Radiomanganese Studies on the Mouse, Rat and Pancreatic Fistula Dog

Abstract

Localization of Mn54 following the intraven. admn. of labeled MnCl2 was shown for mice, rats, and dogs. Pancreatic juice which was collected prior to the injn. of a Mn soln. (7 mg. of Mn labeled with 333 [mu]c of Mn 54) into one dog contained 5-20 [mu]g. of Mn and juice collected subsequently contained 5 [mu]g. Radioactivity measurements provided an estimate of the Mn turnover rate in the pancreas. The most probable value for the amt. of Mn which appeared in the juice per day was 11% of the Mn in the gland. The level of activity at 2 hrs. from time zero was 1.0% of the dose per liter of pancreatic juice and 0.9% at 24 hrs. in contrast to 24.5, 1.2, 0.5, 0.2, and 0.05% of the dose/liter of plasma at 2, 10, 30, and 60 min., and 24 hrs. from time zero. The Mn54 output varied periodically with the feeding schedule and appeared to be proportional to the output of protein N. Similar results were obtained using a dog which was given 7 mg. of Mn labeled with 541 [mu]c. of Mn54. Thus, since pancreatic tissue normally has a high concn. of Mn, the appearance of labeled Mn in the juice seems to be the result of a secretory process.