Independent effects of early-life experience and trait aggression on cardiovascular function.
Early-life experience (ELE) can significantly affect life-long health and disease, including cardiovascular function. Specific dimensions of emotionality also modify risk of disease, and aggressive traits along with social inhibition have been established as independent vulnerability factors for the progression of cardiovascular disease. Yet, the biological mechanisms mediating these associations remain poorly understood. The present study utilized the inherently stress-susceptible and socially inhibited Wistar-Kyoto rats to determine the potential influences of ELE and trait aggression (TA) on cardiovascular parameters throughout the lifespan. Pups were exposed to maternal separation (MS), consisting of daily 3-h separations of the entire litter from postnatal day (P)1 to P14. The rats were weaned at P21, and as adults were instrumented for chronic radiotelemetry recordings of blood pressure and heart rate (HR). Adult aggressive behavior was assessed using the resident-intruder test, which demonstrated that TA was independent of MS exposure. MS-exposed animals (irrespective of TA) had significantly lower resting HR accompanied by increases in HR variability. No effects of MS on resting blood pressure were detected. In contrast, TA correlated with increased resting mean, systolic, and diastolic arterial pressures but had no effect on HR. TA rats (relative to nonaggressive animals) also manifested increased wall-to-lumen ratio in the thoracic aorta, increased sensitivity to phenylephrine-induced vascular contractility, and increased norepinephrine content in the heart. Together these data suggest that ELE and TA are independent factors that impact baseline cardiovascular function.
Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama; Cell, Molecular, and Developmental Biology, Graduate Biomedical Sciences, University of Alabama at Birmingham, Birmingham, Alabama;
Samir
S
Rana
Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama;
Phyllis C
PC
Pugh
Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama;
Erin
E
Katz
Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama;
Sara A
SA
Stringfellow
Center for Clinical and Translational Science, University of Alabama at Birmingham, Birmingham, Alabama;
Chee Paul
CP
Lin
Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama;
J Michael
JM
Wyss
Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa;
Harald M
HM
Stauss
Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, Alabama;
C Roger
CR
White
Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama; School of Neuroscience, Virginia Tech, Blacksburg, Virginia; and.
Sarah M
SM
Clinton
Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama; School of Neuroscience, Virginia Tech, Blacksburg, Virginia; and Department of Psychiatry and Behavioral Medicine, Virginia Tech Carilion School of Medicine, Roanoke, Virginia iakerman@carilionclinic.org.
Ilan A
IA
Kerman
D000374:Aggression / Q000502:physiology*; D000375:Aging / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D004644:Emotions / Q000502:physiology*; D005260:Female; D006321:Heart / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D008016:Life Change Events; D008297:Male; D008426:Maternal Deprivation; D051381:Rats; D011921:Rats, Inbred WKY
blood pressure; coping; emotionality; heart rate; maternal separation