title: Lateral parabrachial nucleus and serotonergic mechanisms in the control of salt appetite in rats.
abstract: This study investigated the effects of bilateral injections of serotonergic receptor agonist and antagonist into the lateral parabrachial nucleus (LPBN) on the ingestion of water and 0.3 M NaCl induced by intracerebroventricular angiotensin II (ANG II) or by combined subcutaneous injections of the diuretic furosemide (Furo) and the angiotensin-converting enzyme inhibitor captopril (Cap). Rats had stainless steel cannulas implanted bilaterally into the LPBN and into the left lateral ventricle. Bilateral LPBN pretreatment with the serotonergic 5-HT1/5-HT2 receptor antagonist methysergide (4 micrograms/200 nl each site) increased 0.3 M NaCl and water intakes induced by intracerebroventricular ANG II (50 ng/microliter) and 0.3 M NaCl intake induced by subcutaneous Furo + Cap. Pretreatment with bilateral LPBN injections of a serotonergic 5-HT2A/2C receptor agonist DOI (5 micrograms/200 nl) significantly reduced 0.3 M NaCl intake induced by subcutaneous Furo + Cap. Pretreatment with methysergide or DOI into the LPBN produced no significant changes in the water intake induced by subcutaneous Furo + Cap. These results suggest that serotonergic mechanisms associated with the LPBN may have inhibitory roles in water and sodium ingestion in rats.
authors.affiliation: Department of Psychology, University of Iowa, Iowa City 52242-1407, USA.
authors.forename: J V
authors.initials: JV
authors.lastname: Menani
authors.forename: R L
authors.initials: RL
authors.lastname: Thunhorst
authors.forename: A K
authors.initials: AK
authors.lastname: Johnson
mesh_terms: D000662:Amphetamines / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001066:Appetite / Q000502:physiology*; D002216:Captopril / Q000494:pharmacology; D004326:Drinking / Q000187:drug effects; D004338:Drug Combinations; D005665:Furosemide / Q000494:pharmacology; D007276:Injections, Intraventricular; D007279:Injections, Subcutaneous; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D011149:Pons / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D012965:Sodium Chloride
chemical_list: D000662:Amphetamines; D004338:Drug Combinations; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D000804:Angiotensin II; D012701:Serotonin; D012965:Sodium Chloride; D005665:Furosemide; D002216:Captopril; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine; D008784:Methysergide