Investigation of Contractile Receptors in Guinea Pig Ileum using Agonists and Antagonist

Running head: PHARMACOLOGY LABORATORY REPORT
Pharmacology laboratory report
Name of the Student
Name of the University
Author’s Note:

1PHARMACOLOGY LABORATORY REPORT
Topic:
Investigation of the interrelationships between contractile receptors of the guinea pig
ileum using agonists (acetylcholine and nicotine) and antagonist (Atropine).
Introduction:
Academic evidence reported that nicotinic acetylcholine receptors (nAChRs) are
present in the circular smooth muscle of guinea pig (Zhou et al. 2013). Agonists and
antagonists have known to stimulate mediate the activity of this receptors (Meurs et al. 2013).
Therefore, in this study interrelationships between the receptors were studied by using
agonists and antagonist. Effect of antagonist were studied against the two agonists and half
maximal effective concentrations (EC50s) were calculated.
Methods:
Tissues were collected from the ileum of guinea pig provided which was kept in
Tyrode’s solution. Tissues were prepared according to the practical guide provided. After that
two dilutions of the agonists (acetylcholine (ACh) and nicotine) at 10-3 and 10-4M from the
stock solution of 10-2M. Viability test of the tissues were performed using ACh after the
setting up and calibration of the laboratory instruments. Agonists’ response amplitudes of
ACh and nicotine were measured using the Labscribe software. After that antagonist effect
were studied using Atropine. Atropine solution were used at stock concentration which is 1 x
10-6 M.
Results:
Table 1 below represents the data regarding associated response and percentage
response against ACh dose and its corresponding antagonist responses.

2PHARMACOLOGY LABORATORY REPORT
Table 1: Response of ACh and its response against Antagonist Atropine
Eg Antagonist ( Atropine 1.00E-7
FBC)
ACh (FBC) M Response (g) % Response Response (g) % of Max agonist
only response
1.00E-08 0.019 0.46 0 0
3.00E-08 0.426 20.33 0 0
1.00E-07 1.381 33.49 0 0
3.00E-07 3.400 82.46 0 0
1.00E-06 3.730 90.46 0 0
3.00E-06 4.123 100 0 0
1.00E-05 3.423 82.02 0 0
3.00E-05 3.374 81.83 0 0
1.00E-04 2.565 62.21 0.156 3.78
3.00E-04 1.747 42.37 4.045 98
Table 2 below represents the data regarding associated response and percentage
response against Nicotine dose and its corresponding antagonist responses.
Table 2: Response of Nicotine and its response against Antagonist Atropine
Eg Antagonist ( Atropine 1.00E-7
FBC)
Nicotine (FBC) M Response (g) % Response Response (g) % of Max
agonist only
response
1.00E-06 0.089 4.139 0.083 3.86
3.00E-06 0.0402 18.69 0.124 5.767
1.00E-05 0.865 40.25 0.376 17.48
3.00E-05 1.878 87.35 0.381 45.6
1.00E-04 2.15 100 1.404 48.37
3.00E-04 2 93 1.4 65.11