Abstract
This report describes the specific cytotoxicity of iodoacetic acid (IAA) in selectively destroying the fibroblastoid cells and stimulating the in vitro function of neonatal B cells prepared from rat pancreases. Under culture conditions with a basal medium containing 5.5mM D-glucose alone, the responses to insulin secretagogues tested were abolished by day 7 of culture. In contrast, the addition of 10μM IAA enhanced either insulin release evoked by D-glucose (16.7mM), L-leucine (10mM) and 2-ketoisocaproate (10mM) or the cellular insulin content to approximately twice the initial levels (day 0). L-Glutamine (10mM) augmented the stimulatory effect of L-leucine or 2-ketoisocaproate. Moreover, the continuous application of IAA significantly increased the rates of glutamine oxidation in endocrine cells after 7 days of culture. On the other hand, the IAA-supplemented medium did not preserve the function of A cells. The phase-contrast microphotograph examination revealed the selective removal of fibroblasts from the monolayer cultures. This corresponded very closely with a remarkable reduction in culture DNA content.
