Effects of organophosphate phenyl saligenin phosphate and polyether carboxylic ionophore lasalocid on motor nerve conduction velocity, neuropathy target esterase enzyme activity, and clinical ataxia in chickens

Abstract

Organophosphates (OP) are widely used chemicals in agriculture and industry. Some OPs produce a delayed type of neuropathy affecting human and animals following exposure. Subacute neurotoxic doses of some OPs can be potentiated by concomitant exposure to certain chemicals. Lasalocid is a polyether carboxylic ionophore used as a growth promotant and anti-coccidial in the cattle and poultry industries, respectively. Lasalocid is also known to induce peripheral neuropathy. Neurotoxicity of phenyl saligenin phosphate (PSP) and lasalocid and possible interaction were studied in chickens by evaluating motor nerve conduction velocity (MNCV), clinical ataxia, and neuropathy target esterase (NTE) enzyme activity. Forty-eight fryer chickens were divided into four groups as follows: Group 1 (control), group 2 was injected with single subcutaneous (s.c.) PSP (5 mg/kg), group 3 received oral lasalocid sodium (20 mg/kg, b.i.d., for 2 days), and group 4 received single s.c. PSP injection plus oral lasalocid sodium. MNCVs were decreased in groups 2, 3, and 4 compared to control. While there was no difference in MNCV between groups 2 and 3 (p > 0.05), MNCV in group 4 were significantly lower than in groups 2 and 3 (p < 0.05). NTE activities were significantly lower in PSP and PSP+lasalocid groups than in control and lasalocid group (p < 0.05). Onset of ataxia in group 4 appeared early and was exacerbated compared to groups 2 and 3. In conclusion, PSP and lasalocid could induce a significant decrease in MNCV and produce ataxia. Neuropathic OPs could be exacerbated by polyether ionophore lasalocid.