الفهرس Only 14 pages are availabe for public view
 |  | from | 201 |  |  |
| | | from | 201 | | |
Abstract
Summary and Conclusion
Administration of lead result in an increase in lead serum concentration administration of antioxidant (zn, se) and ca result in significant decrease in the lead level of the blood. While addition of succimer had a prominent effect in decreasing the serum lead level which was nearly restored to the normal.
Administration of lead for goats result in highly significant decrease in the level of both T3 and T4 in the serum. Administration of antioxidant and ca restore the level of T3 and T4 in the blood. Administration of succimer had also the same result.
Exposure of goats for lead toxicity result in a significant increase the of the serum level of both cholesterol and triglyceride which were restored by administration of antioxidant & ca or succimar.
Administration of lead for goats had no significant effect on serum glucose concentration and there was a great variation in the concentration of this element in the blood of normal ruminant animals. On the other hand lead toxicity had a delirious effect on the total serum protein concentration. Administration of antioxidant +Ca alone or with succimer to lead exposed goats restored its effect.
Determination of serum TBARS revealed a highly significant increase of its level in lead exposed goats antioxidant alone or with succimer had prominent effect on the level of these elements as it was completely restored to its normal level.
A highly significant increase in the serum level of both urea and cereatinine was constantly observed in lead toxicated goats. Such changes were antagonized by administration of antioxidant & Ca alone or with succimer. An increase in serum level of both urea and cereatinine denotes damage of the kidney.
A significant increase in the large sized follicles areas of the thyroid gland in lead exposed animals were reported. However both medium sized & small sized follicles were statistically not affected. Administration of both anti oxidant & Ca alone or with succimer completely restores the surface area of the large follicles to its normal measurement.
A highly significant decrease in the area of islands of Langerhans was observed in lead exposed goats. Administration of antioxidant and Ca partially restore the area of the islets. However when succimer was administered with both antioxidant + Ca and succimer completely restored it.
In-group II administered antioxidant + Ca the micro morphological changes were nearly normal. That is to say antioxidant and Ca inhibit the pathologic effect of lead on the thyroid tissue. Like wise in group III both antioxidant + Ca and succimer succeed to normalize the micro morpholgical appearance of the thyroid tissue.
Lead toxicity induces histopathological changes of degenerative nature in the adrenal gland of group I. Including vacuolar degeneration of the adrenal cortex, fibrous thickening of the capsule, and vascular changes consist of congestion and hemorrhage. In the adrenal medulla the lesion was vacuolar degeneration of chromaphine cell along with lymphocytic infiltration.
Administration of antioxidant and Ca restore the normal morphology of both adrenal cortex and adrenal medulla like wise administration of these two elements and succimer also normalize the micro morphological appearance of the adrenal gland.
The pancreas in lead exposed goats suffered a micromorpholgical change of necrobiotic type, as the cells of islets of Langerhans were severely exhausted. A sever depletion of cellular population of these islets was a prominent feature of all examined cases. Replacement fibrosis of destroyed cell was seen in some areas. Administration of antioxidant and calcium alone or with succimer completely restores the cellular population of the islets of Langerhans.
Angiopathic changes observed in the blood vessel of lead exposed group I were those of degenerative or proliferative nature. In the heart muscles myocardial degeneration inter muscular hemorrhage and lymphocytic infiltration in the interstitium was the outstanding histopathological feature. The large sized blood vessels thoracic and abdominal aorta showed endothelial cell degeneration, sloughing of degenerated cell, and disruption of smooth muscles with an increase in the fibrous tissue in between smooth muscle cell of the media. Atheromatus plaques were sometimes seen in the blood vessel of the parenchymatus organs namely liver and kidney perivascular fibrosis and perivascular lymphoid cell reaction were observed in spleen and kidney.
A minimal cardiovascular degenerative change was observed in goats administrated antioxidant plus Ca. These changes were of very mild degree and observed only in the heart consist, of myocardial degeneration and perivascular edema. The large and medium sized blood vessels had a nearly normal morphologic appearance. When succimer was administered along with antioxidant and Ca. for lead exposed animal, angiopathic changes were totally missed.
In reproductive toxicity. Clinical study revealed that lead toxication in male goat had a deleterious effect on the reproductive behavior of the animal. Complete loss of libido was observed when the male lead toxicated goat when it was put with the adult females. The male was unable to serve females although they are kept together for 7 weeks. Attempts to obtain semen sample from male goat using artificial vagina were also failed.
The two adult females used for the purpose of studying reproductive toxicity were left with the male animal for 7 weeks but pregnancy didn’t occur although pregnancy test and ultra sonograopy were carried out periodically in the department of Vet. Gynecology and obstetrics, Assiut University.
Histopathological studies of the testis of adult male animal exposed for lead toxicity for 7 weeks demonstrate a sever prominent histopatholgial changes, of degenerative nature in all anatomical parts of the testis, including seminiferous tubules interstitial tissue and epididymis. With disappearance of mature sperms from the lumen of seminiferous tubules and epidydimis, decrease amount of sartoli cells and hyalinization and proliferation of connective tissue in the interstitial tissue.
A deleterious pathomorpholglcal changes were observed in the ovary, including wide spread proliferation of connective tissue sclerosis of its small sized arterioles entimal hyperplasia and medial hypertrophy of medium sized artery. Most of the ovarian follicles showed degenerated ova.
from our investigation we can concluded that: -
Lead toxicity in goats resulted in pathomophological changes of degenerative nature and moderate degree in some the endocrine organs including thyroid parathyroid, adrenals and pancreas.
These micromophological changes were associated with functional disturbances of these endocrine organs, which reflected on its related hormonal secretions. Although compensatory mechanism of the animal sometimes was succeed to compensate for these functional disturbances.
Administration of antioxidant and Ca alone or with succimer for lead exposed goats succeeded in most insistences in restoring the functional disturbances of the above mentioned endocrine organs. Moreover, it also played a great role in combating the pathomorphological changes induced by lead toxicity in these endocrine organs.
Cardiopathic and angiopathic changes of moderate degree were observed in the myocardium, large blood vessels (thoracic and abdominal aorta) and medium sized and small arterioles in the parenchymatus organs. Such changes might play role in the tissue damage induced by lead toxicity.
Administration of antioxidant and Ca alone or with succimer play significant role in minimizing the deleterious effect of lead on the cardiovascular organs.
Reproductive toxicity was evident in both adult male and female goats exposed for lead toxicity clinically and histopathologicaly with a prominent sever infiltirity.