Changes in heart rate, blood pressure and renal sympathetic nerve activity induced by microinjection of capsaicin into area postrema in rats
10.3321/j.issn:0371-0874.2000.05.017
- VernacularTitle:最后区微量注射辣椒素对大鼠血压、心率和肾交感神经放电的影响
- Author:
Bao-Jian XUE
1
;
Rui-Rong HE
Author Information
1. 河北医科大学
- Keywords:
capsaicin;
area postrema;
mean arterial pressure;
heart rate;
renal sympathetic nerve activity;
ruthenium red;
MK-801
- From:
Acta Physiologica Sinica
2000;52(5):435-439
- CountryChina
- Language:Chinese
-
Abstract:
The effects of capsaicin microinjection into area postrema (AP) on mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA) were investigated in 36 anesthetized Sprague-Dawley rats. The results obtained are as follows. (1) Following microinjection of capsaicin (10 μmol/L, 50 nl) into the AP, MAP, HR and RSNA were significantly increased from 12.34±0.53 kPa, 328.52±7.54 bpm and 100±0% to 15.17±0.25 kPa (P<0.001), 354.81±8.54 bpm (P<0.001) and 156.95±7.57% (P<0.001), respectively. (2) Ruthenium red (RR, 100 mmol/L, 0.2 ml, iv), a capsaicin receptor antagonist, significantly inhibited these effects of capsaicin. (3) Pretreatment with a NMDA receptor antagonist MK-801 (500 μg/kg, 0.2 ml, iv) also reduced these effects of capsaicin. The above results indicate that microinjection of capsaicin into AP induces excitatory effects on MAP, HR and RSNA, which are mediated by capsaicin receptors with glutamate involvement.
