Plasma glucose and insulin concentrations after implantation and surgical resection of a transplantable rat insulinoma

Although significant advances have been made during the past decade concerning the diagnosis, treatment and management of patients with an islet B-cell tumour (Frerichs & Creutzfeldt, 1976; Anonymous, 1981; Marks & Rose, 1981), much remains to be learnt about the basic nature of the defect and the general effects of insulin-secreting tumours (insulinomas) on metaolism. To answer these questions, attention has been given to the development of an animal model suitable for more detailed and thorough investigation (Baba et al., 1979; Creutzfeldt et a[., 1980). Various approaches have been used for tumour induction, ranging from the administration of chemicals to exposure to ionizing radiations. Despite the low success rate, numerous islet-cell tumours with widely different characteristics have been induced (Baba et al., 1979; Creutzfeldt et al., 1980). However, few tumours have been found to be suitable for propagation by serial transplantation (Chick et al., 1980). The present report describes plasma glucose and insulin concentrations after implantation and surgical resection of a transplantable rat insulinoma. The original tumour was induced several years ago by X-ray irradiation (Chick et al., 1977). It has since been adopted as a convenient alternative source of large amounts of