THE ACTIONS OF DRUGS ON THE GUINEA-PIG ISOLATED ILEUM Lab Report

THE ACTIONS OF DRUGS ON THE GUINEA-PIG ISOLATED ILEUM - Lab Report Example Q2 (ii): When testing the agonist action of the morphine-like drugs, it is observable that, through the depressant action of the morphine-like drugs, it was difficult to assess the potencies because the tachyphylaxis developed rapidly. In this case, it is important to use small doses of the drug while exposing the gut to the drugs at the intervals that do not go below 30 minutes. The inhibitory effect of morphine on the twitch of longitudinal muscle was induced by the coaxial stimulation, hence leading to the dose-response curve of order ââ€" . Upon sing nalorphine-like drugs, the depressant action of the N-allyl analogue of the morphine was having the similar order to that of morphine. However, tachyphylaxis development was much more rapid with nalorphine than with morphine. When testing the antagonist action of the morphine-like drugs, tachyphylaxis was able to develop with all compounds tested, which was a strong indication on the possibility of exhibiting antagonist action under suitable conditions. In this experiment, techyphylaxix was able to develop more rapidly than compared to using the agonist. Basing on the agonist activity of the antagonists, the conventional method used for testing antagonism did not yield the decisive results. The antagonism through low concentrations of morphine of the inhibitory effect of morphine upon twitch of the longitudinal muscle was able to induce coaxial stimulation. Q3: Through using the experimental protocol or two log curves, there is a possibility of an error occurring. To avoid such errors, the formula can be modified into that of the critical ratio approach (CR). The CR is the concentration of agonist at the presence of the antagonist required for producing a fixed response to the linear part of the concentration. It is thus advisable to use the equation that relates CR to KB, which is expressed