Abstract
Treatment of bovine lymphocytes isolated from animals which were either infected with Mycobacterium bovis or sensitized to a purified protein derivative (PPD‐B) from this organism induced an increase in the transport of α‐aminoisobutyric acid (AIB) and α‐methylaminoisobutyric acid (MeAIB). PPD‐B did not stimulate these transport activities in lymphocytes from nonsensitized animals. The transport stimulation was first measurable after about 7 hours of treatment, reached about a two‐fold enhancement after 20 hours, and continued to increase to 30‐ to 40‐fold after 6 days. The stimulation of AIB transport was inhibited by both ouabain and cycloheximide. Experiments to determine transport system specificities in nonstimulated lymphocytes showed that MeAIB transport was primarily by the Na^+^‐dependent, A‐system, and leucine transport was mostly by Na^+^‐independent system(s). In contrast, AIB transport was about 25% by the A‐system, 25% by at least one Na^+^‐dependent, non‐A‐system, and 50% by one or more Na^+^‐independent system(s). Analysis of the three components of AIB transport after treatment with PPD‐B showed that: (1) transport by both the A‐system and the Na^+^‐independent system(s) was stimulated; (2) A‐system transport was stimulated to a larger extent than Na^+^‐independent transport; and (3) Na^+^‐dependent, non‐A‐system transport was not stimulated significantly.