RESUMO
The objective of the present study was to evaluate the effects of low-molecular-weight chitosan (LMWC) on the growth performance, immune responses and intestinal health of weaned pigs challenged by enterotoxigenic Escherichia coli (ETEC). A total of 32 weaned pigs were randomly allocated to four treatments: non-challenged (fed with basal diet), ETEC-challenged (fed with basal diet) and ETEC-challenged plus 50 or 100 mg/kg LMWC supplementation, respectively. After 11â¯days feeding, the non-challenged pigs were infused with sterilised Luria-Bertani culture, while the remaining pigs were infused with 2.6â¯×â¯1011 colony-forming units of ETEC. At 3â¯days post-challenge, all pigs were administered d-xylose at 0.1â¯g/kg body weight. One hour later, blood samples were obtained, and the pigs then euthanised to collect intestinal samples. Data showed that only 100â¯mg/kg LMWC supplementation attenuated (Pâ¯<â¯0.05) the average daily gain reduction caused by ETEC. Furthermore, besides the decreased (P < 0.05) serum tumour necrosis factor-α and immunoglobulin (Ig) G concentrations detected in ETEC-challenged pigs supplemented with LMWC at 50 or 100 mg/kg, the higher dose (100 mg/kg) also decreased (P < 0.05) the serum IgM concentration and increased (P < 0.05) the villus height and villus height-to-crypt depth ratio in both the jejunum and ileum, and the sucrase activity in the ileal mucosa. Moreover, LMWC supplementation (50 or 100 mg/kg) in ETEC-challenged pigs elevated (Pâ¯<â¯0.05) the mRNA levels of jejunal mucosal peptide transporter 1 and ileal mucosal peptide transporter 1, divalent metal transporter 1 and zinc transporter 1, and decreased (Pâ¯<â¯0.05) the ileal and caecal E. coli abundances, while 100 mg/kg LMWC additionally elevated (Pâ¯<â¯0.05) the ileal Bacillus abundance, and caecal and colonic Bifidobacterium abundances. These results suggest that LMWC helps alleviate ETEC-induced growth retardation in weaned pigs, which could be associated with the inhibition of the immune responses and improved intestinal health.
Assuntos
Quitosana/uso terapêutico , Suplementos Nutricionais , Escherichia coli Enterotoxigênica , Infecções por Escherichia coli/dietoterapia , Transtornos do Crescimento/dietoterapia , Animais , Quitosana/química , Citocinas/sangue , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/complicações , Infecções por Escherichia coli/patologia , Transtornos do Crescimento/sangue , Transtornos do Crescimento/etiologia , Transtornos do Crescimento/patologia , Imunoglobulinas/sangue , Intestinos/efeitos dos fármacos , Intestinos/enzimologia , Intestinos/patologia , Lactase/sangue , Peso Molecular , Sacarase/sangue , Suínos , Desmame , alfa-Glucosidases/sangueRESUMO
We studied the effects of L-carnitine treatment in the acyl flux of erythrocyte membranes from uremic patients. We found a significantly lower relative proportion of long-chain acyl-CoA (LCCoA) to free CoA (FCoA) in patients than in control subjects. In addition, patients had reduced activities of both carnitine palmitoyltransferase (CPT) and glycerophospholipid acyltransferase (LAT; CoA dependent), and increased ratios of long-chain acylcarnitine (LCAC) to free carnitine in their erythrocytes. These data support the hypothesis that acyl-trafficking is altered in erythrocytes in uremia. After treatment with L-carnitine, we observed a significant increase in CPT and LAT activities as well as in the LCCoA-FCoA ratio, and a significant decrease in the ratio of LCAC to free carnitine. These results support the conclusion that L-carnitine supplementation improves erythrocyte flux in uremic patients.