Studies of Antiprostatic Agents in the Baboon 1

Studies on diseases of the human prostate, both benign and cancerous, have been greatly hampered by the relative unavailability of a suitable animal model system. However, recent studies in the baboon indicate that the prostate of this subhuman primate resembles that of man in some respects (1, 2) and can be investigated as a possible surrogate for human studies, particularly those involving chemotherapeutic agents for cancer of the prostate. The present study consists of a number of investigations concerned with several pros-tatic parameters, following the administration of 3 antiprostatic agents to baboons, and include the effects on the following: (1) several enzymatic systems of the baboon prostate, (2) the localization of labeled zinc in the gland, and (3) prostatic weight, histology and blood flow. All of these pro-static facets have unique features which can be affected by a number of hormonal agents, e.g., androgens and estrogens, influencing prostatic function and anatomy. The experiments were designed to ascertain the manner in which these parameters would be altered by the several drugs administered. These drugs have been shown to have antiprostatic actions in rodents and dogs, but, as far as we know, they have not been studied extensively in baboons. Methods and Materials. Adult male baboons (Papio anubis) weighing 20 kg or more were used in the studies. The prostate removal technique has been previously described (3, 4). The total gland was removed from the animals and the 2 parts of the baboon prostate (caudal and cranial) separated with ease (1-4). These lobes resemble, respectively, the central and peripheral zones of the human prostate. A slow iv infusion of Ringer's lactate solution was maintained through the duration of the experiments.