The method followed here is the method of Awouters et al. (1978) with modification. The original method included only male wistar rats (220–250 g), where they were starved overnight before treatment with the selected drug in the next morning. In the present study, rats of either sex (180–200 g) are fasted for 18 hours. ....
EVALUATION OF ANTIDIARRHOEAL AGENTS
Castor Oil-Induced Diarrhoea in Rats
The method followed here is the method of Awouters et al.
(1978) with modification. The original method included only male wistar rats
(220–250 g), where they were starved overnight before treatment with the
selected drug in the next morning. In the present study, rats of either sex
(180–200 g) are fasted for 18 hours. Animals are housed in six in each. Varying
doses of the test drugs are admin-istered orally by gavage as suspension to
different groups of animals. The next group received dipehnoxylate (5 mg/ kg)
orally as suspension as standard drug for comparison. Other group that served
as control is treated with the control vehicle only.
One hour after treatment, each animal receives 1 ml of
castor oil orally by gavage and then observed for defeca-tion. Up to 4th hour
after the castor oil challenge, the presence of characteristic diarrhoeal
droppings are noted in the transparent plastic dishes placed beneath the
indi-vidual rat cages.
The effects of the test drug like the standard
antidiar-rhoeal agent, diphenoxylate, are calculated based on the frequency of
defecation when compared to untreated rats. Both substances also should reduce
greatly the wetness of faecal droppings.
Gastrointestinal Motility Tests
Rats are fasted for 18 h and placed in different cages containing
six in each. Each animal is administered orally with 1 ml of charcoal meal (3%
deactivated charcoal in 10% aqueous tragacanth). Immediately after that the
first few groups of animals are administered orally with the test drug at
varying doses. Next group receives atropine (0.1 mg/kg, i.p), the standard drug
for comparison. The last group is treated with aqueous tragacanth solution as
control. Thirty minutes later, each animal is killed and the intestinal
distance moved by the charcoal meal from the pylorus is cut and measured and
expressed as a percent-age of the distance, the charcoal meal has moved from
the pylorus to the caecum.
The antidiarrhoeal test drugs decrease propulsion of the
charcoal meal through the gastrointestinal tract when compared with the control
group by this model which is comparable to that of atropine (standard drug)
which reduces the motility of the intestine significantly.
PGE2-Induced Enteropooling
In this method, rats of the same stock as above are deprived
of food and water for 18 h and are placed in six perforated cages with six
animals per cage. The first few groups of rats are treated with varying doses
of the test drug. The last two groups are treated with 1 ml of 5% v/v ethanol
in normal saline (i.p.). The last group of this is then treated with the
control vehicle, which served as control. Immediately after-wards, PGE2
is administered orally to each rat (100 μg/kg) in 5% v/v ethanol in normal
saline. After 30 minutes, each rat is killed and the whole length of the
intestine from the pylorus to the caecum dissected out and its contents are
collected in a test tube and the volume is measured.
PGE2 induces significant increase in the fluid
volume of rat intestine when compared with control animals receiving only
ethanol in normal saline and control vehicle. The antidiarrhoeal test drugs
inhibit this PGE2-induced enteropooiing. Statistical analysis is
performed by student’s ‘t’ test, and in all the cases results are expressed as
mean ± SE.
Related Topics
TH 2019 - 2024 pharmacy180.com; Developed by Therithal info.