Lead poisening causes iron anemia, melatonin helps to improve this
situation:
Role of melatonin in ameliorating lead induced haematotoxicity.
Othman AI, Al Sharawy S, El-Missiry MA.
Zoology Department, Faculty of Science and Clinical Pathology,
Mansoura University, Mansoura 35516, Egypt.
Owing to the risks of heavy metals-induced severe
haematopoietic disorders, it is important to investigate these
chemicals for their haematotoxicity and the possible ways to
ameliorate their toxicity. The effects of melatonin on
lead-induced haematotoxicity have, therefore, been examined in
rat blood and bone marrow. When adult male rats were injected
intramuscularly with lead acetate (10mgkg(-1)) daily for 7
days, the erthrocytic count, haematocrite value and haemoglobin
content were significantly decreased. The counts of platelets,
total leucocytes and lymphocytes in the peripheral blood were
also significantly lower in lead-treated rats than in control
animals. The total granulocyte count was significantly elevated
in the peripheral blood of the same lead-treated rats.
Significant decreases in polychromatic and pyknotic erythroid
series as well as lymphocytes in bone marrow of the
lead-intoxicated rats were also demonstrated. Meanwhile, the
neutrophiles were increased in the same treated rats. The
erythropoietin level was significantly decreased and the lead
concentration was increased in the plasma of the lead-treated
rats compared with the control rats. Bone marrow examination of
the rats treated with lead for 7 days showed erythroid
hyperplasia with a sign of dyserythropoiesis and demonstrated
ringed sideroblasts in varying proportions. Daily pretreatment
with melatonin (30mgkg(-1)) intragastricaly, concurrently with
lead injection for 7 days significantly prevented the changes
recorded in the peripheral blood parameters. The changes
observed in the bone marrow polychromatic erythroid,
lymphocytes and the neutrophiles were significantly ameliorated
by coadministration of melatonin and lead compared with
lead-treated rats, while the pyknotic erythroid series was
still significantly low. The levels of erythropoietin and lead
in plasma were not changed in melato [Formula: see text]
-treated group compared with lead only treated rats. In
addition, melatonin administration ameliorated the decrease in
erythroid cell count in bone marrow. Less dyserythropoiesis and
megaloblastic changes were observed in bone marrow film when
melatonin was concurrently administered with lead. In the same
animals, iron staining of the bone marrow cells showed absence
of ringed sideroblasts. In conclusion, the present results
indicate that melatonin has the ability to protect the
haematopoietic cells from the damaging effects of exposure to
lead. This protection might be attributed to the antioxidative
power of melatonin.
PMID: 15225674 [PubMed - in process]