Resection Of Pheochromocytoma, Blood Pressure, Heart Rate Variability Analysis And Tumor Gene Expression Characteristics

Objectives: 1 To analyze the blood pressure, heart rate and catecholamines changes in patients undergoing resection of pheochromocytoma and to investigate factors that can exacerbate the hemodynamic instability; 2 To compare the mRNA expression difference between pheochromocytoma tissue and adjacent "normal" tissue and to investigate if any gene expression difference attributes to hemodynamic instability and its correlation with blood pressure, heart rate and catecholamines secretion. Methods: 14 patients with sporadic pheochromocytoma undergoing elective resection were recruited in this study. Preoperative data were collected and anesthesia procedures were standardized; invasive radial artery blood pressure (systolic, diastolic and mean artery pressure) was monitored and recorded at 2 minutes intervals; blood samples were drawn from internal jugular vein at 4 time points, anesthetized but before the operation (point 1), skin incised (point 2), tumor manipulated (point 3) and tumor excised (point 4) respectively , for catecholamines measurement. Tumor tissue and adjacent "normal" tissue specimen were also collected for mRNA expression comparison.Means and standard deviations of systolic, diastolic and mean artery blood pressure were calculated for each patient, and the mean artery blood pressure, heart rate, catecholamines secretion at 4 time points (anesthetized but before the operation, skin incised, tumor manipulated and tumor excised) were compared.Total RNA was extracted from both pheochromocytoma and adjacent tissue, after DNase I treatment, were amplified with DD-RT-PCR (differential display reverse transcription polymerase chain reaction). The differentially expressed cDNA were displayed after electrophoresis on a 3.5% denaturing polyacrylamide gel, differential displayed bands were excised from the gel and subcloned into pGEM-T easy vector, probes were prepared for each clone, total RNA were Dot blotted with each probe respectively to find out the positive probe (clone). The sequence of each positive clone was compared to the entries of Genbank, DDBJ and EMBL to find out its identity. For each positive clone, Dot blotting was carried out once more to...