Effect of Infused Streptomycin in the Mammary Gland. ∗

Abstract

Summary

(1) Streptomycin infused into the normal bovine mammary gland in amounts ranging from 100,000 to 500,000 units per quarter could be detected in milk samples as long as 48 hours following infusion. As determined by the assay procedure used, the concentration did not fall below 20 units / ml in any of the samples after a 24-hour interval. (2) The concentration per ml in the sample was found to vary with (1) the size of the dose (2) time interval between infusion and sampling and (3) milk production of individual quarters. (3) At no time was there sufficient streptomycin present in the blood to be detected by the assay procedure used. However, in both the cow and goat significant amounts were found in urine samples as long as 27 hours following infusion. (4) Under the conditions of these experiments streptomycin was found to be relatively non-toxic when infused into the normal bovine mammary gland.