Morphology and chemistry of brown rat,Rattus norvegicus,preputial and clitoral glands

In contrast to previous results from laboratory rats, when sexual dimorphism occurred, clitoral glands from wild female rats were heavier and accounted for a greater proportion of body mass than preputial glands from wild males. Gland length and weight increased with body weight, but gland weight as a proportion of body weight did not. Preputial and clitoral glands showed seasonal differences in size: at one site glands were smaller in December than in April. Maturity, estrus, and pregnancy had no significant effect on clitoral gland size, but immature males had proportionally smaller preputial glands than mature males, and the absolute gland weight, but not gland weight as a proportion of body weight, increased with testes weight. There were no differences between the sexes in lipid production, which increased with preputial or clitoral gland weight. An homologous series of aliphatic acids and their methyl and ethyl esters, plus squalene, cholesterol and lanosterol, was revealed by GC-MS study of the trimethyl silyl derivatized lipid extract. Males and females could be distinguished by principal component analysis of chromatogram peaks.     

Demonstration of an odorous intramale primer effect in short-tailed vole,Microtus agrestis L.

Anal (proctodeal) glands of maleMicrotus agrestis housed in social isolation undergo severe atrophy. Their weight and volume is significantly lower than those of the stock control males. The atrophied glands can be revived by subjecting deprived voles to various social odors. Atrophied glands of isolated males do not respond to the odors of male and female urine, voided feces of females, and unvoided feces of males. Atrophied anal glands of males exposed to voided male feces (which have passed the orifice of the anal gland) and soiled bedding from adult males show strong recrudescence. The mean weight and volume of the glands and plasma testosterone level are significantly higher than of males maintained in complete social isolation, although they are significantly less than those of stock control males. Atrophied glands of socially deprived males strongly respond to the odor of ethereal extract of gland secretion. In males exposed daily to anal gland secretion extract, the weight and volume of the gland and plasma testosterone level increase and are not significantly different from those of stock controls. They enjoy higher plasma testosterone levels and consequently larger and more active anal glands than complete isolates.     

Odor of the muskox

The behavior of captive male muskoxen was observed closely during their characteristic superiority display, the anatomy of the preputial region was studied in two adults and three calves, and preputial washings and preorbital gland secretion were subjected to gas chromatography and mass spectroscopy. During the superiority display, the prepuce was everted to form a pendulous tube tipped with a fringe of matted hair. Owing to the movement of the animal, the urine that dribbled from the preputial opening was liberally applied to the long guard hairs of the belly. The superiority display was almost exclusively confined to dominant males and apparently accounted for their odor. In the quiescent state, the hair seen around the preputial opening was drawn inside and formed an 8 cm-wide band on the lining of the prepuce. The preputial washings contained large amounts of benzoic acid andp-cresol. The infraorbital gland secretion contained cholesterol, benzaldehyde, and a homologous series of saturated -lactones ranging from 8 to 12 carbons. The latter compounds and the natural secretion smell similar to the human nose.     

Volatile Components in Metatarsal Glands of Sika Deer, Cervus nippon

GC-MS analysis of the metatarsal gland secretion from a female sika deer, Cervus nippon, showed 35 major volatile compounds that included 13 straight-chain carboxylic acids, a single branched-chain carboxylic acid, 9 straight-chain aldehydes, 3 monounsaturated aldehydes, 5 long-chain alcohols, a ketone, and cholesterol. The four most abundant compounds were heptanal, nonanal, octanoic acid, and 6-methyl-2-heptanone. Many of the compounds have previously been found in cervid secretions, but the unsaturated aldehydes, (E)-2-octenal, (E)-2-nonenal, and (E)-2-decenal, have not previously been reported in the glands of any cervid. The compounds in this gland may be pheromones, since metatarsal gland odor has been implicated in chemical communication among conspecifics of other cervids.     

Volatile compounds from excreta of laboratory mice (Mus musculus)

Volatile components of all the excretory products deposited by house mice may contribute to their ability to identify their own territories. When mice were placed on a clean surface, they deposited feces, secretions discharged from the anus (anal secretion) and urine. Exposure to several clean surfaces in succession caused a decline in the number of fecal pellets and urine spots deposited and an increase in the number of anal smears. The volatile compounds emanating from feces and anal secretion appeared to be qualitatively and quantitatively different from those emanating from urine, but many compounds with short retention times appeared to be common to feces and anal secretion. Introducing volatiles from feces of strange males into the territory of a singly housed male altered the site at which the resident animal deposited its feces but had no effect on the site at which it urinated. Introducing the feces or the anal secretion of a male mouse into the environment where it encountered a strange conspecific appeared to improve its success in encounters with a conspecific. It was concluded that at least some of the volatile compounds that enable mice to distinguish their own territory from those of neighboring groups may be derived from feces and that many fecal volatiles may originate from the secretions of glands opening into the digestive tract.     

Straight and Branched-Chain Fatty Acids in Preorbital Glands of Sika Deer, Cervus nippon

Using GC-MS analysis, 11 major volatile compounds were found in the preorbital gland secretion from a female sika deer, Cervus nippon. These compounds are the C14 through C18 straight-chain fatty acids, (ZZ)-9,12-octadecadienoic acid, 12-methyltridecanoic acid, 13-methyltetradecanoic acid, 14-methylpentadecanoic acid, 14-methylhexadecanoic acid, and 15-methylhexadecanoic acid. The five branched-chain acids make up over 29% of the volatiles in the gland. This is the first time branched-chain carboxylic acids have been reported from ungulate preorbital glands.     

A comparison of the effectiveness of the odors of rabbits,Oryctolagus cuniculus,in enhancing territorial confidence

In 14 series, each of 100 tests, involving 350 individual animals it has been shown that odors derived from the anal, inguinal and chin glands and urine strengthen to different degrees the confidence of European wild rabbits,Oryctolagus cuniculus. In the tests, two rabbits were put together on otherwise neutral ground previously treated with the odor from one of the contestants. The confidence of the rabbits was determined from an assessment of the record of the time to first physical contact, the frequencies of approaches and aggression, the number of attempts to escape, and also by making a subjective assessment of their general deportment. The results confirm earlier conclusions on the territorial functions of the anal and chin glands, the role of inguinal glands in individual identification, and the behavioral role of urine. On otherwise neutral ground the rabbits' own chin secretions were found to be the most effective in stimulating the confidence of males and that of their female partners. The odor of the anal gland secretions of males stimulated a similar but slightly weaker effect. The anal gland secretions of females influenced their own confidence but not that of males. Urine seemed to play a more important role in affecting the confidence of females than of males. Inguinal gland secretions had least effect. Odor from this source generally did not influence the confidence of the experimental animals; secretion from the inguinal glands of males had a slight effect on the behavior of their female partners.     

Volatile Compounds from Anal Glands of the Wolverine, <Emphasis Type="Italic">Gulo gulo</Emphasis>

Dichloromethane extracts of wolverine (Gulo gulo, Mustelinae, Mustelidae) anal gland secretion were examined by gas chromatography–mass spectrometry. The secretion composition was complex and variable for the six samples examined: 123 compounds were detected in total, with the number per animal ranging from 45 to 71 compounds. Only six compounds were common to all extracts: 3-methylbutanoic acid, 2-methylbutanoic acid, phenylacetic acid, α-tocopherol, cholesterol, and a compound tentatively identified as 2-methyldecanoic acid. The highly odoriferous thietanes and dithiolanes found in anal gland secretions of some members of the Mustelinae [ferrets, mink, stoats, and weasels (Mustela spp.) and zorillas (Ictonyx spp.)] were not observed. The composition of the wolverine’s anal gland secretion is similar to that of two other members of the Mustelinae, the pine and beech marten (Martes spp.).     

Transcriptional Differences in Lipid-Metabolizing Enzymes in Murine Sebocytes Derived from Sebaceous Glands of the Skin and Preputial Glands

Sebaceous glands are adnexal structures, which critically contribute to skin homeostasis and the establishment of a functional epidermal barrier. Sebocytes, the main cell population found within the sebaceous glands, are highly specialized lipid-producing cells. Sebaceous gland-resembling tissue structures are also found in male rodents in the form of preputial glands. Similar to sebaceous glands, they are composed of lipid-specialized sebocytes. Due to a lack of adequate organ culture models for skin sebaceous glands and the fact that preputial glands are much larger and easier to handle, previous studies used preputial glands as a model for skin sebaceous glands. Here, we compared both types of sebocytes, using a single-cell RNA sequencing approach, to unravel potential similarities and differences between the two sebocyte populations. In spite of common gene expression patterns due to general lipid-producing properties, we found significant differences in the expression levels of genes encoding enzymes involved in the biogenesis of specialized lipid classes. Specifically, genes critically involved in the mevalonate pathway, including squalene synthase, as well as the sphingolipid salvage pathway, such as ceramide synthase, (acid) sphingomyelinase or acid and alkaline ceramidases, were significantly less expressed by preputial gland sebocytes. Together, our data revealed tissue-specific sebocyte populations, indicating major developmental, functional as well as biosynthetic differences between both glands. The use of preputial glands as a surrogate model to study skin sebaceous glands is therefore limited, and major differences between both glands need to be carefully considered before planning an experiment.     

Marking urine and preputial gland secretion of male bank voles (Clethrionomys glareolus L.) chemical analyses and behavioral tests

Urine and preputial gland secretion of male bank voles were analyzed by gas chromatography (GC) and mass spectrometry (MS) (selected ion monitoring, SIM). GC-MS analyses showed the presence of hexadecyl acetate in preputial gland secretion and in marking urine but not in metabolic urine. Female bank voles responded more strongly to marking urine of males than to metabolic urine, and they responded more to preputial gland secretion (pure or added to urine) than to metabolic urine. Dominant males spent more time and marked more frequently in response to hexadecyl acetate-enriched urine than to urine alone. The opposite reaction was shown by subordinate males. The results suggest that the acetate functions in the bank voles' dominance interactions.     

Chemical analysis of sternal gland secretion of paper waspPolistes dominulus (Christ) and its social parasitePolistes sulcifer (Zimmermann) (Hymenoptera: Vespidae)

The secretion of the tegumental glands of the fifth and sixth gastral sternites ofP. dominulus and of its social parasiteP. sulcifer was analyzed by gas chromatography-mass spectrometry. Seven long-chain carboxylic acids have been identified: hexadecanoic, octadecadienoic and octadecenoic acids are the major components of the gland secretion ofP. dominulus and octadecenoic acid the main compounds ofP. sulcifer sternal gland secretion. The same carboxylic acids have been found on the nest pedicel.     

Neutral lipids from the temporal gland of the African elephant,Loxodonta africana

Lipids from inactive and active temporal glands of the African elephant,Loxodonta africana, were isolated and fractionated. The inactive gland had a much higher total lipid content per gram of fresh tissue than the active gland. Lipids from the inactive gland consisted predominantly of neutral lipids while the active gland contained large quantities of phospholipids. Neutral lipids from the active gland contained much more hydrocarbons, cholesterol, and alkoxy glycerides than neutral lipids from an inactive gland. The alkoxy glyceride fraction did not contain any alkenyl glycerides. The hydrocarbons consisted of a mixture containing predominantly straight chain even numbered saturated and unsaturated hydrocarbons from C₁₈–C₃₀. Fatty acids from various fractions were investigated by gas liquid chromatography. Those from the active gland were characterized by a higher percentage of unsaturated acids. The change, from inactive to the active state involves mainly a reduction in palmitic and an increase in oleic acid content.     

Castor sacs and anal glands of the north american beaver (Castor canadensis): their histology,development, and relationship to scent communication

Both sexes of beavers possess a pair of castor sacs and a pair of anal glands located in paired subcutaneous cavities between the pelvis and the base of the tail. The castor sacs are not glandular in the histological sense, hence references to these structures as preputial glands or castor glands are misnomers. The wall of the castor sacs is plicate and comprised of three distinct zones: an outer layer of vascular connective tissue, a two-to five-cell-thick layer of mitotic epithelial cells, and several densely packed layers of cornified epithelium which grade into more widely separated sheets toward the lumen. Monocultures of a gram-positive facultatively anaerobic bacterium were present in the lumen of all castor sac preparations. Differences in the frequency of castoreum deposition were not attributable to differences in the structure of the castor sacs. The anal glands of beavers are holocrine sebaceous glands. These glands develop more rapidly than the castor sacs. Anal gland tissue from embryos exhibited cellular characteristics associated with the production of sebum. Secretory activity was evident in all preparations. The relationship of castoreum and anal gland secretion to scent communication among beavers is discussed.     

Anal gland secretion of European mole: Volatile constituents and significance in territorial maintenance

The chemical composition of the volatile components of the anal gland secretion of mature and immature moles of both sexes was examined by gas chromatography and mass spectrometry. The compounds in the secretion of adult males appear to vary little throughout the year and are similar to those from the adult female outside the breeding season. The secretions are dominated by C₅-C₁₀ carboxylic acids. Female glands regress as they enter proestrus, accompanied by profound changes in the chemical composition of the secretion with early disappearance of the carboxylic acids. In juvenile moles, the composition of the secretion changes as the animal matures, with carboxylic acids becoming dominant only as the animal reaches maturity. Anal gland secretion probably plays an important role in territorial maintenance.     

Odorant Source Used in Eurasian Beaver Territory Marking

Mammals use urine, feces, or the secretion of specialized skin glands to mark their territories. These sources can carry different information and, thus, have different functions. Presently it is not known if beavers (Castor spp.) deposit castoreum (primarily a mixture of secondary metabolites from urine) from the castor sacs and secretion from the anal glands (AGS) together or alone when scent marking their territories. We hypothesized that castoreum would be the main scent signal used in the defense of beaver territories during winter and predicted that castoreum would be deposited more often than AGS. A total of 96 scent marks on snow were collected from January 1 to March 31, 1997–1999 in the Bø River, Telemark County, Norway. In order to obtain control material, we chemically analyzed AGS and castoreum from 60 dead beavers collected during January–May 1997–1999. We compared the compounds found in the dead beavers with compounds found in the scent marks on snow. Samples were analyzed by using gas chromatography–mass spectrometry (GC-MS). All 96 scent marks contained compounds from castoreum, whereas compounds from AGS were found in only four scent marks. This suggests that beavers do not specifically deposit AGS on scent mounds as they do with castoreum and that the AGS compounds we found probably were remnants of AGS from the feet or fur following pelt lubrication or coprophagy behavior. We conclude that castoreum is the main scent signal used in the defense of beaver territories during winter.     

Intersexual Differences in Chemical Composition of Precloacal Gland Secretions of the Amphisbaenian <Emphasis Type="Italic">Blanus cinereus</Emphasis>

Pheromonal communication seems to be especially important in amphisbaenians, a group of reptiles morphologically and functionally adapted to fossorial life. Both male and female amphisbaenians (Blanus cinereus) produce copious amounts of a secretion from the precloacal glands. Analysis by gas chromatography–mass spectrometry revealed that these secretions contain 29 major lipophilic compounds, including several steroids (mainly cholesterol and cholesteryl methyl ether), n-C₉ to n-C₁₈ carboxylic acids (more diverse in males), and methyl and long-chain (waxy)-type esters of carboxylic acids, along with squalene (mainly in males) and tocopherol (only in females). There were clear intersexual differences in the presence/absence of some compounds, such as some fatty acids, steroids, and tocopherol, and in the relative proportions of some shared compounds, such as squalene. These differences may explain how the sexes of this amphisbaenian discriminate one another based on scent alone. The abundance of steroids and waxy esters in secretions of both male and female amphisbaenians may be useful to scent mark underground tunnels to facilitate orientation by these organisms.     

Studies of lipid class and fatty acid profiles of rat mammary tumors induced by 7,12-dimethylbenz(a) anthracene

The lipid class and fatty acid composition profiles of mammary glands of female rats fed a nutritionally adequate diet are compared to those of tumors induced in the mammary glands by intravenous injection of dimethylbenz(a)anthracene of animals fed the same diet. Ca. 95% of the lipids of the mammary glands of the control group of animals consisted of triglycerides; glycolipids and phospholipids were present in only minor amounts. In contrast, the lipids of the mammary tumors contained much lower amounts of neutral lipids and higher concentrations of phospholipids. The glycolipid fraction was a minor component of both tissues but differed greatly in composition. The composition of the phospholipid and neutral lipid fractions, particularly the latter, of the mammary tumors also differed from that of the mammary glands of the control animals. The neutral lipids of the tumor tissues contained elevated levels of free fatty acids and cholesterol and much lower concentrations of triglyceride compared to the mammary gland lipids. Differences also were observed in the fatty acid composition of tumor and mammary gland lipid. The greatest differences occurred in the concentrations of polyunsaturated fatty acids which were generally much higher in the tumor lipids.     

Amaranth Oil Increased Fecal Excretion of Bile Acid but Had No Effect in Reducing Plasma Cholesterol in Hamsters

Hamsters were fed for 4 weeks on four different diets: control (C) (balanced diet containing 20 % corn oil as the lipid source), hypercholesterolemic (H) (identical to C but containing 12 % coconut oil, 8 % corn oil and 0.1 % cholesterol as the lipid source), amaranth oil (A) (identical to H without corn oil but with amaranth oil), and squalene (S) (identical to H but admixed with squalene in the ratio found in amaranth oil). There were no significant differences in lipid profile, and in the cholesterol excreted in the animals’ feces from amaranth oil (A) and squalene (S) groups. Fecal excretion of bile acids was greater in the amaranth oil (A) and squalene groups (S) as compared to the other groups. The scores of steatosis and parenchymal inflammation observed in the amaranth oil (A) and squalene groups (S) were superior to the ones observed in the other groups. Our findings demonstrated that amaranth oil, and its component squalene, increased the excretion of bile acids but did not have a hypocholesterolemic effect in hamsters fed on a diet containing high amounts of saturated fat and cholesterol.     

Constituents of temporal gland secretion of the African elephant,Loxodonta africana

Temporal gland secretion (TGS), obtained from 15 different mature African elephants in Kruger National Park was analyzed for volatile constituents. Only five volatile components were present.p-Cresol was present in all samples, but phenol was found as an appreciable component of only one sample and as trace amounts in six others. Three sesquiterpenes were identified, the latter two being new natural products:E-farnesol, farnesol hydrate (3,7,11-trimethyl-2,10-dodecadien-1,7-diol), and farnesol dihydrate (3,7,11-trimethyl-2-dodecen-1,7,11-triol). These sesquiterpenes represent the first isolated from mammals. Ten samples of TGS, serum, and saliva were assayed for cholesterol, urea, and proteins including several enzymes.