Pentagastrin, histalog, glucagon, secretin, and perchlorate were intravenously injected into mice in order to investigate the hormonal regulation of 99mTc pertechnetate uptake by gastric mucosa. Pentagastrin significantly increased uptake; the effect of histalog was weaker. Secretin did not alter the uptake. Glucagon produced some diminution, and perchlorate significantly inhibited gastric uptake. Hormones may play a role in improving the sensitivity and specificity of diagnostic tests for Meckel's diverticulum.