Cardiovascular Health 3.1 (Heart): Sex, steroids , and cardio protection controversies Flashcards
(29 cards)
What is the number 1 cause of death?
Heart disease
By how long are heart diseases delayed in women vs men?
~10 year delay.
Do pre-menopausal women have a higher chance of an ischaemic event?
No, its a lower risk.
Women respond to drugs differently. Give an example with viagra.
Used in heart therapy in male models. Clinical trials on women had no effect. Found to be dependent on oestrogen levels. Had no effect on post-menopausal women who have low levels.
What are oestrogen levels dependent on?
Testosterone.
What does aromatase do?
Catalyses testosterone to oestrogen conversion.
What happens to oestradiol and testosterone levels in males?
Testosterone levels decrease
Oestradiol levels remain stable.
What happens to oestradiol and testosterone levels in females?
Both decrease.
What are the three oestrogen receptors on the heart?
ERa, ERb, and GPER (g protein coupled).
What effect does testosterone have on skeletal muscle?
Anabolic effect.
Is cardiac hypertrophy in response to pathology greater in males or females? What does this suggest?
Males. Suggests testosterone drives hypertrophy.
Does the heart hypertrophy with no pathology?
Yes it does.
How can sex steroids influence muscle fibre contractility?
Can change how Ca2+ enters the cell, influencing contractility.
Is the extent of myocyte contraction greater or smaller in females vs males?
It is smaller in females vs males.
How does oestrogen affect sarcoplasmic Ca2+? Which pathway does it activate? What is a consequence of this?
Downregulates the release of Ca2+ from the sarcolemma. Done by activating the PI3K and AKT pathway. Suppresses cell death.
Are men or women more likely to die of a sudden cardiac death?
Men
What happens to risk of subsequent heart failure in pre menopausal women?
More likely to have one.
What is ischaemia?
Lack of oxygen to supply metabolic demand.
What is reperfusion?
Unblocking a thrombosis via thrombolytics.
What are the consequences of reperfusion (name 3)?
Can cause an increase in the amount of reactive oxygen species, and can overload cells with Ca2+, causing contractile dysfunction and cells rip apart. Cell death.
What is the difference between males and females in response to reperfusion following ischaemia (name 3)?
Females sustain less damage, less necrosis, and lower arrhythmia duration.
What happens to a females response to reperfusion id they had a hysterectomy beforehand? What does this suggest?
They lose their cardioprotection. Suggests oestrogen mediates cardioprotection.
Is oestrogen made in just the ovaries?
No, made in many structures.
Does the heart produce oestrogen, and if so, where? How can it be detected?
Yes, it is secreted to have a local effect.
Aromatase used to detect this. Atria in humans have aromatase.
