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Broiler Chickens Express High‐Affinity and Gradient Alkaline Phosphatase Activity along the Intestinal Longitudinal Axis
Author(s) -
Zhou Kevin,
Burello Nicole A,
Wang Weijun,
Archbold Tania,
Leung Haley,
Kiarie Elijah,
Fan Ming Z
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.968.10
Subject(s) - broiler , ileum , jejunum , duodenum , alkaline phosphatase , zoology , incubation , phosphatase , biology , amen , medicine , chemistry , endocrinology , enzyme , biochemistry
Broiler chickens have been increasingly bred to grow fast and reach their market body weight within 6 to 7 weeks of age. Alkaline phosphatases (AP) have a key role in dephosphorylating endotoxin lipopolysaccharides (LPS) and other emblematic members of pathogen‐associated‐molecular patterns (PAMPs) such as ATP, thus preventing gut dysbiosis and disorders. However, roles of AP in maintaining gut health in young broiler chickens remain to be elucidated. This study was carried out to determine AP activity kinetics in the duodenal, jejunal, and ileal segments of young broiler at pH 7.4 and 41°C by using the chromogenic synthetic substrate P ‐nitrophenyl phosphate (pNPP). Ten 28‐d old broiler (Ross 708) chickens that have been maintained on a standard grower corn soybean meal diet were euthanized for collecting duodenum, jejunum and ileum tissue samples. The pNPP kinetic experiments were conducted with 16 gradient concentrations of pNPP, ranging 0 – 6 mM in incubation media. All enzymatic incubations were conducted with about 16 μg protein of the homogenized small intestinal segmental tissues. The kinetics (parameter estimates ± SE, P < 0.05) of the broiler small intestinal segmental AP activities of hydrolyzing pNPP were obtained, including V max values (μmol/mg protein·min, n = 80) of 0.419 ± 0.020, 0.196 ± 0.008, and 0.076 ± 0.003; and K m values (uM, n = 80) of 9.6 ± 5.2, 11.8 ± 5.2, and 38.1 ± 10.0 in the duodenum, jejunum, and ileum, respectively. Pooled t‐test showed that the V max was higher ( P < 0.05) in the duodenum than in the jejunum by 1.1‐fold, and than in the ileum by 4.5‐fold, respectively while the V max value was higher ( P < 0.05) in the jejunum than in the ileum by 1.6‐fold. Whereas the K m value was lower ( P < 0.05) in the duodenum than in the jejunum by 19%, and than in the ileum by 75%, respectively while the K m value was lower ( P < 0.05) in the jejunum than in the ileum by 69%. Our results reveal that young broiler chickens express a very high‐affinity duodenal AP isomer with several times of higher enzyme affinity when compared with reported bovine, human and porcine intestinal AP hydrolyzing pNPP. Results of this study show that young broiler chickens express a declining pattern of gradient maximal AP enzyme activity and enzyme affinity from the duodenum to the ileum along the small intestinal longitudinal axis when using the chromogenic substrate pNPP for representing the generic emblematic PAMPs members. Support or Funding Information NSERC Discovery Program of Canada and Metagen Enzyme Corporation