Download Clara Cell Differentiation in the Albino Rat Ultrastructural and

‫ البوابة ا إل لك ترونية‬-‫بوابة ا إلبحاث العلمية‬
‫جامعة المنيا‬
‫دكتوراه‬
Clara Cell Differentiation in the Albino Rat : Ultrastructural and
Cytochemistry for Ki-67 (MIB-1) and CC 10 Proteins /
‫ التركيب المجهرى الدقيق وكيمياء الخلية للكشف عن البروتينات‬/ : ‫تطور خاليا كالرا فى الفأر االبيض‬
CC 10 Ki-67 (MIB-1).
2009
)‫عنوان الرسالة (باللغة االنجليزية‬
)‫عنوان الرسالة (باللغة العربية‬
‫تاريخ النشر‬
ِAbdu, Nashwa Fathy Gamal.
‫المؤلف‬
Nashwa Fathy Gamal Abdu ; Supervisor Saadia Ragab Said, Entesar Ali Saber,
Azza Houssein Ali.
‫المشرفين‬
Thesis (Ph.D) - Minia University. Faculity of Medicine.Histology Department.
‫الدرجة العلمية‬
--
‫موضوع الرسالة‬
)‫(ملخص باللغة العربية‬
Clara cells are non-ciliated, non-mucous
secretory epithelial cells lining the
pulmonary airways. The purpose of this
study was to assess the following changes
in Clara cells in the conducting airways
of the albino rat: 1) The spatial and
temporal pattern of development and
distribution of Clara cells in the normal
airway epithelium. 2) The role of Clara
cells in the cell renewal in the steady
state. 3) The cellular morphology and
ultrastructural peculiarities of Clara
cells. Twenty timed pregnant albino rats
were used in this study. Five fetuses and
neonates were used for each age group of
the study. The normal distribution and
the f .. mctional maturation of Clara cells
during their differentiation were detected
immunohistochemically using the CC10
protein antibody. Clara cell contribution
to the proliferation was detected
immunohistochemically by using the
proliferation marker Ki-67 antibody. The
‫موضوع الرسالة‬
)‫(ملخص باللغة االنجليزية‬
‫ البوابة ا إل لك ترونية‬-‫بوابة ا إلبحاث العلمية‬
‫جامعة المنيا‬
nature of Clara cell secretions was
detennined histochemically by the P AS/
AB. Scanning electron microscopy
marked the surface changes during
maturation regarding the mechanisms of
secretion.
Transmission
electron
microscopy characterizes the morphologic changes that accompany the
functional differentiation of Clara cell .
The important finding in this study
included; defining the time point ( age) at
which Clara cell protein is first
manufactured by cells in the developing
rat lung, timing of Clara cell
phenotypical
maturation,
and
demonstarion of the normal distribution
of Clara cells in the bronchial rree. The
expression of CC 1 0, was detected in the
apex
of
distal
onciliated airway cells by the 19 DGA.
Clara cells were gradually . creased from
the terminal to the respiratory
bronchioles at all studied ges. The
intensity of the reaction varied in cells.
The strongest labeling< brSummary and
Conclusion
was in the apical region of the cells.
Labeling was increased by 7 DPN to the
same intensity and distribution of adult.
The Clara cell population was virtually
restricted to the bronchioles. The lining
epithelium was formed of single layer, at
all studied ages, but showed gradual
increase in height during maturation .
The present study demonstrated that
Clara cells In adult rats contribute
substantially to cell renewal in normal
conducting airway epithelium either in
the terminal or the respiratory
bronchioles. Clara cells were extensively
positive for Ki-67 either in the terminal
or in the respiratory bronchioles
prenatally and early postnatally, this
decreased by the age of21 DPN, and were
present in few number at the adult age .
Clara cells were Alcian blue-positive
indicating that they contained acid
mucopolysaccharide .During prenatal
‫ البوابة ا إل لك ترونية‬-‫بوابة ا إلبحاث العلمية‬
‫جامعة المنيا‬
life, Clara cells appeared to have PAS
positive granules within a bluish alcian
blue background. This was interpreted
by the transmission electron microscopic
study which revealed that Clara cells
contained much of glycogen granules in
the cytoplasm at 19 DGA ,decreased by 1
day postnatally and then disappeared
that could explain why Clara cells after
these ages appeared with a bluish
cytoplasm without red granules in
sections stained with PAS/ Alcian blue .
The morphometric study demonstrated
an age- dependent pattern in CC 1 0
expression which restricted to the
bronchioles. There was a variation in the
number of cells labeled at the different
airway levels, which gradually increased.
By 7 DPN they reached a mature
phenotypic distribution in the terminal
and in the respiratory bronchioles
(59.2% %79.7 ,respectively) which
resembled those of the adult in the
terminal and in the respiratory
bronchioles (60.4%, 80.1% respectively).
The contribution of Clara cells to the
proliferation compartment is higher in