Sexual differences and effects of castration on secretory mode and intracellular calcium ion dynamics of golden hamster Harderian gland

The aim of the present work was to study the sexual differences in secretory mechanisms and intracellular calcium ion dynamics in the Harderian gland of the golden hamster. In both sexes the Harderian gland consisted of small and large lobes. In the intact control male glands the secretory portions of both lobes showed wide lumina that contained secretory material and cytoplasmic fragments, suggestive of the occurrence of exocytosis and apocrine secretion. After perfusion with HEPES-buffered Ringer's solution containing 10 microM carbamylcholine (CCh), the glandular cells showed features of enhanced secretion and a rise in intracellular calcium concentration ([Ca2+]i). In the intact control female gland the lumina of most secretory portions in the large lobe contained porphyrin accretions, and exocytosis was the sole secretory mechanism. Stimulation of the large lobe with 10 microM CCh did not raise [Ca2+]i or cause enhanced secretion. The small lobe in females resembled the male gland in secretory functions, and CCh administration caused enhanced secretion and a rise in [Ca2+]i. Castration in males abolished apocrine secretion; exocytosis became the sole secretory mechanism, and stimulation of the glandular cells with CCh did not cause enhanced secretion or induce a rise in [Ca2+]i. To the contrary, in females, castration restored apocrine secretion and CCh administration caused enhanced secretion and a rise in [Ca2+]i. Castration did not affect the secretory mechanisms and the effect of CCh on the glandular cells in the small lobes of both male and female glands. The present study points to the possibility that sex hormones may control the functioning or expression of muscarinic receptors in the Harderian gland of the golden hamster.     

Functional morphology of the mammiliform penial glands ofLittorina saxatilis (Gastropoda)

Summary The functional morphology of the mammiliform penial glands ofLittorina saxatilis has been investigated with both light and electron microscopy. These penial glands line the ventral edge of the penis and orient with the female mantle during copulation. Secretions are released from the penial glands to this interface where they probably function in adhesion. The penial gland secretions comprise heterogeneous granules as well as apocrine and mucous secretions. The heterogeneous granules are produced in separate multicellular glands arranged in a series of lobes that lie outside a thick smooth muscle layer enclosing the lumen. Each glandular lobe is surrounded by a thin layer of smooth muscle. Secretions are transported in individual cellular processes that pass through the thick smooth muscle layer and empty into the lumen. Surrounding the lumen is an epithelium containing apocrine secretory cells as well as occasional goblet-type, mucous cells. The combined action of the muscles forces secretions out of the lumen through the penial papilla, onto the external surface of the mammiliform penial gland. Longitudinal muscles extend into the penial papilla enabling its protrusion or retraction. Retraction of the penial papilla following secretion release is thought to create negative pressure beneath the penial gland producing suction adhesion. The visco-elastic properties of the penial gland secretion are qualitatively different from foot mucus and may represent specialization to an adhesive function.     

Lectin histochemical study on the infraorbital gland of the Japanese serow (Capricornis crispus)

Histology and lectin histochemistry were performed in the infraorbital gland of the Japanese serow. The gland is composed of glandular tissues and a pouch filled with the secretion. The tissues consist of an inner layer of sebaceous glands and an outer layer of apocrine glands. The male sebaceous layer is made up of the ordinary type, whereas the female's layer consists of the ordinary and modified types. In the apocrine gland stained with Arachis hypogaea (PNA), nine different patterns of glandular tubules were distinguished on the basis of staining of the cytoplasm, the Golgi area of secretory cells and secretion. Secretory modes of apocrine secretion and exocytosis were included in these stainings. Myoepithelial cells stained constantly with Glycine max (SBA) except when only the Golgi area of secretory cells was positive. The modified sebaceous gland was stained with PNA, SBA, Ricinus communis I (RCA), Triticum vulgaris (WGA), Canavalia ensiformis (Con A) and Ulex europaeus I (UEA), while the ordinary type was positive in PNA, RCA, SBA, WGA and Con A. The secretion in the pouch was stained with PNA, RCA, SBA, Dolichos biflorus (DBA), WGA and Con A. These findings suggest that the modified sebaceous gland contains large amounts of glycoconjugates and the apocrine gland shows a cyclic secretory process of apocrine secretion and exocytosis.     

The spermathecal complex in Ips typographus (L.): Differentiation of the spermathecal gland related to age and reproductive state

The spermathecal complex of the bark beetle, Ips typographus, comprises the following elements: spermathecal duct, spermatheca and spermathecal gland. The spermathecal duct connects the vagina and the spermatheca and consists of a cuticular tube surrounded by an epithelial layer and circular muscles. The spermatheca is bottle-shaped and has a cuticle-lined lumen. Muscles are attached to both ends of the spermatheca. The spermathecal gland which is connected to the spermatheca possesses three cell types: glandular, hypodermal, and ductule. The glandular cells have different structural characteristics depending on the age and reproductive state of the females. After the emergence of the brood, two different kinds of secretory material are present in the glandular cells. There is evidence that one type of secretion is emitted during the first few days after brood emergence, while the other type accumulates to be secreted during later stages.     

莱氏拟乌贼缠卵腺的显微与超微结构

为了解莱氏拟乌贼(Sepioteuthis lessoniana)缠卵腺的结构和功能,本研究采用组织切片技术和透射电镜技术对该腺体进行显微与超微结构观察.结果显示,缠卵腺由腺壁组织、分泌叶瓣和结缔组织组成.其中,腺壁组织由外膜层和肌肉层组成,位于腺体外部;分泌叶瓣是腺体的主要部分,由分泌细胞和支持细胞组成,分泌细胞具有...     

An unusual type of secretory cell in the ventral pedal gland of the gastropod mollusc Buccinum undatum L.

The ventral pedal gland in the foot of the mature female whelk Buccinum undatum L. consists of a shallow pouch containing a layer of elongated cells which partially penetrate a basement membrane overlying layers of smooth muscle. This glandular epithelium contains acid mucopolysaccharide cells, ciliated and interstitial cells as well as the upper parts of a new type of subepidermal gland cell. These gland cells consist of an elongated extracellular tubular duct formed by an invagination of the cell membrane and lined by numerous microvilli. Into this duct are discharged packets of a densely staining secretion. The secretion packets are produced in Golgi regions around the nuclei of the cells and are passed up through the cell to the base of the duct through or along an extensive assemblage of microtubules. The secretion packets show organized internal structure and may contain aromatic aldehydes and protein associated with the sclerotization of the egg capsules, which pass through the gland after leaving the genital tract.     

脉红螺消化系统的形态学研究

脉红螺消化系统由十二个器官组成。其消化管壁都由粘膜层、粘膜下层、肌层和外膜四层结构构成。作者对消化腺的细胞进行了较详细的描述,并利用组化方法测定消化腺细胞中含有的酶类。作者还对部分器官的超微结构进行了观察。     

Paracloacal glands of Alligator mississippiensis: A histological and histochemical study

The histology of the paracloacal 'musk' glands of adult American alligators ( Alligator mississippiensis ) is described. The gland is a single secretory sac with a single duct and a central lumen partially occluded by a central, cylindrical conglomerate of cells and secretion product. The capsule of the gland consists of an outer layer of smooth muscle and an inner layer of connective tissue containing collagen and elastin fibres. Septa carrying blood vessels radiate from the connective tissue layer of the capsule to the border of the central conglomerate. Parenchymal cells containing lipid droplets enlarge from the periphery to the centre of the gland. Secretions formed by degeneration of cells in the central cylinder are concentrated near the secretory duct. Histochemical tests indicate lipids but not mucopolysaccharides in the glandular exudate.     

Nervous control of mammalian salivary glands

In the production and flow of saliva, sympathetic and parasympathetic nerves generally cooperate, although variations between the different salivary glands are considerable, particularly in the sympathetic innervation. In the submandibular gland of the dog, sympathetic impulses cause secretion via beta-adrenoceptors, and since sympathetic motor effects are elicited via alpha-adrenoceptors it is possible to study separately motor and secretory effects in this gland. Such experiments indicate that myoepithelial contractions serve to accelerate the salivary flow and to support the secreting acinar cells and prevent back-flow of fluid from the luminal system into the glandular tissues. The contractions are elicited reflexly from the oral mucosa together with secretion. A potentiation interaction between sympathetic and parasympathetic nerves occurs in the formation of the primary saliva. In parotid glands of rabbits and rats such an interaction has been demonstrated in the secretion of amylase.     

Venom gland of the ichneumonid Diadromus collaris： morphology, ultrastructure and age-related changes

Females of the solitary parasitoid Diadromus collaris （Insecta： Hymenoptera： Ichneumonidae） lay eggs in the pupae of Plutella xylostella （Lepidoptera： Plutellidae）, and the venom is synchronously injected into hosts. The venom apparatus consists of two glandular tubules terminating in a common reservoir, A ductule connects the reservoir with the sting apparatus, by which the reservoir content enters the latter. Secretory units line the two glandular tubules. All secretory cells belong to dermal gland type Ⅲ. Dermal gland cells in glandular tubules are more abundant and developed than those in the reservoir. There are extensive rough endoplasmic reticulum and electrondense vesicles, and the microvilli are well developed. By the cuticle-lined central funnel secretion products of secretory units reach the reservoir. Moreover, the secretory apparatus undergoes age-related changes. The secretory units in the venom gland are better developed and more vigorous 7 days after eclosion than those 1 day after eclosion; autolytic processes occur 15 days after eclosion, and the tissue of the reservoir is more prostrate 15 day after eclosion than those 1 day after eclosion. The ovipostion peak of this parasitoid, about 3-7 days after eclosion, corresponds with the period when the venom gland is highly developed in the life span of the wasp.     

Schistosoma mansoni: defined system for stepwise transformation of cercaria to schistosomule in vitro

Defined conditions are described for the in vitro production of large numbers of tail-free viable schistosomules. These consist of (1) the centrifugation of cold cercarial suspension and the incubation of the packed cercariae in a minimal volume of medium at 30 C for 40 min to effect tail loss and glandular secretion; (2) the isolation of the bodies by resuspension and sedimentation and (3) the induction of surface changes by incubating the bodies in inactivated serum or a defined tissue culture medium for a further 40 min interval at 37 C with mild agitation.The resultant schistosomules are characterized by the depletion of their penetration gland contents, loss of tail, fluoride and water sensitivities, complement insensitivity, negative “Cercarien-hüllen Reaktion,” and loss of the surface coat as demonstrated by periodic acid-Schiff (PAS) staining and electron microscope observations.     

Heat production, blood flow, O2 uptake and CO2 output in the secretary process of the dog submandibular gland (author's transl)

1. Under normal circulation of the dog submandibular gland, the electrical stimulation induced a massive salivary secretion (about 0.35 ml . min-1.g-1 gland weight) and an increase in the glandular temperature (about 0.2 degrees C). The heat production was calculated of about 60 mW.g-1. 2. Clamping of the glandular artery made both of secretion and heat production to be transient. The early peak of secretion was about 0.12 ml.min-1.g and that of heat production was 7 approximately 10mW,g-1. Then each 1 ml secretion followed about 4.6 J heat production. 3. Under constant blood flow in the glandular circulation, the secretory process was divided clearly into 2 phases of peak and plateau. The glandular temperature increased about 0.12 degrees C with an early temperature drop. In the secretory plateau phase, the secretary rate was about 0.043 ml.min-1.g-1, the heat production was about 5 approximately 7 mW.g-1 and each 1 ml secretion caused about 8.2 J heat production. 4. The rate of oxygen uptake was about 20.9 microl.min-1g-1 at the resting state. The maximum during secretion was about 192 microliter.min-1.g-1. THe half time of the recovery process of O2 uptake tended slightly longer than that of heat production. 5. THe rate of CO2 output was about 21.8 microliter.min-1.g-1 at resting. The maximum during secretion was about 142 microliter.min-1.g-1 R. Q. were about 1 at resting and about 0.74 under secretion.     

Ultrastructural changes in the oviduct of the laying hen during the laying cycle

The ultrastructural changes occurring in the fully functional oviduct of Isa Brown laying hens were studied during various stages of the laying cycle. Hens were killed at different positions of the egg in the oviduct. The oviduct was lined by ciliated and non-ciliated cells (also referred to as granular cells). The granular cells in the infundibulum contributed to secretion during egg formation, whereas ciliated cells showed little evidence of secretion. Ultrastructural changes were recorded in the granular and glandular cells of the distal infundibulum. In the magnum, the surface ultrastructure revealed glandular openings associated with the ciliated and granular cells. Cyclic changes were recorded in the glandular cells of the magnum. With respect to the three observed types of glands, the structure of gland type A and C cells varied at different egg positions in the oviduct, whereas type B cells represented a different type of gland cell containing amorphous secretory granules. The surface epithelium of the isthmus was also lined by mitochondrial cells. Two types of glandular cell (types 1 and 2) were recorded in the isthmus during the laying cycle. Intracisternal granules were found in type 2 cells of the isthmus. A predominance of glycogen particles occurred in the tubular shell gland. The granular cells in the shell gland contain many vacuoles. During egg formation, these vacuoles regressed following the formation of extensive rough endoplasmic reticulum; the reverse also occurred. The disintegrated material found in the vacuoles may have been derived from the disintegrating granules. The Physiology Teaching Unit, University of New England, provided financial support to K. Chousalkar for this study.     

Morphometric study of the blood-carrying capillaries during the administration of a liquid into the salivary gland]

The physiological saline was injected into the excretory duct of the cat parotid gland under the pressure of 30, 70 and 120 cm H2O. It was found with the aid of transmission electronic microscopy, morphometry and statistical analysis that the liquid injection into the gland produces compression of the blood capillaries weaving the acinus. The compression of the capillary tubes is shown by a significant reduction in space given to the lumen of the capillaries and their endothelial layer. The compression of the capillary tubes is combined with a two-fold lessening suggest that the additional blood volume entering the gland in response to its perfusion by the liquid does not reach the blood capillaries and is thrown off into the vein vessels through the shunt communications and that regulation of the blood volume getting into the cat parotid gland capillaries is likely to depend on the hydraulic and osmotic state in the interstitial space of glandular lobes.     

Morphology and secretion of glandular trichomes in Tamus communis

Light and scanning electron microscopical investigations were carried out to study distribution, morphology and secretion of glandular trichomes during leaf development in Tamus communis . During leaf growth glandular trichomes arise continously from single protodermal cells. At maturity, they are composed of a 6-celled gland head, a secretory neck cell, an "endodermal" cell, and one basal or reservoir cell. During the early stage of secretion, several regularly arranged crater-like pores differentiate on the cuticular surface of the gland head. Through these pores (1–1.5 μm in diameter), the secretion flows out as a thin film or as rods (0.4 μm in diameter) spreading on the trichomes and on the leaf surface. Histochemical tests indicate that the secretion is composed of a small amount of carbohydrates and an abundant fraction of lipophilic material. Proceeding towards senescence, the wall degeneration of the gland head gives rise to a strong histochemical reaction for insoluble polysaccharides. The results presented are compared with those of other investigations on the pattern of secretion in glandular trichomes.     

Silk Production after Mechanical Pulling Stimulation in the Ampullate Silk Glands of the Barn Spider, Araneus cavaticus

Synthesis of protein by the major ampullate silk glands in the barn spider, Araneus cavaticus was stimulated by depleting the storage of silk protein in the ampulla by mechanically pulling fiber from the spigot. After this treatment, fine structural changes of the glandular epithelium during silk production were examined using light and transmission electron microscopes. In the process of rapid production, major secretory silk was synthesized at the tail region via rER of glandular epithelial cells, and was transported into the ampulla region. The mature secretory product in glandular epithelium appears almost spherical vacuoles which were grown up by fusion with the surrounding small vesicles including the secretory silk. Unlike to a typical process of the secretion, the ampullate silk of tail region seems to bypass either concentrating or packaging steps by the Golgi apparatus. However there's no doubt that the Golgi apparatus also play an important role in the secretory process of the ampulla region. After mechanical pulling stimulation, both epithelia of ampulla and tail regions appeared as a thinner layer of columnar cells with less definitive cell membrane. There are few secretory droplets within these cells, thus causing this region to stain much lighter. It is obvious that the cell loses part of its cytoplasm in this process, and disorganization of the secretory product occurs when it is extruded from the cells by a apocrine release.     

Localization of calcium in the secretory cells of the mammary glands in response to oxytocin

Distribution of Ca2+ ions, precipitated by means of pyroantimonate potassium, has been investigated electron microscopically in secretory cells of the mammary gland of lactating white mice. In the glandular cells, that are at the state of inhibition of secretory activity, the cytochemical reaction product is localized on the internal side of the basal, lateral and apical parts of the plasmolemma, in mitochondrial matrix, in cisterns and in the Golgi complex vesicles, in the nuclear areas, occupied by euchromatin. Oxytocin effect produces a certain complex of ultrastructural changes in the cell accompanied by redistribution of Ca2+ ions. Amount of precipitate in mitochondria decreases. It is revealed in the lumen of dilated canals of the granular endoplasmic reticulum, in the zone of decondensated nuclear chromatin, in the Golgi complex vesicles. The vesicles become larger and fuse with each other. The changes mentioned demonstrate increased synthetic and transport processes, occurring in the glandular epithelium of the mammary gland after oxytocin effect.     

Female genital system of the folding-trapdoor spider Antrodiaetus unicolor (Hentz, 1842) (Antrodiaetidae, Araneae): ultrastructural study of form and function with notes on reproductive biology of spiders

The genitalia of the female folding-trapdoor spider Antrodiaetus unicolor are characterized by two pairs of spermathecae that are arranged in a single row and connected to the roof of the bursa copulatrix. Each single spermatheca is divided into three main parts: stalk, bowl, and bulb, which are surrounded by the spermathecal gland. The epithelium of the spermathecal gland is underlain by a muscle meshwork and consists of different types of cells partly belonging to glandular cell units (Class 3 gland cells) that extend into pores in the cuticle of the stalk and bowl. Interestingly, the bulb lacks glandular pores and is characterized by a weakly sclerotized cuticle. This peculiarly structured bulb probably plays an important role in the discharge of the sperm mass. It is suggested that by contraction of the muscle layer the sperm mass may be squeezed out, when the bulb invaginates and expands into the spermathecal lumen, pushing the sperm to the uterus lumen. Each glandular unit consists of usually one or two central secretory cells that are for the most part surrounded by a connecting cell that again is surrounded by a canal cell. The canal cell, finally, is separated from the other epithelial cells (intercalary cells) located between the glandular units by several thin sheath cells that form the outer enveloping layer of the unit. The secretions are released through a cuticular duct that originates proximally between the apical part of the connecting cell and the apical microvilli of the secretory cells and runs into a pore of the spermathecal cuticle. The glandular products of the Class 3 gland cells likely contribute to the conditions allowing long-term storage of the spermatozoa in this species. Details regarding the ovary, the uterus internus, and the uterus externus are reported. Most of the secretion that composes the chorion of the egg is produced in the ovary. Glandular cell units observed in the uterus externus differ structurally from those in the spermathecae and likely play a different role. Finally, we briefly discuss our results on the female genitalia of A. unicolor in the light of knowledge about the reproductive biology of spiders.     

Intercellular junctions in the corpora cardiaca of locusts

Summary The intercellular junctions in the corpora cardiaca of the locusts Schistocerca gregaria and Locusta migratoria were investigated by transmission electron microscopy. In the glandular lobes, complexes consisting of scalariform junctions and associated mitochondria, comparable to those previously observed in ion transporting epithelia, are formed between gland cells, and more rarely between gland cells and the neurons innervating them. Their structure and abundance are apparently unaffected by the stage of development or by the various experimental conditions employed. In the neural lobe, scalariform junctions form between glial cells and show close association with the endoplasmic reticulum. Gap junctions are present among glandular, neural and glial elements, and are formed between cells of the same type and of different types. Contacts resembling punctate tight junctions are widely distributed in the gland, but would be unlikely to form a barrier to diffusion. Septate junctions are formed exclusively between glial cells.     

Defence glands in the giant spiny phasmid Extatosoma tiaratum

Adults of Extatosoma tiaratum liberate a strong smell when handled. The smell is associated with a colourless, volatile liquid which is apparently harmless to man. It is ejected on to the thorax of the insect, and on to the hands of the investigator, from a pair of tubercles located on the anterior border of the prothorax. The tubercles have a slit-like aperture through which the secretion is sprayed on attack. The secretion is produced by two glands in the thorax, each comprising a pair of tubes which unite just beneath the tubercle. The tubes consist of a thick, glandular epithelium lined with a thin layer of cuticle; most of the gland is enveloped in a layer of muscle. The defence reaction is discussed in relation to that of other phasmids.