D. Herrenosaenz et al., EFFECTS OF 3-NITROBENZOTHIAZOLO[3,2-A]QUINOLINIUM CHLORIDE (NBQ) AND DOXORUBICIN ON LENS REGENERATION IN THE ADULT NEWT - A MORPHOLOGICAL-STUDY, Differentiation, 55(3), 1994, pp. 169-174
The antitumor drug 3-nitrobenzothiazolo [3,2-a]quinolinium chloride (N
BQ) stimulates the in vivo lens regeneration in the adult newt Notopht
halmus viridescens and induces a differentiated state in HL-60 leukemi
a cells. Because the cytotoxic drug doxorubicin (Adriamycin) induces d
ifferentiation of HL-60 cells in vitro we decided to compare the effec
t(s) of doxorubicin with NBQ on lens regeneration in vivo. Both drugs
were injected intraperitoneally at six different schedules. Morphologi
cal criteria of the different regeneration stages were used in the ana
lysis of the regenerates. NBQ stimulated lens regeneration independent
ly of the time intervals and the stage of regeneration at which the dr
ug was administered. There was an increase in the mean number of mitos
es suggesting that NBQ stimulated cell proliferation. Doxorubicin admi
nistered for five days did not modify the regenerative process. On the
other hand, doxorubicin given for periods of nine or more days after
lentectomy, strongly inhibited the formation of a new lens. Thus, the
inhibitory effect of doxorubicin is dependent on the continuous long t
erm contact with the tissue. Although NBQ and doxorubicin are both DNA
intercalators, they induced the effects on lens regeneration through
different mechanisms.