Dehorionization of DANIO RERIO embryos to assess the acute toxicity of organomineral chelate complexes

Abstract

One of the main issues when working with fish embryos is the throughput of the chorion. It is believed that heavy metals can also be blocked by chorion. In the context of studying the acute toxicity of an organomineral chelate complex containing metals such as iron, manganese, copper, zinc, and cobalt, modification of standard tests is required. A possible approach to studying the effect of chorion on the results of acute toxicity may be the removal of chorion (dehorionization). The aim of the study was to compare the sensitivity of dehorionized embryos in assessing the acute toxicity of organomineral chelate complexes. The research was conducted at the Department of Biochemistry and Physiology of the St. Petersburg State University of Veterinary Medicine. The object of the study was the embryos of Danio rerio. To obtain caviar, the parent pairs were planted in spawning jigs. Dehorionization was performed mechanically at 24 hpf (pharyngula stage). After dehorionization, the embryos were transferred to agarose-coated wells of 24-well tablets filled with 2 ml of solution per well. During the study, 15 concentrations of the studied dietary supplement were produced, varying by 2.0 times (64...0.0039 g/l). Working concentrations were prepared by diluting dietary supplements with E3 medium. The results of comparing the sensitivity of de- and nondehorionized embryos in assessing the acute toxicity of organomineral chelate complexes were obtained. It was shown that the LC50 of the studied drug for non-dehorionized embryos is 3.754 g/l, for dehorionized embryos the LC50 is 2.326 g/l. The data indicate that the removal of the chorion leads to an increase in the toxicity of the drug for Danio rerio embryos.