The study based on cardiac tissue regeneration under the influence of Vitamin A, Emblica ad Arjuna. Comparatively analysis was observed during complete research work.
2. Heart is a vital organ and It has long been known that the
heart is one of the least regenerative organs in the body.
Owing to the lack of organ donors and complications
associated with immune suppressive treatments ,scientists
are continuously looking for new strategies to regenerate
the injured heart.
Mammals, including human, form scar tissue after cardiac
damage like that caused by a heart attack. This scarring
permanently impairs heart function. But certain model
amphibians can regrow heart tissue after injury.
Vitamin A was found to be good model to accelerate heart
regenerative ability in anuran amphibians.
3. It was decided to explore whether anuran amphibians(frogs
& toads) could regenerate heart tissue under the influence
of Vitamin A
The high regeneration ability of amphibians provides a
valuable model system to gain basic information on
regeneration that may be transferable to human trauma and
diseases that cause damage to such structures.
Transplantation technique will open new doors in the field
of cardiac tissue engineering.
In the present study both parameters will be
discussed i.e. heart regeneration in vivo and in
transplantation set up under the influence of Vitamin A.
4. Young (3 toe stage) and mature (5 toe stage) tadpoles
of the toad, were employed as experimental animals.
Experiment was completed in two series.
In the first series a small cut was made in skin on
anterior ventral surface in 40 tadpoles to expose the
heart and then the tip of ventricle part of heart was
incised.
Operated half (20) animals were reared in tap water
(controls) and remaining half (20) in vitamin A
solutions (5 IU/ml) for first three days and then
transferred into water.
5. In second series of experiment-meshed heart tissue was
implanted into a pit made on mid-lateral position of tail in
40 host tadpoles. Half (20) of the operated tadpoles with
implants were reared in water(control) and remaining (20)
were reared in vitamin A solution(5 IU/ml) for first three
days and then transferred into water. Experiment was
terminated on day 15 after operation.
6. PHOTOGRAPH SHOWING
AMPUTATION LEVEL OF
VENTRICLE PART OF THE
HEART .
PHOTOGRAPH SHOWING
IMPLANTATION OF
CARDIAC TISSUE IN MID
LATERAL POSITION OF TAIL
OF TADPOLES.
7. Mode of experiment Stage of experimental
animals
Groups (After
operation animals
reared in)
Day of preservation No. of preserved
animals
Percentage of heart
regeneration
SI
(Heart regeneration in
vivo) Amputation of
tip of the ventricle
3 toe stage young
tadpoles
Control IA
in water( 1-15 days)
3
7
15
5
5
10
40%
Vit. A treated IB
3days in Vit. A, then
reared in water
3
7
15
5
5
10
65%
5 toe stage mature
tadpoles
Control IC
in water( 1-15 days)
3
7
15
5
5
10
30%
Vit. A treated ID
3days in Vit. A, then
reared in water
3
7
15
5
5
10
55%
Series 1: Percentage of heart regeneration in situ in the tadpole of the Toad.
8. Mode of experiment Stage of
experimental animals
Groups (After
operation animals
reared in)
Day of preservation No. of preserved
animals
Percentage of heart
regeneration
SII
(Implantation of
mashed heart tissue
in pit on the tail
region)
3 toe stage young
tadpoles
Control IIA
in water( 1-15 days)
3
7
15
5
5
10
30%
Vit. A treated IIB
3days in Vit. A, then
reared in water
3
7
15
5
5
10
55%
5 toe stage mature
tadpoles
Control IIC
in water( 1-15 days)
3
7
15
5
5
10
20%
Vit. A treated IID
3days in Vit. A, then
reared in water
3
7
15
5
5
10
45%
Series II: Cardiac Tissue Regeneration from mashed heart Tissue at ectopic site in the Tadpoles of Toad.
9. Heart regeneration in present results clearly demonstrate an ability of
toad tadpoles to heal myocardial injuries.
Vitamin A has proved to be significant chemical model to induce and
accelerate heart regeneration in both modes of experiments.
In first mode of experiment.
The percentage of heart regeneration in vivo in 3 toe stage tadpoles it
was 65% in Vit-A treated cases and 40% in control (water), and in 5 toe
stage tadpoles percentage of heart regeneration is 55% in Vit.A treated
and 30% in control (water) cases.
In second mode of experiment
The percentage of heart regeneration in vivo in 3 toe stage tadpoles it was
55%in Vit-A treated cases and 30% in control (water) but in 5 toe stage
tadpoles the percentage of regeneration is 45% in Vit. A treated and 20% in
control (water) cases.
10. The regeneration ability declines according to the animal age.
The basic pattern of heart regeneration was found similar in
both Vit-A treated as well as untreated control group tadpoles.
For the study of sequential events occurred during heart
regeneration, operated animals were preserved at different time
intervals (Day 5,10 and d15).By day 5 ,the wound showed
proper healing (Fig.3),whereas on day 10 the wound showed
rapid resolution of granulation tissue and a restoration of normal
myocardial architecture.
11. PHOTOGRAPH SHOWING
COMPLETE HEART
REGENERATION ON DAY 15
AFTER OPERATION.
(RH = REGENERATED HEART)
PHOTOGRAPH SHOWING COMPLETE
HEART REGENERATION VENTRICLE
PART ON DAY 15 AFTER OPERATION.
(RV= REGENERATED VENTRICLE)
12. PHOTOGRAPHS OF CARDIAC TISSUE
IMPLANTS ON ECTOPIC SITE
SHOWING DEVELOPMENT,
DIFFERENTIATION AND GROWTH OF
THE IMPLANTS ON DAY 15. (20×)
(DEH=DEVELOPING ECTOPIC HEART)
PHOTOGRAPH IS SHOWING
CARDIAC MUSCLES CELLS OF
HEART.
(CMC – CARDIAC MUSCLES
CELLS)
13. On the wound site or injury site generation of new cells
observed that were indistinguishable from neighboring
healthy heart cells.
Promising results obtained in the second phase of
experiment. The mode of experiment was ectopic
transplantation of meshed cardiac tissue. The cardiac
patches could survive and beat for up to 15 days after
engraftment on the tail.
14. In light of the above results obtained in the present study
,amphibian system can make a substantial contribution to
our understanding of heart regeneration
These important areas for research have the potential to
provide basic information that could be used to induce and
control heart repair in mammals.
The findings also suggest that all vertebrates including
human, might possess this regenerative capability and that
methods could be developed to tap it.
Transplantation technique opens new doors
in the field of cardiac tissue engineering.