Bioassay of Oxytocin

1. BIOASSAY OF
OXYTOCIN

2.  Oxytocin is a peptide hormones and
Neuropeptide.
 Oxytocin is normally produced by
the paraventicular nucleus of
the hypothalamus and released by the posterior
pituitary.

3.  Oxytocin is a natural hormone that causes the uterus to
contract.
 Oxytocin is used to induce labor or strengthen labor
contractions during childbirth, and to control bleeding
after childbirth.
 Oxytocin is also used to stimulate uterine contractions
in a woman with an incomplete or threatened
miscarriage.

4. The potency of oxytocin injection is
determined by comparing its activity with
that of the standard preparation of oxytocin
under the conditions of the following
method of assay.

5.  The standard preparation is a freeze dried
preparation of oxytocin with albumin and citric or
any other suitable preparation, the potency of
which had been determined in relation to
the International standard
 The Unit is the specific oxytocin activity
corresponding to that yielded by 0.0005 g of the
Standard preparation.

6. THE DRY POWDER (20 UNITS)
WEIGHED
WASHED
TUBE IS PLACED IN BOILING WATER
COOLED
FILTERED
FILTRATE (2 UNITS/ml)

7. Test animals
Use female rats in
dioestrous, weighing
between 120 and 200 g
anoestrus female guinea
pigs weighing between
175 g and 350 g.

8. By contraction of the rat uterus
 Inject 100 microgram of oestradiol intramuscularly.
 Kill the rat and suspend one horn of the uterus in a bath
containing Locke ringers solution.
 Maintain the bath at a temperature of 32º.

9.  Oxygenate the solution.
 Record the contractions produced by the addition
to the both of two doses of the Standard
Preparation suitably diluted with the above
solution.
 The doses should be such as to produce clearly
discriminated contractions.

10.  The required doses : Between 10 and 50micro Units
per ml.
 When maximal contraction has replace the bath liquid
by a fresh reached solution.
 The doses should be added at regular intervals of 3 to 5
minutes.

11.  Dilute the preparation under examination so as to obtain
responses on the addition of two doses similar to those
obtained with the Standard
 The ratio between the two doses of the preparation under
examination should be the same as that between the two
doses of the Standard Preparation and this ratio should kept
constant throughout the assay

12.  Prepare The two doses of Standard and the
two doses of the test should be and given in a
random order and at least six responses to
each should be measured.
 Measure all the responses and the result of the
assay by standard statistical methods.

13.  ttps://www.scribd.com/doc/28887077/Oxytoci
n-bioassay
 https://joe.bioscientifica.com/view/journals/jo
e/29/3/joe_29_3_009.xml