Study of effect and mechanism of midbrain periaqueductal gray NO on development of hypertension in stressed rats / 中国应用生理学杂志

<p><b>AIM</b>To study the role of NO in the midbrain periaqueductal gray (PAG) in the development of stress-induced hypertension (SIH).</p><p><b>METHODS</b>The model of stress-induced hypertension (SIH) rat was established by electric-foot in company with noise, NADPH-d histochemistry technique was used to investigate the change of nitric oxide synthase (NOS) positive neurons. Selecting and using microinjection and radioimmunoassay, we studied the effects of blood pressure and the content of Ach in rostral ventrolateral medulla (RVLM) after microinjection of L-NNA into PAG.</p><p><b>RESULTS</b>(1) The blood pressure increased, the cell number decreased and the grey degree value increased for the NOS positive neurons of PAG dorsolateral subdivision in SIH rats, and the content of Ach increased in RVLM. (2) Following microinjection of 100 mmol/L 0.1 microl L-NNA into PAG, the mean arterial pressure (MAP) and the content of Ach in RVLM increased in control rats, whereas the change of MAP was significantly smaller in SIH rats than control.</p><p><b>CONCLUSION</b>The plastic change of NOS positive neurons of PAG in SIH rats may be involved in the development of SIH, which may be mediated by Ach in RVLM.</p>

Intracellular dialysis with a microcatheter inserted into the patch-clamp pipette / 生理学报

In this paper we present an easily available method of intracellular dialysis via a microcatheter inserted into glass pipette during patch clamp experiment. An oblique hole through the glass pipette holder (above the lateral hole for cell-seal suction) is drilled, through which a microcatheter (O.D.=0.1 mm) made from the universal pipetter tip by hand-drawing passes and sticks out of the holder mouth in parallel with the Ag-AgCl electrode. With a syringe connected to the microcatheter, substitution of intracellular solution and intracellular dialysis of drugs can be achieved easily. Compared with repatch technique and intracellular solution substitution techniques used abroad, this method operates more easily and can produce more reliable results.