Effects of Age on Fasting Blood Glucose, Liver and Muscle Glycogen Levels in the Common African Toad Bufo regularis

Abstract

Ageing is associated with elevated blood glucose levels, insulin resistance and pancreatic islet dysfunction. The age-related dysfunction of glucose metabolism has been well studied in humans and rodents. However, there is paucity of information on ageing and glucose metabolism in amphibians. This study was designed to investigate the effect of ageing on fasting blood glucose, liver and muscle glycogen levels in the common African toad, Bufo regularis. Toads of different sizes were randomly picked and used for the study. They were fasted for 24hours and anaesthetized with sodium thiopentone (50mg/kg) given intraperitoneally. Blood samples were collected from truncus arteriosus for blood glucose determination while the liver and muscle glycogen levels were determined using anthrone reagents methods. Ages of toads were determined using modified skelectochronology technique. The fasting glucose level increased with advancing age while liver and muscle glycogen levels decreased with age in Bufo regularis. The results suggest that glucose metabolism slows down with age in the toads and demonstrated similarities between the toads, humans and rodents in relation to age-related changes in glucose and glycogen metabolism.