Immunoreactivity for thymosin beta 4 and thymosin beta 10 in the adult rat oro-gastro-intestinal tract.

ABSTRACT

Thymosin beta 4 (Tß4) and thymosin beta 10 (Tß10) are two members of the ß-thymosin family, involved in multiple cellular activities in different organs in multiple animal species. Here we report the expression pattern of Tß4 and Tß10 in rat tissues, in the gut and in annexed glands. The two peptide were differently expressed Tß4 was absent in salivary glands whereas Tß10 was expressed in parotid and in submandibular glands. Tß4 was mildly expressed in the tongue and in the oesophagus, where Tß10 was absent. A similar expression was found in the stomach, ileum and colon mucosa. In pancreas Tß4 reactivity was restricted to the Langerhans islet cells; Tß4 was also detected in the exocrine cells. Both peptide were not expressed in liver cells. When the rat expression pattern in rat organs was compared to reactivity for Tß4 and Tß10 in humans, marked differences were found. Our data clearly indicate a species-specific expression of Tß4 and Tß10, characterized by the actual unpredictability of the expression of these peptides in different cells and tissues. The common high expression of Tß4 in mast cells, both in humans and in rats, represents one of the few similarities between these two species.