title: Cardiovascular autonomic dysfunction in non-obese diabetic mice.
abstract: It is known that diabetes is associated with autonomic dysfunction; however, data about autonomic function in non-obese diabetic mice (NOD) remain scarce. We evaluated the autonomic profile of NOD mice. Female mice, 24-28 week old, were divided in two groups: NOD (n = 6) and control (n = 6, Swiss mice). NOD mice with glycemia ≥ 300 mg/dl were used. Heart rate variability (HRV) and arterial pressure variability (APV) in time and frequency domains, symbolic analysis of heart rate (HR) and baroreflex sensitivity were evaluated. HR and arterial pressure (AP) were similar between the groups; however, HRV (total variance of RR interval: NOD=21.07 ± 3.75 vs. C = 42.02 ± 6.54 ms(2)) and the vagal modulation index RMSSD were lower in NOD group (4.01 ± 0.32 vs. 8.28 ± 0.97 ms). Moreover, the absolute and normalized low-frequency (LF) components were also enhanced in NOD (normalized = 61.0 ± 4.0%) as compared to control mice (normalized = 20.0 ± 4.0%). Both the absolute and normalized high-frequency (HF) components were lower in NOD (normalized = 39.0 ± 4.0%) when compared to the control group (normalized = 80.0 ± 4.0). In the symbolic analysis the 0V pattern, an indication of sympathetic activity, was higher in NOD and 2 LV pattern, an indication of parasympathetic activity, was lower in the NOD than in the control group. Both bradycardic and tachycardic responses were decreased in NOD (3.01 ± 0.72 vs. 4.54 ± 0.36 bpm/mmHg and 2.49 ± 0.31 vs. C = 3.43 ± 0.33 bpm/mmHg) when compared to the control group. Correlation analysis showed negative correlations between vagal indexes (RMSSD, %HF and 2LV) and glycemic levels. In conclusion, NOD mice develop severe diabetes correlated with autonomic dysfunction.
authors.affiliation: Hypertension Unit, Heart Institute (InCor), School of Medicine, University of São Paulo (FMUSP), 44 Dr Eneas de Carvalho Aguiar Avenue, 05403-000 São Paulo/SP, Brazil; Nove de Julho University, Sao Paulo/SP, Brazil. Electronic address: oscaralbuquerque@yahoo.com.br.
authors.forename: Oscar A
authors.initials: OA
authors.lastname: Moraes
authors.forename: Juliana A
authors.initials: JA
authors.lastname: Colucci
authors.forename: Leandro E
authors.initials: LE
authors.lastname: Souza
authors.forename: Kátia B
authors.initials: KB
authors.lastname: Scapini
authors.forename: Ivana C
authors.initials: IC
authors.lastname: Moraes-Silva
authors.forename: Cristiano
authors.initials: C
authors.lastname: Mostarda
authors.forename: Kátia
authors.initials: K
authors.lastname: De Angelis
authors.forename: Dulce E
authors.initials: DE
authors.lastname: Casarini
authors.forename: Maria Cláudia
authors.initials: MC
authors.lastname: Irigoyen
mesh_terms: D000818:Animals; D001342:Autonomic Nervous System Diseases / Q000097:blood / Q000503:physiopathology*; D017704:Baroreflex / Q000502:physiology*; D001786:Blood Glucose / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D002318:Cardiovascular Diseases / Q000097:blood / Q000503:physiopathology*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D051379:Mice; D016688:Mice, Inbred NOD / Q000097:blood / Q000502:physiology; D009765:Obesity
chemical_list: D001786:Blood Glucose
keywords: Autonomic nervous system; Baroreflex; Diabetes mellitus; Inbred NOD; Mice