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Central Institute of Fisheries Education, Mumbai
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Papers by Desmond Cave
Toxicological Sciences, 1990
Previous work has shown that m-dinitrobenzene is a testicular toxicant in rats in vivo, and in vi... more Previous work has shown that m-dinitrobenzene is a testicular toxicant in rats in vivo, and in vitro produces comparable morphological changes in rat testicular Sertoli-germ cell cocultures. m-Dinitrobenzene is metabolized both in vivo and in the in vitro system to m-nitroaniline m-nitroaniline and m-nitroacetanilide. These metabolites do not provoke testicular toxicity in vivo or in vitro. We have therefore proposed a pathway for the metabolism of m-dinitrobenzene to m-nitroaniline and m-nitroacetanilide, which involved the intermediate m-nitrosonitrobenzene (1-nitroso-3-nitrobenzene, NNB). When tested, m-nitrosonitrobenzene, at equimolar doses to m-dinitrobenzene, produced similar morphological changes in the culture system to those exhibited by m-dinitrobenzene. However, m-nitrosonitrobenzene produced a greater toxicity than did m-dinitrobenzene (as measured by germ cell detachment). When the intracellular thiol levels were reduced in the cocultures pretreated with diethyl maleate, the toxicity of both m-dinitrobenzene and m-nitrosonitrobenzene was enhanced. In contrast, pretreatment of cocultures with agents known to increase cellular thiol (cysteamine) or scavenge reactive intermediates (cysteamine or ascorbate) reduced the toxicity of m-dinitrobenzene and m-nitrosonitrobenzene. We propose that m-dinitrobenzene requires metabolic activation before it can exert its toxicity to Sertoli cells, and it appears that the toxic species is m-nitrosonitrobenzene or a further metabolite of m-nitrosonitrobenzene.
Archives of Environmental Contamination and Toxicology, 1994
During a subchronic toxicity and reproduction study with tri-n-butyltin oxide (TBTO) concentratio... more During a subchronic toxicity and reproduction study with tri-n-butyltin oxide (TBTO) concentrations of 0, 24, 60, and 150 mg/kg diet in Japanese quail, preliminary data on hematology and serum biochemistry were obtained. The absence of serious effects in blood parameters in both adult quail and developing chicks are discussed in view of the adverse effects of TBTO on reproduction.
Human & Experimental Toxicology, 1995
1 A method of continuous infusion in the unrestrained rat is described, which provides a scientif... more 1 A method of continuous infusion in the unrestrained rat is described, which provides a scientifically accept able and easily maintained rodent model for use in toxicological investigations. 2 Sprague Dawley SPF rats had cannulas implanted into the vena cava via the femoral vein, and were continu ously infused with physiological saline for a total of 28 or 90 days. 3 The results indicate that there was no change in body weight, food consumption, clinical observations or clinical biochemistry of infused rats when compared to non-infused rats. There were small changes in haema tological parameters, however none were toxicological ly significant. Urinary volume was increased and uri nary specific gravity and osmolality were decreased. At macroscopic and microscopic examination there were findings of scar formation associated with the area of surgery and minimal irritation in the area of the vena cava which accommodated the cannula. 4 These results indicate that implantation of a cannu...
Toxicological Sciences, 1990
Previous work has shown that m-dinitrobenzene is a testicular toxicant in rats in vivo, and in vi... more Previous work has shown that m-dinitrobenzene is a testicular toxicant in rats in vivo, and in vitro produces comparable morphological changes in rat testicular Sertoli-germ cell cocultures. m-Dinitrobenzene is metabolized both in vivo and in the in vitro system to m-nitroaniline m-nitroaniline and m-nitroacetanilide. These metabolites do not provoke testicular toxicity in vivo or in vitro. We have therefore proposed a pathway for the metabolism of m-dinitrobenzene to m-nitroaniline and m-nitroacetanilide, which involved the intermediate m-nitrosonitrobenzene (1-nitroso-3-nitrobenzene, NNB). When tested, m-nitrosonitrobenzene, at equimolar doses to m-dinitrobenzene, produced similar morphological changes in the culture system to those exhibited by m-dinitrobenzene. However, m-nitrosonitrobenzene produced a greater toxicity than did m-dinitrobenzene (as measured by germ cell detachment). When the intracellular thiol levels were reduced in the cocultures pretreated with diethyl maleate, the toxicity of both m-dinitrobenzene and m-nitrosonitrobenzene was enhanced. In contrast, pretreatment of cocultures with agents known to increase cellular thiol (cysteamine) or scavenge reactive intermediates (cysteamine or ascorbate) reduced the toxicity of m-dinitrobenzene and m-nitrosonitrobenzene. We propose that m-dinitrobenzene requires metabolic activation before it can exert its toxicity to Sertoli cells, and it appears that the toxic species is m-nitrosonitrobenzene or a further metabolite of m-nitrosonitrobenzene.
Archives of Environmental Contamination and Toxicology, 1994
During a subchronic toxicity and reproduction study with tri-n-butyltin oxide (TBTO) concentratio... more During a subchronic toxicity and reproduction study with tri-n-butyltin oxide (TBTO) concentrations of 0, 24, 60, and 150 mg/kg diet in Japanese quail, preliminary data on hematology and serum biochemistry were obtained. The absence of serious effects in blood parameters in both adult quail and developing chicks are discussed in view of the adverse effects of TBTO on reproduction.
Human & Experimental Toxicology, 1995
1 A method of continuous infusion in the unrestrained rat is described, which provides a scientif... more 1 A method of continuous infusion in the unrestrained rat is described, which provides a scientifically accept able and easily maintained rodent model for use in toxicological investigations. 2 Sprague Dawley SPF rats had cannulas implanted into the vena cava via the femoral vein, and were continu ously infused with physiological saline for a total of 28 or 90 days. 3 The results indicate that there was no change in body weight, food consumption, clinical observations or clinical biochemistry of infused rats when compared to non-infused rats. There were small changes in haema tological parameters, however none were toxicological ly significant. Urinary volume was increased and uri nary specific gravity and osmolality were decreased. At macroscopic and microscopic examination there were findings of scar formation associated with the area of surgery and minimal irritation in the area of the vena cava which accommodated the cannula. 4 These results indicate that implantation of a cannu...