Histochemical distribution of acid mucopolysaccharides and some active transport enzymes in the lingual glands of Jaculus jaculus L. (Dipodidae, Mammalia).

From examination of the structural data obtained for the tongue of rodent Jaculus jaculus, it has been possible to deduce that it is lined with filiform papillae in the dorsal epithelium and that it has a rich glandular apparatus consisting of anterior serous glands which are located immediately after the apex and composed of epithelial cells arranged in a single synctitial layer, and both nucous and seromucous acini (Weber's glands) in the posterior portion of the tongue on the lateral sides and ventromedian region respectively. In the tip glands there is an elaboration of protein material; both neutral and acid glycoproteins are absent. In the posterior Weber's glands acidic moieties in the mucosubstances are due mainly to sialomucins and hyaluronidase resistant sulfomucins; in the seromucous acini on the other hand, mucopolysaccharides with vicinal hydroxyl groups and proteins are present. The histoenzymological tests employed to detect the succinic dehydrogenase and carbonic anhydrase also revealed the two reactions in the seromucous acini. Their presence is discussed on the basis of their having a probable role in the salivary production mechanisms in the same way as those cells which have a very strong secretory activity, or those involved in ionic reabsorption processes. The role of granular catalase activity in the duct cells is assumed to be able of protecting the glandular parenchyma from bacterial attacks. The presence also of acid glycoproteins within the lingual glands is correlated with taste sensation in view of the current revaluation of the role played by the proteoglycans in neuronal functions.