PHA2PGA: Pharmacology A

Ileum pharmacology

PRACTICAL ASSIGNMENT

Student name:- SHRADDHA KAMBLE

Student ID :- 20894407

1.How often is length measured during an experimental cycle? [13] Why that

often?

Þ The experimental cycle's length is measured three times in three

increments. The first length is measured half a minute after the agonist is

inserted. The second length is measured after the first wash, after the

cycle has finished half of its time. After the first wash out, the third length

is measured to evaluate if the ileum is practically free of the agonist and,

as a result, if it is slowly reverting to its normal length before any further

agonist administration.

2. How does ‘occupancy’ translate into ‘response’?

Þ The percentage of receptors occupied by the agonist, as well as the

variation in this percentage with agonist concentration, is known as

occupancy. The greater the occupancy and consequently the response, the

higher the agonist concentration. Depending on the agonist's variation,

the relationship between occupancy and response changes. Because of its

high effectiveness of 1, a full agonist will elicit the greatest response - a

100 percent response will be elicited even if the occupancy is not 100

percent. A partial agonist can give a maximal response even if the

occupancy is 100 percent since its efficacy is less than one.

3.Consider the dose-occupancy (left) and dose-response (right) curves. Sketch

how they would change with affinity and efficacy.

Þ Affinity refers to a drug's ability to attach to a certain receptor. Because

the KA constant rises and the reaction's backward rate rises in comparison

to the forward rate, affinity causes the occupancy to shift to the right. As a

result, antagonist-receptor complexes are less likely to form at any given

concentration.

Þ Efficacy is a term that refers to the relationship between dosage

occupancy and the onset of a reaction. If the drug's efficacy is less than 1,

the maximum reaction won't be achieved (maximum efficacy). The

response curve might also shift right or left due to affinity.