Experiments on the action of efferent nervous system drugs on isolated intestinal muscles
The isolated intestinal muscle of animals still has the characteristics of excitation and contraction in a suitable environment of nutrient solution. Since there are M receptors, receptors and β receptors distributed on the intestinal muscle, when certain drugs are added to the nutrient solution, they can bind to the corresponding receptors, agonize or block the corresponding receptors, causing the intestinal muscle to contract or relax. The purpose of this experiment is to learn the experimental setup and methods of isolated intestinal muscle and to observe the effects of cholinomimetics and anticholinomimetics, adrenomimetics and antiadrenomimetics on isolated intestinal muscle.
Operation method
Bio-signal processing system detection method
Principle
The isolated intestinal muscles of animals still have properties such as excitation and contraction in a suitable nutrient solution environment. As there are M receptors, α receptors and β receptors distributed on the intestinal muscle, when adding drugs such as Ach (N,M receptor agonist), atropine (M receptor blocker), rutaecarpine (M receptor agonist), adrenaline (α,β receptor agonist), and neostigmine (anticholinesterase) into the nutrient solution, the drugs can bind with the corresponding receptor, agonize or block the corresponding receptor, and cause the intestinal muscle to contract or relax. relaxation. Barium chloride is a non-receptor-acting toxic compound, which has a direct excitatory contraction effect on the intestinal muscle and is commonly used in pharmacological experiments.
Materials and Instruments
Rabbit Move I. Steps Caveat 1. The experimental animals were fasted with food but not water 24 h before the experiment to keep the intestinal lumen free of feces. 2. The temperature of the Tissue solution in the petri dish was maintained at 37-38 °C, otherwise the intestinal muscle activity would be affected. 3. After each administration, the animals should be rinsed with Tissue solution 3 times, and the retention time of each intake should be ≥1 min. Common Problems I. Which efferent nerve drugs have a significant effect on intestinal muscle activity? Describe their mechanism of action and clinical significance. For more product details, please visit Aladdin Scientific website.
Tai's solution Acetylcholine chloride solution Atropine sulfate solution Hirsutine nitrate solution Epinephrine hydrochloride solution Propranolol hydrochloride solution Neostigmine bromide solution Barium chloride solution
Biosignal Processing System Constant Temperature Bath Irrigation Pump Tension Transducer Iron Bracket Isolated Organ Irrigation Bath L-shaped Vent Tube Air Pump Small Beaker Large Beaker Syringe Petri dish Surgical Wire Needle Holder Surgical Needle Tweezers Marker Pen
⒈ 1 rabbit, hit the head to death, immediately dissected, gently cut off the jejunum and the upper part of the ileum, immersed in cold Tissue solution, the mesentery along the intestinal wall to separate off, with Tissue solution to the intestinal contents of the intestinal content of the rinse, the intestines cut into 2 ~ 2.5 cm long intestinal segments for spare parts, such as not for immediate use, you can put the intestinal segments into Tissue solution, placed in a refrigerator for preservation, generally maintain the vitality of the 12 hours or so.
PEAK Before the experiment, adjust the thermostat, keep the temperature at 37～38 °C, fill the bath with Tissot's solution and mark the height of the liquid level. Inject air (1～2 bubbles per second) through the air pump.
3) Start the BL-420 Bio-Signal Processing System, connect the tension transducer to the corresponding channel, and fix the tension transducer on the iron stand.
Singed a section of intestinal tube, threaded at both ends, one end fixed on the small hook of the ventilation tube, put into the bath, the other end connected to the tension transducer. After the isolated intestinal segment is stabilized for 5-10 min, debug the BL-420 Bio-Signal Processing System: set up the incremental shift, speed, print channel, screen and curve color, etc..
Be careful to enter the recording state: trace a section of normal contraction curve, and then sequentially add drugs to the bath for the experiment.
Note: After each addition of the drug, until the effect is obvious, use the TES solution to rinse 3 times, wait until the curve returns to the level before the drug, and then trace a section of the baseline, and then add the next drug. If the intestinal tube response has failed, a section of the intestinal tube may be replaced.
① 0.2 ml of 0.001% Ach solution, when the intestinal muscle activity curve drops to the baseline, rinse 3 times consecutively.
② Repeat ①, add 0.1% Atropine 0.2 ml when the effect reaches the highest point, record the change of the curve and then rinse 3 times consecutively.
③ Add 1% barium chloride 1.0 ml, add 0.1% atropine 1.0 ml immediately when the action reaches the peak, and record the curve change.
④After the activity of intestinal muscle stabilized, add 0.1% Hirsutine 0.5 ml, observe and record the curve of intestinal muscle activity, and then rinse for 3 times in a row.
⑤ Add 0.1% atropine 0.5 ml, when the effect is obvious, add 0.1% Hirsutine 0.5 ml, observe and trace the curve of intestinal muscle activity and then flush for 3 times consecutively.
(6) Add 0.01% epinephrine 0.5 ml, observe and trace the activity curve of intestinal muscle after 3 consecutive rinses.
(vii) Add 0.3% propranolol 0.5ml, contact 2~3min, then add 0.01% epinephrine 0.5ml, observe and trace the activity curve of intestinal muscle after 3 consecutive rinses.
(8) Add 0.05% neostigmine 0.5ml, observe and trace the activity curve of intestinal muscle.
Second, the results print out the experimental curve, and discuss the curve.