title: The influence of restricted calorie intake on peritoneal macrophage function.
abstract: Malnutrition leads to immune dysfunction with greatly increased morbidity. However, restrictive dietary regimens are also known to preserve immune function in autoimmune-susceptible mice. The macrophage (Mø) is central to both immune effector and autoregulatory functions and is critical to host-defense mechanisms. The aim of this study was to investigate the effect of calorie restriction on Mø functions in mice. Female, 6- to 8-wk-old, Swiss Webster mice were randomized to ad libitum feeding for 7 or 21 d (n = 10 mice/group), restricted feeding (13.5 to 14.0 g/cage/d; n = 10) for 7 d, or restricted feeding (16.5 to 17.0 g/cage/d; n = 10) for 21 d. These restrictions were equivalent to a decrease in calorie intake of 21.9% and 5.1%, respectively, over 7 and 21 d. All mice were allowed free access to water. On days 8 and 22, respectively, the mice were killed, and peritoneal Møs were isolated by lavage and adhered to 96-well polystyrene tissue-culture-treated plates. After stimulation with lipopolysaccharide, supernatant prostaglandin E2 and interleukin-6 levels were measured by enzyme-linked immunosorbent assay. Supernatant NO2- in response to stimulation with lipopolysaccharide and interferon-gamma was determined by the Greiss reaction. Prostaglandin E2 production was significantly elevated in peritoneal Møs from the calorie-restricted mice compared with the ad-libitum-fed mice after 7 d. After 21 d, production of both prostaglandin E2 and nitric oxide was significantly increased (P < 0.05) in peritoneal Møs from the restricted mice compared with the ad-libitum-fed mice. These results indicate that calorie restriction influences immune function by altering prostaglandin E2 and nitric oxide generation by Møs.
authors.affiliation: Department of Surgery, New York-Presbyterian Hospital, Weill Medical College of Cornell University, 525 East 68th Street, Room F-739, New York, NY 10021, USA.
authors.forename: P P
authors.initials: PP
authors.lastname: Stapleton
authors.forename: J
authors.initials: J
authors.lastname: Fujita
authors.forename: E M
authors.initials: EM
authors.lastname: Murphy
authors.forename: H A
authors.initials: HA
authors.lastname: Naama
authors.forename: J M
authors.initials: JM
authors.lastname: Daly
mesh_terms: D000818:Animals; D004038:Diet, Reducing; D015232:Dinoprostone / Q000032:analysis; D002149:Energy Intake / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007371:Interferon-gamma; D015850:Interleukin-6 / Q000032:analysis; D008070:Lipopolysaccharides / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D051379:Mice; D009569:Nitric Oxide / Q000032:analysis; D011897:Random Allocation
chemical_list: D015850:Interleukin-6; D008070:Lipopolysaccharides; D009569:Nitric Oxide; D007371:Interferon-gamma; D015232:Dinoprostone