Effect of angiotensin II and losartan on the phagocytic activity of peritoneal macrophages from Balb/C mice.
Angiotensin II (AII), a product of rennin-angiotensin system, exerts an important role on the function of immune system cells. In this study, the effect of AII on the phagocytic activity of mouse peritoneal macrophages was assessed. Mice peritoneal macrophages were cultured for 48 h and the influence of different concentrations of AII (10(-14) to 10(-7) M) and/or losartan, 10(-16) to 10(-6) M), an AT1 angiotensin receptor antagonist, on phagocytic activity and superoxide anion production was determined. Dimethylthiazoldiphenyltetrazolium bromide reduction and the nucleic acid content were used to assess the cvtotoxicity of losartan. A stimulatory effect on phagocytic activity (P < 0.05) was observed with 10(-13) M and 10(-12 M) AII concentrations. The addition of losartan (up to10(-14) M) to the cell cultures blocked (P < 0.001) the phagocytosis indicating the involvement of AT1 receptors. In contrast, superoxide anion production was not affected by AII or losartan. The existence of AT1 and AT2 receptors in peritoneal macrophages was demonstrated by immunofluorescence microscopy. These results support the hypothesis that AII receptors can modulate murine macrophage activity and phagocytosis, and suggest that AII may have a therapeutic role as an immunomodulatory agent in modifying the host resistance to infection.
Belline
Paula
P
Disciplinas de Nefrologia e Medicina Interna, Núcleo de Medicina e Cirurgia Experimental, Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, 13083-970 Campinas, SP, Brasil.
da Melo
Patrícia Silva
PS
Haun
Marcela
M
Palhares
Fernanda Boucault
FB
Boer
Patrícia Aline
PA
Gontijo
José Antônio Rocha
JA
Figueiredo
José Francisco
JF
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D019808:Losartan / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010587:Phagocytosis / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D000959:Antihypertensive Agents; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D019808:Losartan