Distribution of GnRH immunoreactive cells and nerves in gastro entro-pancreatic system of rats was studied by using immunogold-silver staining. The GnRH immunoreactive epithelial cells can be seen in the stomach, small intestine, large intestine and pancreas. The apical portion of these GnRH postive epithelial cells extended to the luminal surface of surface epithelium and glands, and they belong to the open type endocrine cells. The GnRH immunoreactive nerve cells can be found in submucous plexus, myenteric plexus and serosa of the stomach and small intestine. The GnRH postive nerve fibers can be seen in lamina propria and submucosa of the small intestine. These results suggest that the GnRH may play an important role in the regulation of digestion.

The distribution and morphology of 5-HT immunoreactive endocrine cells in the gastrointestinal tract of 5 adult rats were studied by the immunohistochemicael PAP method with nickel-intensified DAB on paraffin sections of intestine rolls. The density of 5-HT immunoreactive endocrine cells in the gastrointestinal tract of the rat is highest in the pylorus, duodenum and colon and moderate in the jejunum, ileum, caecum and rectum and lowest in the body of the stomach. The 5-HT immunoreactive endocrine cells are various in shape. Some of them have several processes extending between other epithelial cells. The basal portion of some endocrine cells have processes with 5-HT positive substance accumulating in their ends. The processes of the basal portion of some endocrine cells extend into lamina propria through the basal membrane. The 5-HT positive substance of many endocrine cells can be found to extend to luminal surface of the crypt or intestinal tract. These results indicate that the 5-HT immunoreactive endocrine cells can release 5-HT by both endocrine and exocrine ways.

The distribution of dopamine-immunoreactive endocrine cells and nerves in the digestive tract of guinea-pigs was examined with the ABC immunostaining technique. Dopamine-immunoreactive endocrine cells were observed in the pyloric antrum, small intestine and colon. The highest density of the positive ceils was found in the duodenum. From the jejunum to the colon the number of immunoreactive cells gradually decreased. A similar population of the positive cells was seen in the antrum and colon. Dopamine-immunoreactive nerve fibres were mainly located in the lamina propria and submucosa of the digestive tract. There were more positive fibres in the small intestine than in the stomach and colon. The dense networks of immunoreactive fibres were demonstrated in the villi. Some positive nerve fibres penetrated into the superficial and glandular epithelia. This representation indicated that the epithelial cells were directly innervated with the dopamine containing nerves.

Objective To investigate the effect of GnRH-A in gastric cavity on the function of somatostatin cells in the digestive tract of rats. Methods The immunohistochemical ABC method and enzyme-link immunoassay were used in the experiment. Results The densities of the somatostatin positive cells in the stomach and duodenum of the experiment groups were 26^6?3^893 and 51^7?2^214 respectively,and significantly lower than those in stomach 48^3?6^019 and duodenum 58^5?4^454 of control groups respectively(P

Objective To study the effect of FSH on the secretion of gastrin in the rat stomach,offering experimental evidence for reproductive endocrine hormone regulating digestive function. Methods The FSH was directly injected into the stomach of rats to observe the change of density of gastrin immunoreactive positive cells in the stomach by immunohistochemical SABC method and the gastrin level in circulating blood and gastric liquid by ELISA. Results Compared with the control group,which was injected with saline into the stomach,the density of immunoreactive positive cells was significantly increased in the stomach with FSH treatment group(P

Dopamine is one of the bioactive amines which regulate many physiological functions. In order to study its localization and quantification in tissues with immunohistochemistry and radioimmunoassay, authors immunised New Zealand rabbits with dopamine-BSA (bovine serum albumin) complex and succeeded in the production of the specific antiserum. The antiserum was tested on routine paraffin sections of Bouin's fixed guinea-pig digestive tract with the ABC technique. The titre of the antiserum was 1:1000-1:2000. Results of substitution, absorption and cross-absorption tests proved that the positive staining obtained with the antiserum demonstrated the specific immunoreaction between the antibody to dopamine and the antigen in the tissues.

Localization and quantitation of GnRH, somatostatin (SS), and ?-endorphin (?-EP) in human placentalvilla were studied using immunogold-silver staining method. GnRH and SS immunoreactive positive substance existed in the cytotrophoblasts of many placental villi and in syncytiotrophoblasts of few placental villi, ?-EP immunoreactive positive substance localized in syncytiotrophoblasts of many placental villi and in cytotrophoblasts of few placental villi. These results suggest that the cytotrophoblasts and syncytiotrophoblasts are able to synthesize these three kinds of regulatory peptides, however, SS and GnRH may be synthesized mainly in the cytotrophoblasts, ?-EP mainly be synthesized in the syncytiotrophoblasts. The amount of GnRH and ?-EP in placenta villi show obvious change with progress of pregnancy. This change show a negative relationship between the GnRH and ?-EP, which suggested that there may be a functional reciprocal inhibition between the GnRH and ?-EP.

Distribution and morphology of argyrophil and argentaffin cells in small intestine of 11 rats were studied by means of Huang's method of argyrophil reaction and Singh's method of argentaffin reaction on paraffin sections of intestine rolls. The results are as follows:1. The density of argyrophil and argentaffin cells in rat small intestine is the highest in the duodenum and progressively decreases from jejunum to ileum.2. The staining intensity of argyrophil and argentaffin cells is lowest in the basal portion of crypts and progressively increases from crypts to villus. Intensely stained argyrophil and argentaffin cells in the villus tip were observed. The basal portion of the argyrophil cells has cytoplasmic processes extending to connective tissue of the lamina propria and the argyrophil granules are released to lamina propria along these processes. Argyrophil granules can usually be found to extend to the luminal surface of these cells; occasionally they were observed extracellularly in the gland cavity, suggesting that argyrophil and argentaffin cells may have both endocrine and exocrine functions.3. Some argyrophil cells can be found in connective tissue of the lamina propria. The cells are irregular in shape and possesses processes. There are argyrophil granules in perikaryon and the processes and occasionally outside the cells. The argyrophil cells in the lamina propria are the same as those among epithelial cells in shape, argyrophil property and density of the granules. It is possible that these cells belong to endocrine cells.

Objective:To clone the single chain variable Fv of anti-idiotype monoclonal antibody against vibrio alginolyticus.Methods:Total RNA was extracted from hybridoma cell 2F4 secreting MAb against vibrio alginolyticus and cDNA was amplified by retropolymerase chain reaction(RT-PCR),the expression vector pTAT-AL1 was constructed for the recombinant V_H-V_L expression.The transformed E.coli BL21 cells were propagated and induced by IPTG.Results:The V_H gene contained 369 base pairs and encoded 123 amine acid residues;The V_L gene contained 339 base pairs and encoded 113 amine acid residues;There were four FRs three CDRs and two characteristic cysteine residues in the V_H and V_L gene,respectively.ELISA results showed the ScFv retained almost the same antigen affinity and specificity as its parent monoclonal anitbody.Conclusion:The single chain variable Fv of anti-idiotype monoclonal antibody against vibrio alginolyticus was constructed successfully and expression products was found in the periplasmic space and inclusion bodies.This ScFv might be a new generation of gene engineering vaccine of the anti-idiotype monoclonal antibody against vibrio alginolyticus in fishery.

Objective To construct,express and identify the anti-idiotypic antibody single chain variable fragment(scFv) against Edwardsiella tarda.Methods By using RT-PCR method,the variable regions of the heavy and light chain of the anti-idiotypic monoclonal antibody(mAb) 1E11 against Edwardsiella tarda were cloned and joined with a(Gly4Ser)3 linker,and the scFv in the orientation of VL-linker-VH was constructed.It was then cloned into vector plasmid pET-28a,expressed in Escherichia coli BL21(DE3),and confirmed by SDS-PAGE,Western blot and ELISA.Results The recombinant scFv could be expressed in E.coli BL21(DE3) in a fusion protein pattern.The expression product was in the form of an inclusion body and the purified fusion protein was obtained after being purified and refolded.The SDS-PAGE and Western blot analysis showed that the molecular weight of scFv protein was 27 ku.Indirect ELISA confirmed that the scFv had the binding activity to the antigen.Conclusion The recombinant anti-idiotype scFv has been successfully constructed and expressed in E.coli BL21(DE3),providing the basis and potential for preparation of genetically engineered vaccine against Edwardsiella tarda.