Effects of Zinc Adaptation on Histological Morphology, Antioxidant Responses, and Expression of Immune-Related Genes of Grass Carp (Ctenopharyngodon idella)

The study was conducted to evaluate the effect of zinc adaptation on histological morphology and antioxidant and immune responses of grass carp(Ctenopharyngodon idella). A total of 180 young grass carp (20.0 ± 2.0 g) was equally distributed into 9 groups, and triplicate groups were subjected to 0 μg/L Zn²⁺ (control group), 200 μg/L Zn²⁺, and 300 μg/L Zn²⁺ solution for 42 days, respectively. The results indicated that the liver and gill have obvious pathological changes after long-term adaptation to zinc except the intestine; the zinc adaptation can positively influence intestinal morphology. The activities of GPX (glutathione peroxidase activity), SOD (superoxide dismutase), and CAT (Catalase) were significantly increased in zinc treatment groups (P < 0.05). The genes expression levels of CuZnSOD (copper zinc superoxide dismutase), CAT, Hsp70 (heat shock protein-70), IL-1b (interleukin-1-b), and TGF-β1 (transforming growth factor-β1) were upregulated in the gill and intestine of grass carp following waterborne adaptation to zinc solution for 42 days (P < 0.05). In conclusion, zinc adaptation has different effects on organs of grass carp and may reduce the inflammatory response of the body's gills and intestines by improving the body's antioxidant and anti-stress defense capabilities.

Complete resection of the gastric antrum decreased incidence and severity of delayed gastric emptying after pancreaticoduodenectomy

BACKGROUND

Delayed gastric emptying (DGE) is the main complication after pancreaticoduodenectomy (PD), but the mechanism is still unclear. The aim of this study was to elucidate the role of complete resection of the gastric antrum in decreasing incidence and severity of DGE after PD.

METHODS

Sprague-Dawley rats were divided into three groups: expanded resection (ER group), complete resection (CR group), and incomplete resection (IR group) of the gastric antrum. The tension (g) of remnant stomach contraction was observed. We analyzed the histological morphology of the gastric wall by different excisional methods after distal gastrectomy. Moreover, patients underwent PD at our department between January 2012 and May 2016 were included in the study. These cases were divided into IR group and CR group of the gastric antrum, and the clinical data were retrospectively analyzed.

RESULTS

The ex vivo remnant stomachs of CR group exhibited much greater contraction tension than others (P < 0.05). The contraction tension of the remnant stomach increased with increasing acetylcholine concentration, while remained stable at the concentration of 10 × 10^-5 mol/L. Furthermore, 174 consecutive patients were included and retrospectively analyzed in the study. The incidence of DGE was significantly lower (3.5% vs. 21.3%, P < 0.01) in CR group than in IR group. In addition, hematoxylin-eosin staining analyses of the gastric wall confirmed that the number of transected circular smooth muscle bundles were higher in IR group than in CR group (8.24 ± 0.65 vs. 3.76 ± 0.70, P < 0.05).

CONCLUSIONS

The complete resection of the gastric antrum is associated with decreased incidence and severity of DGE after PD. Gastric electrophysiological and physiopathological disorders caused by damage to gastric smooth muscles might be the mechanism underlying DGE.

Growth performance, lipid metabolism, and health status of grass carp (Ctenopharyngodon idella) fed three different forms of sodium butyrate

Sodium butyrate (SB) can be coated with fatty acid matrix. In this study, the effects of three SB forms, being zero-lipid-coated (SB-A), half-lipid-coated (SB-B), and 2/3 lipid-coated (SB-C) (w/w), on growth, lipid metabolism, and health status of grass carp (Ctenopharyngodon idella) were investigated. The three forms of SB were added to a control diet to form three SB diets, Con., SB-A, SB-B, and SB-C, where the pure SB in each SB diet was kept at the same level (500 mg kg^-1). A total of 216 C. idella (14.10 ± 0.60 g/fish) were allotted into four groups (triplicate per group) and fed the four diets respectively for 56 days, and then fish were sampled and determined. Fish growth was not affected by any of the three forms of SB. Viscerosomatic index, intraperitoneal fat index, and crude lipid of hepatopancreas and muscle were significantly decreased and villus height of intestine and mRNA expression of MyD88 and TLR22 in hepatopancreas were significantly improved in SB diets compared with control (p < 0.05), respectively. MiSeq sequencing of the V3-V4 region of bacterial 16S rRNA gene revealed that SB increased the relative abundances of intestinal healthy bacteria, Fusobacteria and Bacteroides, and the abundances of Cetobacterium decreased in the SB-C group. In conclusion, the present results showed that three forms of SB, without affecting the growth of fish, respectively decreased lipid accumulation and probably have a beneficial effect on health of C. idella.