Axillary odors

Leyden J., McGinley K., Hoelzle K., Labows J., et al. (1981). The microbiology of the human axillae in relation to axillary odors. J Invest Dermatol 77, 413-416. 

Preti G., et al. (1990). Human axillary odors their communicative function, structure and origin. Proc Am Chem Soc 200, 12 (abs). 

Preti G., Spielman A., Zeng X.-N. and Leyden J.J. (1995). The characteristic female axillary odors and their precursor proteins qualitative compraison to males. Chem... 

Shelley W., Hurley H. and Nichols A. (1953). Axillary odor, an experimental study of the role of bacteria, apocrine sweat, and deodorants. Arch Dermatol 68, 430-446. 

Spielman A., Sunavala G., Harmony J., Stuart W., et al. (1998). Identification and immunohistochemjcal localization of protein precursors to human axillary odors in apocrine glands and secretions. Arch Dermatol 134, 813-818. 

Spielman A., Zeng X., Leyden J. and Preti G. (1995). Proteinaceous precursors of human axillary odor — isolation of two novel odorant binding proteins. Experientia 51, 40-47. 

Wysocki C.J., Zeng C. and Preti G. (1999). Specific anosmia and olfactory sensitivity to 3-methyl-2-hexanoic acid a major component of human axillary odor. Chem Senses 25, 652 (abs. 330). 

Zeng C Leyden J Spielman A. and Preti G. (1996). Analysis of characteristic human female axillary odors — qualitative comparison to males. J Chem Ecol 22,237-257. 

Cemoch, J.M. and Porter, R.H. (1985) Recognition of maternal axillary odors by infants. Child. 

Doty, R.L., Green, P.A., Ram, C. and Yankell, S.L. (1982) Communication of gender from human breath odors relationship to perceived intensity and pleasantness. Horm. Behav. 16, 13-22. Doty, R.L., Kligman, A., Leyden, J. and Omdorff, M.M. (1978) Communication of gender from human axillary odors Relationship to perceived intensity and hedonicity. Behav. Biol. 23, 373-380. 

Axillary odors of male and female humans contain the same compounds (Ce-Cii acids andE-3-methyl-2-hexenoic acid), but in different ratios. The characteristic odor resides in acidic compounds (Zeng etal, 1996b). 

Besides steroids, axillary odor also contains normal, branched, unsaturated aliphatic acids with 6 to 11 carbon members. Most abundant is (E)-3-methyl-2-hexenoic acid. Both this compound and its (Z)-isomer are found in the aqueous phase hydrolysate and the aqueous phase incubated with bacteria. It is assumed that precursors are water soluble and converted to odoriferous compounds by the axillary flora (Zeng etal., 1992). 

The compound responsible for much of the underarm odor is 3-methyl-2-hexenoic acid in both its (E) and (Z) isomers (Zeng et ah, 1991). Breath can also communicate gender information. However as with axillary odor, breath from men tends to be classified as stronger and more unpleasant than that of women Doty etal, 1982). 

Male axillary odor, thought to arise from volatile acids and volatile steroids, was collected on pads worn in the armpit for 6-9 hours. Alcohol extract of these samples was applied to the upper lip of each subject and left there for at least 6 hours. The cycles of women receiving the axillary extract three times per week for an average of 13.5 weeks became less variable and the number of aberrantly long cycles was reduced. 

The axillary odor of women, collected over 10 different 3-day sections of the menstrual cycle and applied to the upper lip of recipients, had a different effect. The cycles of the receiving women became more synchronized with the cycle of the donor female (Preti et al, 1986), measured as difference in menses onset in terms of days. Wilson (1987) and Weller and Weller (1993) have criticized these experiments but still they remain pioneering studies in an extremely difficult field. 

In a later experiment, two pheromones from axillary odor of young women influenced the estrus cycle of other women (Stern and McClintock, 1998). Armpit secretion that appears odorless to humans was applied daily between the upper lip and nose of healthy young women and had two opposite effects depending on the menstrual phase of the odor donors. Secretion from nine donor women, collected on pads in their armpits during the follicular phase of their cycles... 

Chemically, androstenol and dehydroepiandrosterone sulfate, found in male axillary secretion (Brooksbank etal, 1974), occur in active samples. Aliphatic acids with 2 to 18 carbon members may also contribute to the axillary odor (Preti etal, 1987). 

The influence of odors such as perfumes and fragrances on human behavior is assumed to he acquired, and the responses elicited depend on the often complex previous social experiences. The response will be altered if a laboratory experiment eliminates contextual stimuli (Kirk-Smith and Booth, 1987). Social odors include those of the well-known security blankets in toddlers, familiarly scented bed sheets in new surroundings, and treating insomnia with mother s axillary odor on handkerchief. Removal of bad body odors (diet, metabolism defects) that disrupt interpersonal harmony appears to be universal. 

Zeng, C., Spielman, A. L, Vowels, B. R., etal. (1996a). A human axillary odorant is carried by apolipoprotein D. Proceedings ofthe National Academy of Sciences of the USA 93,6626-6630. 

Zeng, X.-N., Leyden, J. J., Brand, J. G., etal. (1992). An investigation of human apocrine gland secretion for axillary odor precursors. JournalofChemicalEcology 18,1039-1055. 

Can hnmans reliably identify gender and individnals by body odors The answer to this qnestion matters very mnch in a nnmber of contexts of social and sexnal behavior snch as parent-offspring bonding, mate choice, or nepotism. A classical experiment has examined the role of the axillary odor, the most powerfnl hnman scent. This odor is the resnlt of bacterial action on the secretion of the axillary glands. These skin glands are of the apocrine type which is a modified sweat gland that prodnces an aqneons secretion. 

Doty RL, Omdorff MM, Leyden J, Klingman A (1978) Communication of gender from human axillary odors Relationship to perceived intensity and hedonicity. Behav Biol 23 373-380... 

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