Nitric Oxide and Superoxide Anion Production Decrease with Age in Resident and Activated Rat Peritoneal Macrophages

Immunological Investigations

Özkaya

Özdemir

et al. 2004

Aging is associated with decline in the functioning of immune cells and reductions in serum L-arginine and excretion of nitric oxide metabolites. Studies have shown that L-arginine plays an important role in many physiological, biological and immunological processes. The present study was performed to determine if treatment with L-arginine could prevent age-related changes in phagocytic function of peritoneal macrophages. The effects of L-arginine on phagocytic activity of peritoneal macrophages were compared between young and middle-aged rats. Studies were performed in four groups of rats for 8 weeks: group 1 (3 month-old) received physiological saline; group 2 (3 month-old) received L-arginine (160 mg/kg/day); group 3 (12 month-old) received physiological saline; group 4 (12 month-old) received L-arginine (160 mg/kg/day). There were no significant differences in percentage of cells which were phagocytized. However, the phagocytosis of activated charcoal by peritoneal macrophages reduced with age. Thus, the phagocytic index was lower in macrophages of middle-aged rats. L-arginine treatment increased phagocytosis by peritoneal macrophages of both young and middle-aged rats. L-arginine-induced augmentation in phagocytosis by macrophages were much higher in the middle-aged rats compared with young rats. In summary, we found that L-arginine prevented the age-related reduction in phagocytic capability of peritoneal macrophages.

Section: Discussionmentioning

confidence: 65%

Effect of L‐Arginine on Age‐Related Changes in Macrophage Phagocytic Activity

Immunological Investigations

Özkaya

Özdemir

et al. 2004

“…Phagocytic cells (neutrophils, monocytes, and macrophages) are the first line of defence system of the organism against the infectious agents (Babior, 2000;Alvarez et al, 1996). Macrophages accomplish nonspecific immune function through what is known as phagocytosis.…”

Section: Discussionmentioning

confidence: 99%

Effect of stress‐induced lipid peroxidation on functions of rat peritoneal macrophages

Cell Biology International

Tan

Bülbül

et al. 2004

The aim of the present study was to investigate the effects of stress-induced lipid peroxidation on macrophages' functions. Animals were subjected to 4 h immobilization at 4 degrees C in restraining devices. The peritoneal macrophages obtained from rats exposed to cold and restraint stress exhibited an increase in lipid peroxidation and a decline of chemotaxis and phagocytosis compared with control rats. After supplementation with vitamin E, the increment in thiobarbituric acid reactive substances (TBARS) content as the oxidative stress marker and the decline of chemotaxis and phagocytosis in peritoneal macrophages observed during cold-restraint stress was significantly removed. No significant change in catalase activity of peritoneal macrophages was observed in groups exposed to cold-restraint stress and treated with vitamin E. These findings indicate that phagocytic and chemotactic capacities of peritoneal macrophages are decreased by cold-restraint stress and this effect of stress may be related to lipid peroxidation.

“…Several authors [30,31] have reported an age-dependent increase in plasma membrane viscosity in various cells. Alvarez et al [32] demonstrated that the plasma membrane fluidity decreases in peritoneal macrophages due to aging. This findings are also corroborated by our demonstration that the chemotactic activity in inflammatory cells from elderly rats decreases and that this decline may be related to the decrease in plasma membrane fluidity.…”

Section: Discussionmentioning

confidence: 99%

Effect of <i>L</i>-Carnitine on Carrageenan-Induced Inflammation in Aged Rats

Ağaç

Derın³

2003

Gerontology

Background: It is known that L-carnitine is a cofactor in the transport of fatty acids across the inner mitochondrial membrane for β-oxidation. However, L-carnitine is an antioxidant compound widely used for the treatment of deficits in functions due to the aging process. Objective: The purpose of the study was to investigate the effect of L-carnitine on carrageenan-induced inflammation in aged rats. Methods:L-Carnitine (50 mg/kg/day) or control vehicle was given by gavage for 30 consecutive days to young (2-month-old) and aged (24-month old) rats. 6 ml of air was injected subcutaneously into the dorsum of each rat, followed 2 days later by 4 ml of 2% carrageenan. After 2 days, the exudate was collected from the inflamed site of each rat. The quantity of collected exudate and the number of cells which have migrated to the inflamed site were determined. Results: No differences were observed in quantity of exudate in all groups; a decrease in the number of exudate cells was established in aged rats. However, L-carnitine treatment significantly increased the number of exudate cells in both young and aged rats. The exudate cells from the aged rats exhibited a decline of both phagocytic and chemotactic activities as compared with those from the young rats, and the decreased functions were significantly enhanced by L-carnitine treatment. However, superoxide anion release was seen to be unchanged in exudate cells due to aging, and L-carnitine intake decreased the production of superoxide anion by these cells in young and aged rats. Conclusions: These findings demonstrate that L-carnitine is capable of restoring the age-related changes in the functions of inflammatory cells. Moreover, L-carnitine may play a protective role in the tissue destruction in inflammation by decreasing the superoxide anion production.