Summary.The incidence and course of development of diabetes was studied for 12 months after subtotal pancreatectomy in five strains of rats. Operations were performed on 5-7-week old-male animals weighing 100-140 g, and, subsequently, rats with fasting blood glucose levels > 8.3 mmol/1 were considered to be diabetic. In Fi~llinsdorf Albino rats, the proportion of diabetic animals gradually increased during the course of the experiment to a maximum of 83%. In Holtzman and Piebald rats, the highest incidence (58% and 28% respectively) was observed 2-3 months after surgery, after which partial remission of their diabetes occurred. Spontaneously hypertensive rats completely recovered from an initially mild diabetic state within 6 months of the operation. In Lewis rats, only a small number of animals (15%) became diabetic towards the end of the experiment. The severity of diabetes also differed considerably between strains. The pancreatic insulin content in diabetic rats was 2%-7% and in operated non-diabetic rats 17%-26% of values in non-operated control animals of the same age and strain. However, in the operated non-diabetic rats, glucose tolerance and the insulin response to glucose were also impaired.It is concluded that there are marked inter-strain differences in rats concerning the incidence and development of diabetes following subtotal pancreatectomy.Key words: Subtotal pancreatectomy, rat, diabetes, fasting blood glucose, glucose tolerance, insulin secretion, pancreatic-insulin, regeneration.Pancreatectomy is one of the standard procedures in experimental diabetes research. Development of diabetes, however, depends to a large extent on the animal species and the surgical techniques applied [1]. In contrast with dogs [2], total pancreatectomy is difficult to achieve in rats because of the diffuseness of the organ in this species. Furthermore, published data indicate possible differences in the susceptibility of various strains of rats to the development diabetes. For example, in male Wistar Albino rats, the incidence of diabetes was reported to be 90% 6 months after subtotal pancreatectomy [3] and 50% after 3 months [4], while in another, not exactly defined strain (hooded rats), all animals became diabetic within 8 days of the operation [5]. This apparent variation led us to investigate the incidence and the course of development of diabetes during 12 months after subtotal pancreatectomy in five strains of rats available to us from our local breeding station.
Materials and methods
AnimalsMale SPF rats (aged 5-7 weeks, 100-140 g body weight) of the following strains were obtained from the Institut ftir Biologisch-Medizinische Forschung, Ftillinsdorf, Switzerland: Fiillinsdorf-Albino (Wistar derived), spontaneously hypertensive rats (Okamato [6]), Lewis, Holtzman (Sprague Dawley derived) and Piebald (hooded). Approximately 1 week after their transfer to the local animal room (23 ~ 50%-60% relative humidity), the rats were fasted overnight and then anaesthetized with a combination of ketamine-HCl (90 mg/kg, i...