Abstract: Objectives: Histological evaluation of toxic effects of chronic exposure to sodium fluoride (NaF) on
papereas of albino rats and the impact of synchronous administration of selenium and vitamins C and E. Materials
& Methods: The study comprised 60 normal healthy growing adult male albino rats, weighing 200-250 gm. The
animals were divided into three equal groups: Control group received no medications. NaF group received NaF
solution in a dose of 10 mg/kg body weight (BW) once daily for 35 days. Prophylaxis group received one daily dose
of NaF solution in addition to selenium and vitamins C and E. All medications were administered orally using
syringe connected to a 8F pediatric feeding tube. Studied animals were weighed daily for adjustment of the doses of
used medications. After 35 days from the beginning of experiment all animals were sacrificed and pancreas was
extracted for light microscopic (LM) examination of specimens stained with hematoxilin-eosin (I-1x & E) and
Masson's trichrome stain and for electron microscopic examination. Results: The percentage of BW gain was
significantly higher in control group compared to other groups with significantly higher percentage of BW gain in
prophylaxis group compared to NaF group. LM examination of NaF group specimen showed loss of normal
architecture of pancreatic acini with the appearance of many cytoplasmic vacuoles. There is congestion of blood
vessels (BV) with occasional extravasations between acinar cells. Focal condensation of CT around the congested
BV and in between acini. In prophylaxis group, architecture of pancreatic acini was preserved with basal nuclei and
apical zymogen granules. Dark and light cells of islets of Langerhans appeared normal with minimal congestion of
BV. Masson's Trichrome stained sections showed condensation of connective tissue around BV with less CT in
between acini. EM examination of NaF group specimen showed pyramidal acinar cells containing rounded basal
heterochromatic nuclei and well defined rough endoplasmic reticulum (rER). Some mitochondria are intact, while
others are vacuolated with small number of zymogen granules. There were multiple vesicles of variable sizes with
large vesicles having membranous structures and amorphous materials. Nuclei of B-cell of islet of Langerhans were
heterochromatic and its characteristic granules are normal with central dense core separated from their limiting
membrane by clear space, while other granules are vacuolated. In prophylaxis group, specimens showed that some
pyramidal acinar cell had double nuclei and its cytoplasm contains rER,, many zymogen granules and some vesicles.
B-cell had heteroehrornatic nucleus and its characteristic granules had a dense core. A-cell had oval nucleus with
moderate amount of electron dense granules. Conclusion: Chronic fluoride exposure had deleterious effect on
pancreatic structure and ultrastructure with manifested failure to thrive. Such effects could be attributed to redox
state disturbances and could be ameliorated with the use of selenium and vitamins C and E.
fGarruil Alxlel Salara, Esam M Mehlab, Mohamed Al-Shishtawy and Ibrahim Al-Zahrani. |
