Studies on the distribution of beta- and gamma-isomers of hexachlorocyclohexane in rat tissues.

A study of the comparitlve distribution pattern of
β- and γ-isomers of hexachlorocyclohexane (HCH) in
albino rat tissues as a function of duration of treatment
at two dose levels revealed different accumulation
patterns for the two isomers in tissues. In general,
the accumulation pattern was found to be in the order:
fat > kidney > lungs > liver > muscle > heart > spleen > brain
> blood for β-HCH and fat > brain > kidney > muscle > lungs
> heart > spleen > liver > blood for γ-HCH. The tissue
accumulation of β-isomer was always greater than that
of γ-isomer in any tissue except in brain. Brain β-HCH
residue levels were relatively lower than in many other
tissues except blood, whereas brain γ-HCH concentration
was only next to fat. A higher dose or a longer period
of treatment generally produced a more marked elevation
of tissue residue levels in β-HCH fed rats, but not in
γ-HCH treated animals.