Wang J, Pan J Y, Jia B J
Department of Physiology, Sun Yat-sen University of Medical Sciences, Guangzhou 510089, China.
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2001 May;17(2):153-6.
To study the effects of L-arginine, a precursor for the synthesis of nitric oxide, when it was microinjected into the functionally identified depressor area in ventral surface of medulla oblongata (VSMd) on cardiovascular responses.
Artery pressure (AP), perfusion pressure of the kidney (PPK) and heart rate were recorded to study the effects of microinjection of NO related drugs into VSMd.
(1) Unilateral microinjection of L-arginine (60 - 100 nmol) into VSMd produced prominent dose-related pressor effect and increased PPK but without significant changes in heart rate. (2) Microinjection of L-Arg (100 nmol) 3 min after microinjection of methylene blue (10 nmol) into VSMd did not significantly change AP and PPK. (3) Unilateral microinjection L-glutamate (350 nmol) into VSMd elicited depressor effect (-34.97% +/- 4.33%). The depressor effect was significantly dosed related attenuated by prior microinjection L-arginine (60 - 100 nmol) into the same area.
These results suggest that the L-arginine - NO pathway in the VSMd participate in the central regulation of artery pressure and the pathway may have a key role in inhibiting glutamatergic neurotransmission in the anesthetized rats.
研究一氧化氮合成前体L-精氨酸微量注射到延髓腹侧面功能明确的减压区（VSMd）时对心血管反应的影响。
记录动脉血压（AP）、肾灌注压（PPK）和心率，以研究向VSMd微量注射一氧化氮相关药物的影响。
（1）向VSMd单侧微量注射L-精氨酸（60 - 100 nmol）产生显著的剂量相关升压效应，并增加PPK，但心率无明显变化。（2）在向VSMd微量注射亚甲蓝（10 nmol）3分钟后微量注射L-精氨酸（100 nmol），AP和PPK无明显变化。（3）向VSMd单侧微量注射L-谷氨酸（350 nmol）引起降压效应（-34.97% +/- 4.33%）。预先向同一区域微量注射L-精氨酸（60 - 100 nmol）可使降压效应显著呈剂量相关减弱。
这些结果表明，VSMd中的L-精氨酸 - 一氧化氮途径参与动脉血压的中枢调节，且该途径可能在抑制麻醉大鼠的谷氨酸能神经传递中起关键作用。
