Tests acute

Organism Acute test Long-term test... 

Minimal rather than complete protocols tend to be more common in the acute testing of pharmaceutical agents. Drugs will almost always be subjected to at least one subchronic study. Body weight and feed consumption determinations are a standard feature of such studies. Additionally, changes in body weight and feed consumption are more likely in a subchronic than an acute study because the animals are dosed continuously between body weight determinations. 

The second special case arises from inhalation exposures. Because of the arrangement of the circulatory system, inhaled compounds (and those administered via the buccal route) enter the full range of systemic circulation without any first-pass metabolism by the liver. Kerberle (1971) and O Reilly (1972) have published reviews of absorption, distribution and metabolism that are relevant to acute testing. 

A prime practical consideration in the use of the IP route for acute testing should be the utilization of aseptic techniques to preclude bacterial or viral contamination. If these are not exercised, the resulting infected and compromised animals cannot be expected to produce either valid or reproducible indications or actual chemical toxicity. 

Bernard, C. Persoone, G. CoUn, J. Le Du-Delepierre, A. Estimation of the hazard of landfills through toxicity testing of leachates determination of leachate toxicity with a battery of acute tests. Chemosphere 1996, 33, 2203-2230. 

Asmangulyan, T.A. Badalyan, S.O. (1971) Toxicity of chloroprene in an acute test during oral administration. Tr. Erevan, med. Inst., 15, 461-465 (in Russian)... 

Effects on Aquatic Organisms (Refs 14, 41 47). There are a number of reports on the toxicity of TNT to fishes. They are mostly concerned with establishment of an LC50 under a variety of exptl conditions. The most acceptable acute tests are 96-hr flow-thru aquatic toxicity tests in which the exposure concns of... 

Birds were weighed and blood samples taken the day before they left Davis The birds on the acute test were returned to Davis on the same day those that received repeated exposures were returned one week later, two days after their last exposure in the field. In both cases, blood samples were taken the day after their arrival in Davis. The birds were weighed and blood samples taken 2, 8, 15, 22 and 29 days after their first... 

Traditionally the basis for the determination of toxicity has been administration of the test compound, in vivo, to one or more species of experimental animal, followed by examination for clinical signs of toxicity and/or mortality in acute tests. In addition pathological examination for tissue abnormalities is also performed, especially in tests of longer duration. The results of these tests are then used by a variety of extrapolation... 

These newer methods call for testing to be done in a single sex to reduce variability in the test population. This reduction in variability in turn minimizes the number of animals needed. Normally females are used. Although there is usually little difference in sensitivity between males and females, in those cases where there are observable differences, females are most commonly the more sensitive sex. Normally animal suppliers have an excess of female rats because many researchers order only male rats to avoid physiological changes associated with estrus cycling in females therefore preferential use of female animals for acute testing should not result in excess male animals. 

Yang, J.-L. and Chen, H.-C. (2003) Effects of gallium on common carp (Cyprinus carpio) acute test, serum biochemistry, and erythrocyte morphology, Chemosphere 53 (8), 877-882. 

Only the two acute tests with D. magna and T. platyurus showed a high correlation coefficient. This confirms the need for using a wide range of different species covering different phyla to increase the power of a test battery to detect toxic... 

Environment Canada (1992) Biological Test Method Acute Test for Sediment Toxicity Using Marine or Estuarine Amphipods, EPS l/RM/26, Environment Canada, Conservation and Protection Branch, Ottawa, ON, Canada. 

Extrapolation used to infer toxicity from one type of exposure regimen to another is often termed temporal extrapolation. The most common of these extrapolations is that from acute to chronic exposures, but the issue of pulsed versus continuous exposure is also important in assessing possible effects in real-world environmental settings. These extrapolations may involve the use of modified tests with standard species or whole-model ecosystems to simulate realistic exposures such as those of variable duration or those of pulsed exposure for compounds that rapidly dissipate in the environment. In many cases, these involve alterations in exposure route and intensity, both of which can have significant impacts on the toxic responses. Extrapolation from acute responses to NOECs or chronic responses is particularly important as chronic tests are more costly and time-consuming than acute tests. Methods for accurate and precise acute-to-chronic extrapolations have been developed and are available as computer programs such as ACE (Mayer et al. 1999, 2001 De Zwart 2002 Ellersieck et al. 2003) and are discussed in Chapter 6. 

The extrapolation from acute responses to no-observed-effect concentrations or chronic responses is particularly important as chronic tests are more costly and time-consuming than acute tests. Traditionally, relationships between acute and chronic effects were estimated using a simple ratio, the acute-to-chronic ratio (ACR). Where acute and chronic effect measures are available for the same species, this ratio is used to estimate chronic responses in related organisms for which only acute data are available (Stephan and Rogers 1985). This approach is based on the assumption that there is a relationship between the responses in acute and chronic tests, an... 

A latent response in an acute test may occur because the action of the toxic substance causes its effects through a chain of irreversible reactions that take some time to occur. For example, in experiments in which grass shrimps (Palaemonetes pugio) were exposed for 6 hours to the insecticides azinphos-methyl and endosulfan,... 

In the evaluation of toxic characteristics of an inhalable environmental chemical (e.g., carbon monoxide, volatile chemical, or aerosol/particulate), determination of acute inhalation toxicity is an initial study step. It provides information on health hazards likely to arise from short-term exposure by inhalation. Data from an acute test help to establish a dose regimen in subchronic (and other) studies, and may provide additional information on a chemical s mode of toxic action. 

Subchronic dermal toxicity is the study of adverse effects occurring as a result of the repeated daily dermal application of a test chemical to animals for a part (not exceeding 10%) of the life span. In the evaluation of a chemical s toxic characteristics, the determination of subchronic dermal toxicity may be performed after initial information on toxicity has been obtained by acute testing. This study provides information on health hazards likely to arise from repeated exposure via the dermal route over a limited period of time. 

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