title: Macrophage migration inhibitory factor in the nucleus of solitary tract decreases blood pressure in SHRs.
abstract: OBJECTIVE
  The macrophage migration inhibitory factor (MIF) is an intracellular inhibitor of the central nervous system actions of angiotensin II on blood pressure. Considering that angiotensin II actions at the nucleus of the solitary tract are important for the maintenance of hypertension in spontaneously hypertensive rats (SHRs), we tested if increased MIF expression in the nucleus of the solitary tract of SHR alters the baseline high blood pressure in these rats.
  
  
  RESULTS
  Eight-week-old SHRs or normotensive rats were microinjected with the vector AAV2-CBA-MIF into the nucleus of the solitary tract, resulting in MIF expression predominantly in neurons. Rats also underwent recordings of the mean arterial blood pressure (MAP) and heart rate (via telemetry devices implanted in the abdominal aorta), cardiac- and baroreflex function. Injections of AAV2-CBA-MIF into the nucleus of the solitary tract of SHRs produced significant decreases in the MAP, ranging from 10 to 20 mmHg, compared with age-matched SHRs that had received identical microinjections of the control vector AAV2-CBA-eGFP. This lowered MAP in SHRs was maintained through the end of the experiment at 31 days, and was associated with an improvement in baroreflex function to values observed in normotensive rats. In contrast to SHRs, similar increased MIF expression in the nucleus of the solitary tract of normotensive rats produced no changes in baseline MAP and baroreflex function.
  
  
  CONCLUSIONS
  These results indicate that an increased expression of MIF within the nucleus of the solitary tract neurons of SHRs lowers blood pressure and restores baroreflex function.
authors.affiliation: Department of Physiology and Functional Genomics and McKnight Brain Institute,  College of Medicine,  University of Florida, 1600 Southwest Archer Road, PO-BOX: 100274, Gainesville, FL 32610,  USA.
authors.forename: André Henrique
authors.initials: AH
authors.lastname: Freiria-Oliveira
authors.forename: Graziela Torres
authors.initials: GT
authors.lastname: Blanch
authors.forename: Hongwei
authors.initials: H
authors.lastname: Li
authors.forename: Eduardo
authors.initials: E
authors.lastname: Colombari
authors.forename: Débora Simões Almeida
authors.initials: DS
authors.lastname: Colombari
authors.forename: Colin
authors.initials: C
authors.lastname: Sumners
mesh_terms: D000818:Animals; D062186:Arterial Pressure; D017704:Baroreflex; D006332:Cardiomegaly / Q000378:metabolism / Q000503:physiopathology; D000229:Dependovirus / Q000235:genetics; D004195:Disease Models, Animal; D015316:Genetic Therapy; D005822:Genetic Vectors; D006339:Heart Rate; D006973:Hypertension / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D019746:Intramolecular Oxidoreductases / Q000235:genetics / Q000378:metabolism; D008263:Macrophage Migration-Inhibitory Factors / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008845:Microinjections; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D017552:Solitary Nucleus / Q000378:metabolism* / Q000503:physiopathology; D013686:Telemetry; D013997:Time Factors; D016277:Ventricular Function, Left
chemical_list: D008263:Macrophage Migration-Inhibitory Factors; D012333:RNA, Messenger; D019746:Intramolecular Oxidoreductases; C515599:Mif protein, rat