Organ fixation was performed with 5.0% and 10.0% formalin. The research was performed in the histology and
histopathology laboratory of Taoura Veterinary Institute, University of Souk Ahras, Algeria. Organ fixation was performed
with 5.0% and 10.0% formalin. The organs have been sectioned and placed in a coating cassette, placed in the initial pot
of automat impregnation SLEE MEDICAL, which includes 12 stations, ten glass beakers for xylene and alcohol with
digressive degrees of treatment and two pots of paraffin in anodized aluminum. For dehydration and preparation of tissue
for microtome cutting Programmable thanks to the LCD screen, for control of temperature and elapsed time. The step of
coating the tissue samples with the MPS / P1 system. Thin sections of 5.00 7.00 microns were made with a CUT 4062
microtome with manual rotation, put on slide for different staining, Hematoxylin-eosin, impregnation with silver nitrate,
and immuno-histochemistry with markers identification of T lymphocytes.
Examination with an ocular micrometer, distances between divisions of 5 μm. The histological structure of the
parenchyma has been detected. The measurements of each ocular field were carried out in five fields of vision of five
histological sections of each histological slide.
Other sections were subjected to an impregnation with silver nitrate by serial passage in silver nitrate and potassium
permanganate tanks at a decreasing concentration and this in order to visualize the reticular structure of this organ. For
localization of lymphocytes in the functional areas of the spleen, immunohistochemistry is used for the determination and
localization of lymphocytes and macrophages in the parenchyma of organs, also the determination of the cytological
characteristics was carried out using an ocular microscope, antibodies were used to elucidate the T lymphocytes in the
functional areas of the spleen.
The examinations and the taking of the data were carried out on personal computer. The determination of the
histological and cytological characteristics was carried out using an ocular microscope and a stereo MBS-10 microscope.
The quantitative study for the tissue compartments was carried out using the point S system; the data obtained were
analyzed with R program.
RESULTS AND DISCUSSION
The study of the mass of spleens during the antenatal period revealed that the minimum value was 2.43 g found in the
first group, while the maximum value was 6.39 g found in the fourth group (Graph 1), concerning lambs. From the
postnatal period, the minimum value was 6.22 g found in the first group, while the maximum value was 21.52 g found in
the fourth group (Graph 1). The results of morphometric study and mass of this organ on other mammals were conducted
by Vashishtha et al. (2018). Finding significant variations according to age, also, discussed a progressive increase of mass
and revealed that sex has no influence on its development, results found by Jaji et al. (2019). Measurement of fetal
spleens, minimum value of length was 3.61 cm found in first group while maximum value was 4.35 cm found in fourth
group. About width, minimum value was 2.47 cm found in second group, whereas maximum value was 2.95 cm for the
fourth group (Graph 2). Regarding lambs spleen, the minimum length value of 4.54 cm found in first group and maximum
value of 11.67 cm found in fourth group. While minimum width value was 3.29 cm found in first group, and maximum
width was 8.32 cm found in fourth group (Graph 2).
Graph 2 - Morphometric index of some spleens, (cm)
according to the age (days).
Graph 1 - Mass index of spleens (g) according to
antenatal and postnatal period (days).
Optical Microscopic exams revealed that lambs' spleen consisted of stroma and parenchyma (Graph 3). Stroma
mainly formed by capsule and trabeculae that enter into parenchyma. The capsule of this organ consists of two layers, an
external connective tissue (elastic) and internal (muscle), according to Weigert's Hematoxylin and picrofushin (Van Gieson)
staining allowing the organ to change its size and maintain an increase significant of its volume (Figure 1-A). It has been
found that red pulp is composed of splenic sinusoidal capillaries and cellular cords. Splenic sinusoidal capillaries are
limited by single discontinuous epithelium, resting on basement membrane which surrounds sinusoids in discontinuous
way, species situated between sinusoidal capillaries occupied by cellular cords, in the researches of Silva-O’Hare et al.
(2017) have achieved almost the same results, although follicles appeared in the antenatal phase according to our data,
which is not in theory as immunological norm, this result would open new research later.
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Citation: Eddine Djallal R, Amine Mohamed F, Manel H, Khaoula M and Marina L (2020). Morpho-histological study of spleen ontogenesis in lambs during antenatal and