<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">Hyperglycaemia has been observed with exposure to organophosphate insecticides. This study was designed to compare the effects of calcium channel blockers, alpha-adrenergic, beta-adrenergic, and muscarinic receptor blockers, and of free radical scavengers on insulin secretion from diazinon-treated islets of Langerhans isolated from the pancreas of rats using standard collagenase digestion, separation by centrifugation, and hand-picking technique. The islets were then cultured in an incubator at 37 °C and 5 % CO2. In each experimental set 1 mL of 8 mmol L-1 glucose plus 125 μg mL-1 or 625 μg mL-1 of diazinon were added, except for the control group, which received 8 mmol L-1 glucose alone. The cultures were then treated with one of the following: 30 μmol L-1 atropine, 100 μmol L-1 ACh + 10 μmol L-1 neostigmine, 0.1 μmol L-1 propranolol, 2 μmol L-1 nifedipine, 50 μmol L-1 phenoxybenzamine, or 10 μmol L-1 alphatocopherol. In all experiments, diazinon significantly reduced glucose-stimulated insulin secretion at both doses, showing no dose dependency, as the average inhibition for the lower dose was 62.20 % and for the higher dose 64.38 %. Acetylcholine and alpha-tocopherol restored, whereas atropine potentiated diazinon-induced hyposecretion of insulin. Alpha-, beta- and calcium channel blockers did not change diazinon-induced effects. These findings suggest that diazinon affects insulin secretion mainly by disturbing the balance between free radicals and antioxidants in the islets of Langerhans and by inducing toxic stress.</abstract>

Hyperglycaemia has been observed with exposure to organophosphate insecticides. This study was designed to compare the effects of calcium channel blockers, alpha-adrenergic, beta-adrenergic, and muscarinic receptor blockers, and of free radical scavengers on insulin secretion from diazinon-treated islets of Langerhans isolated from the pancreas of rats using standard collagenase digestion, separation by centrifugation, and hand-picking technique. The islets were then cultured in an incubator at 37 °C and 5 % CO2. In each experimental set 1 mL of 8 mmol L-1 glucose plus 125 μg mL-1 or 625 μg mL-1 of diazinon were added, except for the control group, which received 8 mmol L-1 glucose alone. The cultures were then treated with one of the following: 30 μmol L-1 atropine, 100 μmol L-1 ACh + 10 μmol L-1 neostigmine, 0.1 μmol L-1 propranolol, 2 μmol L-1 nifedipine, 50 μmol L-1 phenoxybenzamine, or 10 μmol L-1 alphatocopherol. In all experiments, diazinon significantly reduced glucose-stimulated insulin secretion at both doses, showing no dose dependency, as the average inhibition for the lower dose was 62.20 % and for the higher dose 64.38 %. Acetylcholine and alpha-tocopherol restored, whereas atropine potentiated diazinon-induced hyposecretion of insulin. Alpha-, beta- and calcium channel blockers did not change diazinon-induced effects. These findings suggest that diazinon affects insulin secretion mainly by disturbing the balance between free radicals and antioxidants in the islets of Langerhans and by inducing toxic stress.

Comparative Effects of Calcium Channel Blockers, Autonomic Nervous System Blockers, and Free Radical Scavengers On Diazinon-Induced Hyposecretion Of Insulin From Isolated Islets of Langerhans in Rats

Pharmaceutical Sciences Branch, Islamic Azad University, Tehran

Institute of Medicinal Plants, ACECR, Tehran

Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran

Archives of Industrial Hygiene and Toxicology

Hyperglycaemia has been observed with exposure to organophosphate insecticides. This study was designed to compare the effects of calcium channel blockers,...

Comparative Effects of Calcium Channel Blockers, Autonomic Nervous System Blockers, and Free Radical Scavengers On Diazinon-Induced Hyposecretion Of Insulin From Isolated Islets of Langerhans in Rats

Publié en ligne: 06 juil. 2009

Pages: 157 - 164

DOI: https://doi.org/10.2478/10004-1254-60-2009-1917

Mots clés
organophosphates, oxidative stress, pancreas, rats

This content is open access.

Comparative Effects of Calcium Channel Blockers, Autonomic Nervous System Blockers, and Free Radical Scavengers On Diazinon-Induced Hyposecretion Of Insulin From Isolated Islets of Langerhans in Rats

Publié en ligne: 06 juil. 2009

Pages: 157 - 164

DOI: https://doi.org/10.2478/10004-1254-60-2009-1917

Mots clésorganophosphates, oxidative stress, pancreas, rats

This content is open access.

Mots clés
organophosphates, oxidative stress, pancreas, rats