Inhalation toxicity against

The nasal passages have an olfactory function, but with regard to inhaled toxicants they have primarily a defensive function and form the initial defensive barrier against inhaled... 

The upper respiratory tract, particularly the nose, has a unique anatomy that performs normal physiologic functions as well as innate defense against inhaled toxicants. The nose extends from the nostrils to the pharynx. Inspired air enters the nose through the nostrils. The nasal cavity is divided longitudinally by a septum into two nasal compartments. In most mammalian species, each nasal cavity is divided into a dorsal, ventral, and middle (lateral) meatus by two turbinate bones, the nasoturbinate and maxilloturbinate. These turbinates project from the dorsolateral and ventrolateral wall of the cavity, respectively. In the posterior portion of the nose, the ethmoid recess contains the ethmoturbinate. The nasal cavity is lined by a vascular mucosa that consists of four distinct types of epithelia. In rodents, these epithelia are (1) the stratified squamous epithelium that lines the nasal vestibule and the floor of the ventral meatus in the anterior portion of the nose (2) the non-ciliated, pseudostratified, transitional epithelium that lies between the squamous epithelium and the respiratory epithelium and lines the lateral meatus (3) the ciliated respiratory epithelium that lines the remainder of the nasal cavity anterior and ventral to the olfactory epithelium and (4) the olfactory epithelium (neuroepithelium) that lines the dorsal meatus and ethmoturbinates in the caudal portion of the nose. The relative abundance and exact locations of these upper respiratory epithelium differ among mammalian species. 

Griffiths, G.D., Rice, P., Allenby, A.C., Bailey, S.C., Scawin, J.W., Rice, P., Upshall, D.G. (1995a). Inhalation toxicology and histo-pathology of ricin and abrin toxins. Inhal. Toxicol. 7 269-88. Griffiths, G.D., Rice, P., Allenby, A.C., Bailey, S.C., Scawin, J.W., Rice, P., Upshall, D.G. (1995b). Protection against inhalation toxicity of ricin and abrin by immunisation. Hum. Exp. Toxicol. 14 155-64. 

Allon, N., Raveh, L., Gilat, E., Cohen, E., Grunwald, J., Ashani, Y. (1998). Prophylaxis against soman inhalation toxicity in guinea pigs by pretreatment alone with human serum hutyr-ylcholinesterase. Toxicol. Sci. 43 121-8. 

Griffiths GD, Lindsay CD, Allenby AC et al. (1995b). Protection against inhalation toxicity of ricin and abrin by immunisation. Human Exp Toxicol, 14, 155-164. 

IV. Prophylaxis against Soman Inhalation Toxicity in Guinea Pigs with Human Butyrylcholinesterase (HuBChE)... 

IV. PROPHYLAXIS AGAINST SOMAN INHALATION TOXICITY IN GUINEA PIGS WITH HUMAN BUTYRYLCHOLINESTERASE (HuBChE)... 

The protective effect from pretreatment of human serum butyrylcholinesterase against inhalation toxicity of lethal doses of soman in guinea pigs has been reported (AUon et al. 

Che, M.M., Chanda, S., Song, J., et al, 2011. Aerosolized scopolamine protects against microinstillation inhalation toxicity to sarin in guinea pigs. Toxicol. Mech. Method. 21, 463 72. 

Kassa and Bajgar, 1996 Tuovinen and Hanninen, 1999 Kim et al., 2002). Aerosolized scopolamine was described to protect guinea pigs against inhalation toxicity to sarin (Che et al., 2011). There are other combinations as well, such as the administration of triesterase (Tuovinen and Hanninen, 1999 Tuovinen et al., 1999), procyclidine (Kim et al., 2002 Myhrer et al., 2002, 2003), clonidine (Loke et al., 2001), or sustained release of physostigmine... 

This procedure includes oral toxicity, dermal toxicity, inhalation toxicity, eye irritation, and dermal sensitization. The acute oral and acute dermal toxicity tests were performed in rates to determine the LD50. The evaluation showed that both technical grade of clacyfos and 30 % clacyfos EC had low acute toxicity against rats. Neither significant eye irritation nor negative dermal sensitization of rabbit was observed. 

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