A morphological, histochemical and experimental study of the prostate gland and seminal vesicles of the guinea pig, with special reference to the stroma

by Chan Leung, Franky

Abstract (Summary)
(Uncorrected OCR) Abstract of thesis entitled 'A morphological, histochemical and experimental study of the prostate gland and seminal vesicles of the guinea pig with special reference to the stroma' submitted by CHAN Leung, Franky for the degree of Doctor of Philosophy at the University of Hong Kong in July, 1989. The present study aims to investigate the complex carbohydrates and proteoglycans (PGs) of the lateral prostate (LP) and seminal vesicle (SV) of the guinea pig, using various histochemical methods, and to examine changes in their extracellular matrices (ECM) under different experimental conditions using morphological and cytochemical approaches. Changes which occurred in the stroma were correlated with changes in the glandular epithelial cells. The results of partial characterization of carbohydrates by conventional histochemical methods indicated that neutral glycoconjugates with 1,2-glycol groups and sialic acids {SA} wer present in the luminal border and apical cytoplasm of the epithelial cells, basement membrane (BM) and connective tissue o the lamina propria of the LP. Similar results were demonstrated in the SV except that there were relatively fewer or a complete absence of neutral carbohydrates in the luminal border of the epithelial cells. The BM and the connective tissue at the epithelial-stromal interface, of both glands contained abundant sulphated glycosaminoglycans (GAGs), especially chondroitin sulphate (CS). i The lectin histochemical study showed that glycoconjugates containing mannose (Man), N-acetylglucosamine (GlcNAc), galactose (Gal), N-acetylgalactosamine (GalNAc) and complex oligosaccharides were present in the secretory epithelia of both glands. A difference in the distribution of glycoconjugates containing a /B-GlcNAc and fucose (Fuc) in these two glands was noted. Unlike the prostatic epithelium, that of the SV was largely negative to GS-II and UEA-I indicating that it contained little or no a/13-GlcNAc and Fuc residues. The Golgi apparatus (GA) of the epithelial cells from both glands was rich in GlcNAc, Gal, GalNAc and Fuc residues indicating that it was actively involved in glycosylation. A few isolated epithelial cells in both glands were DBA positive and they may thus represent either endocrine-paracrine (APUD) cells or activated basal cells. Most basal cells, however, demonstrated no specific lectin binding indicating that they contained fewer complex carbohydrates than the glandular cells. The BM and the lamina propria of both glands contained Gal, GalNAc and sialic acids, while the lamina propria of both glands was rich in Man, GlcNAc, Gal, GalNAc, sialic acid and complex oligosaccharides but not Fuc residues. The glycoconjugates were demonstrated ultrastructurally by lectin-gold histochemistry. Con A binding sites which are related to the initial assembly of N-linked oligosaccharides of glycoproteins were seen in the epithelial GER. The Golgi saccules were rich in Man, GlcNAc, GalNAc, Gal and sialic acid. A compartmental organization of the Golgi stack is described and the relationship to sequential addition of sugar residues to oligosaccharides is discussed. The baso-lateral and apical membranes including the microvilli (MV) of the glandular cells contained Man, GlcNAc, Gal, GalNAc and complex sugar residues. ii Man, GlcNAc, Gal and complex oligosaccharides were also demonstrated in the stromal tissues of both glands. The PGs or GAGs in the guinea pig LP and SV were demonstrated ultrastructurally by Cuprolinic Blue (CB), Alcian Blue (AB) and Ruthenium Red (RR) staining. The PGs appeared as various electron dense granules by RR, but were filamentous following CB and AB staining using the critical electrolyte concentration (CEC) method. Three major types of PGs (T1-T3) have been described according to their different locations and sizes. Cytochemical characterization of these PGs by various GAG degrading enzymes showed that Tl PGs, localized in the basal lamina of the glandular epithelia, smooth muscle and capillary endothelium of both glands were heparan sulphate (HS) PGs. T2 PGs closely associated with the major D-band of collagen fibrils were dermatan sulphate (DS) PGs. T3 PGs (CSPGs) were widely distributed in the stroma of both glands in such sites as the interstitial spaces of the lamina propria, the reticular layer below the basal lamina {BL), around individual collagen fibrils or bundles of such fibres, and on the cell surface of fibroblasts. In order to study the importance of ECM to the epithelial cells: three experimental approaches were used to modify the ECM of the stroma of the guinea pig male accessory sex glands: (i) ascorbic acid (Vitamin C) deficiency (VCD) to modify the collagen matrices and PGs; (ii) treatment with a proline analog, cis-4-hydroxy-L-proline (CHP), to inhibit specifically collagen accumulation in the stroma and (iii) treatment with 13-D-xyloside (XYL) to alter PG synthesis. There was a decrease in both collagen fibrils and PGs in the lamina propria of both glands under VCD. VCD also caused iii variable damage to the epithelial BL such as discontinuity detachment of epithelial cells and loss of Tl PGs which also occurred in the stroma. The epithelia underwent involution which was similar to that seen following castration. In the case of castration, however, the lamina propria was densely packed with collagen fibrils. Stimulation of the scorbutic, castrated animals with androgen did not improve either the collagen accumulation in the stroma or the secretory function of the glandular epithelia. The regression of the epithelial cells of both glands under VCD may have resulted from the defective stromal matrices and epithelial BL. Treatment of the castrated, androgen-stimulated guinea pigs with CHP specifically prevented the collagen accumulation in the stroma of both glands and the epithelial BL appeared defective. In the LP, the lamina densa (LD) became thin or interrupted and there was a decrease in the amount of PGs in both BL and stroma. However, in the SV the LD appeared 'thickened' due to deposition of a layer of fibrillary and amorphous substance below the LD. The epithelial cells of both glands were regressed with a reduction in the glycoconjugates containing GlcNAc, Gal, GalNAc and Fuc in the epithelial cytoplasm and GA. There was an increase in the number of basal cells in both glands after CHP treatment and such hyperplasia was particularly prominent in the SV. The hyperplastic basal cells of the SV also expressed glycoconjugates containing Man, GlcNAc, Gal and complex oligosaccharides which were not formed in the normal and control tissues. It was concluded that collagens play an important role in the regulation of growth and function in the male accessory sex glands, as inhibition of collagen accumulation by CHP iv prevented the growth and differentiation of both glands. Treatment of castrated, androgen-stimulated guinea pigs with XYL caused an abnormal increase of GAGs in the lamina propria of both glands as indicated by an increase in alcianophilia in the connective tissue of the lamina propria and an increase in amount of CB-stained materials in the interstitial spaces. The staining pattern of the Tl CB-stained PGs of the BL appeared normal. The secretory activities of stromal fibroblasts and some smooth muscle cells were enhanced as shown by their dilated GER cisternae and well developed GA. The fibroblasts also showed increased reactivities to AB, Con A and WGA. XYL treatment retarded the growth and decreased the secretory activity of the epithelial cells in both glands. XYL caused a swelling of the epithelial GA and GER cisternae, as well as an increase in number of cytoplasmic vesicles. Alteration of the structure of the epithelial GA and function was also reflected by a reduction of PNA and LTA binding in the GA. The results suggest that PG biosynthesis also plays an important role in the growth and function of the male accessory sex glands and that the ECM of the stroma, including the BL, not only act as a structural support for the epithelium, but also play a regulatory role in the growth, cytodifferentiation and function of the male accessory sex glands. v
Bibliographical Information:


School:The University of Hong Kong

School Location:China - Hong Kong SAR

Source Type:Master's Thesis

Keywords:guinea pigs prostate seminal vesicles extracellular matrix epithelial cells


Date of Publication:01/01/1989

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