Extended longitudinal analysis of arterial pressure and heart rate control in unanesthetized rats with type 1 diabetes.
We recorded arterial pressure (BP) and heart rate (HR) in type-1 diabetic rats vs. controls for >6 months. Diabetic rats (DIAB) were maintained on insulin from the day glucose >250 mg/dl ("Day 0"). Weight was similar between groups until ~3 weeks before Day 0 when the weight in DIAB transiently lagged the controls (CONT); this difference was maintained throughout the study, but both groups otherwise gained weight in parallel. Plasma glucose attained 371 ± 109 (SD) mg/dl by day 1 in DIAB. Mean BP was similar across groups, and declined through the initial 4-6 months in both the CONT (at -0.06 ± 0.04 mmHg/day) and in the DIAB (at -0.14 ± 0.21 mmHg/day; NS vs. CONT). HR in the CONT (Month 1: 341 ± 13 bpm) exceeded DIAB (325 ± 25 bpm) through ~6 months after Day 0, and also decreased progressively over this period in CONT (-0.19 ± 0.14 bpm/day) and DIAB (-0.29 ± 0.23 bpm/day; NS vs. CONT) before leveling. The BP power within 0.35-0.45 Hz changed during the 90 min before vs. after the transition from dark to light, and light to dark; there were no between group differences. The slope of the log-log linear portion of the BP power spectrum between 1.0/h and 1/min was similar across groups, and increased in both from month 1 to month 6. Regulatory mechanisms maintain similar profiles in BP and HR in diabetic vs. control animals through the initial half year of the disease.
Department of Physiology, College of Medicine, University of Lagos, Idi-Araba, Nigeria.
Chikodi N
CN
Anigbogu
Richard O
RO
Speakman
Dennis L
DL
Silcox
Laura V
LV
Brown
David R
DR
Brown
Ming C
MC
Gong
Abhijit R
AR
Patwardhan
L Raymond
LR
Reynolds
Dennis G
DG
Karounos
Don E
DE
Burgess
Bobby R
BR
Baldridge
David C
DC
Randall
D000818:Animals; D062186:Arterial Pressure / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000502:physiology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D004195:Disease Models, Animal; D018450:Disease Progression; D006339:Heart Rate / Q000502:physiology*; D017711:Nonlinear Dynamics; D054969:Primary Dysautonomias / Q000097:blood / Q000150:complications / Q000503:physiopathology; D051381:Rats; D011913:Rats, Inbred BB; D013686:Telemetry / Q000379:methods
D001786:Blood Glucose