OBJETIVO: Estudar aspectos funcionais e morfológicos do pólo inferior do baço de ratos tratados ou não com oxigênio hiperbárico no pós-operatório. MÉTODOS: Foram operados 79 ratos, Wistar, pesando 248,7g ± 27 , distribuídos em dois grupos: A - Simulação (n= 40), B - pólo inferior (n=39), e divididos em dois subgrupos: 11 e 70 dias. Cada subgrupo foi subdividido em não tratado com oxigênio hiperbárico (nt) (A11nt-n=10, B11 nt-n= 13, A70nt-n= 10, B70nt-n= 9) e tratado (t); A11t-n=10, B11t- n=9, A70 t- n= 10, B70t- n= 8). Foram dosados os lípides e imunoglobulinas e contadas as plaquetas e os corpúsculos de Howell-Jolly no pré e no pós-operatório. O baço e o pólo inferior foram retirados para histologia. RESULTADOS: Houve aumento do colesterol total (p=0,002), VLDL-colesterol e triglicérides (p= 0,003), da LDL-colesterol (p=0,013) no subgrupo B11nt e não houve alteração nos demais subgrupos. A IgM caiu nos subgrupos B11t (p=0,007), B11nt (p= 0,0000), B70nt (p=0,0005) e B70t (p=0,02) e não alterou no grupo simulação. O número de plaquetas aumentou nos subgrupos B11nt (p=0,002), B11t (p=0,01) e não alterou nos demais subgrupos. Os corpúsculos de Howell-Jolly foram menos numerosos no subgrupo B70nt que no B11nt (p=0,019). A viabilidade do pólo inferior foi melhor no subgrupo B11t que no B11nt; no subgrupo B70 que no B11 e não diferiu entre os subgrupos B70t e B70nt. CONCLUSÃO: A função e a viabilidade do pólo inferior remanescente melhoraram tardiamente. Os animais submetidos à oxigenoterapia hiperbárica apresentaram melhor viabilidade e função do pólo inferior precocemente, mas não tardiamente.

OBJECTIVE: To study the functional and morphological features of the lower pole of the spleen in rats submitted, or not, to postoperative hyperbaric oxygen therapy. METHODS: Seventy-nine Wistar rats, weighing 248.7 ± 27 g, divided into two groups [group A - simulation (n=40), group B - lower pole (n=39)] underwent surgery and were subdivided into two groups: 11 and 70 postoperative days. Each subgroup was subdivided into animals not treated (nt) (A11nt, n=10; B11nt, n=13; A70nt, n=10; B70nt, n=9) and treated with hyperbaric oxygen (t) (A11t, n=10; B11t, n=9; A70t, n=10; B70t, n=8). Blood was collected for measurement of lipids and immunoglobulins, platelet and Howell-Jolly body count before and after surgery. The spleen and lower pole were removed for histology. RESULTS: There was an increase of total cholesterol (p=0.002), VLDL-cholesterol and triglycerides (p=0.003) and of LDL-cholesterol (p=0.013) in subgroup B11nt, and no alterations were observed in the other subgroups. IgM decreased in subgroups B11t (p=0.007), B11nt (p=0.0000), B70nt (p=0.0005), B70t (p=0.02), and no change was observed in the simulation group. The number of platelets increased in subgroups B11nt (p=0.002) and B11t (p=0.01) and remained unchanged in the other subgroups. Howell-Jolly bodies were less numerous in subgroup B70nt than in subgroup B11nt (p=0.019). Lower pole viability was better in subgroup B11t than in B11nt and in subgroup B70 than in B11, and did not differ between subgroups B70t and B70nt. CONCLUSION: Function and viability of the remaining lower pole improved during the late postoperative period. Viability and function of the lower pole were better during the early but not during the late postoperative period, in animals submitted to hyperbaric oxygen therapy.