Fatty acid synthase is expressed mainly in adult hormone-sensitive cells or cells with high lipid metabolism and in proliferating fetal cells.

Animal fatty acid synthase (FAS) is a homodimer protein which synthesizes long-chain fatty acids and is rich in liver, brain, breast, and lung. However, the precise cellular localization of FAS in human tissues has not been elucidated. Immunohistochemistry with a new antibody to human FAS revealed that in adult human tissues FAS is distributed mainly in cells with high lipid metabolism (adipocytes, corpus luteum, hepatocytes, sebaceous glands, and Type II alveolar cells), in hormone-sensitive cells (anterior pituitary, apocrine gland, breast, endometrium, prostate, seminal vesicle, and adrenal cortex), and in a subset of epithelial cells of duodenum and stomach, colon absorptive cells, cerebral neurons, basket cells of cerebellum, decidua, uroepithelium, and epidymis. In fetal cells at 20 weeks of gestation, FAS was mainly present in proliferative epithelial cells of the digestive and respiratory systems, proximal renal tubules, adrenocortical cells, and mesenchymal and hematolymphoid cells. Staining was significant in nonproliferating cells, as observed in adult, and in sympathetic ganglion cells, Leidig cells of testis, and Langhans cells of chorionic villi. FAS is maintained in hormone-sensitive cells and/or cells active in lipid metabolism in the adult and is expressed in proliferating cells in the fetus, suggesting active fatty acid synthesis for energy utilization or membrane lipids.     

Antigenic homogeneity of male Müllerian gland (MG) secretory proteins of a caecilian amphibian with secretory proteins of the mammalian prostate gland and seminal vesicles: evidence for role of the caecilian MG as a male accessory reproductive gland

Whereas in all other vertebrates the Müllerian ducts of genetic males are aborted during development, under the influence of Müllerian-inhibiting substance, in the caecilian amphibians they are retained as a pair of functional glands. It has long been speculated that the Müllerian gland might be the male accessory reproductive gland but there has been no direct evidence to this effect. The present study was undertaken to determine whether the caecilian Müllerian gland secretory proteins would bear antigenic similarity to secretory proteins of the prostate gland and/or the seminal vesicles of a mammal. The secretory proteins of the Müllerian gland of Ichthyophis tricolor were evaluated for cross-reactivity with antisera raised against rat ventral prostate and seminal vesicle secretory proteins, adopting SDS-PAGE, two-dimensional electrophoresis and immunoblot techniques. Indeed there was a cross-reaction of five Müllerian gland secretory protein fractions with prostatic protein antiserum and of three with seminal vesicle protein antiserum. A potential homology exists because in mammals the middle group of the prostate primordia is derived from a diverticulum of the Müllerian duct. Thus this study, by providing evidence for expression of prostatic and seminal vesicle proteins in the Müllerian gland, substantiates the point that in caecilians the Müllerian glands are the male accessory reproductive glands.     

Urethral glands of the male mouse contain secretory component and immunoglobulin A plasma cells and are targets of testosterone.

The occurrence and possible functions of mucosal immunity in the male urogenital tract have not been extensively investigated. In this study we used immunolabeling to localize secretory component (SC) and immunoglobulin (Ig) A in the urogenital tract of the male mouse. SC was located in the ventral prostate, while SC and IgA plasma cells were both detected in the urethral glands in the pelvic and bulbous portions of the urethra. SC and IgA were not observed elsewhere in the urogenital tract. We also examined the ventral prostate and urethral glands of sham-castrated, oil-treated castrated, and testosterone-treated castrated mice. There was a striking reduction in the size of the ventral prostate and urethral glands in oil-treated castrates compared to the other two groups, based on gross and histological morphology. Morphometric analysis showed that the cell and nuclear sizes of the urethral gland acinar cells were reduced after castration and restored to normal size by testosterone treatment. Androgen receptors (AR) were localized in the nuclei of urethral gland cells by immunocytochemistry using anti-AR antibodies. Labeling of SC and IgA plasma cells was similar in the urethral glands and ventral prostates of sham- and testosterone-treated castrates, but was reduced or absent at these sites in oil-treated castrates. These studies show that the ventral prostate and urethral glands may be sites for secretory immunity in the male murine urogenital tract, and that the urethral glands are targets for testosterone.     

Cellular localization of human secretory beta globulin in normal and tumor tissues]

Distribution of secretory beta-globulin (S beta G) which possesses affinity for steroids was investigated immunohistochemically. Tissue specificity of S beta G, produced in adult secretory epithelial cells of the seminal vesicles, salivary glands, prostate, bronchi and mammary gland was discovered. The protein was not detected in fetal and embryonal tissues. S beta G synthesis is abnormal in neoplasms: its expression partly preserves in breast cancer cells and increases in epithelium of mammary ducts near the focus of malignancy. In lung cancer and bronchial glands cells near the focus of neoplastic transformation S beta G positive reaction was not observed.     

Aquaporin-5 (AQP5), a water channel protein, in the rat salivary and lacrimal glands: immunolocalization and effect of secretory stimulation

Aquaporin-5 (AQP5) is a water channel protein and is considered to play an important role in water movement across the plasma membrane. We raised anti-AQP5 antibody and examined the localization of AQP5 protein in rat salivary and lacrimal glands by immunofluorescence microscopy. AQP5 was found in secretory acinar cells of submandibular, parotid, and sublingual glands, where it was restricted to apical membranes including intercellular secretory canaliculi. In the submandibular gland, abundant AQP5 was also found additionally at the apical membrane of intercalated duct cells. Upon stimulation by isoproterenol, apical staining for AQP5 in parotid acinar cells tended to appear as clusters of dots. These results suggest that AQP5 is one of the candidate molecules responsible for the water movement in the salivary glands.     

Cellular distribution of growth hormone-releasing hormone receptor in human reproductive system and breast and prostate cancers

Growth hormone releasing hormone receptor (GHRH-R) mRNA and protein was first localized to the anterior pituitary gland, consequent with the action of its ligand on GH synthesis and release. Subsequent studies found GHRH-R also expressed in the hypothalamus and in systemic tissues including those of the reproductive system. In the present work, we studied the distribution of GHRH-R in human reproductive system of males and females by immunohistochemical method. GHRH-R immunostaining was localized in male reproductive system: Leydig cells, Sertoli and basal germ cells of the seminiferous tubules and prostate secretory cells. GHRH-R immunostaining was also demonstrated in the ovary: oocytes, follicular cells, granulosa, thecal and corpus luteum cells. Endometrial glands, placenta and normal mammary glands also showed GHRH-R immunostaining. Our results demonstrate the localization of GHRH-R in the reproductive system, which may mediate the direct action of GHRH in these tissues. Moreover, GHRH-R was demonstrated in prostate and breast carcinomas, opening a variety of possibilities for the use of GHRH antagonists in the treatment of prostatic and mammary tumors.     

Tissue distribution of pneumadin immunoreactivity in the rat

Pneumadin (PNM) is a decapeptide, originally isolated from mammalian lungs, which exerts a potent stimulating effect on arginine-vasopressin (AVP) release, thereby evoking an antidiuretic effect. We have established a specific radioimmunoassay (RIA) method for rat PNM determination, the sensitivity of which is sufficient for measuring tissue content of the peptide. Moreover, raised antibodies have been used for the immunocytochemical detection of PNM in several rat organs. As expected, high concentrations of PNM were detected by RIA in newborn and adult rat lungs and immunocytochemistry (ICC) localized PNM immunoreactivity (IR) in the bronchial and bronchiolar epithelium. Very high concentrations of PNM were measured by RIA in the prostate, and ICC showed that PNM-IR is contained in the epithelial cells. RIA and ICC demonstrated the presence of low amounts of PNM in the thymus. The highest content of radioimmunoassayable PNM was found in the kidneys and intestinal tract, but dilution test suggested the presence of some interfering substances in these tissues. Accordingly, ICC-detectable PNM-IR was absent in the kidneys and present only in the duodenal criptae and Brunner's glands of the intestinal tract. RIA did not measure sizeable PNM concentrations in the thyroid gland, but ICC showed PNM-IR in C-cells. RIA and ICC did not detected PNM in testes, seminal vesicles, ovaries, uterus, pancreas, liver, spleen, adrenal glands, and heart. Taken together, our findings suggest that PNM, in addition to its role as hypothalamo-pituitary AVP secretagogue, may be involved in the autocrine-paracrine functional regulation of other peripheral organs, like lungs and prostate and perhaps duodenum, thymus and thyroid gland.     

A histochemical study of the secretions of reproductive glands and of the egg envelopes of Achatina fulica (Pulmonata: Stylommatophora)

Histochemical investigations of the secretions of reproductive glands—albumen gland, apical uterus, basal uterus and prostate gland—indicate the presence of galactogen in the albumen gland, acid mucopolysaccharide in the apical uterus, and lipoprotein in the basal uterus and prostate gland of A. fulica. The proteinaceous secretions produced by the glands do differ in their terminal reactive sites. Intense alkaline phosphatase reaction is found in albumen gland and apical uterus; carbonic anhydrase activity could be detected mainly in the uterine glands. The cyclical secretory activity of the reproductive glands has been studied preparatory to egg-laying and in the spent phase. Histochemical characteristics of the egg envelopes—albumen, shell membrane and egg-shell—suggest a possible sequential deposition of glandular products during the descent of eggs through the repv. ductive tract. The factors contributing to the stability and resistant nature of the egg envelopes, and the possible role of nutritive materials contained in reproductive gland secretions in the development of the embryo (even while the eggs are inside the uterus), are discussed.     

Localization of low molecular weight protease inhibitor in serous secretory cells of the respiratory tract

We prepared in rabbits an antiserum against low molecular weight protease inhibitor (LMI) purified from the sputum of patients with purulent bronchitis. Using this antiserum in an immunoperoxidase staining method we found that this inhibitor was located exclusively in the serous cells of the submucosal glands of human upper and lower airways. The inhibitor was localized also in serous cells of the sublingual and submandibular glands. In contrast, LMI could not be demonstrated in the serous cells of the parotid gland. In the tissues investigated a strong association between the localization of the protease inhibitor and lysozyme was observed. Our observations indicate that the inhibitor may be present together with lysozyme as a secretory product in the serous cell granules. The possible consequences of the coexistence of these two proteins in the defense mechanism of the respiratory tract is discussed.     

The female prostate and prostate-specific antigen. Immunohistochemical localization, implications of this prostate marker in women and reasons for using the term "prostate" in the human female

Prostate-specific antigen (PSA) is currently the most frequently used marker for the identification of normal and pathologically altered prostatic tissue in the male and female. Immunohistochemically PSA is expressed in the highly specialized apically-superficial layer of female and male secretory cells of the prostate gland, and as well as in uroepithelial cells at other sites of the urogenital tract of both sexes. Unique active moieties of cells of the female and the male prostate gland and in other parts of the urogenital tract are indicative of secretory and protective function of specialized prostatic and uroepithelial cells with strong immunological properties given by the presence of PSA. In clinical practice, PSA is a valuable marker for the diagnosis and monitoring of diseases of the male and the female prostate, especially carcinoma. In the female, similarly as in the male, the prostate (Skene's gland) is the principal source of PSA. The value of PSA in women increases in the pathological female prostate, e.g., carcinoma. Nevertheless, the total amount of PSA in the female is the sum of normal or pathological female prostate and non-prostatic female tissues production, e.g., of diseased female breast tissue. The expression of an antigen specific for the male prostate, i.e., PSA in female Skene's glands and ducts, and structural and functional parameters and diseases similar to that of the male prostate, have provided convincing evidence of the existence of a prostate in women and definitive preference of the term "prostate" over that of Skene's glands and ducts. The use of the term Skene's glands incorrectly implies that some other structure rather than prostate is involved, promoting the vestigial position of this female organ.     

Histology and histochemistry of the accessory reproductive glands in the male hairy-nosed wombat (Lasiorhinus latifrons)

The accessory male reproductive glands of the hairy-nosed wombat, Lasiorhinus latifrons, are a prostate and three pairs of Cowper's glands. Component units of all are branched tubular structures of varying epithelial makeup and secretory content. The prostate has the carrotlike shape and three consecutive regions commonly found in marsupials. The regions differ in their tubular histology and histochemistry: all contain secretory globules in glandular lumina. Cowper's glands A and B are histologically identical except for the absence of interstitial mast cells from gland G: gland C is characterized by narrower tubules and larger epithelial cells. Histochemical tests for protein, carbohydrate and iron indicate that glycogen is a major secretory product of the prostate (largely posterior region), iron is also secreted (mainly posterior region) and a small quantity of acid mucin is produced (mainly central region). Glycogen is a feature also of anterior prostatic glandular epithelium and of the capping cells of the urethral transitional epithelium. Cowper's gland A has considerable protein in its secretion, gland B a neutral glycoprotein and gland C a sialomucin: the latter two also exhibit cytoplasmic glycogen in their secretory cells.     

Human lipocalin-1, a physiological scavenger of lipophilic compounds, is produced by corticotrophs of the pituitary gland.

Lipocalin-1 (Lcn-1), a member of the lipocalin superfamily that binds a broad array of different chemical classes of lipophilic ligands, is believed to act as a physiological scavenger of potentially harmful lipophilic molecules. Thus far, it was thought to be produced exclusively by a number of exocrine glands and tissues, including lachrymal and lingual glands, prostate, secretory glands of the tracheobronchial tract, and sweat glands. Using Northern blotting analysis, we were able to demonstrate Lcn-1 expression by the human pituitary gland. Moreover, double immunolabeling with antibodies against Lcn-1 and pituitary gland hormones and detection with fluorophore-conjugated secondary antibodies revealed that Lcn-1 is specifically produced by corticotrophs, clearly indicating that its distribution is not restricted to exocrine tissues.     

Histology and histochemistry of the accessory reproductive glands in the male hairy-nosed wombat (Lasiorhinus latifrons)

Summary The accessory male reproductive glands of the hairy-nosed wombat, Lasiorhinus latifrons, are a prostate and three pairs of Cowper's glands. Component units of all are branched tubular structures of varying epithelial makeup and secretory content. The prostate has the carrotlike shape and three consecutive regions commonly found in marsupials. The regions differ in their tubular histology and histochemistry: all contain secretory globules in glandular lumina. Cowper's glands A and B are histologically identical except for the absence of interstitial mast cells from gland B: gland C is characterized by narrower tubules and larger epithelial cells. Histochemical tests for protein, carbohydrate and iron indicate that glycogen is a major secretory product of the prostate (largely posterior region), iron is also secreted (mainly posterior region) and a small quantity of acid mucin is produced (mainly central region). Glycogen is a feature also of anterior prostatic glandular epithelium and of the capping cells of the urethral transitional epithelium. Cowper's gland A has considerable protein in its secretion, gland B a neutral glycoprotein and gland C a sialomucin: the latter two also exhibit cytoplasmic glycogen in their secretory cells.     

Localization of androgen and estrogen receptors in rat and primate tissues

There is now evidence that estrogens and androgens are exerting their effects in different tissues throughout the body. In order to determine the sites of action of these steroids, studies have been performed to identify at the cellular level the localization of androgen receptor (AR) and the two estrogen receptor (ER) subtypes, ERalpha and ERbeta, specially in the rat, monkey and human. In the prostate, AR was observed in the secretory and stromal cells. In the testis, Sertoli, Leydig and myoid cells were labelled. In the epididymis and seminal vesicles, both epithelial and stromal cells contained AR. In the ovary, AR was detected in granulosa and interstitial cells. In the uterus, epithelial, stromal and muscle cells were all immunopositive for AR. In the central nervous system, AR-containing neurons were found to be widely distributed throughout the brain. In the mammary gland, epithelial cells in acini and ducts and stromal cells were demonstrated to express AR. In the skin, AR was detected in keratinocytes, sebaceous and sweat glands, and hair follicles. In addition, AR was also found in anterior pituitary, thyroid, adrenal cortex, liver, kidney tubules, urinary bladder, cardiac and striated muscle, and bone. The ER subtypes are in general differentially expressed. While ERalpha has been predominantly found in anterior pituitary, uterus, vagina, testis, liver and kidney, ERbeta is predominant in thyroid, ovary, prostate, skin, bladder, lungs, gastro-intestinal tract, cartilage and bone. In tissues which contain both receptor subtypes, such as ovary, testis and various regions of the brain, a cell-specific localization for each ER subtype has been generally observed. Altogether, the recent results on the cellular localization of sex steroid receptors will certainly contribute to a better understanding of the specific role of these steroids in different target organs.     

Histology and histochemistry of the reproductive tract of the pulmonate snail,Bulinus truncatus,with observations on the effects of castration on its growth and histology

The reproductive tract of B. truncatus was investigated histologically in order to study possible effects of castration upon the accessory sex glands. In the female part of the reproductive tract—subdivided into albumen gland, oviduct, muciparous gland, oothecal gland, uterus, vagina and bursa copulatrix—13 histochemically different secretory cell types were distinguished. The majority produce different types of (acid) mucopolysaccharides. The roles of the various parts of the female tract in the production of an egg mass were elucidated by comparing the histochemistry of the egg mass to that of the female tract; the abundance and location of the cell types were also taken into account for this purpose.

The male part appeared to contain 12 histochemically different secretory cell types. These produce mainly (phospho lipoproteins together with some polysaccharides and neutral lipids.

Castration causes an acceleration of the growth of the snails. The volumes of female (albumen gland) and male (prostate gland) accessory sex glands were measured on histological sections. It appeared that growth of the albumen gland is not arrested by castration. This was not established beyond doubt for the prostate gland. The results suggest that the stimulating effects of the dorsal body hormone on the growth and synthetic capacity of the female accessory sex glands—such effects have been established for Lymnaea stagnalis—are not exerted via the ovotestis in B. truncatus.     

An immunohistochemical analysis of Rab27B distribution in fetal and adult tissue

Regulated secretory pathways coordinated by small Rab GTPases are critically involved in intercellular communications. Here, we report the expression and localization of Rab27B in developing and differentiated epithelial human tissues by immunohistochemistry. Rab27B is poorly expressed in fetal tissues suggesting that several developmental mechanisms involved in epithelial differentiation and functions are mediated by other secretory Rab GTPases, such as Rab27A or Rab3 family members. In adult tissues, Rab27B is expressed in a wide variety of differentiated secretory epithelial cells, including those lining the salivary gland, gastrointestinal, mammary and prostate tracts. The complex pattern of Rab27B expression indicates that dysregulation of Rab27B-mediated secretion may have profound implications for disease pathology.     

Immunohistochemical studies of the distribution of a basolateral-membrane protein in intestinal epithelial cells (GZ1-Ag) in rats using monoclonal antibodies

The monoclonal antibody (mAb), GZ1, is specific for a 42-kilodalton (kD) protein (designated GZ1-Ag) present among the plasma membrane (PM) proteins of the absorptive cells of rat intestine. This protein only occurs in the basolateral PM and is absent from the microvillus membrane. GZ2 and GZ20 are two other mAbs that are also directed against GZ1-Ag but which specify other antigenic determinants of this protein than mAb GZ1. Used together, these three mAbs allow better characterization of GZ1-Ag and more precise investigation of its distribution and localization in various rat cells. We performed immunohistochemical labelling for GZ1-Ag at both the light- and electron-microscope levels and found that GZ1-Ag is extensively distributed in rat epithelial tissues. However, the amount of this protein present in epithelial tissue shows considerable variation. GZ1-Ag is not present in the secretory cells of terminal portions of most excretory glands or in cells of the endocrine glands and liver. The cells of kidney tubules, except for collecting tubules, also lack GZ1-Ag. Only small amounts of GZ1-Ag are present in the cells of the stratified squamous epithelium and transitional epithelium, the exception being superficial cells. High concentrations of GZ1-Ag occur in the excretory duct systems of glands and in the various kinds of epithelium present in the male and female genital tract. Our results also indicated that the GZ1-Ag in all of these cells has a very similar structure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Broad expression of fructose-1,6-bisphosphatase and phosphoenolpyruvate carboxykinase provide evidence for gluconeogenesis in human tissues other than liver and kidney

The importance of renal and hepatic gluconeogenesis in glucose homeostasis is well established, but the cellular localization of the key gluconeogenic enzymes liver fructose-1,6-bisphosphatase (FBPase) and cytosolic phosphoenolpyruvate carboxykinase (PEPCK) in these organs and the potential contribution of other tissues in this process has not been investigated in detail. Therefore, we analyzed the human tissue localization and cellular distribution of FBPase and PEPCK immunohistochemically. The localization analysis demonstrated that FBPase was expressed in many tissues that had not been previously reported to contain FBPase activity (e.g., prostate, ovary, suprarenal cortex, stomach, and heart). In some multicellular tissues, this enzyme was detected in specialized areas such as epithelial cells of the small intestine and prostate or lung pneumocytes II. Interestingly, FBPase was also present in pancreas and cortex cells of the adrenal gland, organs that are involved in the control of carbohydrate and lipid metabolism. Although similar results were obtained for PEPCK localization, different expression of this enzyme was observed in pancreas, adrenal gland, and pneumocytes type I. These results show that co-expression of FBPase and PEPCK occurs not only in kidney and liver, but also in a variety of organs such as the small intestine, stomach, adrenal gland, testis, and prostate which might also contribute to gluconeogenesis. Our results are consistent with published data on the expression of glucose-6-phosphatase in the human small intestine, providing evidence that this organ may play an important role in the human glucose homeostasis.     

S100ao (alpha alpha) protein is mainly located in the heart and striated muscles

Concentrations of alpha-S100 protein (S100ao or alpha alpha form, and S100a or alpha beta form) and beta-S100 protein (S100b or beta beta form, and S100a or alpha beta form) in various human tissues were determined by employing the enzyme immunoassay system specific to each subunit of bovine S-100 protein. Immunoreactive alpha-S100 protein was found in the heart and striated muscles at high levels of about or more than 1 microgram/mg soluble protein. Concentrations of beta-S100 protein in those tissues were low (less than 50 ng/mg protein). A considerable content of alpha-S100 protein was also found in the kidney and thyroid gland (about 160 and 100 ng/mg protein, respectively), where the beta-S100 content was less than 5 ng/mg protein. The immunoreactive alpha-S100 proteins in the extracts of heart, kidney and brain were eluted in the same fractions from a column of butyl-Sepharose and in the fractions corresponding to a molecular weight of approx. 20 000 from a column of Sephadex G-100. Both alpha-S100 and beta-S100 proteins were found at a relatively high concentration (100-250 ng/mg protein) in the skin and trachea. The alpha-S100 contents in the other peripheral organs, including gastrointestinal tract, lung, liver, spleen, urinary bladder, gall bladder, uterus, prostate and aorta, were low (less than 50 ng/mg protein). Since brains contain about 300 ng alpha-S100 protein/mg soluble protein, it can be concluded that alpha-S100 (or S-100ao) protein is mainly located in the heart and striated muscle tissues.     

Expression of Secretogranin III in Chicken Endocrine Cells: Its Relevance to the Secretory Granule Properties of Peptide Prohormone Processing and Bioactive Amine Content

The expression of secretogranin III (SgIII) in chicken endocrine cells has not been investigated. There is limited data available for the immunohistochemical localization of SgIII in the brain, pituitary, and pancreatic islets of humans and rodents. In the present study, we used immunoblotting to reveal the similarities between the expression patterns of SgIII in the common endocrine glands of chickens and rats. The protein–protein interactions between SgIII and chromogranin A (CgA) mediate the sorting of CgA/prohormone core aggregates to the secretory granule membrane. We examined these interactions using co-immunoprecipitation in chicken endocrine tissues. Using immunohistochemistry, we also examined the expression of SgIII in a wide range of chicken endocrine glands and gastrointestinal endocrine cells (GECs). SgIII was expressed in the pituitary, pineal, adrenal (medullary parts), parathyroid, and ultimobranchial glands, but not in the thyroid gland. It was also expressed in GECs of the stomach (proventriculus and gizzard), small and large intestines, and pancreatic islet cells. These SgIII-expressing cells co-expressed serotonin, somatostatin, gastric inhibitory polypeptide, glucagon-like peptide-1, glucagon, or insulin. These results suggest that SgIII is expressed in the endocrine cells that secrete peptide hormones, which mature via the intragranular enzymatic processing of prohormones and physiologically active amines in chickens.