[A comparative evaluation of the toxic and cumulative properties of the Takal drug group]. / Sravnitelna otsenka na toksichnite i kumulativnite svoistva na lekarstvenata grupa "Takali".

The acute oral and dermal toxicity was studied as well as subacute oral toxicity [30 successive days] and skin irritating effect on experimental animals of new drug form "Takal 9", "Takal 14" and "Takal 16" with proved bactericidal and virucidal activity. A complex of toxicometric, unspecific, haematological, biochemical and histological studies were performed. The compositions "Takal 9", "Takal 14" and "Takal 16" are slightly toxic at oral and dermal application. LD50 for "Takal 9" and "Takal 16" is above 15,000 mg/kg-1 while for preparation "Takal 14" is not reached. At unrepeated dermal application LD50 for the examined group of preparations surpasses 5000 mg/kg-1. The products have no skin-irritative effect. No cumulative effect is established in the conditions of a 30-day oral treatment. On the background of no changes in the serum indices an activation of the aerobic and anaerobic oxidation in the liver is registered in animals treated with ethyl alcohol, "Takal 9" and "Takal 16". These deviations are due, most probably, to the participation of ethyl alcohol as solvent, in "Takal 9" and "Takal 16". On the basis of the experiments, as most suitable for use, is established the preparation "Takal 14".

[An experimental evaluation of the acute and chronic oral toxicity of the antibiotic Bactericin for plant protection]. / Eksperimentalna otsenka na ostrata i khronichnata oralna toksichnost na antibiotika "Bakteritsin" za rastitelna zashtita.

In relation to the future implementation of the antibiotic bactericin in agriculture are carried out acute, subacute and chronic oral experiments on 128 male white rats and 88 female. In order to determine the parameters of acute oral toxicity, doses (200, 120, 80, 60, 50, 40 mg/kg) of the preparation dissolved in polyethylene glycol are applied. In the subacute--1/10 and 1/20 LD50, and in the chronic (four months)--1/50 and 1/100 LD50. The bactericin, meant for treatment of tomatoes before sowing, in rate of acute oral toxicity falls in class II of very toxic pesticides. The acute oral LD50 for male white rats is 73.0 (48.6-109.5) mg/kg-1 and for female--58.0 (39.9-84.0) mg/kg-1. In conditions of subacute (30 oral applications for 45 days) and chronic (four months) experiments no cumulative properties are proved as well as hepatotoxic, nephrotoxic and neurotoxic effect. On the basis of the complex study could be accepted, that the dose 1/100 LD50 (0.7 mg/kg-1) for male rats and 0.4 mg/kg-1 for female) is not active at chronic oral introduction.

Toxicological evaluation of agromet (Metalaxyl) preparation.

A complex toxicological study was carried out in relation to the hygienic standardization of the fungicide preparation Ridomil, whose forthcoming production in this country will be under the name Metalaxyl. The study was performed on sexually mature white rats of both sexes, at oral, dermal and inhalation exposure, acute, subacute and chronic experiments, according to the Bulgarian State Standard. Besides the routine toxicological studies were carried also studies for establishing the long-term effects of the preparation (gonadotropic, embryotoxic and teratogenic, cardiovascular). The results from the study permitted the Agromet preparation to be put in III class--moderately toxic according to limiting index LD50 oral. On the basis of data from the authors study on the general toxicity and long-term effects of Metalaxyl a temporary MAC 4 mg/m3 was proposed.

[The effect of the acetanilide herbicide Acetochlor on the cardiovascular system of white rats]. / Efekt na atsetanilidniia kherbitsid "Atsetokhlor" vurkhu surdechno-sudovata sistema na beli plukhove.

A study is performed on the long-term effect of the chloracetanilide herbicide "Acetochlor" in doses 21.0; 10.6: 5.5 and 2.6 mg/kg-1 in conditions of 6-month oral application and 2-month rehabilitation period on the metabolite processes and the balance of the connective-tissue components in the myocardium and aorta of male white rats. A complex of biochemical and histological methods are performed (activity of succinate dehidrogenase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, adenosin triphosphatase, cytochrome oxidase, fructoso-1,6-diphosphatase, level of the thiol groups, soluble globular, elastine, collagen fractions, insoluble collagen and elastine, general and sulphated glucosamino glycanes). The dose 21.0 mg/kg-1 leads to blocking of the thyol groups, inactivation of succinate dehydrogenase, cytochrome oxidase, adenosin triphosphatase, fructose-1,6-diphosphatase, glucose-6-phosphate dehydrogenase, activation of lactate dehydrogenase, decrease of the soluble globular, elastine, and collagen fractions and increase of the glucoseaminoglycanes in the heart muscle and aorta. The changes established in the heart muscle at 10,6 mg/kg-1 certify for stronger sensitivity of the organ of the aorta wall. The presence of single changes in the examined indices, their complete dying out after the rehabilitation period and absence of structural changes in the myocardium and aorta permit the dose of 5.5 mg/kg-1 to be accepted as not effective in the conditions of chronic experiment concerning the cardiovascular system.