title: GABA in Paraventricular Nucleus Regulates Adipose Afferent Reflex in Rats.
abstract: BACKGROUND
  Chemical stimulation of white adipose tissue (WAT) induces adipose afferent reflex (AAR), and thereby causes a general sympathetic activation. Paraventricular nucleus (PVN) is important in control of sympathetic outflow. This study was designed to investigate the role of γ-aminobutyric acid (GABA) in PVN in regulating the AAR.
  
  
  RESULTS
  Experiments were carried out in anesthetized rats. Renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) were continuously recorded. AAR was evaluated by the RSNA and MAP responses to electrical stimulation of the right epididymal WAT (eWAT) afferent nerve. Electrical stimulation of eWAT afferent nerve increase RSNA. Bilateral microinjection of the GABAA receptor agonist isoguvacine or the GABAB receptor agonist baclofen attenuated the AAR. The effect of isoguvacine on the AAR was greater than that of baclofen. The GABAA receptor antagonist gabazine enhanced the AAR, while the GABAB receptor antagonist CGP-35348 had no significant effect on the AAR. Bilateral PVN microinjection of vigabatrin, a selective GABA-transaminase inhibitor, to increase endogenous GABA levels in the PVN abolished the AAR. The inhibitory effect of vigabatrin on the AAR was attenuated by the pretreatment with gabazine or CGP-35348. Pretreatment with combined gabazine and CGP-35348 abolished the effects of vigabatrin.
  
  
  CONCLUSIONS
  Activation of GABAA or GABAB receptors in the PVN inhibits the AAR. Blockade of GABAA receptors in the PVN enhances the AAR. Endogenous GABA in the PVN plays an important role in regulating the AAR.
authors: Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors: Lei
authors: L
authors: Ding
authors: Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors: Run
authors: R
authors: Gao
authors: Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors: Xiao-Qing
authors: XQ
authors: Xiong
authors: Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors: Xing-Ya
authors: XY
authors: Gao
authors: Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors: Qi
authors: Q
authors: Chen
authors: Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors: Yue-Hua
authors: YH
authors: Li
authors: Department of Physiology and Pathophysiology, Cardiovascular Research Center, Xi'an Jiaotong University School of Medicine, Xi'an 710061, China.
authors: Yu-Ming
authors: YM
authors: Kang
authors: Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors: Guo-Qing
authors: GQ
authors: Zhu
mesh_terms: D052436:Adipose Tissue, White / Q000187:drug effects / Q000502:physiology*; D000344:Afferent Pathways / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D007539:Isonicotinic Acids / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000502:physiology; D008297:Male; D009943:Organophosphorus Compounds / Q000494:pharmacology; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000502:physiology*; D011724:Pyridazines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology; D020888:Vigabatrin / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D007539:Isonicotinic Acids; D009943:Organophosphorus Compounds; D011724:Pyridazines; D005680:gamma-Aminobutyric Acid; C066430:CGP 35348; C049853:gabazine; D020888:Vigabatrin; D001418:Baclofen; C015300:isoguvacine