ABSTRACT
OBJETIVO: Analisar os efeitos agudos do exercício de curta duração em diferentes durações e intensidades sobre leucócitos totais, número e capacidade fagocitária de macrófagos peritoneais. MÉTODO: Foram utilizados ratos Wistar (n= 30, n= 6 por grupo), divididos em 5 grupos: controle sedentário (C); exercitados 5 minutos na intensidade leve ou moderada (5L e 5M, respectivamente); exercitados 15 minutos na intensidade leve ou moderada (15L e 15M, respectivamente). Na intensidade leve, o exercício foi realizado sem cargas; na moderada, foi utilizada carga adicional de 5 por cento do peso corporal dos animais em suas regiões dorsais. A contagem total de leucócitos e monócitos foi realizada no microscópio, cuja leitura foi procedida no aparelho LEUCOTRON TP. A porcentagem da fagocitose foi determinada por contagem em câmara de Neubauer através do número de células que fagocitaram três ou mais partículas de zymosan. Foram utilizados os testes ANOVA two way e Tukey com p < 0,05. RESULTADOS: Foi observado aumento nos leucócitos totais nos grupos exercitados (de 4,12 ± 0,17 x 10(6) para 8,69 ± 1,06 x 10(6) no grupo 5L, 9,5 ± 0,91 x 10(6) no grupo 15L, 12,56 ± 0,9 x 10(6) no grupo 5M e para 11,61 ± 0,6 x 10(6) no grupo 15M); aumento do número de macrófagos peritoneais após 15 minutos de exercício moderado (de 14,07 ± 0,57 x 10(6) para 20,9 ± 1,28 x 10(6)) e da capacidade fagocitária após 5 e 15 minutos de exercício leve de 74,8 ± 0,73 por cento para 79,8 ± 0,8 por cento e 83 por cento ± 0,44 por cento, respectivamente (p < 0,05). CONCLUSÕES: O exercício de curta duração promove aumento na capacidade fagocitária, fato esse de relevância para a reabilitação e esporte.
OBJECTIVE: To analyze the acute effects of short-duration exercise of different lengths and intensities on total leukocytes, peritoneal macrophage count and on the phagocytic capacity of peritoneal macrophages. METHOD: Five groups of Wistar rats were used (n= 30, n= 6 per group): one sedentary control group (C); two groups exercised for 5 minutes at low or moderate intensity (5L and 5M, respectively); and two groups exercised for 15 minutes at low or moderate intensity (15L and 15M, respectively). Low-intensity exercise was done without any load, while moderate-intensity was done with an additional load of 5 percent of the animal's body weight, attached to its back. The total leukocyte and monocyte counts were obtained under a microscope, and the readings were made with the Leucotron TP apparatus. The percentage phagocytosis was determined by counting in a Neubauer chamber, from the number of cells that phagocytized three or more particles of zymosan. Two-way ANOVA and Tukey tests were used, with p < 0.05. RESULTS: There was an increase in total leukocytes in the exercised groups (from 4.12 ± 0.17 x 10(6) to 8.69 ± 1.06 x 10(6) for 5L, 9.5 ± 0.91 x 10(6) for 15L, 12.56 ± 0.9 x 10(6) for 5M and 11.61 ± 0.6 x 10(6) for 15M), an increase in peritoneal macrophage count after 15 minutes of moderate exercise (from 14.07 ± 0.57 x 10(6) to 20.9 ± 1.28 x 10(6)) and an increase in phagocytic capacity after 5 and 15 minutes of light exercise (from 74.8 ± 0.73 percent to 79.8 ± 0.8 percent and 83 percent ± 0.44 percent, respectively) (p < 0.05). CONCLUSION: Short-duration exercise promotes increased phagocytic capacity. This is of importance for rehabilitation and sports.
Subject(s)
Animals , Rats , Exercise , Immune System , Macrophages , Phagocytosis , Physical Therapy Specialty , Rats, WistarABSTRACT
The effect of free cholesterol on the fatty acid composition and growth of rat fetal enterocytes was investigated in the absence and presence of 10 percent (v/v) fetal calf serum. Cholesterol caused a significant reduction of cell number after 6 and 12 h in culture. The fatty acid composition of enterocytes cultured in the presence of serum was also changed by the presence of 20 æM cholesterol. The fatty acid profile was determined by HPLC using fluorescence detection (325 nm excitation and 395 nm emission). Cholesterol (20 æM) increased the proportion (given in percentage of the total fatty acids) of the following fatty acids in cultured cells: lauric (by 42 percent), oleic (by 34 percent), linoleic (by 44 percent) and gamma-linolenic (by 20 percent) acids and reduced the proportion of palmitic (by 12 percent), stearic (by 20 percent), arachidonic (by 21 percent) and docosahexaenoic (by 44 percent) acids. In addition to modifying the content of individual fatty acids, cholesterol increased the polyunsaturated/saturated fatty acid ratio from 0.48 to 0.67 and the unsaturation index from 67.12 to 75.30. This is the first evidence that cholesterol modifies fatty acid composition possibly via de novo fatty acid synthesis and desaturation
Subject(s)
Animals , Male , Female , Pregnancy , Rats , Cholesterol , Enterocytes , Fatty Acids , Cell Division , Chromatography, High Pressure Liquid , Enterocytes , Fatty Acids , Rats, WistarABSTRACT
Food deprivation has been found to stimulate cell proliferation in the gastric mucosa of suckling rats, whereas the weanling period has been reported to be unresponsive in terms of proliferative activity. In the present study we analyze regional differences in the effect of milk or food deprivation on cell proliferation of the epithelia of the esophagus and of five segments of small intestine in suckling, weanling and newly weaned Wistar rats of both sexes. DNA synthesis was determined using tritiated thymidine to obtain labeling indices (LI); crypt depth and villus height were also determined. Milk deprivation decreased LI by 50 percent in the esophagus (from 15 to 8.35 percent) and small intestine (from 40 to 20 percent) of 14-days-old rats. In 18-days-old rats, milk and food deprivation decreased LI in the esophagus (from 13 to 5 percent) and in the distal segments of the small intestine (from 36-40 to 24-32 percent). In contrast, the LI of the epithelia of the esophagus (5 percent) and of all small intestine segments (around 30 percent) of 22-day-old rats were not modified by food deprivation. Crypt depth did not change after treatment (80 to 120 mum in 14- and 22-day-old rats, respectively). Villus height decreased in some small intestine segments of unfed 14- (from 400 to 300 mum) and 18-day-old rats (from 480 to 360 mum). The results show that, contrary to the stomach response, milk deprivation inhibited cell proliferation in the esophagus and small intestine of suckling rats, demonstrating the regional variability of each segment of the gastrointestinal tract in suckling rats. In newly weaned rats, food deprivation did not alter the proliferation of these epithelia, similarly to the stomach, indicating that weanling is a period marked by the insensitivity of gastrointestinal epithelia to dietary alterations.