犬静脉插管长期间断采血法

犬静脉插管长期间断采血法罗俊荷华西医科大学实验动物中心成都６１００４１生物医学研究，特别是药代学研究，常需用犬做实验。要求在短时间内（一般２４—７２ｈ）多次在同一犬体采静脉血，以检测受试药物在机体内的代谢过程。先给犬施行全身浅麻醉，致其活动能力受限，...

梅花鹿血粉胶囊抗缺氧、抗疲劳作用

从抗缺氧、抗疲劳方面对梅花鹿血粉胶囊进行研究。结果表明：１次及多次灌血粉混悬液，均能延长缺氧小鼠的存活时问，并能延长小鼠低温游泳的存活时间。

Relative efficacy of some prokinetic drugs in morphine-induced gastrointestinal transit delay in mice

AIM:To study the relative efficacy of cisapride, metoclopramide,domperidone,erythromycin and mosapride on gastric emptying(GE)and small intestinal transit(SIT) in morphine treated mice. METHODS:Phenol red marker meal was employed to estimate GE and SIT in Swiss albino mice of either sex.The groups included were control,morphine 1 mg/kg(s.c.15 rain before test meal)alone or with(45 rain before test meal p.o.)cisapride 10 mg/kg,metoclopramide 20 mg/kg, domperidone 20 mg/kg,erythromycin 6 mg/kg and mosapride 20 mg/kg. RESULTS:Cisapride,metoclopramide and mosapride were effective in enhancing gastric emptying significantly(P<0.001) whereas other prokinetic agents failed to do so in normal mice.Metoclopramide completely reversed morphine induced delay in gastric emptying followed by mosapride. Metoclopramide alone was effective when given to normal mice in increasing the SIT.Cisapride,though it did not show any significant effect on SIT in normal mice,was able to reverse morphine induced delay in SIT significantly(P<0.001) followed by metoclopramide and mosapride. CONCLUSION:Metoclopramide and cisapride are most effective in reversing morphine-induced delay in gastric emptying and small intestinal transit in mice respectively.

Differential expression of cholangiocyte and ileal bile acid transporters following bile acid supplementation and depletion

AIM: We have previously demonstrated that cholangiocytes, the epithelial cells lining intrahepatic bile ducts,encode two functional bile acid transporters via alternative splicing of a single gene to facilitate bile acid vectorial transport. Cholangiocytes possess ASBT,an apical sodium-dependent bile acid transporter to take up bile acids,and t-ASBT,a basolateral alternatively spliced and truncated form of ASBT to efflux bile acids.Though hepatocyte and ileal bile acid transporters are in part regulated by the flux of bile acids, the effect of alterations in bile acid flux on the expression of t-ASBT in terminal ileocytes remains undear.Thus,we tested the hypothesis that expression of ASBT and t-ASBT in cholangiocytes and ileocytes was regulated by bile acid flux. METHODS: Expression of ASBT and t-ASBT message and protein in cholangiocytes and ileocytes isolated from pair- fed rats given control (C) and 1% taurocholate (TCA) or 5% cholestyramine (CY) enriched diets,were assessed by both quantitative RNase protection assays and quantitative immunoblotting.The data obtained from each of the control groups were pooled to reflect the changes observed following TCA and CY treatments with respect to the control diets. Cholangiocyte taurocholate uptake was determined using a novel microperfusion technique on intrahepatic bile duct units (IBDUs) derived from C,TCA and CY fed rats. RESULTS: In cholangiocytes,both ASBT and t-ASBT message RNA and protein were significantly decreased in response to TCA feeding compared to C diet.In contrast, message and protein of both bile acid transporters significantly increased following CY feeding compared to C diet.In the ileum,TCA feeding significantly up-regulated both ASBT and t-ASBT message and protein compared to C diet,while CY feeding significantly down-regulated message and protein of both bile acid transporters compared to C diet.As anticipated from alterations in cholangiocyte ASBT expression,the uptake of taurocholate in microperfused IBDUs derived from rats on TCA diet decreased 2.7-fold,whereas it increased 1.7-fold in those on CY diet compared to C diet fed groups. CONCLUSION: These data demonstrate that expression of ASBT and t-ASBT in cholangiocytes is regulated by a negative feedback loop while the expression of these transporters in terminal ileum is modified via positive feedback.Thus, while transcriptional regulatory mechanisms in response to alterations in bile acid pool size are operative in both cholangiocytes and ileocytes,each cell type responds differently to bile acid supplementation and depletion.

Positively selected genes of the Chinese tree shrew （Tupaia belangeri chinensis） locomotion system

While the recent release of the Chinese tree shrew （Tupaia belangeri chinensis） genome has made the tree shrew an increasingly viable experimental animal model for biomedical research, further study of the genome may facilitate new insights into the applicability of this model. For example, though the tree shrew has a rapid rate of speed and strong jumping ability, there are limited studies on its locomotion ability. In this study we used the available Chinese tree shrew genome information and compared the evolutionary pattern of 407 locomotion system related orthologs among five mammals （human, rhesus monkey, mouse, rat and dog） and the Chinese tree shrew. Our analyses identified 29 genes with significantly high co （Ka/Ks ratio） values and 48 amino acid sites in 14 genes showed significant evidence of positive selection in the Chinese tree shrew. Some of these positively selected genes, e.g. HOXA6 （homeobox A6） and AVP （arginine vasopressin）, play important roles in muscle contraction or skeletal morphogenesis. These results provide important clues in understanding the genetic bases of locomotor adaptation in the Chinese tree shrew.

Hybrid undulatory kinematics of a robotic Mackerel(Scomber scombrus):Theoretical modeling and experimental investigation

Fishes that use undulatory locomotion occasionally change their inherent kinematics in terms of some natural behavior.This special locomotion pattern was vividly dubbed "hybrid kinematics" by biologists recently.In this paper,we employed a physical model with body shape of a Mackerel(Scomber scombrus),to use the three most typical undulatory kinematics:anguillform,carangiform and thunniform,to investigate the hydrodynamic performance of the so-called "hybrid kinematics" biological issue.Theoretical models of both kinematics and hydrodynamics of the physical model swimming were developed.Base on this model,the instantaneous force produced by fish undulatory body and flapping tail were calculated separately.We also quantitatively measured the hydrodynamic variables of the robotic model swimming with the three undulatory kinematics on an experimental apparatus.The results of both theoretical model and experiment showed that the robot with thunniform kinematics not only reaches a higher speed but also is more efficient during steady swimming mode.However,anguilliform kinematics won the speed race during the initial acceleration.Additionally,the digital particle image velocimetry(DPIV) results showed some difference of the wake flow generated by the robotic swimmer among the three undulatory kinematics.Our findings may possibly shed light on the motion control of a biomimetic robotic fish and provide certain evidence of why the "hybrid kinematics" exists within the typical undulatory locomotion patterns.

An experimental investigation into electromyography, constitutive relationship and morphology of crucian carp for biomechanical “digital fish”

Currently, the integrated biomechanical studies on fish locomotion come into focus, so it is urgent to provide reliable and sys- tematic experimental results, and to establish a biomechanical ＂digital fish＂ database for some typical fish species. Accord- ingly, based on the control framework of ＂Neural Control - Active Contraction of Muscle - Passive Deformation＂, the elec- tromyography （EMG） signals, the mechanical properties and the constitutive relationship of skin, muscle, and body trunk, as well as morphological parameters of crucian carp, are investigated with experiments, from which a simplified database of bio- mechanical ＂digital fish＂ is established. First, the EMG signals from three lateral superficial red muscles of crucian carp, which was evolving in the C-start movement, were acquired with a self-designing amplifier. The modes of muscle activity were also investigated. Secondly, the Young＇s modulus and the reduced relaxation function of crucian carp＇s skin and muscle were de- termined by failure tests and relaxation tests in uniaxial tensile ways, respectively. Viscoelastic models were adopted to deduce the constitutive relationship. The mechanical properties and the angular stiffness of different sites on the crucian carp＇s body trunk were obtained with dynamic bending experiments, where a self-designing dynamic bending test machine was employed. The conclusion was drawn regarding the body trunk of crucian carp under dynamic bending deformation as an approximate elastomer. According to the above experimental results, a possible benefit of body effective stiffness increasing with a little energy dissipation was discussed. Thirdly, the distribution of geometric parameters and weight parameters for a single experi- mental individual and multiple individuals of crucian carp was studied with experiments. Finally, considering all the above re- suits, generic experimental data were obtained by normalization, and a preliminary biomechanical ＂digital fish＂ database for crucian carp was established.