We generalize the reptation model to treat cases where the N segments
of the primitive chain can interact with a static environment (such as
a gel). The rates of tube segment renewal are calculated taking into
account both an external field and local interaction energies. This mo
del can be used, e.g., to study the migration of polymers in a random
environments (where local entropic and elastic effects can play a role
). We then present a study of polymer reptation in a tube with a rando
m (annealed) energy landscape, similar to the one described by Lumpkin
and Zimm. In particular, if an external field is applied, the predict
ions of the biased reptation model are modified. We find that for low
field intensities, the electrophoretic mobility mu scales like 1/N1+al
pha where the exponent alpha greater than or equal to 0 increases with
the strength of the random energies.