ABSTRACT
The objective of the study is to investigate the brain development and atrophy of Diannan small-ear pigs in different ages using magnetic resonance imaging (MRI). A total of 12 Diannan small-ear pigs were included and divided into the young group, adult group, and middle-and-old age (M&O) group according to their age. The brain structure of pigs was scanned using MRI, and the brain data obtained were statistically analyzed by signal conversion and image reconstruction. Compared with the young group, the signals of most brain structures in the adult group and M&O group were significantly decreased (p < 0.05). Compared with the adult group, the signal intensity of the right caudate nucleus and the right lateral ventricle in the M&O group was significantly increased, while the signal intensity of other regions was almost significantly decreased (p < 0.05). Compared with the young group, both adult and M&O groups had some degree of brain atrophy. Brain atrophy in the precuneus and the inferior temporal gyrus was more predominant in the M&O group in comparison with the adult group. The present study demonstrated that the brain signal of Diannan small-ear pigs gradually diminished with age, while the degree of brain atrophy was the opposite, providing the basic data on the brain of Diannan small-ear pigs.
ABSTRACT
OBJECTIVE: To investigate the effect of different doses of dexamethasone (DEX) on sepsis induced acute kidney injury (AKI). METHODS: One hundred and thirty healthy male Kunming mice were randomly divided into sham group, sepsis group, physiological-dose DEX group (0.12 mg/kg), stress-dose DEX group (1.2 mg/kg), and high-dose DEX group (12 mg/kg). The sepsis model was reproduced by cecal ligation and puncture (CLP) method. Histopathological changes in the kidney were observed at 24 hours and 48 hours after CLP. The expressions of glucocorticoid receptor-α (GR-α) in the kidney were detected by immunohistochemistry. The levels of GR-α mRNA and nuclear factor-ΚB (NF-ΚB) mRNA were determined by real-time polymerase chain reaction (PCR). The levels of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in the plasma were measured by enzyme linked immunosorbent assay (ELISA). RESULTS: Compared with sham group mice, sepsis mice showed serious impairment in renal tubules. The mRNA and protein expression of GR-α were decreased, and NF-ΚB mRNA, plasma TNF-α and IL-1ß were elevated. Compared with sepsis group, the histopathological changes in the kidney were mitigated with different levels in groups treated with different doses of DEX. GR-α protein and mRNA were up-regulated, NF-ΚB mRNA and plasma TNF-α, IL-1ß were down-regulated obviously. The best effect could be seen in physiological DEX group [AKI score: 24 hours 1.480±0.334 vs. 3.040±0.517, 48 hours 1.840±0.167 vs. 3.400±0.400; GR-α protein (A value): 24 hours 0.102±0.009 vs. 0.088±0.005, 48 hours 0.103±0.008 vs. 0.085±0.006; GR-α mRNA: 24 hours 0.0400(0.0300, 0.0400) vs. 0.0100(0.0093, 0.0100), 48 hours 0.0350(0.0300, 0.0475) vs. 0.0100(0.0010, 0.0138); NF-ΚB mRNA: 24 hours 0.009±0.001 vs. 0.012±0.000,48 hours 0.011±0.000 vs. 0.013±0.001; TNF-α: 24 hours 105.84±3.84 ng/L vs. 135.52±4.49 ng/L, 48 hours 111.35±3.67 ng/L vs. 141.22±4.46 ng/L; IL-1ß: 24 hours 45.71±2.93 ng/L vs. 64. 12±3.62 ng/L, 48 hours 57.04±3.04 ng/L vs. 74.87±3.67 ng/L; P<0.05 or P<0.01]. CONCLUSIONS: DEX given in physiological-dose could increase renal GR-α level and alleviate the sepsis induced kidney injury. The protective effect was much better than that of high dose DEX.
