Lab report
Abstract: Sympathetic nervous system and cardiovascular function in the body.
Acknowledgement: In order to obtain the data for this experiment # collected the data as labpartner.
Introduction: The aim for this experiment in three parts is to present and discuss how the sympathetic nervous
system controls cardiovascular function in the body. By injecting adrenergic agonists and antagonists in a rat
simulation software.
Adrenergic receptors (⍺-1, ⍺-2, β1, β2 & β3)
Alpha-1 receptors are coupled with Gq proteins. The most important locations of alpha 1 receptors are in
smooth muscle, the heart, glands and in neuronal terminals. The receptors can also be found in liver and
adipose tissue. When being stimulated by an agonist it causes peripheral vasoconstriction, for arterioles this
means the afterload is increased, while for veins this means the preload is increased. Other important effects:
contraction of the GI sphincter and bladder sphincter contraction. For the bladder this results in urine retention.
Effects on the eye is dilation of the pupils (mydriasis). Stimulation of the receptor increases glycogenolysis
(breakdown of glucose-1-phosphate to glucose). (1)(2)(3)
Alpha-2 receptors are coupled with Gi proteins. The most important locations of alpha-2 receptors are in
pancreas, the heart, in glands, the eyes and prejunctional nerve terminals. The receptors can also be found in
adipose tissue, bladder and smooth muscles of vessels. When being stimulated it causes a decrease in the
release of norepinephrine and the synthesis, in addition a decrease in insulin release. Other effects are an
increase in platelet aggregation while a decrease in lipolysis.(4)(5)
Beta-1 receptors are coupled with Gs proteins. The most important locations of beta-1 receptors are in the
heart, specifically the SV-, AV-node and in the atrial and ventricular muscle (the myocardium). Locations are to
the kidneys and central nervous system. To some extent it is found in adipose tissue. The effects of simulations
are increase in heart rate (chronotropy), increase of conduction velocity (dromotropy), increased force of
contraction (inotropy). The beta-1 receptors stimulate increase of renin release in the kidneys. (1)(6) (19).
Beta-2 receptors are coupled with Gs proteins. The most important locations of the receptors are in the liver, in
pancreas and in smooth muscle. Particularly smooth muscle of the blood vessels, bronchioles and uterus. The
receptors can be found in the central nervous system and some in the heart. Stimulation of the receptors causes
relaxation of smooth muscle, this causes vasodilatation, relaxation of uterus and bladder relaxation. Other
important effects are increased contractility, glycogenolysis and insulin release. (6)(7)
1
,Beta-3 receptors are coupled with Gs proteins. The most important locations of the receptors are in the bladder
and adipose tissue. Also found in small numbers in the heart and smooth muscle of blood vessels. Stimulation
of the receptor leads to bladder relaxation, increased lipolysis and thermogenesis. (8)
For this experiment adrenergic agonists and antagonists were used. They are sympathomimetic drugs, which
means they cause the effects of the stimulus from the sympathetic nervous system. They have different
specificity and affinity for the receptors mentioned and this results in different responses. Sympatholytic drugs
(antisympathetic) are drugs that inhibit the sympathetic nervous system.(10)
Method:
The software “ Rat Cardiovascular system © J. Dempster, University of Strathclyde (1996-2020) V3.3.7
(30-07.20) ” was utilized in order to perform in-vitro simulations of when injected with different adrenergic
drugs. Stimulation of sympathetic nerves excluding adrenal and “pithed rat” was chosen.
Simulation was started for achieving baseline then the drug was injected, a new experiment for each drug.
Option “symp. nerves (exc. adrenal)” was chosen for administering the stimulation of nerve. Part III: Baseline
was first established by waiting for 1 vertical line, antagonist drug injected first, waited for 1 vertical line,
agonist injected, waited for 1 vertical line. The Window size was then adjusted for optimal reading at the
maximum effect response, screenshots produced in the result part III. Considering this simulation is in a rat we
need to know the normal range, for a healthy adult rat the normal range for heart rate (HR) is 330 - 480 beats
per minute. Heart frequency (HF) baseline from measurements is 7.5. While normal range for arterial blood
pressure (ABP) in a healthy adult rat ranges from 99 -120 mmHg.
Overview simulations (figure number in parentheses)
Part I: Adrenergic antagonist drugs injected Part II: Adrenergic agonists drugs injected
- (1) propranolol 5 mg/kg - (4) norepinephrine 5 μ /kg
- (2) atenolol 5 mg/kg - (5) norepinephrine 10 μ /kg
- (3) phentolamine 5 mg/kg - (6) epinephrine 5 μ /kg
- (7) epinephrine 10 μ /kg
- (8) isoprenaline 5 μ /kg
- (9) isoprenaline 10 μ /kg
- (10) phenylephrine 5 μ /kg
- (11) phenylephrine 10 μ /kg
Part III: antagonist 5mg/kg and then agonist 10 μ /kg Part III: continues
- (12) propranolol 5 mg/kg and epinephrine 10 μ /kg - (18) propranolol 5 mg/kg and isoprenaline 10 μ /kg
- (13) atenolol 5 mg/kg and epinephrine 10 μ /kg - (19) atenolol 5 mg/kg and isoprenaline 10 μ /kg
- (14) phentolamine 5 mg/kg and epinephrine 10 μ /kg - (20) phentolamine 5 mg/kg and isoprenaline 10 μ /kg
- (15) propranolol 5 mg/kg and norepinephrine 10 μ /kg - (21) propranolol 5 mg/kg and phenylephrine 10 μ /kg
- (16) atenolol 5 mg/kg and norepinephrine 10 μ /kg - (22) atenolol 5 mg/kg and phenylephrine 10 μ /kg
- (17) phentolamine 5 mg/kg and norepinephrine 10 μ - (23) phentolamine 5 mg/kg and phenylephrine 10 μ /kg
/kg
2
, Result:
Part I: Adrenergic antagonist drugs injected at 5 mg/kg
Figure 1: Propranolol 5 mg/kg
Figure 2: Atenolol 5 mg/kg
3
Abstract: Sympathetic nervous system and cardiovascular function in the body.
Acknowledgement: In order to obtain the data for this experiment # collected the data as labpartner.
Introduction: The aim for this experiment in three parts is to present and discuss how the sympathetic nervous
system controls cardiovascular function in the body. By injecting adrenergic agonists and antagonists in a rat
simulation software.
Adrenergic receptors (⍺-1, ⍺-2, β1, β2 & β3)
Alpha-1 receptors are coupled with Gq proteins. The most important locations of alpha 1 receptors are in
smooth muscle, the heart, glands and in neuronal terminals. The receptors can also be found in liver and
adipose tissue. When being stimulated by an agonist it causes peripheral vasoconstriction, for arterioles this
means the afterload is increased, while for veins this means the preload is increased. Other important effects:
contraction of the GI sphincter and bladder sphincter contraction. For the bladder this results in urine retention.
Effects on the eye is dilation of the pupils (mydriasis). Stimulation of the receptor increases glycogenolysis
(breakdown of glucose-1-phosphate to glucose). (1)(2)(3)
Alpha-2 receptors are coupled with Gi proteins. The most important locations of alpha-2 receptors are in
pancreas, the heart, in glands, the eyes and prejunctional nerve terminals. The receptors can also be found in
adipose tissue, bladder and smooth muscles of vessels. When being stimulated it causes a decrease in the
release of norepinephrine and the synthesis, in addition a decrease in insulin release. Other effects are an
increase in platelet aggregation while a decrease in lipolysis.(4)(5)
Beta-1 receptors are coupled with Gs proteins. The most important locations of beta-1 receptors are in the
heart, specifically the SV-, AV-node and in the atrial and ventricular muscle (the myocardium). Locations are to
the kidneys and central nervous system. To some extent it is found in adipose tissue. The effects of simulations
are increase in heart rate (chronotropy), increase of conduction velocity (dromotropy), increased force of
contraction (inotropy). The beta-1 receptors stimulate increase of renin release in the kidneys. (1)(6) (19).
Beta-2 receptors are coupled with Gs proteins. The most important locations of the receptors are in the liver, in
pancreas and in smooth muscle. Particularly smooth muscle of the blood vessels, bronchioles and uterus. The
receptors can be found in the central nervous system and some in the heart. Stimulation of the receptors causes
relaxation of smooth muscle, this causes vasodilatation, relaxation of uterus and bladder relaxation. Other
important effects are increased contractility, glycogenolysis and insulin release. (6)(7)
1
,Beta-3 receptors are coupled with Gs proteins. The most important locations of the receptors are in the bladder
and adipose tissue. Also found in small numbers in the heart and smooth muscle of blood vessels. Stimulation
of the receptor leads to bladder relaxation, increased lipolysis and thermogenesis. (8)
For this experiment adrenergic agonists and antagonists were used. They are sympathomimetic drugs, which
means they cause the effects of the stimulus from the sympathetic nervous system. They have different
specificity and affinity for the receptors mentioned and this results in different responses. Sympatholytic drugs
(antisympathetic) are drugs that inhibit the sympathetic nervous system.(10)
Method:
The software “ Rat Cardiovascular system © J. Dempster, University of Strathclyde (1996-2020) V3.3.7
(30-07.20) ” was utilized in order to perform in-vitro simulations of when injected with different adrenergic
drugs. Stimulation of sympathetic nerves excluding adrenal and “pithed rat” was chosen.
Simulation was started for achieving baseline then the drug was injected, a new experiment for each drug.
Option “symp. nerves (exc. adrenal)” was chosen for administering the stimulation of nerve. Part III: Baseline
was first established by waiting for 1 vertical line, antagonist drug injected first, waited for 1 vertical line,
agonist injected, waited for 1 vertical line. The Window size was then adjusted for optimal reading at the
maximum effect response, screenshots produced in the result part III. Considering this simulation is in a rat we
need to know the normal range, for a healthy adult rat the normal range for heart rate (HR) is 330 - 480 beats
per minute. Heart frequency (HF) baseline from measurements is 7.5. While normal range for arterial blood
pressure (ABP) in a healthy adult rat ranges from 99 -120 mmHg.
Overview simulations (figure number in parentheses)
Part I: Adrenergic antagonist drugs injected Part II: Adrenergic agonists drugs injected
- (1) propranolol 5 mg/kg - (4) norepinephrine 5 μ /kg
- (2) atenolol 5 mg/kg - (5) norepinephrine 10 μ /kg
- (3) phentolamine 5 mg/kg - (6) epinephrine 5 μ /kg
- (7) epinephrine 10 μ /kg
- (8) isoprenaline 5 μ /kg
- (9) isoprenaline 10 μ /kg
- (10) phenylephrine 5 μ /kg
- (11) phenylephrine 10 μ /kg
Part III: antagonist 5mg/kg and then agonist 10 μ /kg Part III: continues
- (12) propranolol 5 mg/kg and epinephrine 10 μ /kg - (18) propranolol 5 mg/kg and isoprenaline 10 μ /kg
- (13) atenolol 5 mg/kg and epinephrine 10 μ /kg - (19) atenolol 5 mg/kg and isoprenaline 10 μ /kg
- (14) phentolamine 5 mg/kg and epinephrine 10 μ /kg - (20) phentolamine 5 mg/kg and isoprenaline 10 μ /kg
- (15) propranolol 5 mg/kg and norepinephrine 10 μ /kg - (21) propranolol 5 mg/kg and phenylephrine 10 μ /kg
- (16) atenolol 5 mg/kg and norepinephrine 10 μ /kg - (22) atenolol 5 mg/kg and phenylephrine 10 μ /kg
- (17) phentolamine 5 mg/kg and norepinephrine 10 μ - (23) phentolamine 5 mg/kg and phenylephrine 10 μ /kg
/kg
2
, Result:
Part I: Adrenergic antagonist drugs injected at 5 mg/kg
Figure 1: Propranolol 5 mg/kg
Figure 2: Atenolol 5 mg/kg
3
