Lithium, a drug of choice in bipolar
affective disorders, also affects the metabolism and cell proliferation in a diverse array of organisms. In this study, we investigated the effect of
lithium on
bombesin-mediated function in excretion and growth of the pancreas and the salivary glands. The weight,
protein content,
amylase concentration and salivary flow rate of the pancreas, parotid and the submandibular glands were determined in male Wistar rats after consumption of either water or
lithium chloride (600 mg/l) for 14 days and each group received s.c. injection of either saline or
bombesin (10 microg/kg) during the last 4 days of experiment. Our results revealed that administration of
bombesin in
lithium-treated group not only suppressed pancreas and parotid weight augmentation due to
bombesin, but also significantly decreased pancreas growth. Chronic
lithium consumption significantly inhibited the
protein content augmentation due to
bombesin in the salivary glands. Getting
bombesin, as well as saline in
lithium-treated group, resulted in notable decrease in
salivary protein content.
Protein content of pancreatic gland increased considerably in the
bombesin-injected groups either treated with saline or
lithium. In conclusion, the stimulatory effect of
bombesin on the growth and
protein content of the pancreas and the salivary gland was inhibited by
lithium.
Lithium seems to be a potent inhibitor of
growth factors induced by
bombesin probably through inhibiting
phosphatidylinositol 4,5,bisphosphate hydrolysis.