Experimental diabetes insipidus in a marsupial, Macropus eugenii (Desmarest)

A new method is described for placing lesions in the supraoptico-neurohypophysial tract to produce diabetes insipidus. The method is particularly useful with species such as Macropus eugenii in which different individuals show a large variation in relative skull measurements. The development of the diabetes insipidus syndrome in the tammar wallaby (Macropus eugenii) is shown to have essentially the same triphasic pattern of urine production as in eutherians. Increased values of adrenal corticosteroids (less than 16 mug/100 ml plasma) were observed in the oliguric interphase. This has not been previously reported and we suggest that these increased values are most probably due to potentiation of corticotrophic releasing factor by the uncontrolled release of vasopressin during this phase.