CHELCHELEH M, ALLAMEH A, HAJIZADEH E, RASSAEE M. COMPARISON OF THE PATTERN OF DIST RI BUTION OF AFLATOXIN B 1 METABOLITES IN ADULT AND NEWBORN RATS. Med J Islam Repub Iran 1996; 9 (4) :347-350
URL:
http://mjiri.iums.ac.ir/article-1-1655-en.html
From the Department of Biochemistry, Faculty of Medical Sciences, Tarbiat Modarress University, P.O.Box 141554838, Tehran, Islamic Republic of Iran.
Abstract: (4046 Views)
Recently we have reported that newborn rats are deficient in the key enzymes
involved in the biotransformation of aflatoxin Bl (AFBl), a known
hepatocarcinogen. Based on these data, in vivo experiments were carried out in
order to investigate the bioavailability of this carcinogen in newborn rat tissues.
Administration of a single dose (i. p.) of [3HlAFB 1 to groups of adult and neonatal
rats resulted in the differential distribution of AFB 1 metabolites in these animals.
Uptake of aflatoxins by neonatal rats was about 50% of that in adults at all time
intervals. In newborn liver, the level of aflatoxin reached its maximum 6 h after
injection, and gradually decreased during the following 12 aod 24 h. In adult liver
the uptake was highest 2 h after AFB 1 administration.
A decrease of radioactivity in liver relative to time was associated with a surge
in aflatoxin levels in the sera of both age groups. Excretion of AFB 1 metabolites
was comparatively faster from newborn than from adult kidneys. Much lower
radioactivity was measured in tissues such as stomach, intestine and lungs
compared to liver. These observations indicate that the neonatal rat liver is less
efficient in the bioactivation of AFBl, as a result of which free AFB 1 (nonmetabolized)
may remain for a longer period of time in the organs of immature rats.