To investigate the melatonin receptor(MR) gene and protein expression in human HUT78 cell line, total RNA of HUT78 cells was isolated by single-step method of acid guanidinium-thiocyanate-phenol-chloform, and mt 1 and MT 2 mRNA were determined by reverse transcription-polymerase chain reaction(RT-PCR). The Envision method was applied to immunohistochemistry to identify and localize mt 1 and MT 2 protein. The mt 1 cDNA fragment of the expected size of 370bp was determined, but the MT 2 cDNA fragment of the expected size of 320bp was not determinable by RT-PCR. Sequencing result indicated that the positive product coincided with the cDNA of human mt 1. The mt 1 protein was observed by immunohistochemistry. These buffy positive granules were scattered with some areas stronger than the others, and were primarily located in cytoplasm and membrane, with rare location in nucleus; meanwhile the MT 2 protein was not observed. These results demonstrated the mt 1 mRNA and protein expression in HUT78 cell line. It is indicated that melatonin has directly immune-regulative effects on T lymphocyte, The changes of MR in physiological and pathological stages need to be investigated.

AIM: To investigate the melatonin receptor (MR) gene and protein expression in the human peripheral blood lymphocytes. METHODS: Total RNA of human peripheral lymphocytes was isolated by single step method of acid guanidinium-thiocyanate-phenol-chloform, mt 1 and MT 2 mRNA were determined by the reverse transcription-polymerase chain reaction(RT-PCR). Immunohistochemistry was applied to identify and localize mt 1 and MT 2 protein. RESULTS: 1 1 kb mt 1 mRNA was detected by Northern blot, but 1 1 kb MT 2 mRNA was not detected. The mt 1 cDNA fragment of the expected size of 370 bp was determined and the MT 2 cDNA fragment of the expected size of 320 bp was not determined by RT-PCR. Sequencing result indicated that the positive product coincided with the cDNA of human mt 1. The mt 1 protein was observed by immunohistochemistry. These buffy positive granules were scattered with some areas stronger than the others, and primarily located in cytoplasm and membrane, with rare location in nucleus; meanwhile the MT 2 protein was not observed. CONCLUSION: These results demonstrated the mt 1 mRNA and protein expression in human peripheral leukocytes. It is indicated that melatonin has directly immune-regulative effects on peripheral lymphocytes.

The purpose of this study was to test whether oxygen carriers could decrease tissue injury in a rat model of acute myocardial infarct. The study included 3 groups: SD rats in group II and group III were subjected to permanent occlusion of their left anterior descending coronary arteries; SD rats in group I were subjected to sham-operation. The success of modeling was assartained by ECG. Then the rats were given drug via caudal veins for 2 days. A quantitative evaluation was made with an automatic device for interpretation of cardiac troponin T (cTnT); heart staining was made for the calculation of myocardial infarction size (MIS); and myocardial tissue was taken and subjected to routine pathological hematoxylin-eosin (HE) staining for showing myocardial cell injury. cTnT in the sham-operation group was significantly lower by comparison with that in the model group (P < 0.01), and it was slightly lower in the oxygen carriers group than that in the model group, but there was no statistically significant difference (P = 0.18); MIS was significantly smaller in the sham-operation group than that in the model group (P < 0.01), and it was greater in the model rats than that in the oxygen carriers rats (P < 0.05). HE staining of myocardicum in the oxygen carriers group was significantly better than that in the model group (P < 0.01). The evidence suggested that oxygen carriers increased oxygen supply to ischemic myocardium, reduced the myocardial injury, and thus might offer a novel treatment of myocardial infarction.
Animals ; Blood Substitutes ; pharmacology ; Hemoglobins ; metabolism ; Male ; Myocardial Infarction ; metabolism ; Oxygen ; metabolism ; Rats ; Rats, Sprague-Dawley ; Troponin T ; metabolism