Experimental Preparation and Setup

Methods

Experimental Preparation and Setup

• Tissue preparation: Isolated Guinea-Pig ileum
• Bubbled with: Carbogen (95% O2: 5% CO2)
• Physiological Solution: Holman’s solution
• Resting Tension: 1g
• Temperature: 34°C

Drug solutions and dilutions

Drug solutions of Carbachol (CCh) at concentrations of 10-2M, 10-3M, 10-4M and 10-5M were prepared from the stock solution of 10-1M CCh via ten-fold stock solutions.

1. 0.2ml (200uL) of 10-1M CCh added to 1.8ml (1800uL) of Holman’s solution, preparing 2ml (2000uL) of 10-2M CCh.
2. 0.2ml (200uL) of 10-2M CCh added to 1.8ml (1800uL) of Holman’s solution, preparing 2ml (2000uL) of 10-3M CCh.
3. 0.2ml (200uL) of 10-3M CCh added to 1.8ml (1800uL) of Holman’s solution, preparing 2ml (2000uL) of 10-4M CCh.
4. 0.2ml (200uL) of 10-4M CCh added to 1.8ml (1800uL) of Holman’s solution, preparing 2ml (2000uL) of 10-5M CCh.
5. Cumulative concentration-response curves were able to be constructed through these concentrations of CCh obtained.

Measuring responses in guinea-pig ileum to Carbachol

The responses to each concentration of drug of Carbachol (CCh) was measured and cumulative curves were constructed from these values. This was measured as changes in tension (g) to the pre-agnostic baseline. Prior to the addition of any drug solutions, the pre-agonistic baseline was measured. This was subsequently subtracted from each maximum response after the addition of drug concentrations.

Results

Table 1.1 - Calculated class data of the response of Carbachol to isolated guinea-pig ileum comparing variation in time and the effect it has on the initial resting tension of the tissue.