Anticonvulsive Effects of Sodium Phenobarbital
Experimental purposeExperimental purpose
To master the anticonvulsive effects of sodium phenobarbital and the elementary process of chi square test.
To be familiar with the experimental condition of screening Anticonvulsants.
Sedative and hypnotics are among the most widely prescribed drugs worldwide.
Major therapeutic use is to cause sedation or encourage sleep. Anxiety states and sleep disorder are common.
Action and useAction and use
sedative and hypnotics apt to induce sedative and hypnotics apt to induce tolerance and dependence tolerance and dependence
induce P-450 systeminduce P-450 system adverse effects are commonadverse effects are commonanticonvulsive effects anticonvulsive effects generalized tonic-clonic seizuresgeneralized tonic-clonic seizures
anesthesia and preanesthetic anesthesia and preanesthetic medication medication
enhance CNS depressionenhance CNS depression graded dose-dependent depression of graded dose-dependent depression of
CNS is a characteristic of sedative-CNS is a characteristic of sedative-hypnotics. hypnotics.
at still higher doses---coma and deathat still higher doses---coma and death
MechanismMechanism
It can activate GABAA receptor,
potentiate GABA action on chloride
entry into the neuron.
The GABAA receptor chloride ion channel complex has a structure assembled from five subunits.
Barbiturates Benzodiazepines
a increase the open time of Cl- channel
b increase the open frequency of Cl- channel
Adverse effectAdverse effect
drug hangover: tiredness after awakes tolerance: induce P-450 system addiction: abrupt withdrawal may cause
tremor, anxiety, weakness, restlessness, nausea and vomiting
respiratory depression allergy
PoisoningPoisoning: overdoses can cause death,
depression of respiration and central
cardiovascular depression.
Treatment: artificial respiration;
purging the stomach of its contents;
alkalinization of blood and urine; hemodialysis
Experimental animals
Mice (of either gender), 18~22g
Experimental apparatusExperimental apparatus
Mouse cage
injector
Experimental drugsExperimental drugs
50mg% Dimefline ih0.4% Sodium Phenobarbital ip0.9% Sodium Chloride (Normal
Saline) ip
Experimental indicationExperimental indication
Tetanic straighten in hind limbs is positive.
Experimental procedureExperimental procedure
Take 48 mice, weigh them.All mice are assigned randomly to
experiment group and control group according to the principle that equal weight between groups.
Students are divided into twelve
groups, every group takes twe mice from experiment group and control group respectively. Mark each mouse, record the marker in the table.
Mice in experiment group are
administered Phenobarbital intraperitoneal at the dose of 0.5ml/20g. Similarity, mice at the dose 0.5mg/20g. Similarity, mice in control group are administered 0.9% Sodium Chloride intraperitoneal at the dose of 0.5ml/20g.
After 30 minutes, each mouse is administered 50mg% Dimefline subcutaneously in the dose of 0.5ml/20g.
After administering Dimefline, we observe the responds of mice for 30 minutes. If there is convulsive respond, we need to record it.
In the end, all students summary the results. Record the positive and negative number in experiment group and control group in the table.
Analyze and handle the resultsAnalyze and handle the results
We analyze the results with chi square test to see if there is statistical difference in the percentage of convulsion between experiment group and control group.
1. Calculate χ2 value
(1) Calculate χ(1) Calculate χ22 value with basic value with basic formula:formula:
Table 1. Descriptive chart of results A T A-T (A-T)2/T
Experiment group Positive number
negtive number
Control groupTotal Positive number
negtive number
total
A: observed value T: theory value
(2) Calculate χ(2) Calculate χ22 value with value with quadruple tabular form:quadruple tabular form:
Table 2. Descriptive chart of results
Experiment group Control group ∑
positive number a b
negative number c d
∑
χ2= (ad-bc)2×n / (a+b) (a+c) (c+d) (b+d)
2. Compare the observed value with theory value to assess if there is statistical difference.
QuestionQuestion What are the methods of making convulsion
model? How to observe drug’s anticonvulsive effect?
Why anticonvulsive drug be administered before administering make convulsion drugs in our experiment?
Which data does the experiment data belong to? Which method we choose to analyze? How to do it?