Department of Pharmacology Sree Siddaganga college of Pharmacy

Tumkur-572 102Karnataka

WHAT IS ADRENALINE?

Adrenaline or epinephrine is a hormone released from the adrenal gland.

It is one of the major neurotransmitters is the body.

HOW DOES ADRENALINE ACT ?

Adrenaline acts through receptor mechanisms, in the sympathetic nervous system.

The receptors being α and β receptors.

What is the use of adrenaline?

It is often used in cardiac resuscitation

To reverse severe allergic reaction.

People who are allergic to bees may carry an Epi-Pen.

How is Adrenaline bioassayed ?

PREPARATIONS ACTIVITY ASSAYED

Blood pressure of spinal cat

Rise in B.P

Isolated rabbit duodenum Isolated caecum of fowl Isolated rat uterus

Inhibition of the tone

Standard Preparation Adrenaline standard

solution is prepared in 0.1 N HCl.

Dilutions are made with saline.

Suitable concentration is 1:10,000

Method using Anaesthetised Dog:

A medium size dog(10-13kg) is anaesthetised with phenobarbitone sodium in a dose of 25 mg/kg i.v.

B.P is recorded on a kymograph after cannulating carotid artery with arterial cannula , connected with mercury manometer.

The animal should be given 0.001-0.002 mg of atopine to paralyse the vagus nerve.

Adrenaline is injected into the femoral vein through venous cannula.

Two successive responses of the same dose of adrenaline are noted.

The similar responses after same

doses, is an indication that there is

no variation in BP.Then the test and standard

samples are given in alternate till

both produce similar rise in BP.

Method Using Rabbit’s Duodenum:

A rabbit weighing 2-3 kg is killed by headblow method.

Dissected and duodenum is isolated.

The duodenum is suspended in the inner bath of mammalian organ bath.

Inner bath is filled with Tyrode solution, maintained at 37.5 0C.

Muscle allowed to stabilize for 30 mins.

Rhythmic contractions are recorded by means of the isotonic frontal writing lever on the kymograph.

Adrenaline relaxes the duodenum.

De Jalon’s Method on Rat’s Uterus:

A virgin female rat (100-150 g) is used.

The rat is killed by headblow method.

Abdomen opened, uterine horns are isolated and placed in De Jalon solution

De Jalon's solution

NaCl - 9.0gmKCl - 0.42gm CaCl2 - 0.06gm NaHCO3 - 0.5gm Glucose - 0.5 gm/L

Uterine horns are ligated and suspended in mammalian organ bath containing modified ringer solution.NaCl - 9.0 gmCaCl2 - 0.06 gmKCl - 0.45 gmDextrose – 0.5 gmNaHCO3 – 0.5 gmDistilled water – 1000 ml

Two identical contractions for 30 seconds with carbochol are recorded (0.75 mcg/ml)

Response from 3 different doses of standard adrenaline and 1 intermediate dose test adrenaline is recorded.

The percentage reduction in carbochol induced contractions are recorded.

Straub’s Method:

A glass cannula is passed through the aorta and valves into the ventricle of heart, so that the solution is pumped up and down in the cannula with every beat.

A graph paper is attached behind the cannula to give an estimate of force of contracton of systole.

Every beat is recorded by attaching the tip of the ventricle through a thread to a lever.

Very widely used for the detection of small quantity of adrenaline.

Adrenaline increases the force of contraction of heart.

On Spinal

The spine of the cat is exposed.

Spine is destroyed by passing a stiff wire down the spinal canal.

This causes a precipitous fall in BP.

Then adrenaline is given in i.v route and observed for the rise in BP.

Bioassay of Noradrenaline

Preparation Activity assayed

BP of pithed cat Rise in BP

It can be assayed

By using aneasthetised dog also.

The procedure is same as the method used for bioassay of adrenaline.