Lecture 6. Stress and CV disease. Evidence from animal models.
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Lecture 6. Stress and CV disease. Evidence from animal models
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Transcript of Lecture 6. Stress and CV disease. Evidence from animal models.
Lecture 6.
Stress and CV disease. Evidence from animal models
Why study animal models?
When is a risk factor casual
Temporality Strength of relationship
Consistency Biological gradient
Biological Plausibility Coherence
Outcome Specificity Intervention evidence
Illustrative animal studies on hypertension
Cage designed to force social interaction in mice. Used to compare Blood Pressure in mice raised in groups or in isolation by Henry (Henry & Stephens 1977 Stress, Health and the Social Environment
Initial BP 2 8 21 Control
Days
100
112
124
136
148
160
Blo
od
Pressu
re m
m H
g
Henry. Effects of social encounters on mice reared alone
Blood Pressure
Blood pressure rises the longer the mice reared in isolation have to interact with others.
2 months 6 months 9 months
Months in experiment
100
112
124
136
148
160
BP
mm
hg
Effects of withdrawing mice from stressHenry & Stevens
Constant exposure
Removed from stress
If mice returned to isolation early enough then blood pressure reverts to normal. If kept in social group for several month then effects cannot be reversed
Forsyth RP (1971). Regional blood flow changes during 72 hour avoidance schedules Science, 173, 546-548. In Steptoe AS (1981). Psychological factors in cardiovascular disorders. (Old but still a great book)
Coronary artery disease. The studies of social stress in cynomolgus monkeys by Manuck & Kaplan
Words you main not have come across
Arteriosclerosis
Atheroma, Atherosclerosis, Atherosclerotic plaque
Thrombus
What causes a Myocardial infarction: Plaque rupture and blocked coronary artery
Manuck & Kaplans studies of stress in monkeys hard to get in Aberdeen libraries. Original study in:
Kaplan JR, Manuck SB et al, 1983 Social stress and atherosclerosis in normocholesterolemic monkeys. Science, 220, 733-734.
Much of the work on female monkey’s in Kaplan, JR et al (1995) Psychosocial factors, sex differences and atherosclerosis: lessons from animal models. Psychosomatic Medicine, 58, 598-611.
Manuck, monkeys treated with beta blockade
Manuck, Effects of dominance in female monkeys (cf males)
Reversal of dominace effect after ovaries removed, cf CHD increase in postmenopausal women
HR reactivity relates to Plaque in ovariectomised female monkey’s, Manuck et al., 1997 Arteriosclerosis, Thrombosis and Vascular Biology, 17, 1774-17779
