Resumen

PIZZANI, Pablo et al. Effect of Incresing Concentrations of Phytic Phosphorus on the Activity of the Phytase and Alkaline Phosphatase Enzymes in the Intestinal Epithelium of Young Sheep.. Rev. Cient. (Maracaibo) [online]. 2008, vol.18, n.1, pp.59-64. ISSN 0798-2259.

With the objective to know the effect of supply in growing concentrations of phytic phosphorus on the activity of the enzymes phytase and alkaline phosphatase in the intestinal epithelium of young sheep, it was carried out an experiment with incresing concentration of phytic phosphorus: 0% (T1), 40% (T2), 60% (T3), and 80% (T4). The animals consumed the diets as for 4% of the body weight during four weeks. Lapsed this period, all the animals of the rehearsal were sacrificed, and the activity of the enzymes was determined in homogenates of the epithelium of the different sections of the thin intestine (duodenum, jejunum and ileum). The results showed values of phytase activity at level of the duodenum of: 1.43; 1.85; 1.82 and 0.69 nmoles/min/mg protein for concentrations of T1, T2, T3, and T4, respectively, with a significant decrease (P<0.05) when 80% of the phosphorus of the portion was as phytic phosphorus. In the jejunum it stayed the same tendency with activities: 0.40; 1.75; 1.31 and 0.55 (nmoles/min/mg protein) with the same concentrations of phytic phosphorus. Likewise, the activity values of the alkaline phosphatase at level of the duodenum were of: 890; 1550; 1395 and 472 (µmoles thymolphthalein/min/mg protein) for concentration of phytic phosphorus mentioned. When the proportion of phytic phosphorus in the diet was 80% of the total phosphorus, the values of enzymatic activity diminished significantly (P<0.05). This tendency was similar at the jejunum: 632; 1151; 749 and 405 (µmoles thymolphthalein /min/mg protein) and ileum: 107; 225; 157 y 71 (µmoles thymolphthalein/min/mg protein) with the same concentrations of phytic phosphorus. These results show that the activity of the phytase and of the alkaline phosphatase at the intestinal epithelium increased, when the content of phytic phosphorus with regard to the total phosphorus was between 40 and 60%. However, when the proportion is the same or superior to 80% decreases the activity of both enzymes. This could be explained by the relative saturation of the enzymes phytase and alkaline phosphatase by the sustrate.

Palabras clave : Phytase; alkaline phosphatase; phytic phosphorus; intestinal homogenates; sheep.