ABSTRACT
INTRODUCTION: The reduction of endogenous nitric oxide (NO) production during hepatic ischemia-reperfusion injury, generally via a reduction in endothelial NO synthase activity, leads to liver injury. We hypothesized that administration of an exogenous NO donor into the portal vein may ameliorate hepatic blood flow reduction after a period of ischemia. MATERIAL AND METHODS: A total of 90 min of ischemia (portal vein and hepatic artery) was applied in 15 anesthetized pigs, using the Pringle method under sevoflurane anesthesia. All animals were administered either saline (control group, n = 8) or sodium nitroprusside (SNP, n = 7) as exogenous NO donor drugs into the portal vein, 30 min before and after ischemia. The portal venous blood flow and hepatic artery blood flow were measured continuously using transonic flow probes attached to each vessel. Endogenous NO (NOx = NO2- + NO3-) production was measured every 10 min using a microdialysis probe placed in the left lobe of the liver. RESULTS: In the SNP group, portal venous flow remained unchanged and hepatic artery flow significantly increased compared to baseline. Although the production of liver tissue NOx transiently decreased to 60% after ischemia, its level in the SNP group remained higher than the control saline group. CONCLUSION: Regional administration of SNP into the portal vein increases hepatic arterial flow during ischemia reperfusion periods without altering mean systemic arterial pressure. We speculate that administration of an exogenous NO donor may be effective in preventing liver injury via preservation of total hepatic blood flow.
Subject(s)
Liver Circulation/drug effects , Liver Diseases/prevention & control , Nitric Oxide Donors/administration & dosage , Nitroprusside/administration & dosage , Reperfusion Injury/prevention & control , Animals , Drug Evaluation, Preclinical , Hepatic Artery/drug effects , Ischemic Preconditioning/methods , Liver/blood supply , Liver/drug effects , Liver/metabolism , Nitric Oxide/metabolism , Portal Vein , Random Allocation , SwineABSTRACT
OBJECTIVE: Alkaline phosphatase (ALP) and osteocalcin (OC) are the markers of new bone formation. Quantitative study of ALP and OC in the process of new bone formation helps to understand the ongoing of this cascade and contributes to make diagnosis in clinical treatment. METHODS: 8-week-old male C57BL/6J mice and primary osteoblasts from neonatal C57BL/6J mice calvaria were used in this experiment. HE staining, Northern blot and Real Time PCR methods were employed to detect the histological changes and the expression pattern of ALP and OC. RESULTS: In vivo study showed that after fracture the expressions of both ALP and OC kept on increasing which were peaked on the 10 day, then started decreasing gradually. In vitro study on primary osteoblasts showed that the expressions of ALP and OC reached peak on the 14th day in differentiation culture medium and started decreasing from this time point till the 21st day. CONCLUSION: The expression of ALP and OC in the process of new bone formation parallels with the development of osteoblasts, it increases with the differentiation of osteoblasts and becomes decreasing with the maturation of osteoblasts. The reciprocal relationship between the expression pattern of ALP and OC and development of osteoblast helps to maintain homeostasis.
Subject(s)
Alkaline Phosphatase , Osteocalcin , Animals , Bone and Bones , Cell Differentiation , Male , Mice , Mice, Inbred C57BL , Osteoblasts , SkullABSTRACT
Objective To find out a proper way to detect green fluorescent protein (GFP). Methods Kidneys, livers and femurs from GFP transgenic mice and C57BL/6J wild type mice were employed for in vivo study.The samples were dehydrated with alcohol and acetone individually before embedding, then frozen, paraffin and resin sections were made for the detection of GFP. C3 P12 cells which derived from calvaria bone cells of GFP transgenic mouse were used for the detection of GFP in vitro. Cells were exposed to alcohol, acetone and PBS after paraformaldehyde fixation. Laser scanning microscopy was employed for GFP detection. Results In frozen sections, both kidney and liver samples which exposed to 4% buffered paraformaldehyde fixation had strong GFP signals, while GFP signal disappeared completely in fresh frozen sections without fixation. Much stronger GFP intensity was found in acetone treated samples than in alcohol treated paraffin sections, but without apparent difference in GFP intensity in acetone and alcohol treated resin samples. Acetone and alcohol made no difference in fixed C3 cells in different time courses. Conclusion Acetone treated paraffin sections are preferable for GFP detection.
