Archs oral Bid. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Vol. 38, No. 4, pp. 299-302, 1993 0003-9969/93 $6.00 + 0.00 Printed in Great Britain. All rights reserved Copyright 0 1993 Pergamon Press Ltd IMMUNOHISTOCHEMICAL DEMONSTRATION OF ANDROGEN RECEPTORS IN HUMAN SALIVARY GLANDS M. LAINE,’ M. BLUER,* T. YLIKOMI,’ P. TUOHIMAA,’ K. AITASALO,’ R.-P. HAPPONEN’ and J. TENOVUO’ ‘Institute of Dentistry, University of Turku, SF-20520 Turku, 2Department of Biomedical Sciences, University of Tampere, 33101 Tampere and ‘Department of Otolaryngology, University Central Hospital of Turku, SF-20520 Turku, Finland (Accepted I December 1992) Summary-Androgen receptors were demonstrated in human salivary glands by immunohistochemistry using polyclonal antibodies. Fresh, clinically healthy salivary gland samples (two from minor, seven from parotid and eight from submandibular glands) of both sexes were used. Frozen tissue sections were incubated with the antibody against human androgen receptor and visualized by an indirect immunoper- oxidase technique. Androgen receptors could be detected in all salivary tissues studied. Positive staining was confined to nuclei of almost all acinar cells as well as to the majority of nuclei in ductal cells. Very few of the nuclei of connective tissue and endothelial cells stained positively. The presence of androgen receptors in human salivary glands suggests possible direct effects of androgens on these tissues. Key words: human salivary glands, androgens, immunohistochemistry, androgen receptors. INTRODUCTION The effects of androgens on salivary glands have mainly been studied in rodents. The submandibular glands of the male mouse are particularly affected, and androgens greatly influence the growth, differentation and secretory activity of their granular ducts. After puberty these ducts are larger and greater in number in male than in female mice, and andro- gens play an important part in maintaining this difference (Lacassagne 1940). All cells are exposed to androgens in vivo. Their selective action on target tissues depends on the presence of intracellular receptor proteins, which bind the hormone or its metabolites. Androgens have growth-promoting effects, and they enhance the synthesis of many enzymes and growth factors in their target tissues. Rodent salivary glands contain androgen receptors (Takuma et al., 1977; Minetti et al., 1985) and are thus considered target organs of androgens. Human salivary glands have no gender-associated morphological features, but they are larger in men than in women. The effects of male sex steroids on human salivary glands are poorly understood. Human submandibular and parotid glands of both sexes metabolize androgens (ElAttar, 1974, Coffey and Crutchifield, 1977; Djsseland et al., 1982). This metabolism may regulate the androgenic activity of the glands. The composition of female saliva varies under hormonal conditions such as in pregnancy and with the menstrual cycle (Cockle and Harkness, 1978; Orosz et al., 1980; Tenovuo et al., 1981; Laine Abbreviations: BSA, bovine serum albumin; PBS, phosphate- buffered saline. et al., 1988), suggesting that female sex steroids affect salivary composition. No such data are available on male hormones in human saliva. Although several assays have been developed for the detection of androgen and other steroid receptors, their exact cellular localization has become possible only recently. Autoradiography gives anatomical in- formation about the receptors but it is disturbed by non-specific background labelling. The most com- monly used biochemical assay, the ligand-binding method, requires homogenization of tissue. When homogenized tissue is used, the heterogeneous distri- bution of the receptors may be masked in tissues such as salivary glands that contain several different cell types. Furthermore, secretory proteins may increase the non-specific binding of the hormone. New immunohistochemical techniques require only a small tissue sample and the location of both occupied and unoccupied receptors can be determined. The difficulty of obtaining specific antibodies against human androgen receptors has limited the use of this method. Many tissues of the head and neck region, e.g. the larynx and gingival tissue of both sexes, are target organs for androgens (Saez and Sakai, 1976; Southren et al., 1978). To our knowledge, only two studies have sought to detect sex-steroid receptors in human salivary glands (Lamey et al., 1987; Ruizeveld de Winter et al., 1991). Lamey et al. used the ligand-binding method for the detection of oestrogen and progesterone receptors in healthy and neoplastic salivary gland tissue; neither tissue was found to contain receptors. Ruizeveld de Winter et al. used an immunohistochemical method to study several human tissues, with a monoclonal anti-human androgen receptor antibody. They did not find any