adrenoreceptors 1

Question 1

hypertensives ?

Answer 1

Antihypertensives are a class of drugs that lower blood pressure for patients that suffer from high blood pressure to reduce the risk of cardiovascular issues such as a heart attack. The drugs include propranolol, atenolol , bisoprolol and prazosin.   
 

Question 2

antianginal ?

Answer 2

Antianginal are a class of drugs that slow down the heart rate and take the strain off of the heart by reducing the heart rate.  The drugs include propranolol and atenolol.  

 

Question 3

antiasthmatic ?

Answer 3

Antiasthmatic drugs are a class of drugs that widen the airways in asthmatic sufferers making it easier for them to breathe. The drugs include salbutamol and salmeterol. These drugs are normal used in asthmatic patients which are mild to moderate in severity.  

Question 4

benign prostatic hypertrophy ?

Answer 4

Benign prostatic hypertrophy. As the prostate becomes enlarged this can constrict the tubules coming out of the bladder which makes it painful to urinate. This class of drugs including doxazosin and tamsulosin which relax and widen these tubes and relive the pressure.  

Question 5

what is noradrenaline ?

Answer 5

Noradrenaline is neurotransmitter in postganglionic sympathetic nerves  

 

Noradrenaline & adrenaline released as hormones from adrenal medulla (located on top of the kidneys) and they circulate in the blood to have effect on distant organs.  

 

Noradrenaline & adrenaline act via α- & β-adrenoceptors 

 

α1, α2, β1, β2 subtypes , by having the subtypes of receptors it allows flexibility of the response to the same drug depending on the receptor it acts on.  

Question 6

how are adrenoreceptors classififed ?

Answer 6

Adrenoreceptors are classified as they responds to adrenaline. You can get drugs that are specific for the adrenoreceptors and selective for a certain subtype. If they are non-selective they can act on all the subtypes or like salbutamol they can be selective, Salbutamol is beta 2 selective drug.  

Question 7

how are these receptor subtypes classififed ?

Answer 7

Now we can sequence the genome, however back when they were first discovered it was how they responded to drugs and their effects on tissues.

Question 8

oliver and Schafer?

Answer 8

Oliver and Schafer in 1896 discovered that the adrenal gland once extracted caused an increase in the arterial blood pressure. Adrenaline was isolated and identified in which was then tested on tissues in organ baths

Question 9

Langley ?

Answer 9

Langley in 1905 then discovered that adrenaline holds the ability to excite some tissues and inhibit other, this difference in effects was classified as a receptive substance as it can initiate effects once bound to receptors.

Question 10

Dale ?

Answer 10

Dale in 1906-1913 was investigating whether adrenaline increases blood pressure, after analysing adrenaline it was found that it causes a decrease in blood pressure. This was not the effect they believed would occur, therefore, they suggested the theory that there are 2 receptor types.

Question 11

Noradrenaline methyl group ?

Answer 11

Noradrenaline contains one methyl group

Question 12

isoprenaline methyl group ?

Answer 12

soprenaline has 2 methyl groups

Question 13

Alquist ?

Answer 13

Alquist in 1948 studied how noradrenaline , adrenaline and isoprenaline interacted with receptors and their effects in tissues. He discovered that in some tissues , the order of action called potency showed adrenaline to be the most potent, followed by noradrenaline and isoprenaline being the least potent. However , he realised that the order of rank potency differed in tissues, therefore there must be different receptors.

Question 14

in some tissues noradrenlaine no response ?

Answer 14

In some tissues noradrenaline wasn’t giving a response, it was getting removed and up taken by other factors. This is called re uptake and it helps avoid overstimulation of the receptors

Question 15

alpha adrenoreceptors rank potency ?

Answer 15

or the alpha adrenoreceptors the rank order agonist potency is noradrenaline> adrenaline&raquo_space; isoprenaline

Question 16

beta receptors rank potency ?

Answer 16

For the beta adrenoreceptors the rank order agonist potency is isoprenaline>adrenaline>noradrenaline.

Question 17

alpha antagonists ?

Answer 17

alpha receptors are ergotoxine, phentolamine and phenoxybenzamine

Question 18

beta antagonists ?

Answer 18

propranolol as their antagonist.

Question 19

location beta one ?

Answer 19

Beta one receptors are commonly found in the heart and they regulate the force and rate of contraction. Adrenaline caused and increase in the rate of force and contraction while causing a decrease in the intestinal motility.

Question 20

beta two receptors ?

Answer 20

Beta two receptors are commonly found in the bronchioles of the lungs and arteries of the skeletal muscles. Adrenaline caused no major effect on the heart , while they caused vasodilation , bronchodilation and relaxation of the uterus in the smooth muscle.

Question 21

atypical beta brown adipocytes ?

Answer 21

Atypical beta-adrenoceptor on brown adipocytes as target for anti-obesity drugs. These agonists had a big effect on the breakdown of fat cells called adipocytes. These agonists didn’t have a good effect on the beta one or beta 2 responses on the heart , lungs or uterus. Due to this lack of effect it shows there must be another subtype present. 

 

Stimulating the Beta 3 receptors caused sympathetic nerves to release noradrenaline which stimulated the non-shivering thermogenesis process which burns calories. Novel agonists are for the atypical b-adrenoceptor 3.