Toxico-kinetics, recovery efficiency and microsomal changes following administration of deltamethrin to black Bengal...

A study of the toxico-kinetics, recovery percentage from different substrates, cytotoxicity and role of cytochrome P450 and b5 of liver microsome in the metabolism of deltamethrin were carried out in female black Bengal goat. The ALD50 value of deltamethrin in goat by intravenous route lies between 0.2 and 0.6 mg kg-1. Intravenous disposition kinetics using a dose of 0.2 mg kg-1 showed that the maximum blood concentration of deltamethrin was recorded at 0.5 min, followed by rapid decline, and a minimum concentration was detected at 6 min after administration. The following values were obtained: Vdarea 0.148 (+/- 0.02) litre kg-1; t1/2 (alpha) 0.22 (+/- 0.02) min; t1/2 (beta) 2.17 (+/- 0.37) min; Kel 1.05 (+/- 0.24) min-1; AUC 4.30 (+/- 0.45) micrograms min ml-1; ClB 0.05 (+/- 0.006) litre kg-1 min-1; T-B 1.93 (+/- 0.58); fc 0.40 (+/- 0.05). After 10 min, liver retained the maximum residue, and heart, adrenal gland, kidney, spleen, fat and brain also held the insecticide; liver, fat, heart and spleen retained residue after 30 min, and bone, liver and fat retained residue after 60 min of intravenous administration. Oral absorption of deltamethrin was poor and inconsistent, and approximately 65% of administered dose was recovered from faeces and gastrointestinal contents. The excretion of deltamethrin through urine was meagre, and only 0.01 and 0.013% of the administered dose was recovered after 3 and 5 days of oral administration respectively. All the tissues retained the residue after 3 days; while fat, rumen, reticulum, omasum, abomasum, large and small intestine and bone retained the residue after 5 days of oral administration; and the percentage recoveries were 1.73 and 0.027 respectively. Deltamethrin reduced the level of cytochrome P450 content of liver microsomal pellet of goat after 5 days of oral administration. Histopathological examination of liver, kidney, heart, spleen brain and lung sections of treated goats did not reveal any pathological changes.