title: Natriorexigenic effect of DAMGO is decreased by blocking AT1 receptors in the central nucleus of the amygdala.
abstract: μ-Opioid receptor (μ-OR) activation with agonist [D-Ala², N-Me-Phe⁴, Gly⁵-ol]-enkephalin (DAMGO) in the central nucleus of the amygdala (CeA) induces sodium (0.3M NaCl) intake in rats. The purpose of this study was to examine the effects of pre-injections of losartan (AT1 angiotensin receptor antagonist) into the CeA on 0.3 M NaCl and water intake induced by DAMGO injected bilaterally in the same area in rats submitted to water deprivation-partial rehydration (WD-PR) and in rats treated with the diuretic furosemide (FURO) combined with a low dose of the angiotensin-converting enzyme inhibitor captopril (CAP) injected subcutaneously (FURO/CAP). Male Sprague-Dawley rats with stainless steel cannulas implanted bilaterally into the CeA were used. In WD-PR rats, bilateral injections of DAMGO (2 nmol in 0.5 μL) into the CeA induced 0.3 M NaCl and water intake, and pre-treatment with losartan (108 nmol in 0.5 μL) injected into the CeA reduced 0.3 M NaCl and water intake induced by DAMGO. In FURO/CAP rats, pre-treatment with losartan (108 nmol in 0.5 μL) injected into the CeA attenuated the increase in 0.3M NaCl and water intake induced by DAMGO (2 nmol in 0.5 μL) injected into the same site. The results suggest that the natriorexigenic effect of DAMGO injected into the CeA is facilitated by endogenous angiotensin II acting on AT1 receptors in the CeA, which drives rats to ingest large amounts of hypertonic NaCl.
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China; Department of Physiology, Medical College of Henan University of Science and Technology, 263# Kaiyuan Avenue, Luoyang, Henan 471023, PR China.
authors.forename: J-B
authors.initials: JB
authors.lastname: Yan
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China; Department of Oral Biology, Xi'an Jiaotong University College of Stomatology, 98# Xiwu Road, Xi'an, Shaanxi 710004, PR China.
authors.forename: H-L
authors.initials: HL
authors.lastname: Sun
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China.
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China.
authors.forename: K
authors.initials: K
authors.lastname: Chen
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China.
authors.forename: B
authors.initials: B
authors.lastname: Sun
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China.
authors.forename: L
authors.initials: L
authors.lastname: Song
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China.
authors.forename: W
authors.initials: W
authors.lastname: Yan
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China.
authors.forename: X-L
authors.initials: XL
authors.lastname: Zhao
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China.
authors.forename: S-R
authors.initials: SR
authors.lastname: Zhao
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China.
authors.forename: H
authors.initials: H
authors.lastname: Qiao
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China.
authors.forename: B
authors.initials: B
authors.lastname: Hu
authors.affiliation: Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, 76# West Yanta Road, Xi'an, Shaanxi 710061, PR China; Department of Oral Biology, Xi'an Jiaotong University College of Stomatology, 98# Xiwu Road, Xi'an, Shaanxi 710004, PR China. Electronic address: jqyan810@gmail.com.
authors.forename: J-Q
authors.initials: JQ
authors.lastname: Yan
mesh_terms: D000679:Amygdala / Q000187:drug effects / Q000378:metabolism*; D000701:Analgesics, Opioid / Q000494:pharmacology*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D002216:Captopril / Q000494:pharmacology; D004232:Diuretics / Q000494:pharmacology; D004327:Drinking Behavior / Q000187:drug effects*; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology*; D005665:Furosemide / Q000494:pharmacology; D019808:Losartan / Q000494:pharmacology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism*; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage*; D013997:Time Factors; D014867:Water; D014868:Water Deprivation
chemical_list: D000701:Analgesics, Opioid; D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D004232:Diuretics; D044140:Receptor, Angiotensin, Type 1; D017673:Sodium Chloride, Dietary; D014867:Water; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D005665:Furosemide; D002216:Captopril; D019808:Losartan
keywords: angiotensin II; losartan; sodium appetite; the central nucleus of the amygdale; μ-opioid receptors