ABSTRACT
Differences of protonated and lithiated leucine-enkephalin(LE) were investigated by hydrogen deuterium exchange-mass spectrometry(HDX-MS) combined with quantum chemistry calculation. The results revealed that the protonated ions possessed very high product yield with all hydrogen atoms being exchanged, while the reaction of lithiated LE stopped after exchanging five hydrogen atoms in the same experimental conditions. The different HDX behaviours probably indicated their conformational differences. To further clarify the experimental results, the most stable conformations of protonated and lithiated leucine-enkephalin were calculated by density functional theory. It was found that terminal amino group was the most thermodynamically stable protonation site,while Li+in coordination of four carbonyl oxygen atoms formed the most favourable lithiated LE. The reaction field reduction of lithium LE was probably due to the less acidity of hydrogen atoms and the increasing rigid conformation change induced by lithium ion.
ABSTRACT
Objectives In order to study the endogenous opioid polypeptides involved in pathogenesis of epidemic encephalitis-B and the clinical therapeutic efficacy.Methods ①Leucine-enkephalin,?-endophin and Dynorphin levels in plasma and and CSF of patients with epidemic encephalitis-B during critical stage and convalescent stage were measured by radio-immunoassay.②Naloxone therapeutic efficacy in patients with epidemic encephalitis-B were investigated.Results Opioid polypeptides levels In plasma and CSF were significantly higher in critical stage and dropped to normal levels in convalescent stage.③We demonstrated that endogenous opioid polypeptides special antagnoist agent-Naloxone was a very important therapy agent for epidemic encephalitis-B patients.Therapy group efficacy was significantly better than control group.Conclusions These results demonstrate that endogenous opioid polypeptides involves in the physiopathologic changes of epidemic encephalitis-B.
ABSTRACT
This study demonstrated with the immunocytochemical ABC method that thedistribution pattern of TH,5-TH,SP,L-ENK and OXY immunoreactive fiberswere alike in the intermediate zone of the thoracic and upper lumbar spinal cord.These fibers located in the lateral funiculus,lateral horn,intermediate gray and thearea surrounding the central canal,forming a transversal fiber band with most ofthe fibers in the lateral horn.In the lateral horn,TH,5-HT,SP and L-ENKimmunoreactive fibers and terminals aggregated in fiber clusters and numerous fib-ers made up a longitudinal bundle running through the fiber clusters.These immuno-reative fibers and terminals surrounding the central canal and distributed mainly dorsalto it.TH and 5-HT fibers accumulated in midplane where some fibers ran in alongitudinal fiber bundle and bilateral fibers and terminals distributed sparsely.SP and L-ENK fibers and terminals were relatively less in the midplane whiledense laterally.All kinds of the immunoreactive fibers were found close to theependyma.Two small 5-HT fiber bundles ran parallel and lateral to the centralcanal and a small SP fiber bundle ventral to it.Moderate immunoreactive fiberswere found periodically in the intermediate gray and formed distinct bands to linkfiber clusters in the lateral horn and fibers dorsal to the central canal.The imm- unoreactive fibers in lateral funiculus accumulated near the lateral horn and mostdensely in upper thoracic cord.OXY-containing fibers were much less than theothers,thus obvious fiber clusters,longitudinal bundle or transversal bands had notbeen found.In general,the distribution pattern of some monoaminergic and pepti-dergic fibers in the intermediate zone was provided with a laddershaped configura-tion.The two longitudinal immunoreactive fiber bundles——dorsal to the centralcanal and within the lateral horn,located medial and lateral in the spinal grayrespectively,and the transversal bands appeared periodically in the intermediate graybridging between the two longitudinal bundles.This configuration of immunorea-ctive fibers coincided with nuclear regions which contained preganglionic sympatheticneurons as well as their dendrites.
ABSTRACT
Immunoelectron microscopic technique was used in the present study to observe the serotonin (5-HT)-, substance P (SP)-, and leucine-enkephalin (L-Enk)-like immunoreactive ultrastructures in the nucleus raphe magnus (NRM) of the rat. 5HT-like immunoreactive (5-HT-LI) axonal terminals were found to form axosomatic, axo-dendritic, and axo-axonic synapses with non-5-HT-LI neuronal cell bodies, 5-HT-LI and non-5-HT-LI dendrites, and non-5-HT-LI axonal terminals respectively. Non-5-HT-LI axonal terminals formed axo-somatic and axo-dendritic synapses with 5-HT-LI neuronal cell bodies and dendrites. SP-LI (or L-Enk-LI) axonal terminals formed axo-somatic, axo-dendritic synapses with SP-LI (or L-Enk-LI) and non-SP-LI (or non-L-Enk-LI) neuronal cell bodies and dendrites, respectively. L-Enk-LI axonal terminals constituting axo-axonic synapses with L-Enk-LI axonal boutons were observed less frequently. The most common synaptic type made by 3 kinds immunoreactive profiles mentioned above was axo-dendritic synapses made by non-immunoreactive axonal terminals with immunoreactive dendrites. The majority of the immunoreactive axonal boutons were mainly filled by clear spherical vesicles, but sometimes were mixed with small number of flat and granular vesicles. The immunoreactive products were irregular electron-dense substances, and were located on both inner and outer surfaces of the vesicles, or on the surface of the membranous cell organelles in the cytoplasm, etc.
ABSTRACT
The different distributions of substance P(SP)-and leucine-enkephalin (L-ENK)-like immunoreactive neurons in the midbrain raphe nuclei of the rats have been studied, using PAP immunocytochemical technique. The results showed four main points: 1. SP-containing immunoreactive cell bodies were only seen in the most caudal part of the dorsal raphe nucleus, the average number of SP-positive cell bodies was about 167 in each animal. The L-ENK-like immunoreactive positive cell bodies were found almost in the whole length of the dorsal raphe nucleus, the L-ENK-positive cell bodies were about 132 in each animal. 2. L-ENK-Iike immunoreactive perikarya were mainly located in the midline area of the dorsal raphe nucleus. Besides the above areas, SP-containing immunoreactive cell bodies were also located bilaterally in the extended area from the raphe. 3. L-ENK-containing immunoreactive cell bodies constantly appeared in the median raphe nuclei, the average number was about 199 in each animal, but SP-containing immunoreactive bodies were only observed in this nucleus of two rats. 4. Some SP-like immunoreactive cell bodies or processes were observed in the vincinty of vascular walls, but the L-ENK positive neurons were not found similar results. The present experiment showed that the SP-like immunoreactive perikarya is located in the median raphe nuclei of the rat.