Acute and Subacute Effects of Injury on the Canine Alveolar Septum: Methods (1)
The manner of exposing the canine lung to papain and the preparation of the lung specimens has been described by Parra et al’ Briefly, conditioned animals were used after a 30-day period of observation. They were debarked and treated for ectoparasites and endoparasites and immunized against rabies, distemper, leptospirosis, hepatitis and parvovirus. They were anesthetized (pentobarbital sodium, 25 mg/kg of body weight) and provided with a tracheal divider. With the animal on its right side, a solution of crude papain (33 mg/kg of body weight) in 24 ml of physiologic saline solution and containing 4 percent (1 ml) India ink (Pelikan Co., Hannover, West Germany) as a marker for later biopsy was instilled into the airway to the right lung while the left lung was ventilated with room air. Papain was obtained from Winthrop Laboratories, New York, NY, and assayed against benzoyl-arginine-ethyl ester and found to have an activity of 1 unit/mg. One unit was defined as one micromole of benzoyl-arginine-ethyl ester hydrolyzed. This dose was chosen because it had previously been shown in our laboratory to produce significant pulmonary emphysema within one month.
Ten minutes after instillation, the papain solution was allowed to drain out by gravity. The animal was allowed to recover unless it was to be sacrificed the same day. Control dogs were untreated (two animals) or treated in the same manner as experimental animals, except that only physiologic saline solution with India ink as a marker for biopsy was instilled into the right lung 4 h before sacrifice (one animal). The two chronic preparations were given one dose of 250,000 units of penicillin G and 0.25 g of streptomycin IM. asthma inhalers