Structural changes induced by gibberellic acid in the renal cortex of adult male albino rats

1.1.Background:Plant growth regulators (PGRs) are not nutrients, but chemicals that promote and influence growth, development and differentiation of cells and tissues of the plant. Gibberellic acid (GA3) is one of the PGRs, which is widely used to increase plant size, production and plants availability all the year. However, PGRs must be used cautiously to decrease its probable toxicity on some body organs including the kidney. 1.2.Materials and methods: 40 adult male albino rats were divided equally into two groups. A.       Group I:Control group: subdivided into two equal subgroups. SubgroupIa(control –ve): Rats given only regular diet. Subgroup Ib(control +ve): Rats given (NaOH) vehicle for gibberellic acid. B.       Group II:Treated group: was given 75 ppm of gibberellic acid orally by gastric tube, the treated group was further subdivided into two equal subgroups. Subgroup IIa:Rats given gibberellic acid for only 2 weeks. Subgroup IIb:Rats given gibberellic acid for 2 months. The kidneys were extracted to obtain pieces from the renal cortex for histological examination. Blood samples were taken to assess kidney functions by measuring serum urea and creatinine. Morphometric analysis was also done. 1.3.Results:H&E-stained sections of subgroup IIa revealed distended glomeruli, obliterating Bowman's spaces. Distortion of the renal tubules, areas of hemorrhage and congested blood capillaries were noticed. Subgroup IIb revealed shrinkage of many glomeruli with marked widening of Bowman's space. Some tubular changes were detected in the form of dilatation, tubular lumens containing exfoliated cells and hyaline casts. PAS-stained sections of treated subgroups showed a weak PAS reaction in the brush borders of the proximal convoluted tubules compared to control subgroups. Masson's trichrome-stained sections of treated subgroups revealed many collagen fibers in the renal interstitium around renal corpuscles and tubules in comparison with control subgroups. Biochemical analysis showed that the highest levels of serum urea and creatinine are present in the subchronic group. Morphometrical analysis showed that the thickness of Bowman's space, diameter of convoluted tubules and number of inflammatory cells are significantly increased in the treated groups when compared with control groups. 1.4.Conclusion:The study implied that administration of gibberellic acid induced toxic effects on the renal cortex. So, occupational and environmental exposure to gibberellic acid should be limited.