1
|
Ikeda S, Sato K, Fujita H, Ono-Minagi H, Miyaishi S, Nohno T, Ohuchi H. Harderian Gland Development and Degeneration in the Fgf10-Deficient Heterozygous Mouse. J Dev Biol 2024; 12:16. [PMID: 38921483 PMCID: PMC11205083 DOI: 10.3390/jdb12020016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/26/2024] [Accepted: 05/29/2024] [Indexed: 06/27/2024] Open
Abstract
The mouse Harderian gland (HG) is a secretory gland that covers the posterior portion of the eyeball, opening at the base of the nictitating membrane. The HG serves to protect the eye surface from infection with its secretions. Mice open their eyelids at about 2 weeks of age, and the development of the HG primordium mechanically opens the eye by pushing the eyeball from its rear. Therefore, when HG formation is disturbed, the eye exhibits enophthalmos (the slit-eye phenotype), and a line of Fgf10+/- heterozygous loss-of-function mice exhibits slit-eye due to the HG atrophy. However, it has not been clarified how and when HGs degenerate and atrophy in Fgf10+/- mice. In this study, we observed the HGs in embryonic (E13.5 to E19), postnatal (P0.5 to P18) and 74-week-old Fgf10+/- mice. We found that more than half of the Fgf10+/- mice had markedly degenerated HGs, often unilaterally. The degenerated HG tissue had a melanized appearance and was replaced by connective tissue, which was observed by P10. The development of HGs was delayed or disrupted in the similar proportion of Fgf10+/- embryos, as revealed via histology and the loss of HG-marker expression. In situ hybridization showed Fgf10 expression was observed in the Harderian mesenchyme in wild-type as well as in the HG-lacking heterozygote at E19. These results show that the Fgf10 haploinsufficiency causes delayed or defective HG development, often unilaterally from the unexpectedly early neonatal period.
Collapse
Affiliation(s)
- Shiori Ikeda
- Department of Cytology and Histology, Medical School, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | - Keita Sato
- Department of Cytology and Histology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | - Hirofumi Fujita
- Department of Cytology and Histology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | - Hitomi Ono-Minagi
- Department of Cytology and Histology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | - Satoru Miyaishi
- Department of Legal Medicine, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | - Tsutomu Nohno
- Department of Cytology and Histology, Medical School, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | - Hideyo Ohuchi
- Department of Cytology and Histology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| |
Collapse
|
2
|
Roshdy K, Massoud D, Al-Otaibi AM, Abumandour MMA. Histology, histochemistry and fine structure of the lacrimal gland in the one-humped camel (Camelus dromedarius). Anat Histol Embryol 2024; 53:e13051. [PMID: 38741549 DOI: 10.1111/ahe.13051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 04/27/2024] [Accepted: 05/02/2024] [Indexed: 05/16/2024]
Abstract
Our research aimed to provide complete histological, histochemical and ultrastructural features of the lacrimal gland of the one-humped camel (Camelus dromedarius) as well as novel insights into its adaptability to the Egyptian desert. Our study was applied to 20 fresh lacrimal glands collected from 10 camels instantly after their slaughtering. The results revealed that the gland was a compound tubulo-acinar gland, and its acini were enclosed by a thick connective tissue capsule that was very rich in elastic and collagen fibres. The gland acini had irregular lumens and were composed of conical to pyramidal cells. The nuclei of secretory cells were found in the basal part, and the cytoplasm was eosinophilic and granular. The glandular tissue consisted of serous and mucous acini and seromucous secretory cells. Histochemically, there was a significant amount of neutral mucopolysaccharides in the acini in which mucous cells had a significant periodic acid-Schiff (PAS)-positive reaction, whereas seromucous cells had a mild PAS-positive reaction. Ultrastructurally, the lacrimal cells had numerous secretory vesicles with contents of moderately to highly electron-dense cytoplasm. The nuclear envelope consisted of two prominent membranes surrounding the peri-nuclear cisterna. The acinar cells had numerous electron-lucent and moderately electron-dense secretory granules, mainly situated on the apical surface, and secreted their contents into the lumen. The luminal surface of the mucous secretory cells represents the remains of secretory granules discharged by the merocrine mechanism. In conclusion, the mucous secretion is believed to aid in the washing and moistening of the eyeball, particularly in dry, hot and dusty environments.
Collapse
Affiliation(s)
- Karam Roshdy
- Department of Histology and Cytology, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Abees, Egypt
| | - Diaa Massoud
- Department of Biology, College of Science, Jouf University, Sakaka, Saudi Arabia
| | - Aljohara M Al-Otaibi
- Department of Biology, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Mohamed M A Abumandour
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Abees, Egypt
| |
Collapse
|
3
|
Klećkowska-Nawrot J, Barszcz K, Stegmann KO, Goździewska-Harłajczuk K. The organ of vision morphology of the southern two-toed sloth (Choloepus didactylus Linnaeus, 1758; Pilosa, Choloepodidae). Anat Histol Embryol 2024; 53:e12984. [PMID: 37822296 DOI: 10.1111/ahe.12984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 09/07/2023] [Accepted: 10/02/2023] [Indexed: 10/13/2023]
Abstract
The Choloepus didactylus is a species belonging to the Choloepodidae family of the Folivora suborder. This study concerns the anatomical, morphometrical, histological and histochemical examination of the eye tunics, eyelids and orbital glands in the three adult Choloepus didactylus coming from the Wroclaw Zoological Garden. The cornea consists of four layers since Bowman's membrane was absent. The presence of palisades of Vogt formed from 14/15 to 20/21 layers of epithelial cells was demonstrated. Macroscopically, the tapetum lucidum was not identified, while degenerative choroidal tapetum lucidum cellulosum was found microscopically. The ciliary muscle was found with our histological approach. The pupil was round in shape (post-mortem). The presence of tarsal glands has not been demonstrated in both eyelids. The conjunctiva-associated lymphoid tissue (CALT) has been shown in the upper and lower eyelids. The superficial gland of the third eyelid produced a seromucous secretion. The third eyelid was shaped like a curved arch and composed of hyaline cartilage. The deep gland of the third eyelid was big and multilobar acinar simple with serous character. The lacrimal gland produced mucous secretion. The results of our research indicate that the features of the eye anatomy in the southern two-toed sloth (C. didactylus) are also typical of the Folivora suborder and have common features and differences with Vermilingua.
Collapse
Affiliation(s)
- Joanna Klećkowska-Nawrot
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Karolina Barszcz
- Department of Morphological Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, Warsaw, Poland
| | | | - Karolina Goździewska-Harłajczuk
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| |
Collapse
|
4
|
Klećkowska-Nawrot JE, Goździewska-Harłajczuk K, Barszcz K. Comparative study of the eyelids and orbital glands morphology in the okapi (Okapia johnstoni, Giraffidae), Père David's deer (Elaphurus davidianus, Cervidae) and the Philippine mouse-deer (Tragulus nigricans, Tragulidae). Histol Histopathol 2019; 35:185-202. [PMID: 31271442 DOI: 10.14670/hh-18-144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The accessory organs of the eye represent part of the protective system of the eyeball. In the present study, an examination of the accessory organs of the eye of three species of captive ruminants was performed using light microscopy. In the okapi, the superficial gland of the third eyelid and lacrimal gland were complex branched multilobar tubular glands formed by mucous units with tubular secretory portions and no plasma cells. The deep gland of the third eyelid was absent in the okapi and present in both the Père David's deer and the Philippine mouse-deer. In the Philippine mouse-deer, the deep gland had a very thick connective capsule and thick interlobar septae. It contained fewer lobes forming the gland parenchyma compared to Père David's deer and other ruminants. Organized lymphoid follicles were present within the upper and lower eyelids only in the okapi and Père David's deer, while diffuse lymphocytes were observed in the Philippine mouse-deer. The orbital glands in the Père David's deer had a multilobar tubuloacinar structure with numerous plasma cells and a mucoserous character. In contrast to the Philippine mouse-deer, these glands had a serous character. The presence of several macroscopic and microscopic structural differences of the examined accessory organs of the eye in the three captive ruminant species may be understood within an ecological context and may be associated with different habitat-specific environmental conditions.
Collapse
Affiliation(s)
- Joanna Elżbieta Klećkowska-Nawrot
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
| | - Karolina Goździewska-Harłajczuk
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
| | - Karolina Barszcz
- Department of Morphological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| |
Collapse
|
5
|
Klećkowska-Nawrot JE, Goździewska-Harłajczuk K, Darska M, Barszcz K, Janeczek M. Microstructure of the eye tunics, eyelids and ocular glands of the Sulawesi bear cuscus (Ailurops ursinusTemminck, 1824) (Phalangeridae: Marsupialia) based on anatomical, histological and histochemical studies. ACTA ZOOL-STOCKHOLM 2018. [DOI: 10.1111/azo.12251] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Joanna E. Klećkowska-Nawrot
- Department of Biostructure and Animal Physiology; Faculty of Veterinary Medicine; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Karolina Goździewska-Harłajczuk
- Department of Biostructure and Animal Physiology; Faculty of Veterinary Medicine; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Marta Darska
- Faculty of Biology and Animal Science; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Karolina Barszcz
- Department of Morphological Sciences; Faculty of Veterinary Medicine; Warsaw University of Life Sciences; Warsaw Poland
| | - Maciej Janeczek
- Department of Biostructure and Animal Physiology; Faculty of Veterinary Medicine; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| |
Collapse
|
6
|
Klećkowska-Nawrot JE, Goździewska-Harłajczuk K, Łupicki D, Marycz K, Nawara T, Barszcz K, Kowalczyk A, Rosenberger J, Łukaszewicz E. The differences in the eyelids microstructure and the conjunctiva-associated lymphoid tissue between selected ornamental and wild birds as a result of adaptation to their habitat. ACTA ZOOL-STOCKHOLM 2017. [DOI: 10.1111/azo.12223] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joanna E. Klećkowska-Nawrot
- Department of Animal Physiology and Biostructure; Faculty of Veterinary Medicine; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Karolina Goździewska-Harłajczuk
- Department of Animal Physiology and Biostructure; Faculty of Veterinary Medicine; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Dariusz Łupicki
- Museum of Natural History of the Faculty of Biology and Animal Science; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Krzysztof Marycz
- Electron Microscopy Laboratory; Faculty of Biology and Animal Science; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Tomasz Nawara
- Electron Microscopy Laboratory; Faculty of Biology and Animal Science; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Karolina Barszcz
- Department of Morphological Sciences; Faculty of Veterinary Medicine; Warsaw University of Life Sciences; Warsaw Poland
| | - Artur Kowalczyk
- Division of Poultry Breeding; Faculty of Biology and Animal Science; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Joanna Rosenberger
- Division of Poultry Breeding; Faculty of Biology and Animal Science; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Ewa Łukaszewicz
- Division of Poultry Breeding; Faculty of Biology and Animal Science; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| |
Collapse
|
7
|
CONJUNCTIVAL BACTERIAL FLORA, ANTIBIOGRAM, AND LACRIMAL PRODUCTION TESTS OF COLLARED ANTEATER (TAMANDUA TETRADACTYLA). J Zoo Wildl Med 2017; 48:7-12. [DOI: 10.1638/2015-0251.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
8
|
Kelleher Davis R, Doane MG, Knop E, Knop N, Dubielzig RR, Colitz CMH, Argüeso P, Sullivan DA. Characterization of ocular gland morphology and tear composition of pinnipeds. Vet Ophthalmol 2012; 16:269-75. [PMID: 23067374 DOI: 10.1111/j.1463-5224.2012.01073.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The importance of tear film integrity to ocular health in terrestrial mammals is well established, however, in marine mammals, the role of the tear film in protection of the ocular surface is not known. In an effort to better understand the function of tears in maintaining health of the marine mammal eye surface, we examined ocular glands of the California sea lion and began to characterize the biochemical nature of the tear film of pinnipeds. PROCEDURES Glands dissected from California sea lion eyelids and adnexa were examined for gross morphology, sectioned for microscopic analysis, and stained with hematoxylin and eosin. The tear film was examined using interferometry. Tears were collected from humans and pinnipeds for the analysis of protein and carbohydrate content. RESULTS The sea lion has sebaceous glands in the lid, but these glands are different in size and orientation compared with typical meibomian glands of terrestrial mammals. Two other accessory ocular glands located dorsotemporally and medially appeared to be identical in morphology, with tubulo-acinar morphology. An outer lipid layer on the ocular surface of the sea lion was not detected using interferometry, consistent with the absence of typical meibomian glands. Similar to human tears, the tears of pinnipeds contain several proteins but the ratio of carbohydrate to protein was greater than that in human tears. CONCLUSIONS Our findings indicate that the ocular gland architecture and biochemical nature of the tear film of pinnipeds have evolved to adapt to the challenges of an aquatic environment.
Collapse
Affiliation(s)
- Robin Kelleher Davis
- Schepens Eye Research Institute, Massachusetts Eye and Ear, 20 Staniford St., Boston, MA 02114, USA.
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Gasser K, Fuchs-Baumgartinger A, Tichy A, Nell B. Investigations on the conjunctival goblet cells and on the characteristics of glands associated with the eye in the guinea pig. Vet Ophthalmol 2011; 14:26-40. [PMID: 21199277 DOI: 10.1111/j.1463-5224.2010.00836.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To investigate the distribution and density of conjunctival goblet cells (GC) and to study the anatomy and microscopic characteristics of glands associated with the eye in the guinea pig. PROCEDURES Twenty-five guinea pigs were used. Meibomian gland openings were counted using biomicroscopy. Conjunctiva, eyelids and glands were embedded in glycol methacrylate and paraffin. Sections were stained with hematoxylin and eosin (H&E), periodic acid Schiff's reaction (PAS) and Alcian blue (AB). RESULTS Highest GC densities were found in the bulbar and palpebral region of the nasal conjunctiva (GC index: 13.7-16.4%). Lowest GC densities (GC index: 0.0-1.0%) were found in 3/4 limbal regions (nasal and temporal upper eyelid, temporal lower eyelid). Guinea pigs have 27.1±3.0 (mean±SD) meibomian gland openings in the upper lid and 25.7±2.3 in the lower lid. Difference between upper and lower lid was significant (P=0.037). Two subconjunctival sebaceous glands occur temporal to each eye. The Harderian gland is very large. In the lacrimal gland three different cell types were distinguished both according to the cell structure and histochemical staining. CONCLUSIONS Goblet cell densities are lower in guinea pigs than in dogs and horses. Positive staining with PAS and AB could be an indication that mucins are produced in the lacrimal gland. If so, they may contribute to the mucin layer of the tear film. Both the extraordinarily large Harderian gland and the subconjunctival sebaceous glands produce lipids and may contribute to the lipid layer of the tear film.
Collapse
Affiliation(s)
- Karin Gasser
- Clinic for Surgery, Dentistry and Ophthalmology, Department of Companion Animals and Horses, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | | | | | | |
Collapse
|
10
|
Rehorek SJ, Hillenius WJ, Sanjur J, Chapman NG. One gland, two lobes: Organogenesis of the “Harderian” and “nictitans” glands of the Chinese muntjac (Muntiacus reevesi) and fallow deer (Dama dama). Ann Anat 2007; 189:434-46. [PMID: 17910397 DOI: 10.1016/j.aanat.2006.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The nictitans and Harderian glands are enigmatic glands situated in the anterior aspect of the orbit. Traditionally, the nictitans and Harderian glands of mammals have been considered to be two fundamentally distinct glands. However, a consistent, unambiguous distinction between these two glands has remained elusive due to conflicting anatomical and histochemical definitions. The Harderian gland was originally described, and first distinguished from the nictitans gland, in adult deer. We examined the organogenesis and histochemistry of the anterior orbital glandular mass in two species of deer (Muntiacus reevesi and Dama dama) to determine whether it comprises two distinct glands or one bilobed gland. The anterior orbital regions of 30 fetal specimens of both species, along with some adult material, were examined histologically. Four stages of glandular organogenesis were observed. Most notably, both glandular portions developed from the same inception point, but the deep lobe developed faster than the superficial lobe. The common inception point and the relationship of the collecting ducts clearly shows that this is a single glandular mass that differentiates into two lobes rather than two distinct glands. Moreover, although the histochemical profiles of the two lobes differ slightly, both lobes produce lipids, which is further indication that these are not profoundly different glands but part of a single, heterogeneously developed gland. Thus, it is proposed that the terms nictitans and Harderian glands, as separate entities, be discontinued and that the entire gland be referred to as the anterior orbital gland (glandula orbitalis anterior), with superficial and deep lobes (pars superficialis and pars profundus, respectively).
Collapse
Affiliation(s)
- S J Rehorek
- Department of Biology, Slippery Rock University, Slippery Rock, PA 16057, USA.
| | | | | | | |
Collapse
|
11
|
Rehorek SJ, Legenzoff EJ, Carmody K, Smith TD, Sedlmayr JC. Alligator tears: a reevaluation of the lacrimal apparatus of the crocodilians. J Morphol 2005; 266:298-308. [PMID: 16163706 DOI: 10.1002/jmor.10378] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The Harderian gland is a poorly understood anterior ocular gland that occurs in most terrestrial vertebrates. Numerous extraorbital functions have been ascribed to the Harderian gland, principally based on its association with the nasolacrimal duct. Few studies have centered on archosaurs and the majority of those available focused solely on the Harderian gland of birds. Little is known about the lacrimal apparatus of the crocodilians. We examined the lacrimal apparatus of several specimens of Alligator mississippiensis anatomically, histologically, and histochemically and studied the embryogenesis of this system. The nasolacrimal duct possesses a distal secretory area, which is more convoluted than that of typical mammals or lepidosaurs. The alligator Harderian gland possesses a unique combination of characteristics found in lepidosaurs, birds, and mammals. Like that of both mammals and lepidosaurs, it is a large, tuboloacinar gland that appears to secrete both mucoprotein and lipids. However, the presence of blood vessels and immune cells is reminiscent of that of the avian Harderian gland. The immunogenesis of the alligator Harderian gland appears to be tied to the development of the vascular system. The presence of a distinct palpebral gland in the anterior aspect of the ventral eyelid is a feature unique to alligators. Based on position, this gland does not appear to be homologous to the anterior lacrimal gland of lepidosaurs. Lymphatic aggregations were also found in the palpebral gland. The presence of interstitial immune cells in the orbital glands of alligators suggests that the alligator lacrimal apparatus, like that of birds, may play a role in the head-associated lymphatic tissue system.
Collapse
Affiliation(s)
- S J Rehorek
- Department of Biology, Slippery Rock University, Pennsylvania 16057-1326, USA.
| | | | | | | | | |
Collapse
|
12
|
Aldana Marcos HJ, Affanni JM. Anatomy, histology, histochemistry and fine structure of the Harderian gland in the South American armadillo Chaetophractus villosus (Xenarthra, Mammalia). ACTA ACUST UNITED AC 2005; 209:409-24. [PMID: 15883851 DOI: 10.1007/s00429-005-0457-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2005] [Indexed: 10/25/2022]
Abstract
The anatomical, histological, histochemical and ultrastructural characteristics of the Harderian gland of the armadillo Chaetophractus villosus were described. The gland is the largest structure in the bony orbit. It is situated in the anteroventral region of the orbit. Obvious structural differences are not observed between males and females. The gland is compound-branched tubulo-alveolar, being characterized by a single layer of columnar cells surrounded by myoepithelial cells. It possesses a single excretory duct opened into the inner canthus. All glandular cells show yellow-green autofluorescence and additionally some glandular lumen may contain dense autofluorescent solid accretions. There are two peculiar and outstanding cytoplasmic features. One is represented by the smooth endoplasmic reticulum (SER), forming a closely woven meshwork. The other one is represented by "membranous bodies" apparently derived from the SER, RER and cytoskeleton with a "Star of David" configuration situated in the supranuclear region. Three types of vesicles are detected in the cytoplasm. Histochemical staining methods reveal lipids, proteins, neutral and acidic containing glycoconjugates in secretory vesicles. The mechanism of secretion appears either merocrine or apocrine. The epithelium of the intra- and inter-lobular excretory ducts suggests secretory activity. Tubulo-acinar glands similar to those seen in the lacrimal gland and nictitans glands are found related to the intralobular and main excretory ducts. The capillary network is characterized by fenestrated endothelium. The stroma possesses unmyelinated axons and plasma cells. The normal secretion of the secretory endpieces, particularly lipids, proteins and glycoconjugates, is complemented by mucous and serous secretions released by ductal cells and glands associated to the ducts.
Collapse
Affiliation(s)
- Hernán Javier Aldana Marcos
- Laboratorio de Histología, Facultad de Medicina, Universidad de Morón, Machado 914, B1708JPD Morón, Argentina.
| | | |
Collapse
|