A Histological and Histochemical Study of Posterior Lingual Gland in Japanese Monkey (Macaca fuscata)

Abstract

Although several studies of salivary glands in the mammals, including monkeys, have been reported, many of them are about major salivary glands, and analyses of minor salivary gland are little. Therefore, the present study performed a histological and histochemical study in order to clarify the posterior lingual gland in monkeys, and to obtain the fundamental findings for comparative study with salivary gland diseases. Lingual tissues were obtained from five adult Japanese monkeys (Macaca fuscata). All the specimens were fixed in 10% neutral formalin solution as soon as those had been removed, and then, paraffin sections were made. The sections were stained with hematoxylin-eosin and PAS-alcian blue pH 2.5. The avidin-biotin-peroxidase complex and direct fluorescence methods using seven kinds of lectin were performed in the present study. Front and back zone of the posterior lingual glands consisted of different type of the acinar cells. The front zone was predominantly composed of PAS-positive acinar cells indicating serous characteristics, whereas back zone mainly consisted of the acinar cells stained with alcian blue pH 2.5 showing mucous characteristics. Serous acinar cells showed positive reactivities for Con A, WGA, RCA-I and UEA-I, whereas DBA was negative. Mucous acinar cells were positive for WGA, RCA-I and UEA-I, but Con A was negative. After neuraminidase digestion, positive reactivities for WGA and PNA were higher in the serous acinar cells compared to non-digestion. These results suggested that the serous cells predominantly contained D-mannose, D-glucose, N-acetyl-D-glucosamine, N-acetyl neuraminic acid, D-galactose and L-fucose residues, whereas the mucous acinar cells had similar sugar residues with the serous acinar cells except for D-mannose and D-glucose residues. Furthermore, the result of neuraminidase digestion suggested that the serous acinar cells mainly contained not only N-acetyl neuraminic acid but also N-acetyl-D-glucosamine and D-galactose residues.