Seasonal changes in the male accessory glands of reproduction in adult Fallow deer (Dama dama)

The accessory glands of reproduction of male Fallow deer ( Dama dama L.) comprise paired ampullae which are expansions of the caudal portions of the vas deferens, paired seminal vesicles, a prostate and a disseminate prostate embedded in the pelvic urethra. All the glands undergo an annual cycle of growth and regression, reaching their maximum development in October at the time of the rut. Parallel changes were observed in the testes.     

Histology of the sternal and suprapubic skin areas in lion tamarins (Leontopithecus sp. Callitrichidae-primates)

Though knowledge regarding the biology and morphology of lion tamarins is scarce in the literature, it is very important for their conservation. This paper focuses on the anatomical and histological aspects of the glands involved in the scent-marking behavior of lion tamarins. It examines the histological aspects of sternal and suprapubic skin sections of specimens that were preserved in formaldehyde and were the property of the Rio de Janeiro Primatology Center Museum. Eighteen specimens from three lion tamarin (Leontopithecus sp.) species (L. rosalia, L. chrysomelas, and L. chrysopygus) were analyzed. Both sexes were represented, and macroscopic hypertrophy was quantified by direct observation of the tegument on the sternal area and classified as discrete, moderate, or accentuated for each specimen. The skin of both sexes had a high degree of histological resemblance to that of other primates, including humans. The epidermis presented stratified squamous keratinous epithelia, with a few cellular layers and dermis with cutaneous appendages (i.e., hair follicles and both sebaceous and sweat glands). The dermal papillae were short, and the sebaceous and apocrine sweat glands resembled those of humans. These glands were present in the dermis of the analyzed skin fragments of both sternal and suprapubic regions in great numbers. Furthermore, we were able to establish a relationship between the macroscopic appearance of the sternal tegument and the degree of microscopic gland hyperplasia.     

Demonstration of β-glucan receptors in the skin of aquatic mammals—a preliminary report

Using immunohistochemistry, the study clearly demonstrates three important β-glucan receptors (Ficolin/P35, MBL, Dectin-1; members of the lectin-complement pathway of innate immunity) in the integument of six marine and freshwater aquatic mammals (Northern fur seal, Common seal, Walrus, Coypu, Capybara, Otter), but only weakly in two dolphin species. Most of the non-dolphin mammals exhibited strong reactions, especially with regard to the skin glands (tubular apocrine glands, sebaceous glands), for L-Ficolin/P35 and MBL. Distinct reaction staining could also be observed in the epidermis and the outer epithelial sheath of primary hair follicles. Positive Dectin-1 staining was limited to secretory cells of the apocrine tubular glands, and to peripheral and central cells of sebaceous glands of the seals. The Capybara was the only animal to show a clear Dectin reaction in the epidermis (stratum granulosum). The findings are discussed with regard to the constant and high microbial challenge of the skin in the aquatic medium, and variations in hair density of the animals.     

cyclinA1基因变异诱导小鼠发生头颈部皮肤病变

目的研究cyclinA1基因变异对活体小鼠动物模型可能产生的影响。方法饲养46只cyclinA1基因变异的小鼠与25只同龄野生型小鼠9～24个月,进行比较观察。对发现病变部位的组织切片和对照标本采用HE染色和免疫组织化学染色方法检查。结果cyclinA1基因变异鼠中,约有24％（11／46）在头颈部发生了深溃疡状的皮肤病变,HE染色结果显示病变及病变周围皮肤过度角化,皮脂腺增生明显。而25只野生型鼠中未见类似改变。以cyclinA1特异性抗体进行免疫组织化学染色结果显示,野生型小鼠的皮脂腺内可以观察到明显的染色,而cyclinA1基因变异小鼠标本中没有染色。结论cyclinA1基因变异是导致本实验中观察到的小鼠发生头颈部皮肤病变的直接或间接原因。     

Localization of sex steroid receptors in human skin

Sex steroid hormones are involved in regulation of skin development and functions as well as in some skin pathological events. To determine the sites of action of estrogens, androgens and progestins, studies have been performed during the recent years to accurately localize receptors for each steroid hormone in human skin. Androgen receptors (AR) have been localized in most keratinocytes in epidermis. In the dermis, AR was detected in about 10% of fibroblasts. In sebaceous glands, AR was observed in both basal cells and sebocytes. In hair follicles, AR expression was restricted to dermal papillar cells. In eccrine sweat glands, only few secretory cells were observed to express AR. Estrogen receptor (ER) alpha was poorly expressing, being restricted to sebocytes. In contrast, ERbeta was found to be highly expressed in the epidermis, sebaceous glands (basal cells and sebocytes) and eccrine sweat glands. In the hair follicle, ERbeta is widely expressed with strong nuclear staining in dermal papilla cells, inner sheath cells, matrix cells and outer sheath cells including the buldge region. Progesterone receptors (PR) staining was found in nuclei of some keratinocytes and in nuclei of basal cells and sebocytes in sebaceous glands. PR nuclear staining was also observed in dermal papilla cells of hair follicles and in eccrine sweat glands. This information on the differential localization of sex steroid receptors in human skin should be of great help for future investigation on the specific role of each steroid on skin and its appendages.     

Seasonal changes in the skin glands of Roe deer (Capreolus capreolus)

Seasonal changes in the specialized skin glands of the forehead, metatarsal gland and interdigital regions of Roebucks are described and compared with glands of the general body surface. In both the forehead region and dorsal skin the sebaceous and apocrine glands enlarge as the testes enlarge and regress after the rut, but the glands of the forehead region are at least three times larger than those of the general body surface. The apocrine glands of the forehead region discharge by exocytosis except at the time of maximum secretion, which precedes total cell breakdown. In the metatarsal and interdigital regions the skin glands are enlarged throughout the year.     

The skin of primates. XXIX. The skin of the pigmy bushbaby (Galago demidovii)

The skin of the pigmy bushbaby (Galago demidovii), the smallest existing prosimian, is largely similar to that of the other African Lorisidae, although this animal has certain peculiar features. The very thin epidermis contains alkaline phosphatase-reactive dendritic cells which resemble those in the other bushbabies and the potto. The hair follicles of this animal are similar to those of the lesser bushbaby, while the sebaceous glands are different from those of the other bushbabies in being reactive for alkaline phosphatase. The histological and histochemical properties of the sweat glands are similar to those of the other bushbabies.     

Mitotic activity in the growing red deer antler

Antlers grow rapidly through the coordinated development of both osseocartilage and skin (velvet). The regional patterns of cell division in these two compartments were assessed by immunochemical detection of proliferating cell nuclear antigen (PCNA) in antlers from one-year-old red deer. The whole antler integument was in a state of growth and/or renewal, particularly the keratinocytes of the basal cell layer of the epidermis near the tip, and hair bulbs and sebaceous glands. More proximally, a zone of weaker mitotic activity was detected. Within the osseocartilagenous compartment, rapid mitosis was particularly apparent within the distal mesenchyme, visible as a dome-shaped band of staining. Mitotic activity of chondrocytes and osteoblasts was more extensive in peripheral areas of developing bone than in the centre. We conclude that the antler tip is the site of most active epidermal growth, and hypothesise that other mechanisms in addition to mechanical stretching play a role in growth of the integument.     

Mise en évidence d''une fonction excrétrice de la peau chez certains cétacés odontocètes et mysticètes

Up to the present there was not believed to be any excretion in the skin of cetaceans because of the absence of sweat and sebaceous glands. It has now been shown that concentrated salty excretion is produced in various cetaceans by numerous epidermal cells dispersed in the whole epidermis. They are not aggregated into glands. Other epidermal cells, likewise scattered in the epidermis, synthetize lipids; this function seems homologous to the sebaceous function of other mammals.     

Phospholipase Cdelta1 is required for skin stem cell lineage commitment

Phosphoinositide-specific phospholipase C (PLC) is a key enzyme in phosphoinositide turnover and is involved in a variety of physiological functions. Here we report that PLCdelta(1)-deficient mice undergo progressive hair loss in the first postnatal hair cycle. Epidermal hyperplasia was observed, and many hairs in the skin of PLCdelta(1)-deficient mice failed to penetrate the epidermis and became zigzagged owing to occlusion of the hair canal. Two major downstream signals of PLC, calcium elevation and protein kinase C activation, were impaired in the keratinocytes and skin of PLCdelta(1)-deficient mice. In addition, many cysts that had remarkable similarities to interfollicular epidermis, as well as hyperplasia of sebaceous glands, were observed. Furthermore, PLCdelta(1)-deficient mice developed spontaneous skin tumors that had characteristics of both interfollicular epidermis and sebaceous glands. From these results, we conclude that PLCdelta(1) is required for skin stem cell lineage commitment.     

Seasonal sebaceous patch in the nectar-feeding bats Leptonycteris curasoae and L. yerbabuenae (Phyllostomidae: Glossophaginae): phenological, histological, and preliminary chemical characterization

Many species of bats secrete a wide variety of substances, frequently associated with olfactory communication. We characterized a seasonal phenomenon of dorsal sebaceous secretion in the Cura?aoan long-nosed bat, Leptonycteris curasoae, in Venezuela, and the lesser long-nosed bat, Leptonycteris yerbabuenae, in Mexico. The phenology of the sebaceous patch was determined, a histological analysis of the affected area was conducted using specimens of L. curasoae from Venezuela, and finally, a preliminary chemical characterization of the substance secreted was performed combining histochemical techniques with gas chromatography and mass spectrometry analyses. The sebaceous patch was detected exclusively in male adult specimens. Individuals presenting it had a variable area of fur covered with a fatty and odoriferous substance at the level of the interscapular zone. Occurrence of the sebaceous patch was cyclical and coincided with the mating season in Venezuela and Mexico. The following histological changes associated with occurrence of the patch were observed: increase of epidermis thickness and decrease of dermis and hypodermis thicknesses, increase in density of sebaceous glands, increase of percentage of skin covered by sebaceous glands, increase of size of sebaceous glands previous to secretion followed, and increase of the sebum volume within sebaceous glands previous to secretion. Several compounds tentatively identified as fatty acids, cholestanes and cholesterol were present in the sebaceous secretion. Based on the evidence obtained, we hypothesize that the sebaceous patch could be involved in olfactory communication, possibly related to mating behavior in these bats.     

Characteristics of microbial association in secretions of various mammalian sebaceous glands

The following secretions of mammalian skin glands were subjected to a microbiological survey: the middle-abdominal glands of great and Mongolian gerbils, the preputial gland of musk deer, the perineal organ of African civet cat, the interdigital skin regions and interdigital glands of bison, European bison, European roe deer, and musk deer. All the secretions were found to contain microbial associations. The composition of bacterial species in the secretions and the quantity of microorganisms varied among different animal species, during the ontogenesis of an animal, and depended on the topography of a gland on an animal body as well as on its functional state in different seasons or upon hormonal changes. The secretions of certain glands contain factors which determine the composition of microbial species in a particular ecological niche and the stability of such a cenosis.     

Postnatal development of the skin of the marsupial native cat Dasyurus hallucatus

Skin development of the Northern native cat was examined from birth to weaning at 150 days post partum. An outer layer of cells, termed the periderm or epitrichium, is present on the epidermis of the newborn. This layer of cells is not discernible at 7 days post partum. Skin development of the native cat differs from that of the eutherian mammal. The periderm of the eutherian is no longer discernible when the developing hairs first penetrate the epidermis. In the marsupial, this loss of the periderm occurs well before the appearance of follicles. Melanocytes and Langerhans cells are seen at day 23 post partum, follicles at day 30, sebaceous glands at day 59, and sweat glands at day 67. Thus, when the mother first leaves her young in the nest at about days 60 to 70 of lactation, the skin is at a stage of development that will assist the young with thermoregulation. The skin continues to develop throughout lactation and attains an adult appearance by day 150 post partum.     

Morphogenesis and renewal of hair follicles from adult multipotent stem cells

The upper region of the outer root sheath of vibrissal follicles of adult mice contains multipotent stem cells that respond to morphogenetic signals to generate multiple hair follicles, sebaceous glands, and epidermis, i.e., all the lineages of the hairy skin. At the time when hair production ceases and when the lower region of the follicle undergoes major structural changes, the lower region contains a significant number of clonogenic keratinocytes, and can then respond to morphogenetic signals. This demonstrates that multipotent stem cells migrate to the root of the follicle to produce whisker growth. Moreover, our results indicate that the clonogenic keratinocytes are closely related, if not identical, to the multipotent stem cells, and that the regulation of whisker growth necessitates a precise control of stem cell trafficking.     

Immunohistochemical Demonstration of Transferrin and Transferrin Receptor in Mammalian Integument

The present study demonstrates the distribution of transferrin and the transferrin receptor in the integument of eleven wild mammalian species using immunohistochemical methods. Both substances were regularly found in or near the peripheral cells of the sebaceous glands, especially of dense-haired animals. The transferrin receptor was also detectable in the epidermis, the secretory portion of tubular apocrine glands, and the outer epithelium of primary hair follicles. Transferrin as well as the transferrin receptor reacted strongly in macrophages of the papillary dermis only in the common seal. The results obtained are discussed with regard to possible biological functions in the skin of the substances demonstrated. Keywords: immunohistochemistry, integument, mammals, transferrin, transferrin receptor     

Histology and cytochemistry of human skin. IX. The distribution of non-specific esterases

1. In the epidermis non-specific esterase activity outlines a strongly reactive band between the stratum granulosum and the stratum corneum. In the epidermis of the palm, there is no such esterase-rich band. 2. The outer sheath of active hair follicles has strong enzyme activity. The degenerating hair bulb in catagen follicles is very strongly reactive, and clusters of cells around the hair club in quiescent follicles are rich in enzyme activity. 3. Strong enzyme activity is found in young sebaceous cells, while decaying sebaceous cells and newly formed sebum are unreactive. Old sebum, however, is very intensely reactive. 4. Only the "dark" cells of eccrine sweat glands show a reaction; the "clear" cells are negative. 5. The cells of axillary apocrine glands abound in enzyme.     

The histological and histochemical characteristics of the hepatoid circumanal glands in the dog: the features of similarity and difference with the skin glands of other types

Three types of skin glands, the derivatives of the outer root sheath of the hair follicle, have been compared, which are represented by hepatoid, sebaceous and apocrine sweat glands. There are three characteristic properties inherent to hepatoid glands, existence of a network of intercellular secretory tubules, lysis of some secretory cells during the duct formation which is not the fatty transformation and cyst formation.     

A histological study of cutaneous glands in the brown brocket deer

We examined the histological structure of 8 skin areas thought to contain cutaneous glands of potential importance in scent communication in 16 brown brocket deerMazama gouazoubira Fisher, 1814, using standard histological techniques. Frontal areas and preorbital sacs had scant glandular development. Sebaceous gland development was prominent in vestibular nasal glands and prepucial glands. Apocrine sudoriferous glands and sebaceous glands were well developed in tarsal glands, the caudal skin area and the interdigital glands of front and hind feet. The tail had a unique arrangement of apocrine sudoriferous glands. Anal glands had moderate glandular development, and metatarsal glands were absent. Several of these glandular areas may be important in the chemical communication among brocket deer.