Sebaceous Gland Size Research Articles

Epidermal differentiation: transgenic/knockout mouse models reveal genes involved in stem cell fate decisions and commitment to differentiation.

Epidermal development and differentiation are similar processes and therefore the study of one is likely to provide insight into the other. The signaling cascades required for epidermal differentiation are largely unknown. Recent evidence, however, has implicated two proteins, p63 and c-Myc, in different stages of epidermal development and differentiation. p63 was shown to be required for embryonic epidermal development. Mice lacking p63 do not develop stratified epithelia and appendages suggesting a role for p63 in the commitment to squamous epithelial lineages. Subsequent stem cell fate decisions are required to form the different structures of stratified epithelia including hair follicles, sebaceous glands, and epidermis. Several genes of the Wnt signaling pathway have been implicated in this process, including c-Myc, a downstream target of the Wnt pathway. Interestingly, targeted overexpression of c-Myc in the basal layer of the epidermis results in an increase in sebaceous gland size and number at the expense of hair follicles. This suggests that c-Myc promotes differentiation of epidermal stem cells into sebaceous glands. In this review, we discuss transgenic/knockout mouse models that have provided evidence linking c-Myc and p63 to different stages of epidermal development and differentiation.

Testosterone-dependent primer pheromone production in the sebaceous gland of male goat.

To test the hypothesis that the primer pheromone responsible for inducing the "male effect" is produced in the sebaceous gland androgen dependently, we examined the correlation between morphological changes of sebaceous glands and the pheromone activity in skin samples taken from castrated goats that had been treated with testosterone. Five castrated goats were implanted s.c. with testosterone capsules to maintain physiological levels of plasma testosterone for four weeks. Skin samples were obtained from the head region on Day 0 (the day of testosterone implant), Day 7, Day 14, Day 28 (the day of testosterone removal), Day 36, Day 42, and Day 56. Matched blood samples were also collected for measurement of testosterone concentration. The pheromone activity of the ether-extracts of the upper dermal layer containing sebaceous glands was assessed by its stimulatory effect on the hypothalamic GnRH pulse generator, which was monitored for changes of specific multiple unit activity (MUA) in ovariectomized estradiol-primed goats as described previously. The sebaceous gland enlarged during the testosterone treatment but reduced in size after testosterone removal. The pheromone activity first appeared in 2 out of 5 goats on Day 7 and in all the 5 goats by Day 28. Fourteen days after testosterone removal (Day 42), the pheromone activity was no longer detectable in any of the 5 goats. In short, the sebaceous gland size and the pheromone activity shifted almost in parallel. The present results provide strong support for the view that the primer pheromone is produced testosterone dependently in the sebaceous gland of the male goat.

Safety of long-term administration of a 0.01% fluocinolone shampoo in allergic dogs.

Nine dogs with allergic dermatitis were bathed twice weekly with a 0.01% fluocinolone shampoo for 6 months to evaluate the shampoo's effects on the adrenal-pituitary axis, serum chemistries, complete blood counts and cutaneous histology. A group of 5 normal control dogs were bathed twice weekly for 6 months with the shampoo vehicle to determine whether or not the stress of bathing would have any effects on the monitored indices. Skin biopsies were evaluated at the beginning and end of the study, and serum chemistries and serum cortisols postadrenocorticotrophic hormone administration were evaluated every 8 weeks. There was no effect of the drug over time on serum chemistries or cortisol. Individual dogs in the treatment group had decreased epidermal and dermal thickness as well as decrease in size or number of sebaceous glands after treatment. None of the dogs exhibited the combination of morphologic changes characteristic of an atrophic dermatosis due to hyperadrenocorticism.

New aspects of the regulation of antler development: reevaluation of old dogmas

New evidence supporting the hypothesis that antlers are display organs used as dispensers of pheromones, has resulted from morphological studies of the distribution and size of sebaceous glands in the velvet. These parameters correlate with the life-style of various investigated cervids. Recent hormonal studies seem to confirm that small, permissive amount of testosterone are required for the initiation and growth of antlers, whereas higher concentrations of testosterone are needed for velvet shedding and hardening of antlers. Testosterone (T) may not be the only hormone involved in the formation and calcification of antlers. The testosterone metabolites estrogen and dihydrotestosterone may be crucial for the formation of bone mantle and for the maintenance of viable tissues in the antler core after velvet shedding. The most profound discovery of antlerogenic research in the last decade was the finding that hard, calcified antlers are viable up to several months after velvet shedding Histological studies have revealed the presence of active osteoblasts and observation of rebuilding activity in hard antlers. In addition, the presence of viable blood supply in polished antlers was confirmed by the presence of fluorescent dye injected intravenously three months after velvet shedding.

Laser hair removal affects sebaceous glands and sebum excretion: A pilot study

Background: During laser-assisted hair removal, sebaceous glands closely associated with hair follicles might also be affected. Objective: We investigated the effect of the long-pulsed ruby laser on sebaceous glands. Methods: Sebum excretion rates (SERs) of 16 subjects were measured quantitatively by means of sebum-absorbent tape and analyzed by means of image analysis techniques on laser-treated sites, compared with adjacent untreated areas. Evaluation was done at an average of 9 months (range, 4.5 to 12 months) after the last treatment. Histologic examinations were performed on 3 representative subjects before treatment, immediately after treatment, and 9 months after the last treatment. Results: Significant increases in SERs were observed in 11 of 16 subjects (68.75%). Three subjects (18.75%) showed lower SERs, whereas 2 subjects (12.5%) demonstrated no difference in SERs between treated and untreated areas. Biopsy specimens showed an apparent reduction in sebaceous gland size. Specimens taken immediately after laser irradiation revealed sporadic damage to sebaceous glands. Conclusion: In some patients a variable but statistically significant increase in sebum excretion occurs 4 to 12 months after ruby-laser hair removal treatment at high fluences. A reduction in sebaceous gland sizes on laser-treated areas was observed. We hypothesize that decreased resistance to sebum outflow may explain this result, following miniaturization or absence of hair shaft after ruby laser treatment. Further study is needed to assess mechanisms for this interesting response. (J Am Acad Dermatol 1999;41:176-80.)

The size of sebaceous glands in relation to the size of hair follicles on the heads of some small mammals (Insectivore, Chiroptera, Rodentia)

Many large sebaceous glands have been described, and functions such as scent production suggested, but gland size has seldom been studied in relation to the surface area of their hair follicles. However, investigating this relationship is essential for establishing whether glands produce more sebum than would be required for lubricating associated hair alone. Here, the relationship between sebaceous gland size and the surface area of the associated hair follicles has been studied. Glands on the heads of 20 species from three orders were compared with those associated with fur hairs. In all species, the fur hairs had small hair follicles with small sebaceous glands, as had the mystacial and submandibular hairs of Rodentia. Medium-sized glands and hairs were found in the mystacial and submandibular region in Insectivora, and in the circumoral region in Chiroptera and Rodentia. Large glands and hairs were found on a pad in the corner of the mouth in Rodentia. Although the size of glands was not directly proportional to hair size, some gross trends were noted. Vibrissae had either no or very small sebaceous glands. It is likely that sebum has to be provided from elsewhere to lubricate their surfaces. The glands on the snout of Insectivora and Chiroptera are clearly enlarged and could probably produce more sebum than would be required for grooming vibrissae alone. In Rodentia, vibrissae were surrounded by small hair and glands, and the nearest glands large enough to provide sebum were the glands on the pad in the mouth corner.

Skin abnormality in aged fyn-/- fak+/- mice.

Focal adhesion kinase (FAK) is a novel non-receptor protein tyrosine kinase implicated in transducing signals from cell surface receptors. Its association with Fyn, a member of the Src family of tyrosine kinases, has been observed in cell lines. To examine in vivo the interaction between these two proteins, Fyn-deficient mice were bred with fak heterozygous mutants (Fak deficiency is embryonic lethal). A majority of animals with the double mutation (fyn-/- fak+/-) displayed a transient impairment in thymocyte development at four weeks of age. However, all of them developed skin abnormalities at the age of 8-12 months. The most prominent among abnormalities was a greatly increased number and size of sebaceous glands. Also, the epidermis was thickened and hyperkeratotic. These observations would suggest involvement of Fyn and FAK in keratinocyte differentiation.

Adrenal steroid precursors exert potent androgenic action in the hamster sebaceous glands of flank organs and ears.

To assess the effect of the androgen precursors dehydroepiandrosterone (DHEA) and androstenedione (4-ene-dione) on androgen-sensitive parameters in the skin of the hamster, these two steroids were released from SILASTIC implants inserted sc into castrated male hamsters. The pigmented area of the flank organs, the size of the underlying sebaceous glands, [3H]thymidine incorporation into these sebaceous glands, and the size of the ear sebaceous glands were measured. The decrease in flank organ size caused by orchidectomy was partially reversed by DHEA and completely reversed by 4-ene-dione, testosterone (T), or dihydrotestosterone (DHT) implants. Similarly, the size of the sebaceous glands of the flank organs was reduced 88.1% by castration, whereas DHEA, 4-ene-dione, T, and DHT implants reversed the effect of orchidectomy. Orchidectomy also decreased the sizes of the sebaceous glands of the ears; DHEA, 4-ene-dione, T, and DHT implants increased their sizes to 50.6%, 81.9%, 91.6%, and 105.8% of the values found in intact hamsters, respectively. Parallel results were observed on the labeling of flank organ sebaceous glands with [3H]thymidine as well as on prostate weight. Serum concentrations of T and DHT became undetectable in castrated hamsters and were increased to intact or slightly elevated values in animals receiving implants of DHEA, 4-ene-dione, or T. The present results show that DHEA and 4-ene-dione are potent stimulators of androgen-sensitive parameters in the sebaceous glands of both the flank organs and ears in the hamster and illustrate the importance of extragonadal or peripheral intracrine formation of active steroids. It is suggested that the castrated hamster supplemented with adrenal precursor steroids is a good model that can closely mimic the human situation, where adrenal steroids play an important role in androgen formation and action in peripheral tissues.

Effects of Topically Applied Spironolactone on Androgen Stimulated Sebaceous Glands in the Hamster Pinna

The effects of spironolactone (5% SYC-201G, a preparation developed for clinical use in acne vulgaris by Searle Yakuhin K.K.), which is known to have antiandrogenic effects by competitively inhibiting dihydrotestosterone at androgen receptor sites, was topically applied to the androgen stimulated sebaceous glands of adult female golden hamsters. Androgen stimulation, induced by intramuscular injection of testosterone propionate (TP) every other day over a two week period, resulted in a 2.5 to 2.7 time increase in the size of the sebaceous glands of the hamster pinna. Once-daily treatment with 5% SYC-201G or matching placebo was applied to androgen-stimulated hamsters on one pinna only during the same period as TP injection. Comparison between the treated and untreated sides revealed a significant suppression in the sebaceous gland size (p < 0.05) by 5% SYC-201G; no such effect was observed with placebo. The difference in the suppression rate of the sebaceous gland size between 5% SYC-201G (23%) and matching placebo (-4.7%) was significant (p < 0.01).

Retinoids and Sebaceous Gland Activity

The marked efficacy of isotretinoin in the treatment of acne is undoubtedly due to its potential to inhibit sebaceous gland activity. The question arises if the anti-acne effect of new oral retinoids can be predicted by using the currently available experimental models. We reviewed the effects of various oral retinoids on sebum excretion in humans and their efficacy in acne. The human data were compared to the results obtained from in vitro and animal models. Oral retinoids such as etretinate, acitretin and the so-called arotinoids were not able to inhibit the sebum production in humans and were ineffective against acne. In various animal models (i.e. sebum production in rats, flank organ size in hamsters, ear sebaceous gland size in hamster, most of these retinoids were shown to be effective. Furthermore, in addition to isotretinoin, some retinoids were able to suppress the proliferation of human sebocytes in vitro. The elucidation of the mechanism of action of isotretinoin on the sebocyte biology is critical for the search of more reliable models and for the discovery of new retinoids with anti-acne activity.

Study of Possible Pharmacological Actions of Aloe arborescens MILLER on Mouse, Hamster and Human Skin.

Aloenin is a major constituent of Aloe arborescens MILLER which has been utilized in Japan as a folk remedy for burns, insect bites, and skin reaction. In the present study, the effects of aloenin on sebaceous gland size, hair growth and damaged skin were investigated. Aloenin significantly promoted hair growth in depilated mice, but did not affect sebaceous gland function in the hamster ear. Aloenin also had recuperative effects on tape-stripped human skin as determined from parameters such as the shape factor of corneocytes, thick abrasion, nuclear ghosts and cellular arrangement of corneocytes. Since aloenin is effective in healing damaged skin, it may be useful for the treatment of dermatological conditions in the future.

Effects of topically applied antiandrogenic compounds on sebaceous glands of hamster ears and flank organs

Growth of sebaceous glands in the ears and flank organs of castrated male hamsters is dependent on androgen substitution. Taking this for granted, a study was done to compare the effects of topical antiandrogenic treatment in vivo on the morphology and size of sebaceous glands with the concomitant changes in in vitro metabolism of 3H-testosterone. The role of dihydrotestosterone in sebaceous gland stimulation was thereby investigated.Topical treatment was carried out with the androgen antagonist 17α-propylmesterolone (PM), with 4-androgen-3-one-17β-carboxylic acid (17β-C), and 17β-N,N-diethylcar-bamoyl-4-methyl-4-aza-5α-androstan-3-one (4-MA), both described as specific 4-steroid-5α-reductase inhibitors, and with progesterone (PRO), which is an androgen receptor antagonist with 5α-reductase inhibiting properties.Regrowth of sebaceous glands after castration and substitution with testosterone propionate or dihydrotestosterone could be inhibited by topical PM and PRO. This occurred irrespective of the influence on testosterone metabolism and irrespective of the mode of substitution. 4-MA, on the other hand, while exhibiting strong 5α-reductase inhibition in vitro, was ineffective in reducing sebaceous gland sizes in vivo. The compound 17β-C was ineffective in every respect. In no case were systemic antiandrogenic effects on prostates and seminal vesicles observed.Our results support the view that the DHT formation rate has no regulatory function for growth of sebaceous glands in hamsters and that PM and PRO counteract the androgenic stimulus by their competitive antagonistic binding to the androgen receptor, but not by their influence on testosterone metabolism.

Effects of topically applied antiandrogenic compounds on sebaceous glands of hamster ears and flank organs.

Growth of sebaceous glands in the ears and flank organs of castrated male hamsters is dependent on androgen substitution. Taking this for granted, a study was done to compare the effects of topical antiandrogenic treatment in vivo on the morphology and size of sebaceous glands with the concomitant changes in in vitro metabolism of 3H-testosterone. The role of dihydrotestosterone in sebaceous gland stimulation was thereby investigated. Topical treatment was carried out with the androgen antagonist 17 alpha-propylmesterolone (PM), with 4-androsten-3-one-17 beta-carboxylic acid (17 beta-C), and 17 beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one (4-MA), both described as specific 4-steroid-5 alpha-reductase inhibitors, and with progesterone (PRO), which is an androgen receptor antagonist with 5 alpha-reductase inhibiting properties. Regrowth of sebaceous glands after castration and substitution with testosterone propionate or dihydrotestosterone could be inhibited by topical PM and PRO. This occurred irrespective of the influence on testosterone metabolism and irrespective of the mode of substitution. 4-MA, on the other hand, while exhibiting strong 5 alpha-reductase inhibition in vitro, was ineffective in reducing sebaceous gland sizes in vivo. The compound 17 beta-C was ineffective in every respect. In no case were systemic antiandrogenic effects on prostates and seminal vesicles observed. Our results support the view that the DHT formation rate has no regulatory function for growth of sebaceous glands in hamsters and that PM and PRO counteract the androgenic stimulus by their competitive antagonistic binding to the androgen receptor, but not by their influence on testosterone metabolism.

Llama Dermatology

As llamas become more common in North America, veterinarians will be called on ever more frequently to deal with their dermatologic problems. Adherence to the basic tenets of the thorough dermatologic work up, including history, physical examination, skin scrapings, cytological examinations, fungal culture, skin biopsies, and assessing response to judiciously chosen trial therapies will offer the best opportunity of arriving at proper diagnoses. Special attention must be paid to the fact that llama skin bears some histological differences that may prove confusing to the uninitiated. A mild degree of hyperkeratosis, a prominent vascular plexus in the superficial dermis that is associated with mild perivascular mononuclear cell accumulations, and regional differences in sebaceous gland size and numbers, all are considered normal findings. Ectoparasites, including sarcoptic mange, chorioptic manage, and pediculosis, appear to be the most common causes of pruritus in the llama. Although ivermectin therapy would appear to be very effective for the treatment of scabies and, indeed, may work well against sucking lice, chorioptic mange and biting lice usually do not respond to this medication. Corticosteroids can be used to treat pruritus in the llama nonspecifically, using the anti-inflammatory dosages established in other species. These drugs are used most appropriately for the management of the allergies that we suspect occur in this species, until better alternative therapies can be developed. Variably pruritic focal areas of alopecia, exudation, and crusting suggest differential diagnoses including bacterial folliculitis and furunculosis, dermatophilosis, dermatophytosis, and coccidioimycosis. The diagnosis of bacterial problems often is made by assessing response to antibiotic therapy. Topical disinfectants and/or systemic penicillin or trimethoprim-sulfadiazine are indicated. Dermatophilosis is treated by cleaning and drying the leasions, applying topical antibiotics, and, occasionally, using parenteral penicillin and streptomycin. Dermatophytosis usually is treated with topical antibiotics only. Captan is one of several therapies of choice. There is no therapy presently available for coccidioidomycosis in the llama. Perhaps most perplexing is the fact that one of the most common dermatopathies seen in the llama is an idiopathic keratinizing disorder that, in some cases, is responsive to zinc supplementation. We have no real idea of the pathogenesis of this problem and recognize that some affected animals will not respond to supplementation.(ABSTRACT TRUNCATED AT 400 WORDS)

Synergistic Antiandrogenic Effects of Topical Combinations of 5α-Reductase and Androgen Receptor Inhibitors in the Hamster Sebaceous Glands

The androgenic action of dihydrotestosterone (DHT) is antagonized by agents that compete with testosterone for the 5 alpha-reductase enzyme and by agents that block the binding of DHT to its receptor. The topical synergistic effect of 5 alpha-reductase (5 alpha RI) and androgen receptor inhibitors (ARI) was determined by measurement of the sebaceous gland size (SGS) of the ventral ear skin of the intact, sexually mature male Syrian hamsters. Progesterone (P), a 5 alpha RI, and spironolactone (SL), an ARI, produced a dose responsive decrease in SGS at topical concentrations of 0.01% to 5.0%. At concentrations of 1, 3, and 5%, P and SL combinations produced neither an additive nor synergistic inhibition of SGS. At very low concentrations of up to 0.10%, neither P nor SL alone produced any effect on SGS. When combinations of these two steroids were applied at low concentrations, SGS decreased unilaterally to approximately 50%. This synergy occurred best at a P:SL ratio of 1:2. The lower effective concentrations of P may be explained by its greater percutaneous absorption. Synergy was also demonstrated at low concentrations with other antiandrogens: cyproterone acetate, canrenone, hydroxyflutamide, and N-N-diethyl-4-methyl-3-oxo-4-aza-5 alpha-androstane- 17 beta-carboxamide. The use of anti-androgen combinations at low concentrations is of value because of the decreased risk of systemic side effects while maintaining potent topical efficacy.

Whole mount technique: an improved hamster ear model to evaluate pharmacologic effects on sebaceous glands.

AbstractAn improved and simplified hamster ear model (whole mount technique; WMT) is described. Excised ear skin specimens were incubated in 2N NaBr at 37°C for 2 hours, yielding a sheet of dermis with the sebaceous glands attached. After Sudan III staining, the areas of the sebaceous glands in the sheet were measured with an image analyzing system. The ratios of a mean area of androgen‐stimulated sebaceous glands/a mean area of non‐treated sebaceous glands (AS/NT) were 2.56 in females and 1.69 in males; these results closely resemble AS/NT ratios found in histological sagittal sections. Over 1.0% concentrations of topically applied cyproterone acetate were highly effective in suppressing the proliferation of sebaceous glands in androgen‐stimulated hamsters, as measured by WMT. Since no routinely processed histological sections are necessary and the exact size of a whole sebaceous gland can be obtained by WMT, this method seems to be useful for routine work to assess the efficacy of topically applied anti‐comedogenic or anti‐lipogenic drugs.

Effect of Isotretinoin on Serum Levels of Precursor and Peripherally Derived Androgens in Patients With Acne

Sebaceous glands are stimulated by androgens and can convert them to more active forms. Isotretinoin, however, has a profound inhibitory effect on sebaceous gland size and function. This study evaluated the effect of isotretinoin on serum levels of precursor and tissue-derived androgens. Twenty-four subjects (15 men and nine women) were treated for 20 weeks with 1 mg/kg/d of isotretinoin. Serum samples were obtained at baseline, 8, 16, and 24 weeks, and assayed for precursor androgens--total testosterone (TT), free testosterone (free T), dehydroepiandrosterone (DHEA), dehydroepiandrosterone-sulfate (DHEA-S); and tissue androgens--dihydrotestosterone (DHT), and its metabolite, 3 alpha-androstanediol glucuronide (3 alpha-diol G). Isotretinoin had no meaningful effects on precursor androgens, except for producing an elevation of free T in women. In contrast, isotretinoin produced depressions in the serum levels of DHT and 3 alpha-diol G in women and in 3 alpha-diol G in men. These decreases are believed to be the result, rather than the cause, of a reduction in the size of the sebaceous glands: The magnitude of the observed decreases may represent the amount of tissue-derived androgens that sebaceous glands normally contribute to the circulating pool.

Effects of intradermally injected and topically applied mouse epidermal growth factor on wool growth, skin and wool follicles of merino sheep.

Twice daily intradermal (ID) injections of mouse epidermal growth factor (mEGF) in sterile saline for 1-4 days into delineated areas of skin of Merino sheep produced dose-dependent changes in wool follicles and fibres, ranging from slight reduction in follicle bulb size and transient disturbance of cuticle formation on some fibres to the induction of catagen of follicles and shedding of fibres with distorted, tapered ends. Regeneration of follicles commenced by day 7. By contrast, ID injections of saline did not affect follicle activity. The epidermis became thicker and more parakeratotic after multiple injections of mEGF than after injection of saline, but was almost normal again by day 14. Persistent small increases in sebaceous gland size, additional to those induced by ID injections of saline, and delayed small increases in sweat gland size also occurred after multiple injections of mEGF. Daily topical applications of mEGF in 50% (v/v) aqueous propylene glycol 5 days each week for 4 weeks did not affect wool growth or the follicles and other skin components. The only effect observed, due to application of the aqueous propylene glycol, was an increase in the number of layers of cornified cells in the stratum corneum of the epidermis, with the cells arranged in clearly discernible stacks. The effects produced by ID injections of mEGF indicate that mEGF acts directly on the pilosebaceous and epidermal components of skin.

Sebum-suppressing activity of the nonpolar arotinoid Ro 15-0778 in rodents.

Retinoids are known to modulate sebaceous gland activity in humans and animals. The nonpolar arotinoid Ro 15-0778 [(E)-1,2,3,4-tetrahydro-1,1,4,4-tetramethyl-6-(1-methyl-2-phenylethen yl) naphthalene] does not contain a polar end group and is devoid of the classical retinoid side effects of hypervitaminosis A. The favorable toxicological profile stimulated the evaluation of this arotinoid in animal models of sebum production. In castrated, testosterone-stimulated male rats, Ro 15-0778 is 50 times more potent than 13-cis-retinoic acid in inhibiting the production and subsequent secretion of sebum. The oral ED50 value of Ro 15-0778 is 30 micrograms/kg, while an oral dose of 0.5 mg/kg inhibited sebum secretion nearly 100%. In testosterone-stimulated female rats, Ro 15-0778 inhibits sebum secretion significantly with an oral ED50 of 140 micrograms/kg and an s.c. ED50 of 75 micrograms/kg. Ro 15-0778 was also evaluated for its ability to prevent testosterone induction of the immature hamster flank organ. The topical ED50 is 0.53 mg/kg and the oral ED50 is 38 mg/kg. This arotinoid is similarly active in mature male hamsters without testosterone treatment. In addition, the retinoid is active topically and orally in reducing the size of the gerbil abdominal sebaceous gland. The compound exhibits no antiandrogenic activity when tested in ventral prostrate and seminal vesicle assays in rats. Additionally, the compound does not have estrogenic activity when tested in the rat uterine weight assay. High doses of Ro 15-0778 in humans did not demonstrate significant sebum-suppressing activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of testosterone and anabolic steroids on the size of sebaceous glands in power athletes.

The effect of testosterone and anabolic steroids on the size of sebaceous glands was studied by means of interactive morphometry in skin biopsies of power athletes. The subjects used self-administered high doses of testosterone and anabolic steroids during a 4-week strength training period. After 4 weeks' use of hormones, the area of sectioned sebaceous glands enlarged significantly by a factor of 89.2% (p less than 0.005). The number of cells in the so-called differentiating cell pool (DCP) and in the undifferentiated cell pool (UCP) also increased significantly (p less than 0.025, p less than 0.05, respectively). The size of the area occupied by UCP cells increased significantly (p less than 0.05). The study suggests that high doses of testosterone and anabolic steroids lead to an enlargement of sebaceous glands in male power athletes.