Histology and histopathology Vol.11, nº 1 (1996)

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Open Access
Cell rounding with «Rip off» detachment
(Murcia : F. Hernández, 1996) Sit, K.H.
The «rounding up» characteristic of mitotic, apoptotic, transformed and non-transformed cells appears to be initiated by various causative factors. Cytoskeletal and adhesion modulations have been implicated. Endocytic intemalization via large channels seen in the rounding of arnoeba and human cells alike, implicate a third mechanism, viz. membrane flow and fusion, where «rip off» detachment sheds parts of the cell to achieve freedom. Mutilation as a means for detachment is also used by moving fibroblasts, linking shape change with movement via a distinct mechanism. While rounding may follow detachment and detachment may follow rounding, «rip off» mutilation, whether selfinflicted or imposed, and modulation of stickiness are fundamentally different processes
Open Access
Fine structure of the retina and pigment epithelium in the creek chub, Semotilus atromaculatus (Cyprinidae, Teleostei)
(Murcia : F. Hernández, 1996) Collin, S.P.; Collin, H.B.; Ali, M.A.
The structure of the light- and dark-adapted retina, the pigment epithelium and the choroid of the creek chub, Semotilus atromaculatus (Cyprinidae, Teleostei) is examined by light and electron microscopy. An extensive network of vitreal blood vessels emanating from the hyaloid artery enters the eye with the optic nerve and overlies the inner limiting membrane. This membrane closely apposes the fine protrusions of the Müller cell processes which traverse the entire retina, dividing the inner retina into alternating fascicles of ganglion cells and optic axons. The inner nuclear layer consists of bipolar, amacrine, Müller cell soma and two layers of horizontal cells. The outer plexiform layer possesses both rod spherules and cone pedicles. Each rod spherule consists of a single synaptic ribbon in either a triad or quadrad junctional arrangement within the invaginating terminal endings of the bipolar and horizontal cell processes. In contrast, cone pedicles possess multiple synaptic ribbons within their junctional complexes and, in the light-adapted state, the horizontal cell processes show spinule formation. Four photoreceptor types are identified on morphological criteria; unequal double cones, large single cones, small single cones and rods. Al1 but the small single cones are capable of retinomotor responses. The rod to cone ratio is approximately 5:l and the rods form two ill-defined rows in the light-adapted condition. The retinal pigment epithelium possesses two types of osmiophilic granules. These are bound within slender microvilli and migrate vitread to surround the photoreceptors in response to light. Bruch's membrane is trilaminar and the vascularised choroid consists of up to three layers of melanocytes. The endothelial borders of the choroidal blood vessels abutting the outer lamina of Bruch's membrane are fenestrated.
Open Access
Lysosomal glycolipid storage in the renal tubular epithelium in mastomys (Praomys coucha)
(Murcia : F. Hernández, 1996) Fujimura, H.; Ogura, A.; Asano, T.; Noguchi, Y.; Mochida, K.; Takimoto, K.
The renal proximal tubular epithelium of MCC strain of mastomys (Praomys coucha) exhibited a number of cytoplasmic vacuoles after conventional paraffin-embedding procedures. These vacuoles were strongly PAS-positive in cryostat sections. Ultrastructurally, they were double membrane-bound structures filled with myelin figures and acid phosphatase-positive electron-dense matrix. Immunofluorescent microscopy revealed that these structures contained GM2 ganglioside. Other tissues or organs were histologically normal. Mating experiments indicated that the ganglioside storage in MCC mastomys is inherited as an autosomal recessive trait.
Open Access
Fine structure of the acinar and duct cell components in the parotid and submandibular salivary glands of the rat: a TEM, SEM, and HRSEM study
(Murcia : F. Hernández, 1996) Watanabe, Y.; Seguchi, H.; Okada, T.; Kobayahsi, T.; Jin, Q.S.; Jiang, X.D.
Parenchymal and stromal components of the rat parotid and submandibular glands were examined by conventional and high resolution scanning electron microscopy (HRSEM). Freezefractured specimens were subjected to HCI and NaOH extraction procedures to better differentiate connective tissue and cellular components. In addition, the internal three-dimensional morphology of the secretory acinar cells and duct cells was revealed by maceration with a dilute osmium tetroxide solution to selectively remove some of the cytoplasmic components. SEM and HRSEM examination of the HC1- treated samples of both glands revealed a fine filamentous network immediately surrounding each acinus. Coarser bundles of collagen that linked neighboring acini were also observed. NaOH-extracted samples selectively removed the cellular components and showed more clearly the three-dimensional structure of the connective-tissue stroma. A densecollagenous network surrounded each lobule while more internal regions consisted of a honeycomblike pattern of evacuated spaces previously occupied by secretory acini. These spaces were smoothened in appearance and often interconnected. Apicallylocated secretory granules and profiles of the rough endoplasmic reticulum and Golgi apparatus in perinuclear regions were encountered in the acinar and duct cells of macerated samples by HRSEM. In addition, a phenylephrine-induced experimental condition performed in some rats resulted in a significant increase in secretory granule size and density of the serous cells.
Open Access
Dynamic interactions of the extracellular matrix
(Murcia : F. Hernández, 1996) Slater, M.
The extracellular matrix (ECM) is a dynamic assemblage of interacting molecules that reorganise and regulate cell functions in response to endogenous and exogenous stimulii. Matrix components may affect cell behaviour directly or indirectly through growth factor sequestration and transmembrane signalling, by controlling the speed of various molecules through the ECM, and the access of growth factors, hormones and neurotransmitters to the cell surface.
Open Access
Fine structure of the retinal pigment epithelium of the barred owl (Strix varia)
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 1996) Braekevelt, Charlie, R.; Smith, S. A.; Smith, B. J.
The retinal pigment epithelium (RPE) as well as the choriocapillaris and Bruch's membrane (complexus basalis) have been studied by light and electron microscopy in the barred owl (Strix varia). The RPE consists of a single layer of cuboidal cells joined laterally by a series of tight junctions that forms part of the blood-ocular barrier. Basally (sclerally) the retinal epithelial cells display numerous deep infoldings while apically (vitreally) microvillar processes interdigitate with the photoreceptor outer segments. Internally the RPE cells show a large vesicular nucleus, plentiful smooth endoplasmic reticulum (SER) and polysomes but very little rough endoplasmic reticulum (RER). Numerous pleomorphic (including ring-shaped) mitochondria are basally located. In the light-adapted state the small melanosomes are almost exclusively located within the apical process indicating that retinomotor movements probably occur. Phagosomes and lysosome-like bodies are present as are myeloid bodies which may show ribosomes on their outer surface. Bruch's membrane is typical of avian species in that it is pentalaminate and the central lamina densa is displaced towards the choroid. The choriocapillaris endothelium is thin but only minimally fenestrated facing Bruch's membrane. Most fenestrations present show a single-layered diaphragm while others display a double-layered diaphragm as noted in other avian species.
Open Access
Experimental vasectomy and testicular structure
(Murcia : F. Hernández, 1996) Sarrat, R.; Whyte, J.; Torres, A.; Lostalé, F.; Díaz, Mª.P.
We have performed an experimental study on rats and dogs to evaluate the long term effects (from 1 to 12 months) of vasectomy on the structure of the testis. From four months after vasectomy onwards, the specimens showed very important changes in the seminiferous epithelium and Sertoli cells, with an obvious thickening of the basement membrane that supports the epithelium. The deterioration depended on the time passed and, over six months after vasectomy, the alterations were very clear and the seminiferous tubules became atrophic and shnink, sometimes without any remains of seminiferous epithelium and with an important hypertrophy of the interlobular interstitial tissue, although we did not see an increase in the number of Leydig cells. Alterations due to vasectomy depend on the animal species, the peculiarities of techniques and, of course, the time passed after surgery.
Open Access
Fine structure of the retinal photoreceptors of the barred owl (Strix varia)
(Murcia : F. Hernández, 1996) Braekevelt, Charlie R.; Smith, S.A.; Smith, B.J.
The photoreceptors of the barred owl (Strix varia) consist of rods, single cones and unequal double cones present in a ratio of about 35:1:3. In the lightadapted condition the rods are of uniform diameter along their entire length and are therefore not felt to undergo photomechanical changes. The rod outer segment consists of a stack of scalloped bimembranous discs enclosed in a limiting membrane. The rod inner segment displays an ellipsoid of mitochondria, much rough endoplasmic reticulum (RER), numerous polysomes, Golgi zones and autophagic vacuoles, but no hyperboloid of glycogen. Single cones show a slightly tapered outer segment and a heterogeneous oil droplet along with an ellipsoid of mitochondria at the apex of the inner segment. Double cones consist of a larger chief member which also displays a heterogeneous oil droplet and a slightly smaller accesory member which does not. Both members of the double cone as well as the single cones show plentiful polysomes and RER as well as Golgi zones in the inner segment, but none of the cones possessed a condensed paraboloid of glycogen. The contiguous membranes of the chief and accessory cones displayed a few presumed junctional complexes. Judging by their elongated shape in the light-adapted state, cones in this species do not undergo retinomotor movements. Rods and both types of cones have both invaginated (ribbon) and superficial (conventional) synaptic sites.
Open Access
Ultrastructure of liver from piglets fed Tower rapeseed oil
(Murcia : F. Hernández, 1996) Cullen, C.; Singh, A.; Shahidi, E.
Effect of Tower rapeseed oil (RO) containing lower (0.4%) erucic acid on the piglet liver was studied by electron microscopy. The animals were placed in two groups of four and were fed the diets for eight weeks. Animals in the treated group were given a basal diet comprising corn-soybean plus Tower RO at a 10% concentration; animals that were given the basal diet with no added oil served as the controls. Architecture of the liver from animals of the control group appeared normal. Ultrastructural changes in the liver of RO-fed animals included dilation of lumens and loss of microvilli in bile canaliculi. In addition, closely aligned mitochondrial cristae, elevated number of peroxisomes, and an unusual increase in the size and number of membrane bound spaces in zone 3 of liver acini were noticed. These alterations may reflect a disturbance in piglet liver functions following Tower RO feeding.
Open Access
Ultrastructure of invertebrate muscle cell types
(Murcia : F. Hernández, 1996) Paniagua, R.; Royuela, M.; García-Anchuelo, R.M.; Fraile, Benito
The muscular cells of invertebrates can be divided into three major classes on the basis of their striation pattem: transversely striated, obliquely striated, or smooth muscle. Transversely striated muscles have either continuous or discontinuous Z lines and, thus, can be subdivided into two types respectively. Of al1 invertebrate muscles, the transversely striated muscle with continuos Z lines is the most similar to the vertebrate skeletal muscle and is present in arthropods, whose musculature (including the visceral muscles) only consists of this cell type. These muscles are multinucleate cells that contain myofibrils showing welldefined sarcomeres. Transversely striated muscles with discontinuous Z lines, consisting of multiple small electrondense patches, are found in the translucent portions of adductor muscles of some bivalves and in the heart muscle of the gastropods. This muscle is formed by mononucleated cells with centrally-located nuclei and a single myofibril. The obliquely striated muscle appears in nematodes, annelids, molluscs, brachiopods and chaetognathes and consists of mononucleated cells with both thick and thin myofilaments which form sarcomeres delimited by Z lines. Myofilaments are not perpendicular but oblique to the Z lines, so that both A and 1 bands may be seen together in each of the three spatial planes of view. Smooth muscle has been reported in coelenterates, annelids, molluscs, brachiopods and echinoderms, but is lacking in arthropods. These muscle cells have a centrally-located nucleus and abundant thin and thick myofilaments without apparent sarcomeres. The most relevant characteristics of invertebrate muscle cells are the following. The thick (myosin) myofilarnents show a variable length (from 2.2 pm up to 6 pm) and width (from 14 nm up to 231 nm) and contain a central core of paramyosin, which is absent in vertebrate muscles. Thick filaments are homogenous in transversely striated muscles and either homogeneous or fusiform in the obliquely striated and smooth muscles. Thin filaments measure 6 nm in diameter. They contain tropomyosin and, only in striated muscles, also troponin. The thinlthick filament ratio varies from 311 to 611, even in smooth muscles. The plaques for filament anchorage (Z lines in striated muscles or electrondense bodies in smooth muscles) contain a-actinin. The striated (transversely or obliquely) muscles show long sarcomeres (up to 9 pm) and the number of thin filaments around each thick filament varies from 3 to 12, so that each thin filament is shared by two thick filaments. Z lines in the striated muscles show a variety of structures that differ from one species to another (filament bundles in nematodes, bars in annelids, small patches in molluscs, etc). Many striated muscles contain titin (connectin) and intermediate filaments and display a sarcotubular system consisting of T tubules and sarcoplasmic reticulum tubules. Both structures form dyads and, more rarely, triads. The location of T tubules as well as the configuration and distribution of sarcoplasmic reticulum vary among muscles and species. Invertebrate smooth muscle differs from that of vertebrates principally in the higher proportion and larger diameter of thick myofilaments. These may be fusiform and their size and number may vary widely among cells. These muscle cells may be classified by the characteristics of both the thick filaments and the electrondense bodies for filament anchorage.
Open Access
Tissutal imaging by nuclear magnetic resonance
(Murcia : F. Hernández, 1996) Sbarbati, A.; Osculati, F.
The present work reviews the main applications of nuclear magnetic resonance (NMR)- technology and, in particular, of magnetic resonance imaging (MRI) to tissutal analysis. To date, MRI represents a precise and reliable tool to investigate morphology and functional modification of tissues in vivo, providing information consistent with histology. MRI has numerous advantages over conventional techniques: it is harmless to tissues; volume measurements in vivo could be useful for morphometric studies; the sarne tissue can be examined severa1 times (e.g. at different ages); several organs can be examined at the same time; serial sections of relevant structures can be obtained in al1 planes, thereby allowing detailed reconstruction of the three-dimensional configuration of organs; motion within a tissue can be detected; and subsequent histological and ultrastructural studies of the tissue are possible. The main drawback (besides the cost of the basic instrumentation) is that resolution is relatively low in comparison with light microscopy. Finally, the analysis of the results is difficult, needing interdisciplinary competence, and MRI methods of tissutal analysis are not yet well standardized. Therefore, in our opinion, MRI is an interesting tool, complementary to other histological techniques, and it cannot be ignored by microscopists. However, in vivo MRI data must be evaluated with caution and histological controls are always required.
Open Access
Ultrastructure and organisation of the retina and pigment epithelium in the cutlips minnow, Exoglossum maxillingua (Cyprinidae, Teleostei)
(Murcia : F. Hernández, 1996) Collin, S.P.; Collin, H.B.; Ali, M.A.
The structure of the light- and dark-adapted retina, pigment epithelium and choriocapillaris of the cutlips minnow, Exoglossum maxillingua (Cyprinidae, Teleostei) is examined by light and electron microscopy. A pronounced vitreal vascularisation overlies the inner retina where the blood vessel walls, the inner limiting membrane and the Müller cell endfeet are al1 closely apposed. The thick Müller cell processes divide the imer plexiform layer and nerve fibre layer into discrete compartments. The ganglion cells do not form fascicles and lie within both the ganglion cell and imer plexiform layers. The inner nuclear layer consists of amacrine, bipolar, Müller cell somata and two rows of horizontal cells. The photoreceptor terminals comprise either multiple (3-5 in cone pedicles) or single (rod spherules) synaptic ribbons. These photoreceptor terminals form either a triad (rods and cones) or a quadrad (cones) mangement of contact with the invaginating processes of the inner nuclear layer cells. The horizontal cell processes of the cone photoreceptor terminals reveal spinule formation in the light-adapted condition. Five photoreceptor types are classified using morphological criteria; triple cones, unequal double cones, large single cones, small single cones and rods. The ratio of rods to cones is approximately 7: 1. Al1 photoreceptor types show retinomotor responses. Only the cones possess accessory outer segments but both rods (8-11) and cones (15-19) possess calycal processes. The retinal pigment epithelium displays retinomotor responses where pigment granules within fine apical processes move vitread to mask the rods in the light. The cells of the retinal pigment epithelium are joined by various types of junctions and contain numerous phagosomes, mitochondria and polysomes. Bruch's membrane or the complexus basalis is trilaminate with two types of collagen fibrils comprising the central layer. The endothelia of the blood vessels of the choriocapillaris, facing Bruch's membrane, are fenestrated. Two to three layers of melanocytes interspersed between large thinwalled capillaries and severa1 layers of collagen fibrils comprise the choriocapillaris.
Open Access
Major histocompatibility complex expression in muscle of rats with graft-versus-host disease
(Murcia : F. Hernández, 1996) hba, Y.; Fujikura, Y.; Sawada, T.; Tokuda, N.; Morimatsu, M.; Fukumoto, T.
Immunohistochemical examination of rat skeletal muscle during graft-versus-host disease (GVHD), a systemic immune reaction, was performed to investigate specific immune reactivities focusing on major histocompatibility complex (MHC) expression and inflammatory cell infiltration of skeletal muscle during a systemic immune reaction. MHC class 11 expression and inflammatory cell infiltration did not increase. MHC class 1 was expressed along the contour of muscle fibres, and most strongly expressed by the cells which were distributed throughout the endomysium and perimysium. Seventy-six percent of these MHC class I+ cells carried endothelial cell-markers, while 24% of them did not. The latter cells were revealed not to be inflammatory cells such as lymphocytes, granulocytes or macrophages when examined by immunostaining using severa1 exudate-cell markers. Neither were they myosatellite cells because they were located outside the basement membrane. These results may be useful for considering animal models of inflammatory myopathies such as polymyositis and dermatomyositis.
Open Access
Argyrophilic nucleolar organizer region (AgNOR) counting in astrocytic gliomas: prognostic value
(Murcia : F. Hernández, 1996) Cardesa, Antonio; Ferreres, Joan-Carles; Figols, J.; Val-Bernal, José Fernando; Cruz Sánchez, F.F.
In 87 astrocytic gliomas the number of AgNORs/nucleus was retrospectively studied and data correlated with the histological type of the tumors and survival. Al1 patients were treated by the same surgical team and with uniform criteria. Statistically significant differences (p<0.01) were found in relation with the AgNOR averages among the histological types of tumors. A statistically significant linear correlation (p<0.05) between the AgNOR values and survival of the patients was also found. Patients with mean AgNOR values higher than 2.23 and lower than 2.9 survived an average of 11.5I9.1 months vs. a sumival in average of 24.4I34.1 months with mean AgNOR values under 2.23 (p<0.05). Patients with AgNOR values higher than 2.9 survived, on average, 7.7I3.9 months. AgNOR counting in astrocytic gliomas is a reproducible, easy, quick method with prognostic value. AgNORs may be successfully applied in routine material to assess the growth potential of astrocytic gliomas.
Open Access
Ultrastructural study of the vascular response in small early gastric cancer
(Murcia : F. Hernández, 1996) Caruso, R.A.; Cicciarello, R.; D'Aquino, Alessandra; Inferrera, C.
The microvasculature of the stroma of four cases of small early gastric cancer (EGC) was investigated by conventional electron microscopy. Severe damage to small and large fenestrated capillaries was observed around endothelium-adherent, partially degranulated neutrophils. The findings suggest the existence of neutrophil-mediated injury of endothelial cells during the development of inflammatory responses in small EGC. The severely injured microvessels exhibited increase in vasopermeability, microhaemorrhage, and platelet aggregates. Other microvascular changes included endothelial cell and pericyte activation as well as basal lamina replications, indicative of repeated episodes of endothelial injury, necrosis and regeneration. This new capillary growth within the old basal laminas shared morphological features with a peculiar angiogenic process described in man and animals.
Open Access
Rhinophyma - unusual expression of simple-type keratins and S1 00A in sebocytes and abundance of VIP receptor-positive dermal cells
(Murcia : F. Hernández, 1996) Wollina, U.
Rhinophyma represents a severe variant of rosacea, a common mid-facial erythematous dermatosis. Increased blood flow and pooling in skin are thought to be involved in its pathogenesis. Since neuropeptides and their receptors are responsible for local blood flow regulation, immunolocalization for the vasoactive intestinal peptide (V1P)-receptor(R) was performed in slice biopsies taken from five patients with glandular rhinophyma. Additional immunostainings included intermediate filaments (keratin, vimentin) and neuroglandular antigen (NGA). In contrast to controls, rhinophyma disclosed not only a more dense distribution of VIP-R positive cells within the endothelium but immunoreactive perivascular large cells. The immature sebocytes stained positive with monoclonal antibody Cam5.2 against glandular antigens and polyclonal anti- S100A. Elastotic connective tissue in the dermis showed a strong immunoreactivity for vimentin and NGA. From these results we suggest that, (a) ligands of the VIP-R may contribute to vascular and dermal alterations in rosacea and (b) immature sebocytes show an unusual antigen expression of SlOOA and glandular keratin.
Open Access
lmmunogold analysis of antioxidant enzymes in common renal cancers
(Murcia : F. Hernández, 1996) Oberley, T.D.; Sempf, J.M.; Oberley, L.W.
Immunogold studies of normal human kidney and common human kidney cancers were performed using polyclonal antibodies to antioxidant enzymes, including antibodies to copper, zinc and manganese superoxide dismutases, catalase, glutathione peroxidase, and glutathione S-transferases and their subunits. Normal tissue adjacent to human renal tumors had the same antioxidant enzyme immunoreactive protein profiles as normal human kidney, thus establishing that the presence of tumor does not alter the levels of antioxidant enzyme immunoreactive proteins in adjacent kidney tissue. Levels of immunoreactive protein for antioxidant enzymes were determined in four common types of malignant renal cancer. In general, tumors had low levels of antioxidant enzymes; however, certain histologic types of renal tumors had high levels of immunoreactive protein for glutathione S-transferase subunits, which could affect their susceptibility to chemotherapy. Studies of transitional carcinoma of the renal pelvis were especially informative since it was possible to compare levels of antioxidant enzyme immunoreactive protein with adjacent normal transitional epithelium; the majority of antibodies resulted in lower levels of immunoreactive protein in transitional cell carcinoma than in adjacent normal transitional epithelium. Our results are discussed in relation to the response of renal tumors to therapy.
Open Access
Histochemical demonstration and analysis of poly-N-acetyllactosamine structures in normal and malignant human tissues
(Murcia : F. Hernández, 1996) Ito, N.; yokota, M.; Nagaike, C.; Morimura, Y.; Hatake, K.; Matsunaga, T.
Poly-N-acetyllactosaminyl structures carry a variety of physiologically and pathologically important carbohydrate antigens and are presumed to have essential roles in the process of cellular recognition, differentiation, malignant transformation and cancer metastasis. Monoclonal antibodies, lectins and endo-Bgalactosidase are useful histochemical tools for detecting and analyzing poly-N-acetyllactosamines in tissue sections. 1 (branched structure) and i (linear structure) antigens recognized by monoclonal antibodies have been shown to be differentiation antigens in mouse embryo and mouse and human teratocarcinoma cells as well as in human erythrocytes. They are also oncofoetal antigens and are expressed in carcinoma cells in severa1 tissues and organs. Immobilized lectins specific to po1y-Nacetyllactosamine structures have been successfully applied for fractioning glycoproteins with po1y-Nacetyllactosamine, but histochemical use of these lectins has been restricted to some animal tissues. Arnong them, pokeweed mitogen agglutinin was used to detect branched poly-N-acetyllactosamine in normal and malignant human colon, demonstrating that it has a highly selective affinity for colorectal carcinomas. Griffonia simplicifolia agglutinin-11 staining following endo-B-galactosidase digestion procedure revealed the presence of poly-N-acetyllactosamine structures with or without blood group-specificities in severa1 normal human tissues. By using this procedure, it was demonstrated that the blood group-related antigens oncofoetally expressed in thyroid carcinoma cells are carried by poly-N-acetyllactosamines containing a domain susceptible to the enzyme digestion. Staining with lectins specific to poly-N-acetyllactosamine in combination with endo-B-galactosidase digestion demonstrated that poly-N-acetyllactosaminyl structures ubiquitously and consistently produced in thyroid papillary carcinomas are highly heterogeneous in their chain length and branching status and quite different from those produced in other thyroid neoplasms. Staining with monoclonal antibodies or lectins combined with endo-B-galactosidase digestion procedures have been proven to be powerful tools for localizing and analyzing different types of poly-N-acetyllactosamine structures in normal and malignant tissues.
Open Access
Cross-reactive and species specific Mycobacterium tuberculosis an t i gens i n the immunoprofile of Schaumann bodies: a major clue to the etiology of sarcoidosis
(Murcia : F. Hernández, 1996) Ang, S.C.; Moscovic, E.A.
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Open Access
Expression of renin in coagulating glands
(Murcia : F. Hernández, 1996) Kon, Yasuhiro; Endoh, Daiji
The presence of an extrarenal or local reninangiotensin system has been noted in several tissues, although their functions have not yet been clarified. Renin from the coagulating gland (CG), is the most recently discovered local renin, and is a significant subject for investigation with histological and molecular biological techniques. Dot-like reactions for renin are detected immunohistochemically in the epithelial cells of CGs of the strains C57BL16 mice. Excretory products of some terminal lumina are also found to be positive for renin. Colloidal gold particles, indicating the presence of renin, are detected in the lysosomal granules, in which they are especially located on the crystalline structure. They are also observed in the production of series of exocrine granules. At the apical region, both reninpositive exocrine and lysosomal granules are secreted by exocytosis. In the development, immunoreactivity for renin is first detected at 6 weeks after birth. After that time, the number of renin-containing cells gradually increase throughout the development. In adults, severa1 pattems of renin immunoreactivity are demonstrated in almost al1 epithelial cells of CGs. At 4 weeks after castration, renin-containing cells in terminal ducts are decreased and remain at very low levels. After testosterone injection, the numerical value of renincontainingis detected in the CGs by Northern blot analysis and hybridohistochemistry. These findings suggest that renin is synthesized depending on testosterone, and released by exocrine secretion. cells is high at 1 week. Finally, renin mRNA