家畜卵泡抑制素的研究进展

抑制素 (Inhibin,INH) ,是一种主要由动物性腺 (卵巢的颗粒细胞和睾丸的支持细胞 )分泌的异二聚体糖蛋白激素 ,由两个三硫键连接两个不同的亚单位 (α和 β)构成 ,对垂体促卵泡素FSH的分泌、合成起选择性负反馈调节物作用。卵泡抑制素免疫中和技术能特异性地刺激机体FSH分泌 ,促进配子生成 ,进而提高动物生殖能力。本文主要就家畜卵泡抑制素的研究进展以及其对家畜生殖的影响作一综述。

Preparation method of an ideal model of multiple organ injury of rat with severe acute pancreatitis

AIM： To establish an ideal model of multiple organ injury of rats with severe acute pancreatitis （SAP）.METHODS： SAP models were induced by retrograde injection of 0.1 mL/100 g 3.5% sodium taurocholate into the biliopancreatic duct of Sprague-Dawley rats. The plasma and samples of multiple organ tissues of rats were collected at 3, 6 and 12 h after modeling. The ascites volume, ascites/body weight ratio, and contents of amylase, endotoxin, endothelin-1 （ET-1）, nitrogen monoxidum （NO）, phospholipase A2 （PLA2）, tumor necrosis factor-α （TNF-α）, interleukin-6 （IL-6） in plasma were determined. The histological changes of multiple organs were observed under light microscope.RESULTS： The ascites volume, ascites/body weight ratio, and contents of various inflammatory mediators in blood were higher in the model group than in the sham operation group at all time points [2.38 （1.10）, 2.58 （0.70）, 2.54 （0.71） vs 0.20 （0.04）, 0.30 （0.30）, 0.22 （0.10） at 3, 6 and 12 h in ascites/body weight ratio; 1582 （284）, 1769 （362）, 1618 （302） （U/L） vs 5303 （1373）, 6276 （1029）, 7538 （2934） （U/L） at 3, 6 and 12 h in Amylase; 0.016 （0.005）, 0.016 （0.010）, 0.014 （0.015） （EU/mL） vs 0,053 （0.029）, 0.059 （0.037）, 0.060 （0.022） （EU/mL） at 3, 6 and 12 h in Endotoxin; 3.900 （3.200）, 4.000 （1.700）, 5.300 （3.000） （ng/L） vs 41.438 （37.721）, 92.151 （23.119）, 65.016 （26.806） （ng/L） at 3, 6 and 12 h in TNF-α, all P 〈 0.01]. Visible congestion, edema and lamellar necrosis and massive leukocytic infiltration were found in the pancreas of rats of model group. There were also pathological changes of lung, liver, kidney, ileum, lymphonode, thymus, myocardium and brain.CONCLUSION： This rat model features reliability, convenience and a high achievement ratio. Complicated with multiple organ injury, it is an ideal animal model of SAR

Expression of early growth response factor-1 in rats with cerulein-induced acute pancreatitis and its significance

AIM： To observe the expressions of early growth response factor-1 （Egr-1） and tissue factor （TF） in rats with cerulein-induced acute pancreatitis and to explore its significance. METHODS： A large dose of cerulein was used to create the experimental acute pancreatitis model in rats. The changes of Egr-1 mRNA and protein in rats were observed during 30 min to 4 h after the treatment and immunohistochemical method was used to observe the localized expression of Egr-1 in tissues. In addition to the mRNA expression of Egr-1 target gene, TF was also observed. A blank control group, and a bombesinadministered group were used for comparison. RESULTS： Alter the stimulation of a large dose of cerulein, the rats showed typical inflammatory changes of acute pancreatitis. Thirty minutes alter the stimulation, the mRNA expression of Egr-1 in the pancreatic tissue reached its peak and then declined, while the expression of Egr-1 protein reached its peak 2 h after the stimulation. Histologically, 2 h after the stimulation, almost all pancreatic acinar cells had the expression of Egr-1 protein, which was focused in the nuclei. The mRNA expression of TF occurred 1 h after the stimulation and gradually increased within 4 h. However, a large dose of bombesin only stimulated the pancreatic tissue to produce a little mRNA expression of Egr-1 and no mRNA expression of Egr-1 protein and TF. CONCLUSION： Egr-1 as a pro-inflammatory transcription factor may play an important role in the pathogenesis of acute pancreatitis by modulating the expression of TF.

Effects of emodin and baicalein on rats with severe acute pancreatitis

AIM: To investigate the therapeutic effects of emodin in combination with baicalein on severe acute pancreatitis (SAP) rats and to explore the mechanism of SAP. METHODS: A total of 112 SAP rats induced by retrograde injection of 5% sodium taurocholate into the biliarypancreatic duct, randomly assigned to a untreated group and three treated groups emodin group, combined emodin and baicalein group, and sandostatin group. Meanwhile, another 28 other rats were selected as sham operation (SO) group. There were 28 rats in each group, 8 rats were in 3 and 6 h groups respectively, and 12 rats in 12 h group. At each time-points, survival rates, ascites volumes, pathological lesion scores of pancreas tissues, serum amylase, tumor necrosis factor-α and IL-6 levels were determined as the indexes of therapeutic effects. RESULTS: The survival rate at 12 h was significantly higher in three treated groups than in untreated group. The ascites volume at 12 h was remarkably less in combined and sandostatin groups than in emodin group, but there was no difference between combined group and sandostatin group (P＞0.05). Serum amylase levels at all time-points were significantly lower in three treated groups than in untreated group. However, they had no difference among treated groups (P＞0.05). Serum TNF-α were lower in three treated groups than in untreated group at all time points. Among the three treated groups, at 6 h, the TNF-α levels of combination and sandostatin groups were lower than those of emodin group. These was no difference between combined and sandostantin. Serum IL-6 concentration at 3 h were lower in combined and sandostatin groups than in untreated group, but at 6 and 12 h they were lower in all treated groups than in untreated group and the combined and sandostatin groups and in emodin group, no difference was found between combined and sandostatin groups at all time-points (P＞0.05). The pathological scores of pancreas at all time points were significantly lower in three treated groups than in the untreated group, and at 6, 12 h, the scores of combined and sandostatin groups were lower than in emodin group. There was no difference between combined and sandostatin groups (P＞0.05). CONCLUSION: Combination of emodin with baicalein has significant therapeutic effects on SAP rats.

α-Lipoic acid protects against cholecystokinin-induced acute pancreatitis in rats

AIM: α-Lipoic acid (ALA) has been used as an antioxidant.The aim of this study was to investigate the effect of α-lipoic acid on cholecystokinin (CCK)-octapeptide induced acute pancreatitis in rats.METHODS: ALA at 1 mg/kg was intra-peritoneally injected, followed by 75 μg/kg CCK-octapeptide injected thrice subcutaneously after 1, 3, and 5 h. This whole procedure was repeated for 5 d. We checked the pancreatic weight/body weight ratio, the secretion of pro-inflammatory cytokines and the levels of lipase,amylase of serum. Repeated CCK octapeptide treatment resulted in typical laboratory and morphological changes of experimentally induced pancreatitis.RESULTS: ALA significantly decreased the pancreatic weight/body weight ratio and serum amylase and lipase in CCK octapeptide-induced acute pancreatitis. However,the secretion of IL-1β, IL-6, and TNF-α were comparable in CCK octapeptide-induced acute pancreatitis.CONCLUSION: ALA may have a protective effect against CCK octapeptide-induced acute pancreatitis.

Experimental and clinical evidence of antioxidant therapy in acute pancreatitis

Oxidative stress has been shown to play an important role in the pathogenesis of acute pancreatitis (AP). Antioxidants, alone or in combination with conventional therapy, should improve oxidative-stress-induced organ damage and therefore accelerate the rate of recovery. In recent years, substantial amounts of data about the efficiency of antioxidants against oxidative damage have been obtained from experiments with rodents. Some of these antioxidants have been found beneficial in the treatment of AP in humans; however, at present there is insufficient clinical data to support the benefits of antioxidants, alone or in combination with conven-tional therapy, in the management of AP in humans. Conflicting results obtained from experimental animals and humans may represent distinct pathophysiological mechanisms mediating tissue injury in different species. Further detailed studies should be done to clarify the exact mechanisms of tissue injury in human AP. Herein I tried to review the existing experimental and clinical studies on AP in order to determine the efficiency of antioxidants. The use of antioxidant enriched nutrition is a potential direction of clinical research in AP given the lack of clues about the efficiency and safety of antioxidant usage in patients with AP.

Acute pancreatitis in aging animals:Loss of pancreatitis-associated protein protection?

AIM:To investigate the effect of age on severity of acute pancreatitis(AP) using biochemical markers,histology and expression of the protective pancreatitisassociated proteins(PAPs).METHODS:AP was induced via intraductal injection of 4% sodium taurocholate in young and old rats.Sera and pancreata were assayed at 24 h for the parameters listed above;we also employed a novel molecular technique to assess bacterial infiltration using polymerase chain reaction to measure bacterial genomic ribosomal RNA.RESULTS:At 24 h after induction of AP,the pancreata of older animals had less edema(mean ± SE histologic score of young vs old:3.11 ± 0.16 vs 2.50 ±-0.11,P < 0.05),decreased local inflammatory response(histologic score of stromal infiltrate:3.11 ± 0.27 vs 2.00 ± 0.17,P < 0.05) and increased bacterial infiltration(174% ± 52% increase from sham vs 377% ± 4%,P < 0.05).A decreased expression of PAP1 and PAP2 was demonstrated by Western blotting analysis and immunohistochemical staining.There were no differences in serum amylase and lipase activity,or tissue myeloperoxidase or monocyte chemotactic protein-1 levels.However,in the most-aged group,serum C-reactive protein levels were higher(young vs old:0.249 ± 0.04 mg/dL vs 2.45 ± 0.68 mg/dL,P < 0.05).CONCLUSION:In older animals,there is depressed PAP expression related to a blunted inflammatory response in AP which is associated with worsened bacterial infiltration and higher C-reactive protein level;this may explain the more aggressive clinical course.

Comparative Study of the Growth and Gonad Development of Clarias gariepinus （Burchell 1822） Fed Diets with Plant and Animal-based Ingredients in Concrete Tanks

A twelve week experiment was conducted to compare the effects of diets with plant-based and animal-based ingredients on growth and gonad development of Clarias gariepinus. One hundred and 12 sub-adult C. gariepinus with an average weight of 205 ×5.09 g, were stocked in six concrete tanks （9 × 4 × 2 m3） containing 20 fish each. Experiment had 3 replicates and animals fed daily at 5% body weights. There was no significant difference （P 〈 0.05） in proximate compositions of the two experimental feeds and controls. Fecundity, gonad weight and gonasomatic index were higher in fish fed diet 13 than A and C. Similarly, growth indices were higher in fish fed diet B than in A and C. Histology of gonads showed a faster development of oocytes of eggs in fish fed animal-based ingredients than plant-based and combined plant and animal diets. Although there were slight differences in growth parameters and gonad development in favor of feed with animal-based ingredients, plant-based feed compared favorably in the growth and gonad development of C. gariepinus. Plant-based ingredients are recommended on the basis of affordability and availability as substitute for animal-based ingredients in C. gariepinus feed.

The effects of gonadal hormones on learning and memory in male mammals： A review

The primary role of the gonadal steroid hormones in mammals is to regulate reproduction and related behaviors; however, both androgens and estrogens are also integrally involved in mediating higher brain function and processes including cognition, neural development, and neural plasticity. In particular, a number of studies show that estradiol modulates dendritic spine growth and synapse density （synaptic plasticity） in the hippocampus of females, and that increased estradiol levels are generally associated with improvements on a variety of learning and memory tasks. While the majority of research has focused on the beneficial effects of estradiol in females, much less attention has been given to testosterone and its effects on learning and memory in males. Similar to estradiol titers in females, testosterone titers in males decline with age, albeit more gradually, and this decline has been correlated with impairment of certain cognitive tasks. Moreover, studies involving both humans and animals indicate that testosterone and its metabolites can augment responding on certain behavioral tasks, depending on the subject＇s current hormonal state, the response required, and the stimuli involved （e.g., those involving spatial or nonspatial stimuli）. While the exact mechanisms by which testosterone exerts its effects on learning and memory are not fully understood, recent findings suggest that testosterone modulates learning and memory in males through an interaction with the cholinergic system. The overall objective of this review is to discuss studies investigating the role of the gonadal hormones in mediating learning and memory processes in male mammals [Current Zoology 57 （4）： 543-558, 2011].