Determination of myoseverin embryotoxic potential by using FETAX.
BACKGROUND
Since MYS is a microtubular poison with a reversible activity, Xenopus blastulae were exposed to MYS to verify the eventual drug-related developmental suspension and the reversibility of this effect.


METHODS
Lethal and teratogenic effects of myoseverin (MYS) were evaluated using the FETAX. Embryos were exposed to different MYS concentrations from stage 8 to stage 47.


RESULTS
Probit analysis gave 12.14 microM LC50 and 7.67 microM TC50 from which 1.58 T.I. is derived. Several malformations were observed such as facial abnormalities, abnormal tail flexure, heart ventricle chamber enlargement and external appendix. MYS led to an arrest of living embryo development. Before MYS removing, exposed blastulae showed the lack of mitotic spindles along with different nuclei alterations. Living embryos, moved in control solution, mainly died around the hatching showing severe malformations likely ascribable to the altered planes of newly occurring mitosis.


CONCLUSIONS
In spite of the low T.I, MYS has to be considered a highly teratogenic compound.
Vismara
Claudio
C
Università degli Studi di Milano, Dipartimento di Biologia, Laboratorio di Biochimica e Biofisica del Citoscheletro, Milano, Italia. claudio.vismara@unimi.it
Bacchetta
Renato
R
Di Muzio
Andrea
A
Mantecca
Paride
P
Tarca
Silvia
S
Vailati
Giovanni
G
Colombo
Roberto
R
D000014:Abnormalities, Drug-Induced; D000818:Animals; D036703:Blastula / Q000187:drug effects; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D005260:Female; D018613:Microscopy, Confocal; D011687:Purines / Q000633:toxicity*; D014982:Xenopus laevis / Q000002:abnormalities*
D011687:Purines; C407365:myoseverin