Mechanisms of depressor effect of norepinephrine injected into subnucleus commissuriu of nucleus solitarius tractus in rabbits.
This experiment aimed to investigate the effect of adrenergic system in the subnucleus commissuriu of nucleus solitrius tractus (CNTS) on renal nerve discharges. Norepinephrine (NE) was microinjected into the CNTS of rabbits and mean arterial blood pressure (MAP) and renal nerve discharges (FRND) were synchronously recorded. The results indicated that (1) microinjection of norepinephine into the CNTS of rabbit could significantly attenuate the frequency of renal nerve discharge, and at the same time decrease markedly the mean arterial pressure. (2) Microinjection of 0.3 nmol yohimbin into CNTS had no significant influence on FRND and MAP, but could attenuate and even reverse the effects of NE on FRND and MAP. These results suggest that microinjection of NE into CNTS may activate the alpha-adrenorecptor located in CNTS and secondarily produce a depressor effect by attenuating the activity of periphenal sympathetic nervous system.
Zhang
Yi
Y
Department of Physiology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Luo
Hongyan
H
Liu
Shenghong
S
Yi
Zhengrong
Z
Li
Ai
A
Hu
Xinwu
X
Liu
Changjin
C
Tang
Ming
M
Liu
Lieju
L
Song
Yuanlong
Y
Gao
Linlin
L
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003864:Depression, Chemical; D005260:Female; D007668:Kidney / Q000294:innervation*; D008297:Male; D008845:Microinjections; D009638:Norepinephrine / Q000494:pharmacology*; D011817:Rabbits; D017552:Solitary Nucleus / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology*; D014666:Vasomotor System / Q000503:physiopathology
D009638:Norepinephrine