ABSTRACT
Using animals in toxicological screening is a controversial issue. To get knowledge about eye irritation, recently only the in vivo Draize-test is accepted, which is one of the most criticized methods because of the injuries inflicted on the test animals. In recent years various in vitro methods have been developed to replace the primary irritation test. Most of these tests are in process of validation. The Draize rabbit eye test, or some modification of this test is essentially the only method for determining ocular irritation that is accepted by authorities. Several in vitro methods have been used to investigate the toxicity of potential eye irritants with the aim of replacing in vitro eye irritation testing. This study reports the results of an alternative approach for predicting irritation potential of agrochemicals. The approach was a two-stage test battery in vitro. The first stage was a cytotoxicity test, the MTT assay. The second stage was the HET-CAM test. The chick chorioallantoic membrane (CAM), being a connective tissue sheet with a visible blood supply, has been proposed as a substrate to identify the eye irritation potential of chemicals. During the HET-CAM test the chemicals are placed directly onto the chorioallantoic membrane. The changes of the vascular injury (haemorrhage, lysis or coagulation) are indications of the potential of the chemical to damage mucous membranes in vivo. MTT assay is a simple method to determine the viability of cells in the presence of a chemical. Cells are cultured with several concentrations of a substance or product, then the ratio of cell destruction is determined. LCC50 (concentration lethal for the 50 % of the cells) is assessed. This is in correlation of the eye irrigative potential of the chemical. In our studies comparative screening was performed with 6 agrochemicals to establish parallel data on alternative test battery (HET-CAM, MTT) and in vivo (Draize) results. In most cases, this study showed a good correlation between in vitro and in vivo data. By these results the present form of an alternative test battery (HET-CAM and MTT) can be proposed as a prescreen method of eye irritation tests.
Subject(s)
Chorioallantoic Membrane/drug effects , Eye/drug effects , Irritants/toxicity , Pesticides/toxicity , Animal Testing Alternatives , Animals , Biological Assay , Cells, Cultured , Chick Embryo , Chickens , Chorioallantoic Membrane/blood supply , Chorioallantoic Membrane/injuries , Dose-Response Relationship, Drug , Humans , Lethal Dose 50 , Rabbits , Tissue Culture Techniques/methodsABSTRACT
Many studies have been published on the human health effects of cyanobacterial toxicity. As a public health concern, we have to mention that the development of contact dermatitis, asthmalike symptoms, and symptoms resembling hay fever during bathing in cyanobacterial blooms have been also described. Microcystis aeruginosa, Anabaena flos-aquae, Aphanizomenon flos-aquae, and Cylindrospermopsis raciborskii are the most common species found in Hungarian freshwaters. A sensitization test on albino guinea pigs, and intradermal reactivity, and occular irritation test on albino rabbits were carried out with freeze-dried algal suspension in physiological salt solution. The sensitivity of guinea pigs is similar to that of humans. Microcystis, Anabaena, Cylindrospermopsis, and Aphanizomenon bloom and strain samples were examined in sensitization and irritation tests and no correlation was found between the toxin content and the allergenic character. The most toxic one (Microcystis aeruginosa) was not the most allergenic sample, but the nontoxic Aphanizomenon was the most allergenic one. The axenic strains were not allergenic at all. The pure microcystin LR was only slightly allergenic even in high concentration (1.5 mg/ml). Water and lipid soluble fractions were obtained by water and chloroform extraction of lyophilized algal suspensions. The chloroform fraction was bound on C18 cartridges and eluted by methanol in nine fractions. Only one of the lipid soluble fractions was skin irritative whereas the strongest irritative effect was shown by the water soluble fraction.
Subject(s)
Eye/drug effects , Hypersensitivity/etiology , Peptides, Cyclic/toxicity , Skin/drug effects , Uracil/analogs & derivatives , Uracil/toxicity , Alkaloids , Animals , Bacterial Toxins , Cyanobacteria/chemistry , Cyanobacteria/physiology , Cyanobacteria Toxins , Fresh Water/chemistry , Guinea Pigs , Hungary , Marine Toxins , Mice , Microcystins , Multiple Chemical Sensitivity , Peptides, Cyclic/isolation & purification , Rabbits , Uracil/isolation & purificationABSTRACT
Three additional pretransferrin types have been identified by one-dimensional PAGE technique in New Zealand White and Californian rabbits. The six alleles are designated PrtA, PrtB, PrtC, PrtD, PrtE and PrtF. It is likely that three of these six alleles are identical to those reported previously.
