensive use. As a result, the understanding of intracellular processes is constantly developing. Cell models and transgenic-mice models represent promising additions. Each model and each species has certain advantages and disadvantages. Variability in susceptibility towards ischemia and reperfusion is also present. The consequences of ischemia can be described as contractile dysfunction and stunning, arrhythmia and infarction each representing different endpoints of injury. The experimental model is also heavily dependent on the endpoint that is chosen for the study. Results obtained in one experimental model can, therefore, not be generalized into universal conclusions about the ischemic heart. With respect to the human and the disease caused by myocardial ischemia, fragments of knowledge put together from different types of experimental models create the background for successful design of potential treatment.

An inhibitor of thromboxane production attenuates tumor necrosis factor release by activated human alveolar macrophages

Tumor necrosis factor alpha (TNF alpha) and thromboxane A2 (TXA2) are major products of the activated alveolar macrophage and serve as key mediators of lung injury. In order to determine if the synthesis of TXA2 and the release of TNF alpha are associated, the production of these inflammatory agents by the human alveolar macrophage (AM), as a result of activation by lipopolysaccharide (LPS), was assessed in the absence and presence of the thromboxane synthase inhibitors UK 38,485 (Dazmegrel) and OKY 046. UK 38,485 and OKY 046 inhibited both LPS-stimulated TXA2 production and TNF alpha release in a dose-dependent manner. Prostaglandin E2 (PGE2) production was not increased by UK 38,485 or OKY 046. Neither LPS nor UK 38,485 had any effect on LTB4 production by AM. Neither UK 38,485 or OKY 046 had any effect on LPS-stimulated interleukin-1 beta release. However, the TXA2 mimetic, U46619, did not stimulate TNF alpha release by AM either in the absence or presence of UK 38,485. These findings suggest that 1) UK 38,485 and OKY 046 are inhibitors of both TXA2 production and TNF alpha release by activated human AM, 2) UK 38,485 probably does not exert its inhibitory action on TNF alpha release through effects on eicosanoid production and 3) the possibility that TNF alpha- and TXA2-induced lung injury may be subject to amelioration by imidazole-based compounds should be further evaluated.