Effect of Harderian adenectomy on the statistical analyses of mouse brain imaging using positron emission tomography

Positron emission tomography (PET) using 2-deoxy-2-[18F] fluoro-D-glucose (FDG) as a radioactive tracer is a useful technique for in vivo brain imaging. However, the anatomical and physiological features of the Harderian gland limit the use of FDG-PET imaging in the mouse brain. The gland shows strong FDG uptake, which in turn results in distorted PET images of the frontal brain region. The purpose of this study was to determine if a simple surgical procedure to remove the Harderian gland prior to PET imaging of mouse brains could reduce or eliminate FDG uptake. Measurement of FDG uptake in unilaterally adenectomized mice showed that the radioactive signal emitted from the intact Harderian gland distorts frontal brain region images. Spatial parametric measurement analysis demonstrated that the presence of the Harderian gland could prevent accurate assessment of brain PET imaging. Bilateral Harderian adenectomy efficiently eliminated unwanted radioactive signal spillover into the frontal brain region beginning on postoperative Day 10. Harderian adenectomy did not cause any post-operative complications during the experimental period. These findings demonstrate the benefits of performing a Harderian adenectomy prior to PET imaging of mouse brains.

Development of harderian gland in female guinea pig: histological and ultrastructural study

The harderian gland is a large orbital structure which open by a duct onto the surface of the nictitating membrane. It is widely assumed that its primary function is to lubricate the surface of the eye. However, a variety of secondary functions have been ascribed to it, with suggestions that it is a site of immune responses for the conjunctival sac, a source of pheromones and/ or thermoregulatory lipids, a source of photoprotective secretions and part of retinal-pineal axis. By means of histological examination, harderian gland of female guinea pig was investigated to demonstrate the structural appearance of the gland at different age and the results were discussed with reference to functional aspect. A total number of thirty animals of different ages [5 animals each] were used in this study. The ages were [newborn, one week, two weeks, three weeks, two months and six months old]. Specimens from HG of each animal were prepared for light, electron and fluorescent microscopy and immunohistochemical examination. This study revealed that the newborn harderian gland showed signs of maturity features of secretory epithelial cells but continued differentiation with the age. Ultrastucture revealed two types of dark secretory epithelial cells [type I, the principle most common and type II, the vesicular]. The latter possess neuro vesicles with dense cores. Three types of light cells I, II and III present. The chief feature of the cytoplasm of these epithetlial cells was large numbers of lipid vacuoles which dominate the apical half of the cell. Secretory endpieces were surrounded by a network of myoepithelial cells. Heterogenous populations of mast cells with cytopasmic granules in different stage of maturity, size and electron density were detected in intersitium since birth. The glandular epithelial cells fluroscences pale yellow green with fluorescent microscope immunohistochemical result showed some glandular cells with chomogramin positive reaction. The present study will give a systematic description on the structure of the female guinea pig harderian gland at different ages

comparative study of the harderian gland in the female rat and female rabbit [A histological, histochemical, scanning electron microscopic and morphometric study]

The Harderian gland [HG] is a large retrobulbar, tubuloalveolar organ. It is present in many animals possessing a nictitating membrane [third eye lid]. Compare the microscopic features of the HG in the female rat [as n example of rodents] with those of the female rabbit [as an example of mammals]. Using histological, histochemical and morphometric techniques on the HG in adult female rat [3 months old] and rabbit [4.5 months old]. A total number of 6 adult animals were used in each species. By gross inspection the Harderian gland is bibbed. In the rat, the two lobes are similar in colour and texture while in the rabbit, the small lobe is white and the large lobe is red [pink]. The gland is covered by a thin C.T. capsule with species variations both in structure and auto fluorescence. In the rat the two lobes show a fundamentally similar histological structure and the secretory epithelium is formed of two types of cells, type A and type B. While in the rabbit the two lobes have different histological structure and each lobe is formed of a single type of cells that differs in both lobes. The contents of the lumina of the tubuloalveoli vary in the two species indicating different modes of secretion. Statistical difference in the arbitrary area of the tububoalveoli between the large and small lobes of the gland is insignificant in the rat but it is significant in the rabbit. In both species a single extra glandular excretory duct is detected at the hilum of the gland. In the rat the wall of the duct possess diverticula and the lining epithelium comprises some serous/or mucous acini. While in the rabbit, the structure of the duct is simple and it is lined by a low columnar epithelium with some goblet cells. Further research will be needed to correlate the different histological structure between the female rat and rabbit HG with the biology of these animals and to their functional significance

Ultrastructural characterization of epithelial cells of rabbit harderian gland with particular reference to their mode of secretion

The present study was carried out to shed some light on the ultrastructure of the rabbit Harderian gland in order to help determine its functions with particular reference to the mechanism of its secretion. Twelve adult male and female rabbits were used in this experiment. Small specimens from the Harderian glands were processed for light and transmission electron microscopic study. Obvious structural differences were not observed between male and finale rabbit Harderian glands. The rabbit Harderian gland appeared bibbed; the pink lobe and white lobe. The pink lobe was formed of simple cuboidal epithelial cells with very large lipid vacuoles while the white lobe was formed of simple cuboidal or columnar epithelium with small irregular lipid vacuoles. Lipid vacuoles could be seen in close contact with the plasma membrane at the luminal surface of the acinar cell to be secreted by merocrine mode of secretion. The apical parts of some cells appeared [is being extruded from the cellular apices towards the lumen to be secreted by apocrine mode of secretion. The white lobe contained intraluminal porphyrins accretions, whereas pink lobe lacks these accretion s. The Golgi complexes amid smooth endoplasmic reticulum were well developed in the cells of the white lobe than in those of the pink lobe. The epithelium of the excretory ducts was seen containing apical granules suggesting secretary activity. The glandular stroma possessed unmyelinated axons and capillaries. This study showed that there was no sexual dimorphism in rabbit Harderian: gland. The different mechanisms of secretions were essentially merocrine and an apocrine type, while the holocrine mode of secretion was unconfirmed. The rabbit Harderian gland might also have an endocrine function in addition to its exocrine function

Harderian gland of wistar rats revised as a protoporphyrin ix producer

In 1694 Johann Jacob Harder described, for the first time, the harderian gland, located near the eye in the great majority of vertebrates, and regarded it as a lacrimal gland. This gland has multiple functions that vary according to the animal species. In the present work, we review the literature on the harderian gland of rats, focusing our study on the detection of great amounts of protoporphyrin IX (PpIX) produced by rodent glands. Protoporphyrin IX is a powerful photosensitizer that is widely used for photodynamic therapy (PDT). We also discuss the anatomic and the histological evidence for the presence of PpIX in the harderian gland of Wistar rats. Protoporphyrin IX has been detected in the lumen and in acinar cells of this gland, as confirmed by fluorescence microscopy. These findings together with numerous reports in the literature suggest that the harderian gland could be useful experimental model for studying the photodynamic process.

Construction and evaluation of a non-laser optical system for photodynamic process excitation

Objetivo: Descrever a construção de uma fonte de luz não-laser, a partir de uma lâmpada de Tungstênio e filtros óticos adequados e demonstrar que sua eficiência em estudos fotodinâmicos, mediados por protoporfirina IX, é semelhante a do laser de Hélio Neônio. Métodos: As regiões Infravermelha e Azul do espectro de emissão óptica de uma lâmpada de Tungstênio foram convenientemente descartadas por processos de absorção, enquanto que a fração centrada na região do vermelho foi removida com o uso de um filtro de interferência. O efeito fotodinâmico foi estudado, em glândula Harderiana de ratos Wistar em razão da produção endógena de protoporfirina IX (PpIX) por estas glândulas. Foram utilizados 20 ratos. Cada animal teve as duas glândulas expostas cirurgicamente, sendo uma delas tratada com a fonte não-laser e a outra mantida como controle. Após tratamento por 30 minutos os animais foram sacrificados e suas glândulas removidas para estudo histológico. Os resultados foram comparados a estudos realizados com laser de Hélio Neônio, já publicados. Resultados: A luz produzida pelo equipamento está centrada em torno de (636 ± 6,5) nm, fornecendo uma densidade de potência de 11,3 mW/cm2. Os efeitos fotodinâmicos produzidos na glândula Harderiana, podem ser observados tanto por espectroscopia de fluorescência como por microscopia ótica. Conclusão: Não foram observadas diferenças significativas nos resultados do efeito fotodinâmico obtidos com a fonte de luz não-laser proposta, em comparação aos resultados conhecidos com o uso do laser de Hélio Neônio.

The structure of the nasal chemosensory system in squamate reptiles. 2. Lubricatory capacity of the vomeronasal organ.

The vomeronasal organ is a poorly understood accessory olfactory organ, present in many tetrapods. In mammals, amphibians and lepidosaurian reptiles, it is an encapsulated structure with a central, fluid-filled lumen. The morphology of the lubricatory system of the vomeronasal organ (the source of this fluid) varies among classes, being either intrinsic (mammalian and caecilian amphibian vomeronasal glands) or extrinsic (anuran and urodele nasal glands). In the few squamate reptiles thus far examined, there are no submucosal vomeronasal glands. In this study, we examined the vomeronasal organs of several species of Australian squamates using histological, histochemical and ultrastructural techniques, with the goal of determining the morphology of the lubricatory system in the vomeronasal organ. Histochemically, the fluid within the vomeronasal organ of all squamates is mucoserous, though it is uncertain whether mucous and serous constituents constitute separate components. The vomeronasal organ produces few secretory granules intrinsically, implying an extrinsic source for the luminal fluid. Of three possible candidates, the Harderian gland is the most likely extrinsic source of this secretion.

La glándula de Harder: un transductor neuroinmunoendrocrino / The Harderian gland: neuroinmunoendrocrine transductor

La glándula de Harder es una glándula túbulo-alveolar localizada en la parte posterior de la órbita ocular de animales que poseen membrana nictitante. En estos mamiferos la glándula contiene una gran cantidad de lípidos. La glándula de Harder de roedores contiene un pigmento café rojizo, el cual ha sido identificado como porfirina. Las funciones de la glándula de Harder son; síntesis y liberación de ferhormonas, fotoprotección y termorregulación, osmoprotección y se le ha propuesto además un papel inmunoendocrino

Diurnal variations in circulating estradiol, testosterone, melatonin and harderian gland porphyrin concentration in Indian palm squirrel, Funambulus pennanti.

A two-peak cyclicity in the plasma level of melatonin, estradiol/testosterone and Harderian porphyrin was noted in F. pennanti. An inverse relationship of Harderian porphyrin with plasma melatonin and a direct relation of it with plasma estradiol/testoserone level were also observed, suggesting that the variation of Harderian, porphyrin concentration may be under the control of both, circulating melatonin and gonadal steroids.

Effect of long-term administration of melatonin on eyes and harderian glands in albino rat.

Pineal hormone melatonin is also synthesized by the ocular structures, retina and Harderian gland. The physiological significance of such production is not fully understood. Daily treatment with melatonin (25 micrograms/rat) for 8 weeks led to an increase in weight of eye balls and fluid within it (P < 0.05). Weight of the Harderian gland in the control and treated rats was not significantly different, though the histological observation revealed an increase in cell height and reduction in lumen diameter in the treated animals. Inter luminal deposits of porphyrin content appeared to be more in the Harderian glands of melatonin treated rats. The retinal tissue indicated degenerative changes in the melatonin treated rats. The results suggest melatonin's influence on level of ocular fluid, structure/function of retina and harderian gland.

New and peculiar cytoplasmic membranous bodies in the acinar cells of the harderian gland of the armadillo Chaetophractus villosus

A new and peculiar morphological feature in acinar cells of the Harderian gland of the South American armadillo Chaetophractus villosus (Mammalia, Dasipodidae) is reported. The gland of adult males and females was studied at macroscopic, microscopic and electron microscopic levels. The gland is the largest structure in the bony orbit. It is located in its medial (nasal) and basal side. It shows a tubuloalveolar structure characterized by large alveoli with a single layer of columnar or cuboidal cells. Myoepithelial cells are located between the secretory ones and the basement membrane. The peculiar morphological feature consists of large intracellular membranous bodies located in the supranuclear cytoplasmic region. They are seen in every acinar cell of males and females. Their size is prominent being almost as large as the nucleus. Only one body is observed in each cell. The structure of the bodies displays an outstanding geometrical pattern which differs completely from other membranous structures described in other species.

Hipervitaminose A experimental no rato. XVII. Estudo estereológico das alterações provocadas pela hipervitaminose A na glândula de Harder de ratos / Experimental hypervitaminosis A in the rat. XVII. Stereological study of the alterations in the Harder's gland of rats submitted to hypervitaminosis A

A hipervitaminose A induz as seguintes alterações na glândula de Harder de ratos: ácinos de menor tamanho constituídos de células mais baixas e lumen amplo, além de núcleos de menos volume quando comparadas às dos controles. Estes dados foram confirmados com técnicas estereológicas adequadas

Effect of pinealectomy and 5-methoxyindoles on Harderian gland activity of the Indian Jungle bush quail Perdicula asiatica.

The present study reveals that the annual Harderian gland weight cycle of P. asiatica has a direct relationship with the testicular cycle and an inverse relationship with the pineal gland cycle. Pinealectomy resulted in a significant decrease of the Harderian gland weight during the recurdescence (March-May) and active (April-June) phases. Subcutaneous implantation of melatonin (aMT) and 5-methoxytryptamine (MT) brought about a significant reduction during the recrudescence and active phases whereas subcutaneous injections of aMT, MT and 5-methoxytryptophol (ML) reduced Harderian gland weight effectively during the morning as well as in the evening hours in the active and inactive phases.

Histopathological Changes of the Extraocular Muscles After the Retrobulbar Anesthesia

Local anesthetics that are commonly used in ophthalmic surgery(0.5% bupivacaine hydrochloride, 2.0% lidocaine hydrohloride, 0.38% bupivacaine-1.0% lidocaine-1:100,000 epinephrine mixture) were injected into the retrobulbar space of rabbit eyes. Physiologic saline was injected into that spaces in control group in the same manner. All three anesthetics produced degeneration of the extraocular muscles to a varying extent. Muscle degeneration was followed by rgeneration of the damaged muscle fibers. In addition to muscle damage, severe damage to harderian gland was also seen in lidocaine-injected group. The optic nerve was not affected. With these findings in rabbits, it is hypothesized that the temporary diplopia and ptosis sometimes seen in patients after ophthalmic surgery might be due to anestheticsinduced damage to the extraocular muscles.

As glândulas cefálicas de répteis e anfíbios brasileiros: III. estudo morfométrico da glândula de Harder de Lygophis Lineatus Dilepis Cope (1862) (Serpentes: Colubridae) / Cephalic glands of brazilian reptilia and amphibia: III. morphometric study of Harderian gland of Lygophis Lineatus Dilepis Cope (1862) (Serpentes: Colubridae)

Os autores estudaram morfológica e morfometricamente a glândula de Harder do Colubrídeo Lygophis Lineatus Dilepis. Baseados nos resultados os autores concluíram: 1) a glândula de Harder é do tipo túbulo-acinoso composto; 2) os ácinos dessa glândula säo constituídos por células sero-mucosas e os ductos por células mucosas; 3) foram avaliados morfometricamente a área acinar, o volume nuclear dos ácinos e ductos e a altura do epitélio dos ductos

A glândula de Harder de Cuniculus Paca (Caviidae, Rodentia), estudo histológico e histoquímico / The Harderian gland of Cuniculus Paca (Caviidae, Rodentia). A histological and histochemical study

Os autores estudaram com métodos histoquímicos, a natureza do material elaborado pela glândula de arder de uniculus paca. Com base nos resultados obtidos, foi possível concluir que o produto de secreçäo desta glândula é constituído de muco-substâncias neutras e ácidas, e radicais proteicos alfa-amino, arginina e cistina