title: [The role of AT1 receptor in the changes in TH immunoreactivity of LC induced by brain cholinergic stimulation].
abstract: OBJECTIVE
  In the present study, we investigated the TH immunoreactivity and the expression of angiotensin AT1 receptor in locus coeruleus after intracerebroventricular (i. c. v.) injection of carbachol in conscious SD rats with immunohistochemistry. Meanwhile the effects of blocking AT1 receptor were also observed.
  
  
  RESULTS
  Both mean optical density and number of TH and AT1 immunoreactive positive neurons were markedly increased in locus coeruleus after 40 minutes of i.c.v. injection of carbachol (0.5 microg). The enhancement was significantly reduced by i. c. v. injection of losartan.
  
  
  CONCLUSIONS
  The results above suggest that i. c. v. injection of cholinergic agonist carbachol can enhance the activity of adrenergic neurons and the expression of AT1 receptor in locus coeruleus. The blockade of AT1 receptor may down regulate the above action induced by carbachol in locus coeruleus.
authors.affiliation: Department of Physiology, Dalian Medical University, Dalian 116027, China.
authors.forename: Qi-Ying
authors.initials: QY
authors.lastname: Yao
authors.forename: Lei
authors.initials: L
authors.lastname: Sun
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Wang
authors.forename: Chun-Ling
authors.initials: CL
authors.lastname: Jiang
mesh_terms: D000818:Animals; D001921:Brain; D002217:Carbachol / Q000494:pharmacology*; D018678:Cholinergic Agents / Q000494:pharmacology; D007276:Injections, Intraventricular; D008125:Locus Coeruleus / Q000187:drug effects* / Q000378:metabolism*; D019808:Losartan / Q000494:pharmacology; D008297:Male; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism*; D014446:Tyrosine 3-Monooxygenase
chemical_list: D018678:Cholinergic Agents; D044140:Receptor, Angiotensin, Type 1; D002217:Carbachol; D014446:Tyrosine 3-Monooxygenase; D019808:Losartan