Protocols
of pharmacology lab
Ø You
are not allowed in laboratories without the lecturer’s permission.
Ø Eating
and drinking are not permitted in the laboratories.
Ø Know
the location of the fire extinguishers in the laboratory where you are working
and how to operate them in an emergency.
Ø Many
operations normally carried out in the laboratories are potentially dangerous
.The greatest care should be taken at all times to ensure your safety and that
of others in the laboratory.
Ø Follow
carefully the procedure given in the schedule or instruction sheet you should
not carry out experiments or make innovations without the approval of your
supervisor ask if you do not fully understand the instructions.
Ø Clearly
label all vessels which contain chemicals with:-
* The
name of chemicals, date of performance
* Your
name and course
Ø Disposal
of chemicals –ask the lecturer or technician.
Ø Solid
matters water immiscible solvents or liquid nitrogen must not be poured down
sinks.
Ø Waste
material solid or paper should be placed in the bins provided use the specially
indicated bins only for glass.
Ø Students
are responsible for the cleanliness of their work benches which should be left
clean, dry and free from apparatus at the end of the practical period.
Ø Condenser
or cooling water tubing must be secured by wire or clips to the tap and to the
apparatus and drain tube securely located in the sink or waste pipe.
Alternatively suitable air condenser may be used.
Ø All
wash your hand after working in the laboratory it is important to wash your
hand both before and after going to toilet after working in the laboratory
Ø Do
not leave broken glass in the sink or on the bench place it in the appropriate
bin for glass.
Ø Solutions
should not be pipetted by mouth use a pipette filter.
Ø All
chemicals and apparatus should be returned to the proper place after use.
Ø
STUDY
OF PARTS OF KYMOGRAPH
Study
of kymograph:
It consists of two parts of:
1. Kymograph
2. Organ
bath
Kymograph:
The word “kymo”
means “motion” and “graph” means “record”. So it is used for reading a wave
like motion.
Parts
of Kymograph:
There are 3
sections:
1. Drum
and drive assembly
2. Electronic
stimulator
3. Electrode
and lever assembly
Different
parts of Kymograph:
1.
Cylindrical
Clamp:
It
is a sort of lock which is used to fix the drum on control shaft.
2.
Smoked
drum:
It
is a metallic cylinder having diameter of 500mm and height is 152mm.
3.
Spindle:
Simple
metallic rod at a tip of kymograph which holds the drum. Its length is 330mm.
4.
Contact
arm:
Black
triangular projection at a base of spindle. It is used to mark the stimuli on
base line.
5.
Contact
Switch:
It
is a square shaped switch at the top of kymograph.
6.
Kymograph
arm:
Adjustable
and movable arm structure at the top of bath assembly.
7.
Frequency
control:
It
is a knob on the front with calibrations giving to divisions, used to control
the frequency of stimuli.
8.
Mode
of switch:
a) Slow
repeated mode provides low frequency.
b) Single
mode is used when we need one stimuli.
c) Repetitive
mode provides increased frequency range of 2-5 stimuli.
9.
Amplitude
control:
Used
for amplitude or strength of current. It is similar to frequency dial and is
divided in to divisions which conduct voltage of 0.3V or 0-20V.
10.
Single
pulse switch:
It
is used for testing the preparations before starting the experiment when it is
passed down through a single impulse.
11.
Main
Switch:
It
is present on the front of kymograph directly connected to main socket.
12.
Indicator
lamp
Red
light shows the presence of current.
13.
External
trigger:
A
special circuit which having an output socket to which two wires are connected.
14.
Voltage
or output socket:
This
is also a current circuit system.
15.
Drum
motor control switch:
Switch
at the outside of kymograph for starting and stopping the drum.
16.
Lever:
Moveable
and adjustable clutch system of kymograph.
Bath
Assembly Dimensions:
§ Length 152mm
§ Depth 76mm
§ Height 29mm
Drum
Speed:
Highly accurate speeds: 0.12, 0.25, 0.50, 0.75, 1.00, 1.25, 2.50 mm/sec
Study of Organ Bath:
§ It is an apparatus used for providing physiological
conditions to tissues.
§ It is composed of small trout and screw thread
which is adjustable.
Parts:
1.
Outer chamber:
Larger chamber with warm water for maintaining
the temperature.
2.
Inner chamber:
Also called as tissue chamber. Tissue is placed
and filled with solution.
Gas diffuser:
§ One end is connected to tissue chamber and one
with cylinder.
Short arm:
§ Tissue
is lied with the help of thread.
Long
arm:
§ It
is attached to kymograph drum.
Adjustment,
Support and Screw:
§ Various
adjustable supports are present.
§ These
are used to hang the tissues with the help of thread.
§ It
is also used to keep frontal writing lever in its place.
Pen
marker:
§ It
is supported by frontal writing lever and filled with ink.
EFFECT OF ANTI-COAGULANT ON
HUMAN BCT
Subject:
§ Human being
Apparatus:
§ Lancet or
needles
§ Spirit lamp
§ Test tube
§ Syringes
§ Stopwatch
§ Capillary tube
Chemicals:
§ Heparin as
anti-coagulant
Procedure:
§ 
Take
two test tubes.
§ Now
add 2 ml of fresh blood in tubes and mark one tube as test and other as
control.
§ Add
heparin.
§ Now
fill the capillary tubes with this blood separately from each test tube.
§ Turn
on the stopwatch
§ After
every 1 minute, break off the small piece of capillary tube until a fibrin
thread appears between the broken ends.
Precautions:
§ Syringes
must be sterile.
§ Don’t
keep the blood openly as it will immediately clot.
§ Apparatus
must be clean.
Results:
§ In
control tube blood will clot after 6-12 minutes.
§ While
in test sample, blood will take about 1 hour to clot due to the presence of
Anticoagulant
EFFECT
OF LIGNOCAINE GEL ON HUMAN
Intro:
A local anesthetic is a medication that causes
reversible absence of pain sensation, although other senses are often affected,
as well. According to therapeutic actions, local anesthetics are of following
types.
1.
Soluble Local Anesthetics: suitable for injections
(subcutaneously) e.g. Procaine HCL
2.
Surface on Local Anesthetics: used only
topically e.g. Cocaine Hydrochloride.
3.
Local Anesthetics of low solubility: for topical use e.g.
Benzocaine
Lignocaine:
§ It is topically
local anesthetic which blocks the nerve conduction of sensory impulse from
periphery.
§ Local anesthetics
abolish sensation in limited area of the body without producing
unconsciousness.
§ The myelinated
fibers that conduct impulses for pain, temperature and autonomic activity are
most sensitive to action of local anesthetics.
§ Lignocaine is
most frequently used. These compounds interacts with protein receptors of Na+
channels to inhibit their activity.
§ By adding vasoconstrictor adrenaline,
absorption is decreased.
§ No study reported on adverse events such as ischaemia distal
to the injection site or cost analysis with use of adrenaline with lidocaine.
Subject:
§ Human
Lignocaine HCL (2% w/v) as
a drug
Apparatus:
§ Lancet or
needles
§ Marker
§ Stopwatch
Procedure:
§ Mark
the circle of an area that is free from blood vessels in forearms.
§ Hold
the forearms of subject and the central point of circle.
§ Take
the right arm as control and left as test arm.
§ Apply
lignocaine gel at whole area and check the sensitivity after every 5 minutes.
§ Repeat
the procedure for checking sensitivity of both arms after 10, 15, 20,25,30,45
and 60 minutes.
Results:
Tabulate
the results and discuss the findings.
Antagonist
effect of Atropine & Pilocarpine on Rabbit eye
Requirements:
§ 2%
atropine
§ 1%
pilocarpine
§ Rabbit
§ Cotton
§ Ruler
Theory:
When the drug counter act or
nullify the action of other drug this phenomenon is called antagonism and drug
is called antagonist.
Types
of antagonist:
Following are
the types of antagonist
1. Pharmacological antagonist:
These are those antagonist in which the
pharmacological action of drug is reduce by the action other drug.
2. Physiological antagonist:
These
antagonist work on different mechanism
§ Analeptics.
§ Narcotic
agent
3. Physiochemical antagonist:
These act due to physical and chemical properties.
EFFECT
OF ADRENALINE ON RABBIT’S EYE
Requirements:
§ Rabbit
§ Scissors
§ Torch
§ Cotton
§ Dropper
§ Normal saline
Procedure:
§ The rabbit is
held in one hand and eyelashes are removed.
§ Left eye is
labelled as control and right as test.
§ Now made a pouch
and instill few drops of adrenaline in test eye.
§ And observe:
1. Size of pupil
2. Light reflex
3. Corneal
reflex
4. Colour of
Conjunctiva
Size of pupil:
It is measured roughly with scale. Dilation of pupil is called mydriasis
and decrease in size of pupil is called miosis. It is measured in mm.
Light reflex:
Light is shed from behind and contraction or dilation of pupil upon
exposure to light is noted.
Corneal reflex:
4 pieces of rolled cotton are touched at
lateral to limbus of eye closure of eye is noted.
Colour of conjunctiva:
The
lower eyelid of rabbit is contracted to exposure the lower palpebral aperture
(opening b/w lids). The vessel of the conjunctiva are observed and congestion
if present is noted.
Results:
§ The experiment
is performed to check if a drug is sympathomimetic or sympatholytic.
§ The
drug binds to the receptors and shows its activity.
§ After
every 5 minutes of pouring drug, pupil is dilated and colour of conjunctiva becomes pale, reflex decreases with time.
§ Hence it is proved that drug is
sympathomimetic. Dilation of pupil us due to the dilation of papillae caused by
adrenaline.
§ The observations shows that drug is
mydriatic in nature.
EFFECT OF DIAZEPAM ON RABBIT
BY IM ROUTE
Requirements:
§ Disposable
syringes
§ Stopwatch
Drug used:
§ Diazepam inj.
Subject:
§ Rabbit
Theory:
Diazepam is a benzodiazepine that
exerts anxiolytic, sedative,
muscle relaxant and anticonvulsant. Most of these effects are
thought to result from a facilitation of the action of gamma amino butyric acid
(GABA), an inhibitory neurotransmitter in the central nervous system.
Procedure:
1.
Take a
healthy rabbit and handle it with care.
2.
Observe
the normal parameters like relaxation of muscle by pulling its legs.
3.
2cc syringe (2 cubic centimeter) of diazepam
(100mg/20ml) is injected into the thigh of rabbit.
4.
Take
the observations such as muscle relaxation in regular intervals of time and
tabulate.
Uses:
1.
Used as muscle relaxant
EFFECT OF FUROSEMIDE ON
RABBIT BY IM ROUTE
Requirements:
§ Disposable
syringe
§ Stopwatch
Drug used:
§ Furosemide inj.
Subject:
§ Rabbit
Theory:
Furosemide works by blocking the absorption of
sodium, chloride and water from the filtered fluid in the kidney tubules,
causing a profound increase in the output of urine (diuresis). The onset of
action after oral administration is within one hour, and the diuresis lasts
about 6-8 hours.
Procedure:
1.
Take a
healthy rabbit and handle it with care.
2.
Take normal observation in micturition (Micturition is
the ejection of urine from the urinary bladder through the urethra to the
outside of the body.)
3.
Inject
the furosemide injection through IM route and note the reading of micturition.
Uses:
1.
For high
blood pressure, diuretics, commonly known as "water
pills," help your body get rid of unneeded water and salt through the
urine. Getting rid of excess salt and fluid helps lower blood
pressure and can make
it easier for your heart to pump.
2.
Diuretics may be used to treat a number
of heart-related
conditions, including high
blood pressure, heart
failure, kidney and liver
problems.
Side effects:
- Frequent
urination.
- Arrhythmia (abnormal heart rhythm)
- Electrolyte abnormalities
- Dehydration:
Signs include dizziness, extreme thirst,
excessive dryness of the mouth, decreased urine output, dark-colored urine
EFFECT OF PHENYLEPHRINE ON
RABBIT’S EYE
Requirements:
§ Torch
§ Cotton wool
§ Dropper
§ Measuring scale
Drug used:
§ Phenylephrine
Subject:
§ Rabbit
Parameters to be
measured:
§ Light reflex
§ Corneal reflex
§ Size of pupil
Procedure:
1.
Take a
healthy rabbit and handle it with care.
2.
Note
down the normal parameters mentioned above of the healthy rabbit.
3.
Use
pinch method to instill the drug into an eye.
4.
Pinch
lower eyelid to make a small pouch.
5.
Instill
1-2 drops of drugs in this pouch and then bring the lid upward.
6.
Keep
it in contact with conjunctiva for 1-2 minutes.
7.
Keep
one eye with drug instilled as test and other as controlled.
EFFECT OF PROPARACAINE ON RABBIT’S
EYE
Requirements:
§ Torch
§ Cotton wool
§ Dropper
§ Measuring scale
Drug used:
§ Proparacaine
Subject:
§ Rabbit
Parameters to be
measured:
§ Light reflex
§ Corneal reflex
§ Size of pupil
Procedure:
1.
Take a
healthy rabbit and handle it with care.
2.
Note
down the normal parameters mentioned above of the healthy rabbit.
3.
Use
pinch method to instill the drug into an eye.
4.
Pinch
lower eyelid to make a small pouch.
5.
Instill
1-2 drops of drugs in this pouch and then bring the lid upward.
6.
Keep
it in contact with conjunctiva for 1-2 minutes.
7.
Keep
one eye with drug instilled as test and other as controlled.
EFFECT OF Timolol ON RABBIT’S
EYE
Requirements:
§ Torch
§ Cotton wool
§ Dropper
§ Measuring scale
Drug used:
§ Timolol
Subject:
§ Rabbit
Parameters to be
measured:
§ Light reflex
§ Corneal reflex
§ Size of pupil
Procedure:
1.
Take a
healthy rabbit and handle it with care.
2.
Note
down the normal parameters mentioned above of the healthy rabbit.
3.
Use
pinch method to instill the drug into an eye.
4.
Pinch
lower eyelid to make a small pouch.
5.
Instill
1-2 drops of drugs in this pouch and then bring the lid upward.
6.
Keep
it in contact with conjunctiva for 1-2 minutes.
7.
Keep
one eye with drug instilled as test and other as controlled.
8.
Above
parameters are measured at 5-15 minutes.
EFFECT OF DIMENHYDRINATE ON
RABBIT BY IM ROUTE
Requirements:
§ Disposable
syringe.
§ Stopwatch
Drug used:
§ Dimenhydrinate
(brand name : Gravinate)
Subject:
§ Rabbit
Theory:
It is an anti-emetic agent usually acting on H1
receptors by showing its antagonistic activity and resulting in sedation and
drowsiness.
Procedure:
1.
Take a
healthy rabbit and handle it with care.
2.
Take
the normal readings of sedation and drowsiness.
3.
Inject
the dimenhydrinate by IM route.
4.
And
note the readings of sedation and drowsiness after equal intervals of time.
Uses:
1.
Anti-emetic agent.
2.
Anti-histaminic activity.
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