Effect of the bendiocarb on the ultrastructure of rabbit skeletal muscle

Abstract

Bendiocarb belongs to the group of carbamate insecticides that inhibit acetylcholinesterase. In agriculture, it is used to control a variety of insects, therefore it is important to examine every potential aspect of its toxicology. The aim of this study was to observe the effect of bendiocarb on the ultrastructure of the skeletal muscle in rabbits. Rabbits in all experimental groups received capsules of bendiocarb (96% Bendiocarb, Bayer, Germany) per os daily at a dose of 5 mg/kg body weight. Samples of skeletal muscles were collected on days 10 and 20. On day 10 of the experiment, muscle fibres were not affected consistently. The observed changes were moderate and focal. Electron microscopy revealed dilatation of sarcoplasmic reticulum, and myofilament disorganization. On day 20 of the experiment, the ultrastructural changes in muscle fibres were more intense and more frequent. The most important alteration was the disruption of the sarcomeres due to the lysis of both thick and thin myofilaments. However, in the unchanged regions of muscle fibres a prominent mitochondrial swelling was observed. Many mitochondria lacked cristae and thus appeared as large membrane-bound cytoplasmic vesicles. The results presented in this study indicate that bendiocarb affects the ultrastructure of skeletal muscles. The intensity of damage (dissolution of myofilaments and disruption of sarcomeres) was related to the duration of administration of bendiocarb.