الفهرس 
Aim of the work
Toxicity and teratogenicity of gibberellic acid (GA3):Only 14 pages are availabe for public view
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Abstract
Gibberellic acid (GA3) is a plant growth regulator that widely used in Egypt, to increase the growth of fruits and vegetables. People may be exposed to residues of GA3 in diet derived from consumption of different types of fruits and vegetables treated with GA3. Although GA3 is widely used in agriculture, little is known about the effect of GA3 on the mammalian tissues. The kidney is one of the common target organs for toxicity as it extracts and concentrates toxic substances.
A total number of 40 adult female and 10 adult male albino rats (3 months aged), weighing 200-300 g, were used in this study. The females were being pregnant after overnight mating with adult male albino rats. The pregnant rats were divided into two groups, group A (control) which was composed of pregnant female rats and received no treatment and group B (20 experimental) which was composed of 20 pregnant female rats and were given GA3 in a dose of 0.2 g/L in drinking water (equivalent to 55mg/kg) from the 14th day of pregnancy until day 21 after delivery. The same dose of GA3 was given to the offsprings after weaning (21 day) till adulthood (3 months). Offspring included in the present study were divided in the same manner as their mothers into control and treated groups. For each group, the offsprings were sacrificed at the following ages: newborn, 10 days and adult (3 months). The animals were anaesthesized by ether inhalation then subjected to intracardiac perfusion of normal saline 0.9% Nacl. At each of the previous ages the kidney specimens were processed for light microscopic examination using Haematoxylin and Eosin stain and Periodic acid Schiff (PAS) stain, electron microscopic examination and immunohistochemical study for detection of Bcl-2 protein. In addition, morphometrical and statistical analysis of the renal cortical thickness was done.
Light microscopic examination of H&E stained sections and semithin sections revealed delayed development of the renal cortex of the newborn and 10 days old rats with maternal GA3 administration in addition to degenerative changes in renal corpuscles and tubules in the three postnatal ages. The renal corpuscles had shrunken glomerular capillary tuft and widened Bowman`s space. The epithelial lining of the renal tubules showed apoptotic nuclei and vacuolated cytoplasm with sloughed epithelial cells and epithelial debris in the tubular lumen. The interstitial tissue revealed inflammatory cellular infiltration, congested blood vessels and extravasation of blood.
Periodic acid Schiff (PAS) stained sections of the renal cortex of the treated rats revealed decrease in PAS reaction in comparison with the control rats.
Electron microscopic examination revealed thickening of the glomerular basement membrane with vacuolated cytoplasm of the podocytes and the endothelial cells. The convoluted tubules revealed vacuolations, degeneration of the cytoplasmic organelles and destructon of the brush border of the proximal tubules.
The immunohistochemical study showed decrease Bcl-2 protein in the renal cortex of the treated animals.
Morphometrical and statistical analysis of the renal cortical thickness showed decrease in the cortical thickness in the treated rats when compared with the control ones of the same age group.