Effects of Glutamine on the Blood Index and Intestinal Mucosal Barrier in Heat Stressed Jilin White Goose

Purpose To investigate the effects of glutamine (Gln) on the blood index of Jilin white goose under heat stress and its protective effect on the intestinal epithelial mucosal barrier system.

Method A total of 180 1-day-old Jilin white geese were randomly divided into three treatment groups: control group (CON), heat stress group (HS) and glutamine group (GLN), in a completely randomized design 6 replications with 10 geese in each replication. On the 69^th day, geese in the CON group and the HS group were intraperitoneally injected with normal saline 0.75 g/kg (bw), and those in the Gln group with Gln 0.75 g/kg (bw). After 24 hours, the geese in the HS group and the Gln group were subjected to heat stress treatment for 4 hours (41 ℃±1 ℃, relative humidity 60%), and then slaughtered. Blood sample were collected for the deamination of diamine oxidase (DAO), D-lactic acid (DLA), lactate dehydrogenase (LDH), corticosterone (CORT), creatine kinase (CK), triiodothyronine (T₃), and thyroid (T₄) activity. The relative expression levels of HSP70, Occludin, Claudin 1 and ZO-1 mRNA were determined by scraping the jejunal epithelial mucosa.

Results (1) Compared with the HS group, the GLN group showed a downward trend in the blood except T₃. (2) GLN induced high expression of HSP70 mRNA (P<0.01), and improved the expression of tight junctional mRNA under heat stress (P<0.01). (3) The trend of relative expression levels of proteins is similar to that of genes.

Conclusion Gln can effectively alleviate the heat stress state of Jilin white goose, and significantly improve the damage to intestinal epithelial mucosal barrier.