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

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 % CO 2 . 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 signifi cantly 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 diazinoninduced hyposecretion of insulin. Alpha-, beta-and calcium channel blockers did not change diazinoninduced effects. These fi ndings 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.

Zinc Oxide Nanoparticles Reduce Apoptosis and Oxidative Stress Values in Isolated Rat Pancreatic Islets

“…Thus, ZnO NPs may increase insulin secretion due to increase in ATP/ADP ratio. As shown in one of previous studies, antioxidant compounds such as alpha-tocopherol prevented free radicals and balanced free radicals and antioxidants in the cell, increasing insulin secretion [33]. The other reason for increasing insulin by ZnO NPs should be justified by its antioxidant property.…”

Neurocognitive, Mental Health, and Glucose Disorders in Farmers Exposed to Organophosphorus Pesticides

“…It is estimated that the number of people who suffer from type 2 diabetes will rise from 171 million in 2000 to 366 million in 2030 (16). Many studies corroborate that OP exposure might contribute to type 2 diabetes (17)(18)(19)(20)(21)(22)(23)(24)(25). Although the overall evidence of neurological and neurobehavioral effects of long-term OP exposure is thought to be small, it is not that diffi cult to fi nd some (26,27).…”

Blockage of both the extrinsic and intrinsic pathways of diazinon-induced apoptosis in PaTu cells by magnesium oxide and selenium nanoparticles

“…Before performing test procedures, according to previous studies, 20,21 the PaTu cell lines (1×10 5 cells/well) were incubated with culture medium in combination with different concentrations of DZ (100, 250, 500, 750, 1,000, 1,500, and 2,000 µM) for 24 hours at 37°C in a 5% CO 2 humidified atmosphere. After treatment, the cytotoxicity was assessed using MTT assay.…”