US EPA

1576459 

Journal Article 

Hexavalent chromium toxicity in pituitary and thyroid glands 

Mahmood, T; Qureshi, IZia; Nadeem, MS; Khan, MA 

2008 

1 

Pakistan Journal of Zoology
ISSN: 0030-9923 

40 

2 

91-97 

WOS:000254230000005 

Hexavalent chromium as K(2)Cr(2)O(7) (60mg/kg(b.w)) was
administered intraperitoneally to male Sprague Dawley rats. In the thyroid gland, chromium
concentration decreased significantly (P<0.01) as compared to the control tissue. Serum FT(3) and
FT(4) levels decreased significantly (P<0.01 and P<0.001 respectively), while serum TSH
concentration increased significantly (P<0.01) than the control. Histologically, in the pituitary
gland, hypertrophy was evident in the anterior pituitary gland hypertrophied, the cellular
density (number of cells/0.021 mm(2)) decreased significantly (P<0.001) and the cellular diameter
increased significantly (P<0.001). In the thyroid gland, follicle number increased significantly
(P<0.001) when compared to control. However, follicular size showed a significant decrease
(P<0.001). The follicles were scattered and aggregated abnormally to form small groups making
large interfollicular spaces due to the disruption of the connective tissue. The height of
epithelial cells also increased. The present study demonstrates that chromium in hexavalent form
causes both structural and functional disturbance to the pituitary and thyroid glands and is
therefore potentially toxic to these tissues. 

pituitary gland; thyroid gland; hexavalent chromium; toxicity; thyroid hormones