Animals protection systems

The O2 molecule is essential to all aerobic forms of life, but many anaerobic organisms (e.g. anaerobic bacteria such as Clostridia spp.) are killed after only brief exposures to molecular O2. However, it is well established that even aerobic organisms, including man and other animals, show signs of oxygen toxicity when exposed to O2 tensions above those normally found in air (i.e. >21% O2). Such toxicity does not normally occur because aerobic cells possess protective enzymes that prevent either the formation or the accumulation of oxygen metabolites. It is only when these protective systems be-... 

Further comparative studies of LI expression were conducted in transgenic plants versus a TMV expression vector. In this case, the cottontail rabbit papillomavirus (CRPV), a close relative of HPV, was used. Rabbits vaccinated with purihed protein were protected against wart development upon challenge with live CRPV despite the fact that VLPs were not detected in this animal model system (Kohl et al., 2006). 

Proksch, P., 1995. The protective system of lichens against being consumed by animals. Dtsch. Apoth. Ztg. 135, 21-24. 

Evidence for a protective role for CCL5 in breast cancer stems from studies in animal model systems, and the relevance of these findings to potential antitumor activities of CCL5 in breast cancer patients is not substantiated as yet. It could be that at initial stages of disease, CCL5 has the potential to elicit T-cell immune activities, and also to recruit monocytes with antitumor functions. However, when the expression of the chemokine is elevated, it is skewed... 

Another way that animals protect themselves in nature is to have a defense system. Skunks use a smelly spray as a defense against enemies. Cheetahs run fast and far. Porcupines wiggle and poke potential predators with their long, prickly quills. This artistic Porcupine has prickly quills, too ... 

Age can be a factor in toxicity. Generally, the very young and very old are more susceptible to the toxic effects of chemicals. The biological systems of children are not fuUy developed and these immature systems can leave them more vulnerable to toxicity. Old age brings about breakdowns or weaknesses in mature protective systems. This also relates to the health status of the individual. As we age we develop more chronic health conditions and diseases, such as diabetes, heart conditions, cancer, or arthritis. These conditions weaken and compromise our overall health status, making us more susceptible to exposures to chemical or biological agents in our environment. Diet has also been shown to have an effect on the toxicity of substances in animal studies. 

CioHgC NOiS. A protective non-systemic fungicide used principally for the control of potato blight. M.p. 160-161 C. It is relatively non-toxic to most animal life although it is harmful to hsh. 

Ozone, known for its beneficial role as a protective screen against ultraviolet radiation in the stratosphere, is a major pollutant at low altitudes (from 0 to 2000 m) affecting plants, animals and human beings. Ozone can be formed by a succession of photochemical reactions that preferentially involve hydrocarbons and nitrogen oxides emitted by the different combustion systems such as engines and furnaces. 

Chinese Herbal Medicines. Many traditional Chinese medicines have been screened for radioprotective activity in experimental animals. In one study of more than a thousand Chinese herbs, a number of agents increased the survival rate of dogs exposed to a lethal dose of y-rays by 30—40%, and some symptoms of radiation injury were ameHorated. These effects are potentially related to stimulation of the hemopoietic and immune systems (130). Extracts of five Chinese dmg plants, as weU as aspirin, effectively protected mice exposed to 7.5—8.0 Gy (750—800 rad) of y-radiation, and increased survival rates by 8—50% (131). Several Chinese traditional medicines, adininistered ip before or after irradiation, protected against Hpid peroxidation in a variety of mouse tissues, including BM, Hver, and spleen, as weU as in mouse Hver microsomal suspensions irradiated in vitro (132). 

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