This document discusses several alternative methods that can be used instead of animal experiments for pharmacological and toxicological screening. It describes the full thickness skin model method which uses skin tissue to evaluate the effects of substances instead of live animals. It also mentions in silico methods which use computer programs and knowledge of similar substances to predict properties without testing. The document outlines the cell line technique using continuous cell lines to screen for effects like anticancer drugs. Finally, it explains the patch clamp technique which studies individual ion channels in isolated cells and kidney tubules as an alternative to testing on whole animals.

1. KARNATAKA COLLEGE OF PHARMACY
DEPARTMENT OF PHARMACOLOGY
PHARMACOLOGICAL AND TOXICOLOGICAL SCREENING METHOD
PRESENTATION OF
ALTERNATE ANIMAL EXPERIMENT
PREPARED BY : SUDARSHAN SINGH
M pharmacy ( dept; pharmacology)

2. CONTENT
Limitation of animal experimentation
Alternate animal experiment
Screening of alternate animal experiment

3. Limitation of animal
experimentation
Animal research and testing to protect and improve
human health is not only unsafe
 But also expensive, time-consuming, and unreliable
Animal models to study human diseases. Species
differences in anatomy, organ structure and function

4.  Examples
 penicillin is toxic to guinea pigs
 aspirin is poisonous to cats

5. Animal Alternatives:
It is not possible to replace whole animal models with
in vitro systems to evaluate drug effects on major organ
systems

6. Alternative techniques: definition
The term ‘alternative’ is used to refer to those
techniques or methods that replace the use of
laboratory animals altogether, reduce the numbers of
animals required,or procedure or technique to
minimize the level of stress endured by the animal.

7.  Screening methods of alternate animal experiment
1) Full thickness skin model (invitro method)*¹.
2) In sillico methods*².
3) cell line technique.
4) Patch clamp method

8. Full Thickness Skin Model:
Robust full thickness skin model
 A test substance is applied to the Full Thickness Skin
Model so that its effect on the skin tissue can be
systematically evaluated. The substance,
e.g. a cream formulation, is applied topically using a
brush

10.  done several times over a period of at least nine days.
 substance on the cell layers in the skin can be studied
 The standardized production of the model, in
combination with its special properties, make it
suitable for use as an in-vitro alternative to animal
testing.

11. In-sillico methods
 Substances with similar chemical structures often have
similar properties
 knowledge of the properties of a few representative
substances is sufficient to be able to deduce the
properties of a series of similar substances.
 certain properties of these representative substances
can also be assumed to be properties of the other
substances in the series.
 The required calculations are performed using
specially developed computer programs.

13. Cell line technique:
 The term cell line refers to the propagation of culture
after the first subculture.
 Once the primary culture is sub cultured, it becomes a
cell line
 A cell line derived by selection or cloning is referred to
as cell strain.
 Cell strain do not have infinite life, as they die after
some divisions.

15.  Types of cell lines:
1) Finite cell line.
2) Continuous cell line.

18.  (1) FINITE CELL LINE:
 The cell line with limited culture life spans are referred to as
Finite cell line.
 The cell normally divide 20-100 times before extinction.
 The actual number of doublings depends on the species, cell
lineage differences, culture conditions etc.

19.  (2) CONTINUOUS CELL LINE:
 The continuous cell lines are transformed, immortal and
tumorigenic.
 A few cells in culture may acquire different morphology and
get altered. Such cells are capable of growing faster resulting
in an independent culture.
 The progeny derived from these altered cells have unlimited
life.

21.  APPLICATIONS OF CELL LINE:
 Screening of anti cancer drugs
 Cell based bioassays
 In vitro screening of several drugs
 Production of anti viral vacci
 Gene therapy
 Recombinant DNA therapy
 Biotechnology

22. PATCH CLAMP TECHNIQUE
 Patch clamp technique is a technique in
electrophysiology that allows the study of individual
ion channels in cells. The technique is used to study
excitable cells such as neurons, muscle fibers and the
beta cells of the pancreas

23. Types of patch

24. Patch cell technique in kidney cell

26. Procedure
 The patch clamp technique can be applied to cultured
kidney cells freshly isolated kidney cells or to cells of
isolated perfused kidney tubules
 Segments of late superficial proximal tubules of rabbit
kidney are dissected and perfused from one end with a
perfusion system

27. Evaluation
In isolated perfused renal tubules, concentration
response curves of drugs which inhibit ion channels
can be obtained with the patch clamp technique

28. Applications of Patch Clamp
Technique:
 For the evaluation of antiarrhythmics agents.
 In kidney cells. Used for isolated ventricular
myocytes from Guinea pigs to study a cardio selective
inhibition of the ATP sensitive potassium channel

29. Thank you