Pharmacology. 10/03/20
Cardiovascular Pharmacology
1. Learning Outcomes
Describe and explain the physiological causes of hypertension, heart failure, angina,
atherosclerosis and thrombosis
Discuss the use of drugs and how they counteract the physiological causes of the above
conditions.
Don’t remember drug names -do remember the receptor systems and physiology behind them.
2. Hypertension
Systole – when the ventricles contract
Diastole – when ventricles relax
Ideal 120/80 mmHg or around there (for 70kg man)
Hypertension - >140/90 mmHg associated with diet rich in salt and fat and obesity, it can also be
idiopathic (cause unknown). As we age it is supposed to increase with age.
Hypotension - <90/60mmHg
3. Blood pressure
Blood pressure is a consequence of vascular tone (level of contraction of vasculature), blood volume
(accumulation of fluid, retention of water) and cardiac output (measure with heart rate and stroke
volume). In situations of stress we can find high blood pressure. Melatonin causes an increase in high
blood pressure (morning hormone) that is why almost all heart attacks happen in the morning.
4. Nervous control
Carotid sinus is a branch point in carotid
artery that has baroreceptors, increase in
arterial blood pressure (artery is smaller or
heart rate higher) will be sensed by it which
will relay that to basal motor centres of the
brain which will send sympathetic impulses
and acetyl choline will be released to
decrease heart rate and increase the size of
the artery (decrease vascular tone). This
response activates the reverse system,
baroreceptor detect and communicate,
release parasympathetic and sympathetic
efferent to increase cardiac output.
Adrenaline and noradrenaline will increase
cardiac output and muscular tone which
will increase blood pressure and return
blood pressure to normal (cycle going on all
the time). Sympathetic control:
Noradrenalin acting at α1 and β1
adrenoceptors in heart. Parasympathetic
control: Acetylcholine acting at M2
receptors in heart.
, Pharmacology. 10/03/20
Cardiovascular Pharmacology
5. Receptors
Adrenergic receptors Gs
stimulates adenylate cyclase
(AC) Gi/o inhibit AC and Gq
stimulates phosphor lipase C
beta (PLCB). Alpha 2 is Gi can
be found (picture) and in
endothelial tissues and can
lead to nitric oxide (NO). B1
are Gs coupled, found in heart
leads to increased heart rate
and force, in kidney leads to
increase renin secretion. B2 is
in smooth, bronchial smooth muscles, etc. to cause relaxation. Direct effect on alpha1 is to cause
vasoconstriction (adrenaline) the indirect effect is to cause NO release and cause vasodilation
(slower effect). Know every receptor except DA.
Acetyl choline receptors This receptors branch into two forms:
- Nicotinic: ion channel receptors usually for sodium, 5 individual subunits which means in
different tissues you could find different conformation of subunits which changes
function of receptor, the different types include muscle, ganglion and CNS
- Muscarinic: are found in different types and they are metabotropic (G coupled). 7
transmembrane domain GPCRs
6. Drugs which control blood pressure
B adrenoceptor antagonists (beta blockers)
Diuretics
Inhibitors of angiotensin converting enzyme
Vasodilators
Cardiovascular Pharmacology
1. Learning Outcomes
Describe and explain the physiological causes of hypertension, heart failure, angina,
atherosclerosis and thrombosis
Discuss the use of drugs and how they counteract the physiological causes of the above
conditions.
Don’t remember drug names -do remember the receptor systems and physiology behind them.
2. Hypertension
Systole – when the ventricles contract
Diastole – when ventricles relax
Ideal 120/80 mmHg or around there (for 70kg man)
Hypertension - >140/90 mmHg associated with diet rich in salt and fat and obesity, it can also be
idiopathic (cause unknown). As we age it is supposed to increase with age.
Hypotension - <90/60mmHg
3. Blood pressure
Blood pressure is a consequence of vascular tone (level of contraction of vasculature), blood volume
(accumulation of fluid, retention of water) and cardiac output (measure with heart rate and stroke
volume). In situations of stress we can find high blood pressure. Melatonin causes an increase in high
blood pressure (morning hormone) that is why almost all heart attacks happen in the morning.
4. Nervous control
Carotid sinus is a branch point in carotid
artery that has baroreceptors, increase in
arterial blood pressure (artery is smaller or
heart rate higher) will be sensed by it which
will relay that to basal motor centres of the
brain which will send sympathetic impulses
and acetyl choline will be released to
decrease heart rate and increase the size of
the artery (decrease vascular tone). This
response activates the reverse system,
baroreceptor detect and communicate,
release parasympathetic and sympathetic
efferent to increase cardiac output.
Adrenaline and noradrenaline will increase
cardiac output and muscular tone which
will increase blood pressure and return
blood pressure to normal (cycle going on all
the time). Sympathetic control:
Noradrenalin acting at α1 and β1
adrenoceptors in heart. Parasympathetic
control: Acetylcholine acting at M2
receptors in heart.
, Pharmacology. 10/03/20
Cardiovascular Pharmacology
5. Receptors
Adrenergic receptors Gs
stimulates adenylate cyclase
(AC) Gi/o inhibit AC and Gq
stimulates phosphor lipase C
beta (PLCB). Alpha 2 is Gi can
be found (picture) and in
endothelial tissues and can
lead to nitric oxide (NO). B1
are Gs coupled, found in heart
leads to increased heart rate
and force, in kidney leads to
increase renin secretion. B2 is
in smooth, bronchial smooth muscles, etc. to cause relaxation. Direct effect on alpha1 is to cause
vasoconstriction (adrenaline) the indirect effect is to cause NO release and cause vasodilation
(slower effect). Know every receptor except DA.
Acetyl choline receptors This receptors branch into two forms:
- Nicotinic: ion channel receptors usually for sodium, 5 individual subunits which means in
different tissues you could find different conformation of subunits which changes
function of receptor, the different types include muscle, ganglion and CNS
- Muscarinic: are found in different types and they are metabotropic (G coupled). 7
transmembrane domain GPCRs
6. Drugs which control blood pressure
B adrenoceptor antagonists (beta blockers)
Diuretics
Inhibitors of angiotensin converting enzyme
Vasodilators
