Immunohistochemical demonstration of steroid C-21 hydroxylase in normal and neoplastic salivary glands

Influence of 2-acetylaminofluorene (2-AAF) on biotransformation and lipid peroxidation in salivary glands and liver from male rats

Salivary glands proved to be active in biotransformation. In microsomes of rat salivary glands 7-ethoxyresorufin O-deethylation (EROD) and 7-pentoxyresorufin O-depentylation (PEROD) were detectable, but with much lower activities than in the liver. Beside the well-known induction of EROD or PEROD in the liver by beta-naphthoflavone (BNF) or phenobarbital (PB), respectively, a marked rise in EROD rate of salivary glands was observed after BNF treatment. Administration of 2-AAF caused an increase in EROD rates in liver microsomes, but a decrease in microsomes of salivary glands. This decrease in EROD rate was accompanied by selective cytotoxic damages in the convoluted granulated tubules of the submandibular glands. No cytotoxic damage occurred in the submandibular glands after a combined administration of the inducer BNF and 2-AAF. This indicates relations between these toxic effects of 2-AAF and changes of 2-AAF-metabolism in BNF-induced rats, maybe in the liver and/or in the submandibular glands themselves.

New approaches in human adrenocortical pathology: Assessment of adrenocortical function in surgical specimen of human adrenal glands

In adrenocortical pathology, it is important to localize the sites of steroid biosynthesis in order to obtain a better understanding of steroid metabolism. Previous morphological techniques, including light- and electron-microscopical examination, histochemistry, and immunohisto-chemistry of steroids, as well as biochemical studies, could not satisfactorily demonstrate which types of cortical cells produce which steroid hormones. Recent purification and characterization of specific steroidogenic enzymes, such as cytochrome P-450, that are involved in adrenal steroid biosynthesis have made it possible to generate specific antibodies and DNA probes against the enzymes that catalyze specific reaction(s) in the complicated biochemical cascade of steroidogenesis. By employing these antibodies and DNA probes, it has became possible to detect the expression of specific steroidogenic enzymes in surgically resected human adrenal cortex and its disorders. This can indicate the site(s) of specific steroid hormone(s) catalyzed by the expressed enzymes.

Immunohistochemical localization of vitamin B12 R-binder in salivary gland tumors. Implications for cell differentiation

Vitamin B12 R-binder, a specific binding protein for vitamin B12, was studied immunohistochemically in normal and 106 neoplastic salivary gland tissues with a monoclonal antibody against vitamin B12 R-binder (R-binder). In normal salivary glands, R-binder localization was restricted to the ductal systems and to mucous acinar cells; serous acinar cells, myoepithelial cells and stromal connective tissues were consistently negative. Among salivary gland tumors, R-binder was present in 87% of pleomorphic adenomas, 100% of monomorphic adenomas, and 40% of adenoid cystic carcinomas; positivity was observed only on luminal surfaces of small ductular elements, indicating that the components closely related to ductal differentiation were rather small in population. R-binder could be detected both in lacunar and non-lacunar cells within chondroid areas of pleomorphic adenomas, suggesting the possibility that chondroid regions arise from metaplastic changes in ductal epithelial cells. In mucoepidermoid tumors, mucous cells and focal squamous cells exhibited cytoplasmic staining. The staining pattern for R-binder in epithelial components of adenolymphomas showed close similarities to those found in normal large excretory ducts. Two acinic cell tumors and one case each of myoepithelioma and malignant myoepithelioma exhibited negative reactivity for R-binder, showing that these neoplasms are solely composed of tumor cells without the characteristics of ductular differentiation. The immunohistochemical examination of salivary gland tumors, employing a monoclonal anti-R-binder antibody, may have some implications for cellular heterogeneity and differentiation in various tumors.