STR/N is an inbred strain of mice which is known to exhibit extreme polydipsia and polyuria. We previously found central administration of angiotensin II enhanced cardiovascular responses in STR/N mice than normal mice, suggesting that STR/N mice might exhibit different cardiovascular responses. Therefore, in this study, we investigated daily mean arterial blood pressure and heart rate, and changes in the baroreceptor-heart rate reflex in conscious STR/N mice and control (ICR) mice. We found that variability in daily mean arterial blood pressure and heart rate was significantly larger in STR/N mice than in ICR mice (p<0.05). There was a stronger response to phenylephrine (PE) in STR/N mice than in ICR mice. For baroreceptor reflex sensitivity, in the rapid response period, the slopes of PE and sodium nitroprusside (SNP) were more negative in STR/N mice than in ICR mice. In the later period, the slopes of PE and SNP were negatively correlated between heart rate and blood pressure in ICR mice, but their slopes were positively correlated in STR/N mice. These results indicated that STR/N mice exhibited the different cardiovascular responses than ICR mice, suggesting that the dysfunction of baroreceptor reflex happened in conscious STR/N mice.

Based on the research of gas flow liquid phase microextraction (GF-LPME) system, a combining interface between GF-LPME system and gas chromatography (GC) and an auto-sampling equipment have been researched and developed, which can be used for rapid extraction, separation, enrichment and sampling for volatile or semivolatile analyte. The control system of the combining technique is designed through virtual instrument technology, and the working conditions of the control system detected by control panel. Experiments show that, this device with the advantages of simple extraction structure, convenient operation, high accuracy and extensible functions, can be used in gas chromatography analysis for complex samples of trace compounds in the area of medicine, agriculture, food, environment, etc.

Based on the carbon fiber cylinder solid phase extraction technology, a system was researched, which can be used to complete step elution, separation and continuous/selective injection for different polar compounds. The process was realized through the valve switching and more than one peristaltic pump controlled by single chip microcomputer. The connector between liquid chromatography (LC) and UV-detector is also available in this paper. The experimental results show that, this combined system meet the requirement of QA/QC in the aspect of simple operation, high precision and repeatability. It can be widely used in online analysis of different polar compounds with liquid chromatography in the fields of environment analysis, drug analysis, life science, etc.