[Angiotensin II in rostral ventrolateral medulla mediates amino acids release from spinally projecting nerve terminals in the spinal cord].
Microdialysis in the intermediolateral column (IML) was employed to examine amino acids release induced by angiotensin II (ANG II) applied into the rostral ventrolateral medulla (RVLM). Microinjection of ANG II (100 pmol, n = 11) into the RVLM significantly increased (P < 0.01) the release of aspartate (from 4.75 +/- 1.01 to 8.90 +/- 2.28 pmol/20 microliters) and glutamate (from 18.99 +/- 8.64 to 73.88 +/- 29.26 pmol/20 microliters) in the spinal cord. The increase of glutamate release was significantly attenuated (P < 0.05) by pretreatment with losartan (10 nmol, n = 8) at the same RVLM site. Immunofluorescence double labeling combined with confocal microscopic observation demonstrated that 62%-91% of the glutamatergic neurons in the RVLM were double-labeled with AT1 receptors, supporting the view that ANG II-induced glutamate release in the spinal cord may arise from the AT1 receptor-containing glutamatergic spinally projecting neurons in the RVLM.
Hu
L
L
Department of Physiology, Medical Center of Fudan University, National Key Laboratory for Medical Neurobiology, Shanghai 200032.
Zhu
D N
DN
Wang
J Q
JQ
Sun
Z J
ZJ
Yao
T
T
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D018698:Glutamic Acid / Q000378:metabolism*; D008297:Male; D008526:Medulla Oblongata / Q000378:metabolism*; D009434:Neural Pathways; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000166:cytology / Q000502:physiology*
D000804:Angiotensin II; D018698:Glutamic Acid