Oxytocin

1. Topic :Oxytocin
Presented by,
R.Venkatesan.
M.Pharm 1st semester
Dept. pharmaceutical analysis
Karnataka college of pharmacy
Bangalore
27-Mar-2023
Presented to,
Dr.C.Sreedhar,
Professor and HOD
Dept. pharmaceutical analysis
Karnataka college of pharmacy
Bangalore
ADVANCED PHARMACEUTICALANALYSIS

2. Content
01
02
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Introduction to
oxytocin
Role of oxytocin
Oxytocin mechanism of
action
Biological assay of
oxytocin

3. Introduction
• Oxytocin (Oxt or OT) is a peptide hormone and neuropeptide
normally produced in the hypothalamus and released by the posterior
pituitary.
• Oxytocin synthesized in both sexes (males and females ), well
recognized physiological effects only in women.
• posterior lobe which produce oxytocin and diuretic hormone.
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4. Role of oxytocin
• It stimulate the contraction of the uterine smooth muscle and memory
gland.
• Oestrogen progesterone and prolactin responsible for production of
milk by mammary gland but ejection require oxytocin.
• It facilitates the contraction of uterus.
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5. Oxytocin mechanism of action
• Neuropeptide made in hypothalamus that stimulate contractions, that
expel the infant from uterus.
• Responsible for milk letdown and triggered by the nipple stimulation
of sucking.
• Oxytocin called love and binding hormone. It has a very special
affect on mothering.
• It enable the growing sense of love and attachment to the infants.
The more the infant suck the more oxytocin is produced.
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7. Biological assay of oxytocin
Principle
 Potency is determined by comparing its activity
Depression of BP
Contraction of uterus
Milk ejection of pressure
 With standard preparation of oxytocin (consisting free dried
synthetic oxytocin peptide with human albumin citric acid)
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8. • Method A
Depression of the BP in the chiken
test animal : cockerel (Young male chiken)
weight : 1.2 – 2.3 kg
• Method B
by contraction of the rat uterus
test animals : female rat
weight : 120g – 200 g
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9. • Method C
Milk ejection pressure in lactating rat
test animals: lactating rat, 2-21 days after parturition
weight : 300g
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10. Method A
Depression of the BP in chiken
Test animals : cockerel (young male chicken ) 1.2 – 2.3kg
 anesthetized cock – prolonged and remove popliteral artery and crural vein.
 canulate the popliteral artery and record BP response
 canulate the crural vein or branchial vein.
 introduce a cannula or thin tube into (a vein or body cavity).
 prepare standard solution with saline. Inject 0.1 – 0.5 ml
 Inject 2 doses of standard solution into cannulate vein is record B.P
response.
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11.  Dose should cause decrease in BP.
 Interval between 2 injection, between 3- 10 mins depend on rate at
which BP return normal.
 Dilute test preparation with saline so as to get same response as
standard.
The ratio between standard and test should be equal.
 if animal rapidly becomes insensitive to repeated injection the
solution another must used.
 Measure all responses are calculated result of the assay by standard
statistical method.
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12. Method B
By contraction of the rat uterus
Test animals: female rat 120 – 200g.
 Inject 100 ug of oestradiol benzoate into female rat before the assay.
 immediately before assay confirm by vaginal smear that rate in
oestrus or pre oestrus.
 Kill rat and suspend one horn of uterus in organ bath containing a
solution of following Nacl, Kcl, Cacl2, NaHCo3, Na2HPo4,
NaH2Po4, Mgcl2, Dextrose.
 Maintain the bath at temperature at of 32 degree celcius.
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13.  Bath liquid require dose between 10 – 50 units/ml.
 Oxygenate solution with mix of 95 % of O2, 5% of CO2 record contraction
of muscle.
 Record contraction produces by addition of two dose of std. preparation.
 when maximum contraction has been reached replace – bath require by
fresh solution.
 Dose should be added at regular interval ( 3 – 5 minutes).
Similarly record the contraction of test preparation as standard.
 Ratio between two dose of test and two dose of standard should be equal
this ratio kept constant through out the assay.
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14. Method C
Milk ejection pressure in lactating rat.
Test animals : lactating rat, 3-21 day after parturition, 300 g
 This test makes use of the milk ejecting properties of oxytocin.
 A rabbit in the first or second week of lactation is anesthetized with
urethane and pentobarbital. Usually, artificial respiration is not necessary.
 One jugular vein is cannulated for injections. One of the six ducts in
nipple of the rabbit is cannulated with a statham strain gauge transducer.
 Two doses of the standard and the test preparation are injected according
to a randomized block or to a latin square design.
Milk ejection pressure is recorded.
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15. THANK YOU