Effect Of Eserine On The Action Of Acetyl Choline On Frog Rectus Muscle
To determine the action of eserine on the action of Acetyl Choline on the frog rectus
Recording Drum or Kymograph Stand with lever Bent glass tube Frog dissection instruments
A pitched frog dissected and rectus abdominis exposed Lower end is fastened to bent glass tube Muscle immersed in beaker containing ringer Two normal contractions are recorded with interval of 3 min Eserine is added to medium and amplitude of contraction is
Observations are recorded on recording drum and interpreted
Eserine potentiates the effect of Acetylcholine on muscle It inhibits both true and pseudo cholinesterase Causes accumulation of choline at motor end plate and
hence increased amplitude of contraction
Effect Of d-Tubocurarine On The Action Of Acetyl Choline On Frog Rectus Muscle
To know the effects of d-Tubocurarine on Acetylcholine contractions of frog rectus muscle
Kymograph or Recording drum Frog dissection instruments Oxygen tube Aerator Simple lever
A pitched frog is laid on a plate. Skin of the abdominal wall is cut and open. Identify the horizontal ladder like fibrous bands of rectus
abdominis muscle. Separate both muscles from the abdominal wall. Pass threads underneath the muscle. Tie the upper ends and lower ends.
Swipe off the upper end with a piece of xiphisternum and lower end with pubic attachment.
The muscle with threads is kept in a beaker with lower end is tied to the oxygen tube and upper end to the simple lever.
It has a counter weight or load of 1.4gm using plasticine. A beaker of ringer solution is kept under the oxygen tube and
oxygen is allowed to pass. Leave the preparation for half an hour. Put sufficient load so that the contractions will be able to raise the
The drum is started and is allowed to rotate for 15 sec After 15 sec, the ringer solution is changed with Acetylcholine solution. After 90 sec, it is replaced with frog ringer solution. The muscle that contracts during Ach exposure, slowly relaxes and
comes to original position Repeat the process until you get equal contractions with Ach. Now immerse the muscle in d-Tc solution for 30 sec Replace with Ach and repeat contractions If 10 micrograms of d-Tc is given, complete depression of Ach
contraction is seen
Stimulatory action of Ach on rectus abdominis muscle Blocking action of curare or d-Tc on Ach induced