| ObjectiveThe model established in SD rat were produced by the method of freely falling body, to investigate the features of gene expression of the resistin following traumatic brain injury and its effect of insulin sensitivity after the trauma.MethodsA total of 216 clean level SD (Spruge-Dawley) male rats were involved in the study, weight 300-350 g. Divided them into six groups using Computer Numbers randomly methods:normal control group, sham operation group, mild injury group, severe injury group, exogenous phosphoric acid lipopolysaccharide (LPS) injection group and RSTN antibody injection group.(N=36). With 10% hydration chlorine aldehyde (0.35g/kg) intra-abdominal inject into rats,fix the head to the stereotactic instrument, cut off the top fur, disinfect the skin, cut the scalp along the midline left, separate the periosteum, with dental drill in the midline 2 mm, close to coronary seam open a 5 mm in diameter of circular window, hard film intact. The left parietal lobe brain damage limitation of rats caused by the self-made improved Feeney traumatic brain injury free fall device:with 20 g farmar in 10 cm high through a metal guide bar to fall, hits on the cone of hard film bring about light damage, the other with 40 g farmar in 25 cm, falling to heavy damage. Exogenous phosphoric acid lipopolysaccharide (LPS) injection group (hereinafter referred to as LPS group) with 10% hydration chlorine aldehyde (0.35 g/kg weight) intra-abdominal inject into rats,then its head is fixed to the stereotactic instrument, anterior fontanelle before for zero value, before after anterior fontanelle in 5 mm, the midline left 4 mm points, using electric drill drill a skull, cut dural, before after anterior fontanelle in 5 mm, the midline left 4 mm in the brain surface with trace syringe needle into the vertical 1.8 mm, slow inject 5 ul LPS solution (25 ug), reserve 2 min, slow pull needle, skin suture, loose solution rats, and back to animal room make its natural waking up. RSTN antibody injection group (hereinafter referred to as RSTN group) take severe damage rats, according to 1 mg/only intraperitoneal injection dose. Normal control group (hereinafter referred to as are group) don't do anything.JiaShouShu group (hereinafter referred to as the false group) only cut scalp and skull open window, from brain damage. In the most severely damage and RSTN group after postoperative at 24 hours,1 week,4 weeks application of neural behavior Longa rating score. Each byte is in postoperative 12 hours,24 hours,72 hours, one week, two weeks,4 weeks tail venous blood sampling for ELISA test blood sugar, serum insulin, serum resistin and based on the calculation of quantitative insulin sensitivity test index (QUICKI), and put to death the rat,take out with side the hippocampus, hypothalamus,cortex organization, for the reverse transcription-the polymerase chain reaction (RT-PCR) method to detect resistin mRNA element and Western blot method to detect resistin protein expression.Results(1) The concentration of serum resistin in normal group and sham operation group group have no significant difference at each time point (all P>0.05).Take sham operation group as a benchmark, light damage group, severe damage group, LPS group and RSTN group in each test date after the success of the modeling(12 h,24 h,72 h,1 w, 2 w and 4 w) all appear significantly increased in serum resistin level (all P< 0.05); The average concentration of serum resistin:severe damage group>RSTN group>LPS group>mild damage> sham operation group (all P< 0.05).Serum resistin in the group with time changing trends:The mild injury group and the severe injury group were elevated after 12 hours,and continue to rise 4w after peak (all P< 0.05).LPS injection group in the 12 h beginning to rise, and 72 h reached the peak, then decreased in 1w and last 4w (all P< 0.05); RSTN group rise to the level of severe damage group in 12 h (P> 0.05), while falling in 24 h,72 h appear again when the rise, continue to rise to 4 w peak (all P< 0.05). Compared with each point between the severe group and RSTN group, the biggest difference point of the concentration of serum resistin is appear in 2 w: RSTN group was dropped 53.4% compared with the severe damage group.(2) Resistin expression (mRNA and protein) has no significant differences between normal group and shame operation group.Resistin expression in the different organization of brain (the hippocampus, hypothalamus, cortex) presentation changing with time trend consistent:to shame operation group as a benchmark, mild damage group to 4 w began to appear expression is significantly improve (P< 0.05). Severe damage in 12 hours of expression is increased, has been to 4 w rising each expression (P< 0.05). LPS group in 12 hours expression is increased, has been to 1 w rising in the expression, to 2w expression begin to decrease and continue to decline to 4w (all P< 0.05). RSTN injection group in 12 hours expression is increased, has been to 4 w rising each expression (P< 0.05). RSTN in the brain in different organization presentation changing with time trend is not the same as:severe damage group and RSTN group of cortex parts of mRNA expression in 4 w are presented down trend (all P< 0.05). Compared with the benchmark, who can detect all the RSTN is statistically significant increase in the expression of damage on the same side in the organization were significantly higher than for each side (P< 0.05).In this research involves the detection place seahorses, head issuing grave and cortex, the increase of the expression of resistin in the hippocampus is the most obvious, followed is the cortex and the hypothalamus (P< 0.05). Compared with each point between the severe group and RSTN group,both of the expression of mRNA of resistin are severe damage group> RSTN groups, but the biggest difference at appeared in 4 w:RSTN group was dropped 77.5% compared with the severe damage group, but with 1 w drop 74.3% is no statistical difference (P> 0.05), minimum points of the difference in appear in 24 h:RSTN group was dropped 60.3%, and the difference between the point was statistically significant (P< 0.05).(3) Blood glucose and insulin concentrations in serum normal group and shame operation group between different time points they have no significant difference (P> 0.05 each). To shame operation group as a benchmark, mild damage group in the 12 h,24 h,72 h the significantly increased (P< 0.05); Severe damage group in the 12 h,24 h,72 h,1 w,2 w,4 w significantly increased (all P< 0.05); LPS group in the 12 h,24 h the significantly increased (P< 0.05); RSTN group in the 12 h,72 h,1 w,2 w,4 w significantly increased (all P< 0.05). The average blood sugar and serum insulin concentrations:severe damage group> RSTN group> LPS group> mild damage> shame operation group (the group> P< 0.05). In the group blood sugar and serum insulin changing with time trend:the mild damage group 12 h beginning to rise,24 h peak,72 h the fall (P< 0.05), to 1 w drop to shame operation group when level (P> 0.05). Severe damage group 12 h beginning to rise, rising to 1 w peak,2 w falls has been to 4 w still has not returned to shame operation group level (all P< 0.05); LPS injection group in the 12 h beginning to rise,24 h peak (all P< 0.05),72 h has been reduced to a level shame operation group (P> 0.05); RSTN group 12 h rise to severe damage level group (P > 0.05), when 24 h fall,72 h appear again when the rise, to 1 w peak when, then declined, continued down to four w still has not returned to the level shame operation group (P< 0.05).(4) According to blood sugar and serum insulin concentrations to formula calculation method for the presentation of the QUICKI insulin sensitivity index:also, QUICKI in normal group and shame operation group between different time points they have no significant difference (P> 0.05 each). To shame operation group as a benchmark, mild damage group in the 12h,24 h,72h significantly reduced (all P< 0.05); Severe damage group in the 12h,24h,72h, 1w,2w,4w significantly reduced (all P< 0.05); LPS group in the 12h,24h significantly reduced (all P< 0.05); RSTN group in the 12 h,72 h, 1 w,2 w,4 w significantly reduced (all P< 0.05). Average QUICKI between groups in numerical comparison:severe damage group< RSTN group< LPS group< slightly damaged< shame operation group (the group P< 0.05). In the group QUICKI changing with time trend analysis:mild damage group 12 h began to drop,24 h reach valley value,72 h rise but still lower than the existing shame operation group (all P< 0.05), to 1 w, has increased the level shame operation to group (P> 0.05). Severe damage group in the 12 h began to drop, continue to rise to 1 w reach valley value,2 w had been rising but still lower than the shame operation group, to 4 w still has not returned to shame operation group level (all P< 0.05); LPS injection group in the 12 h began to drop, 24 h reach valley value (all P< 0.05),72 h has risen to the level shame operation group (P> 0.05); RSTN group 12 h reduce to severe damage level group (P> 0.05),24 h, has increased, but lower than the level shame operation group (P< 0.05),72 h and reduce to 1 w, at the valley, then have increased, values continue to 4 w still has not returned to shame operation group level (all P< 0.05).(5) All categories (except LPS outside group) sample of serum resistin index and according to the blood glucose and insulin index calculation of serum for insulin sensitivity index index both further related analysis, eliminating time points of production that variables, serum resistin and insulin sensitivity index is the significant negative correlation (r=-0.764, P=0.000<0.05).(6) heavy damage group and RSTN injection group between 24 h,1 w,4 w rats and neurobehavioral scores, found that compared between groups, severe damage group and RSTN group in the 24 h,1 w and 4 w neurobehavioral scores are statistically significant, severe damage group was higher than RSTN group (P< 0.05); In the group analysis, to the score 0 shame operation group as the benchmark, severe damage in group of injury within 24 h score is increased,1 w peak, then 4 w begin to fall (P< 0.05). RSTN group's trend was the same(P< 0.05).Conclusions(1) After the occurrence of the traumatic brain injury, the concentration of serum resistin in 12 hours after injury that appear rise, and present the trend of rising until more than 4 weeks after injury, and the extent of increase is in relation to the extent of the damage, damage is heavier, the more obvious increase. Expression of resistin in the mRNA and protein level also presents that similar to the rise and change trend of the serum resistin, but which exist in different organization/organs of brain have differently, the differentiation is not only reflected in the quantity of expression (the hippocampus> the cortex> the hypothalamus, injury> to side), but also reflected in the expression of changing with time trend (the expression of the mRNA resistin in cortex has declined after four weeks of injury). Even for anti-resistin to reflect to play antagonistic action toward to the loci and point of effect of resistin (After the anti-resistin was injected, the concentration of serum resistin had dropped 53.4% in two weeks after injury, and the expression of resistin in the hippocampus generate decreased by 77.5% and 74.3% respectively in 1 w and 4 w after injury).(2) After the occurrence of the traumatic brain injury, blood sugar and serum insulin present the coherent variation trend completely:in 12 hours after injury is significant increases, the peak and duration increased because of the damage degree of process and different, damage is heavier, the higher the peak of the rising, rising schedule is also much longer, then down gradually in 1-4 weeks, recovery or not fully restored to the level before the injury. Insulin sensitivity index revealed a opposite trend:the decrease of insulin sensitivity (insulin resistance) appears with the occurrence of TBI,and in the earliest injury after 12 h, according to different weight injury, gradually reach the valley value in 24 hours-1 weeks, and then returned gradually, in 1-4 weeks restored or not fully restored to the level before the injury.(3) Through the statistical analysis, serum resistin and insulin sensitivity index is the significant negative correlation, namely in traumatic brain injury state, serum resistin is higher,the lower insulin sensitivity of the body, in which the body's resistance to insulin is stronger. Tip resistin may play an important role in the process of insulin resistance that happened in traumatic brain injury rat.(4) Through the establishment of exogenous lipopolysaccharide local injections of produce of pure inflammatory brain damage as contrast analysis, traumatic brain injury that caused the level of serum resistin changes and can't think is just the result of the inflammatory response, traumatic brain injury that the cause of injury difference from the complexity of simple inflammatory reaction and pure with resistin as inflammatory mediators reaction to explain traumatic brain injuries development process and occurrence limitations.(5) Through the intraperitoneal injection of Anti-resistin to intervene the physiological effect of resistin and then observed sugar metabolism and insulin sensitivity index changes, and to the influence of neurobehavioral scores in the corresponding period, we can think that exist certain relevance between serum resistin and nerve function. Control serum resistin levels may be directly or indirectly play a certain degree of neural function protection effect. Serum resistin also is expected to as a reflection of neurological function biochemical indicators even as the future clinical stimulative nerve function recovery intervention sites.
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