Exogenous Steroid Administration Research Articles

Quantification of glucuronidated and sulfated steroids in human urine by ultra-high pressure liquid chromatography quadrupole time-of-flight mass spectrometry

The urinary steroid profile is constituted by anabolic androgenic steroids, including testosterone and its relatives, that are extensively metabolized into phase II sulfated or glucuronidated steroids. The use of liquid chromatography coupled to mass spectrometry (LC-MS) is an issue for the direct analysis of conjugated steroids, which can be used as urinary markers of exogenous steroid administration in doping analysis, without hydrolysis of the conjugated moiety. In this study, a sensitive and selective ultra high-pressure liquid chromatography coupled to quadrupole time-of-flight mass spectrometer (UHPLC-QTOF-MS) method was developed to quantify major urinary metabolites simultaneously after testosterone intake. The sample preparation of the urine (1mL) was performed by solid-phase extraction on Oasis HLB sorbent using a 96-well plate format. The conjugated steroids were analyzed by UHPLC-QTOF-MS(E) with a single-gradient elution of 36min (including re-equilibration time) in the negative electrospray ionization mode. MS(E) analysis involved parallel alternating acquisitions of both low- and high-collision energy functions. The method was validated and applied to samples collected from a clinical study performed with a group of healthy human volunteers who had taken testosterone, which were compared with samples from a placebo group. Quantitative results were also compared to GC-MS and LC-MS/MS measurements, and the correlations between data were found appropriate. The acquisition of full mass spectra over the entire mass range with QTOF mass analyzers gives promise of the opportunity to extend the steroid profile to a higher number of conjugated steroids.

Symptomatic Spinal Epidural Lipomatosis After a Single Local Epidural Steroid Injection

Spinal epidural lipomatosis is a rare disorder that can manifest with progressive neurological deficits. It is characterized by abnormal accumulation of unencapsulated epidural fat commonly associated with the administration of exogenous steroids associated with a variety of systemic diseases, endocrinopathies, and Cushing syndrome (Fogel et al. Spine J 5:202-211, 2005). Occasionally, spinal epidural lipomatosis may occur in patients not exposed to steroids or in patients with endocrinopathies, primarily in obese individuals (Fogel et al. Spine J 5:202-211, 2005). However, spinal lumbar epidural lipomatosis resulting from local steroid injection has rarely been reported. We report the case of a 45-year-old diabetic man with claudication that was probably due to symptomatic lumbar spinal lipomatosis resulting from a single local epidural steroid injection.

Dr. Pope Replies

Back to table of contents Previous article Next article Letters to the EditorFull AccessDr. Pope RepliesHARRISON G. POPE Jr., M.D.,HARRISON G. POPE Jr., M.D.Search for more papers by this author,Published Online:1 Oct 2009https://doi.org/10.1176/appi.ajp.2009.09060846rAboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail To the Editor: We agree with virtually all of the points raised by Drs. Scally and Tan, except for a minor semantic issue regarding their suggestion that anabolic steroid-induced hypogonadism represents a possible “confounding variable” in the diagnosis of anabolic-androgenic steroid dependence. To explain, we need to carefully define our terms. Anabolic steroid-induced hypogonadism is certainly a common physiologic response to chronic anabolic-androgenic steroid exposure, and it may contribute to anabolic-androgenic steroid withdrawal symptoms. Withdrawal symptoms, in turn, are a cluster of physical and psychological symptoms that may occur after discontinuing a drug that induces physiological dependence. Withdrawal symptoms are only one of the seven DSM-IV criteria for substance dependence and are neither necessary nor sufficient for a DSM-IV diagnosis of substance dependence. With these definitions in mind, then, we would say that anabolic steroid-induced hypogonadism represents simply one underlying mechanism for the etiology of anabolic-androgenic steroid withdrawal symptoms and should not be considered a confounder for making a DSM-IV diagnosis of anabolic-androgenic steroid dependence. As an example, opioid withdrawal is caused in part by abnormal signaling at central opioid receptors (1) . However, this abnormal receptor activity is not a “confounding variable” in diagnosing opioid dependence. Rather, it is one of the underlying mechanisms of opioid withdrawal, and opioid withdrawal, in turn, is a frequent (but not necessary) criterion for diagnosing opioid dependence. Similarly, if an anabolic-androgenic steroid user suppresses his own testosterone production as a result of prolonged exogenous anabolic-androgenic steroid administration and then develops consequent hypogonadal symptoms upon withdrawing (2) , these withdrawal symptoms would legitimately count as one criterion (although not a necessary criterion) for the diagnosis of anabolic-androgenic steroid dependence. On the basis of these considerations, we would agree with Drs. Scally and Tan that anabolic steroid-induced hypogonadism needs to be differentiated from anabolic-androgenic steroid dependence, since not all patients who suffer from anabolic steroid-induced hypogonadism will qualify for a diagnosis of anabolic-androgenic steroid dependence. However, we would suggest that anabolic steroid-induced hypogonadism does not disqualify an individual from a diagnosis of anabolic-androgenic steroid dependence either. Instead, anabolic steroid-induced hypogonadism represents one of the primary mechanisms of anabolic-androgenic steroid withdrawal and physiological dependence.Belmont, Mass.The author’s disclosures accompany the original editorial.This letter (doi: 10.1176/appi.ajp.2009.09060846r) was accepted for publication in July 2009.

Prenatal programming of the female reproductive neuroendocrine system by androgens

It has been clear for several decades that the areas of the brain that control reproductive function are sexually dimorphic and that the 'programming actions' of the male gonadal steroids are responsible for sex-specific release of the gonadotrophins from the pituitary gland. The administration of exogenous steroids to fetal/neonatal animals has pinpointed windows of time in an animals' development when the reproductive neuroendocrine axis is responsive to the organisational influences of androgens. These 'critical' periods for sexual differentiation of the brain are trait- and species-specific. The neural network regulating the activity of the gonadotrophin releasing hormone (GnRH) neurones is vital to the control of reproductive function. It appears that early exposure to androgens does not influence the migratory pathway of the GnRH neurone from the olfactory placode or the size of the population of neurones that colonise the postnatal hypothalamus. However, androgens do influence the number and the nature of connections that these neurones make with other neural phenotypes. Gonadal steroid hormones play key roles in the regulation of GnRH release acting largely via steroid-sensitive intermediary neurones that impinge on the GnRH cells. Certain populations of hormonally responsive neurones have been identified that are sexually dimorphic and project from hypothalamic areas known to be involved in the regulation of GnRH release. These neurones are excellent candidates for the programming actions of male hormones in the reproductive neuroendocrine axis of the developing female.

Hypothalamic–Pituitary–Adrenal Axis Response to Sustained Stress after Major Burn Injury in Children

The hypothalamic-pituitary-adrenal (HPA) axis is responsible for stress response after injury, yet its function after severe burn injury in children is unclear. The purpose of this study was to define the effects of burn injury on the HPA axis and to evaluate the utility of total serum cortisol in measuring adrenal function in children with major burns in the 2 months after injury. Children ages 0 to 17 years who were admitted within 72 hours to our pediatric burn center with 20% TBSA or greater full-thickness burns were eligible for the study. Serum total cortisol, adrenocorticotropic hormone (ACTH), dehydroepiandrosterone, vasopressin, Pediatric Risk of Mortality (PRISM) score, serum albumin level, and electrolytes were obtained on admission and weekly for 8 weeks. An ACTH stimulation test (250 microg for children >2 years, 125 microg for children < or =2 years) was administered weekly at 8:00 am. Total serum cortisol was measured before and 60 minutes after the administration of ACTH. Twenty-five children with mean age 7.6 +/- 1.1 years and TBSA burn 41.8 +/- 3.8% were enrolled in the study. Baseline total serum cortisol was 12.4 +/- 0.7 microg/dl in the 8 weeks after injury and increased to 24.4 +/- 0.8 microg/dl after the administration of ACTH. Cortisol level did not correlate with PRISM score, albumin, vasopressin, ACTH, or mortality. Although the adrenal response to acute and chronic stress is intact after severe burn injury, the ACTH/adrenal feedback loop is disrupted. Random total serum cortisol measurements overestimate adrenal dysfunction; thus, ACTH stimulation testing should be used to assess adrenal function before the administration of exogenous steroids.

Critical size of residual adrenal tissue and recovery from impaired early postoperative adrenocortical function after subtotal bilateral adrenalectomy

Background Subtotal bilateral adrenalectomy may preserve adrenocortical function. Little is known about the early postoperative function of the adrenal remnant. Method In 10 patients with bilateral adrenal tumors (pheochromocytomas, adrenocortical nodular hyperplasia, and adrenal metastases), plasma adrenocorticotropic hormone (ACTH), serum cortisol, and maximal cortisol liberation were examined with an ACTH test after subtotal bilateral adrenalectomy, which left 15% to 30% of adrenal tissue in situ. Results In the early postoperative period, all patients had normal basal serum cortisol levels (mean, 415±208 nmol/L; normal morning range, 138-690 nmol/L) but pathologically increased plasma ACTH levels (mean, 55±42 pmol/mL; normal, <10.1 pmol/L). In 6 patients, a pathologic ACTH test result was observed. During follow-up (mean, 11.3±7.6 months), all patients were found to have a normal ACTH test result. None of the patients required steroid supplementation. However, in patients with both familial pheochromocytoma and impaired adrenocortical function during the early postoperative period, the maximal increase of serum cortisol after ACTH stimulation was significantly reduced (mean, 301±86.8 nmol/L) compared with control subjects (mean, 490±132.6 nmol/L; P = .019). Conclusion After subtotal bilateral adrenalectomy left 15% to 30% of adrenal tissue in situ, functional recovery could be observed in all patients. However, subclinical impairment of the adrenocortical function with questionable clinical significance has to be considered in some of the patients. Especially during the early postoperative period, careful observation of the patients without exogenous steroid administration is required.

HRT and cardiovascular disease.

Recent randomized controlled clinical trials failed to confirm a perceived beneficial effect on cardiovascular disease by hormone therapy. Given the huge amount of observational data, as well as experimental data both in humans and various animal species, there is reason to believe that female sex steroids, in particular estrogen, possess cardiovascular benefits. The type, dose, and mode of administration of exogenous sex steroids may modify and even negate the beneficial effects. The results of the randomized trials, especially the WHI, should encourage the scientific community to try to define a target population in which benefits outweigh harm, as it must be regarded as proven that any hormone therapy regimen given to any population will not reach that goal. The recent finding that transdermal estrogens, in contrast to oral preparations, do not seem to be associated with an increased risk of venous thrombosis is challenging. It would seem appropriate to conclude that estrogens prevent arteriosclerosis. On a long-term basis, however, other more rapid effects on the cardiovascular system could be negative. Such an assumption contributes to the explanation of the discordant results from cohort studies versus randomized trials. Admittedly the current picture is complex, but far from definitive, and should challenge us all to continue research in this area.

Lipomatose epidural secundária a corticoterapia.

Spinal epidural lipomatosis is the excessive deposition of unencapsulated fat in the epidural space. This is a rare disorder often associated with high levels of endogenous steroids or the administration of exogenous steroids. A precocious diagnosis is important because it influences the clinical evolution and the therapeutics option. The computed tomography (CT) and magnetic resonance imaging (MRI) are very important to the diagnosis. Authors report a case of a mediastinal and epidural lipomatosis in a man receiving corticoid therapy, with symptoms consistent with acute respiratory failure and progressive paraparesis.

Comparison of steroid hormone patterns in different fat tissues of Synovex-S implanted and control steers

Four different adipose tissues (kidney fat, heart fat, fat over rib, tailhead fat) of six control and seven Synovex-S (containing progesterone and 17β-estradiol benzoate)-implanted steers were investigated for their profiles of progesterone, androgens, and their precursors and metabolites. The steers were implanted with Synovex-S and slaughtered after 84 days. The tissues represent different bovine depot fats. Kidney and heart fat deposit at an earlier stage of development than the other subcutaneous fat tissues was investigated. Androgens, their precursors and progesterone were analysed by GC-MS. Estrogens could not be detected by GC-MS. Resulting hormone patterns were compared between treatments and between fat depots. The statistical Kruskal-Wallis-H-test was used for comparison. The adipose tissues showed similar hormone patterns. Only progesterone showed an increased concentration in adipose tissues of implanted steers. The steroid patterns did not show the influence of exogenous steroid administration.

Rheumatic manifestations of pituitary tumors.

Pituitary tumors may cause rheumatologic problems as a result of under production or overproduction of one pituitary hormone. Excessive growth hormone causes destruction of cartilage by a direct action. Facial and acral changes and arthralgias may be some of the first symptoms of acromegaly. The arthritis associated with acromegaly is often devastating. Carpal tunnel syndrome is very common in patients with acromegaly. Adrenocorticotropin (ACTH) has indirect effects via the action of glucocorticoid on bones, muscles, and the immune system. Proximal muscle weakness is a characteristic feature of Cushing's syndrome. Patients with Cushing's syndrome commonly have osteopenia and osteoporosis that lead to an increase in bone fractures. Avascular necrosis is associated with exogenous steroid administration. The effects of too much glucocorticoid or too rapid withdrawal can be severe. Gonadotropins act via the gonadal steroids and protect bone mass from loss. Prolactin is less involved in rheumatologic disease; the data for which are limited in humans. Pituitary tumors can have manifestations similar to rheumatologic disorders and should be included in the differential diagnosis of these diseases.

Gonadal regeneration in masculinized female or steroid-treated rainbow trout (Oncorhynchus mykiss).

In salmonids, the development of an indifferent gonad into a testis or an ovary is normally determined chromosomally but can be reversed or changed by the administration of exogenous steroids during specific times in embryonic development. Because the gonads of sexually mature rainbow trout (RBT) are capable of regeneration following surgical removal and since regeneration of some tissue involves dedifferentiation, the objective of this experiment was to determine if the phenotypic sex of RBT gonads could be reversed during the regenerative process. In experiment 1, male RBT were surgically gonadectomized (Gx) or left intact and subsequently treated with estradiol-17beta, a steroid that feminizes male RBT embryos. All Gx males regenerated testicular tissue regardless of treatment. Likewise, the gonads of sham-operated, intact fish treated with exogenous estrogen showed no evidence of sex-reversal. In experiment 2, testes from masculinized females (XX genotype; male phenotype) were surgically removed. In all cases, only testicular tissue was regenerated in the masculinized females. Taken together, these results are consistent with the conclusion that gonads of salmonid fishes are not susceptible to sex-reversing stimuli during the regenerative process and that gonadal regeneration in salmonids is a result of cellular proliferation of the remaining gonadal remnant.

Insulin is degraded extracellularly in wounds by insulin-degrading enzyme (EC 3.4.24.56).

The exact mechanism by which insulin reverses impaired wound healing is unknown. Previous investigators have shown that insulin is degraded in experimental wounds, suggesting that the action of insulin may be locally modified. The following study corroborates these findings and identifies the major proteinase responsible for insulin degradation in wound fluid (WF). Adult male Fisher rats were wounded by subcutaneous implantation of polyvinyl alcohol sponges while under pentobarbital sodium anesthesia. WF and serum were collected on 1, 5, 10, and 14 days postinjury. Decreased insulin concentration in late WF correlated with an increased insulin-degrading activity. Multiple proteinases appear to participate in the overall degradation of insulin in WF. However, the primary enzyme responsible for insulin degradation in WF was characterized by immunoprecipitation and immunoblotting and identified as the neutral thiol-dependent metalloproteinase, insulin-degrading enzyme (EC 3.4.24.56). Exogenous steroid administration caused a decrease in WF insulin-degrading activity. Glucagon and adrenocorticotrophin degradation was also observed, whereas minimal degradation of insulin-like growth factors I and II and epidermal growth factor was detected in WF. The ability to extracellularly degrade insulin may represent a unique mechanism for the regulation of this hormone's role in healing wounds.

Transfer of cryopreserved-thawed pre-embryos in a cycle using exogenous steroids without prior gonadotrophin-releasing hormone agonist suppression yields favourable pregnancy results.

We have analysed the use of a programmed cycle of administration of exogenous steroids without prior suppression with a gonadotrophin-releasing hormone agonist (GnRHa) for the transfer of cryopreserved-thawed pre-embryos. From July 1992 to June 1994, 199 cycles (162 patients) were studied. Pre-embryos had been previously cryopreserved at the pronuclear stage using 1.5 M 1,2-propanediol as a cryoprotectant. Preparation of the endometrium was achieved in a step-up regime with transdermal oestradiol patches (0.1 to 0.4 mg). Progesterone in oil (50 mg i.m.) was started on cycle day 13. Pre-embryos were thawed on day 14 and transferred on day 15 after evidence of survival and cleavage. The mean (+/- SD) age of patients undergoing transfer was 35.4 +/- 4.3 years. The mean number of pre-embryos thawed was 4.7 +/- 1.8 with a mean of 3.3 +/- 1.4 pre-embryos being transferred. Eight of the cycles demonstrated follicular development >16 mm prior to thaw and transfer; however, these patients did not demonstrate a luteinizing hormone surge. Mean endometrial thickness on day 13 was 10.8 +/- 2.1 mm. Overall pregnancy rate was 29.2% (57/195). The ongoing or delivery rate was 16.1% (32/195). The rate of preclinical losses per transfer was 6.2% (12/195). Overall, the implantation rate was 6.2% (47/757). Thus, the use of a programmed cycle for cryopreserved embryo transfer yields favourable pregnancy outcome and offers practical advantages to patients. Prior suppression with a GnRHa is not necessary for endometrial preparation.

Participation of gamma-aminobutyric acid in the negative feedback mechanisms of the hypothalamohypophyseotesticular complex.

It is known that gamma-aminobutyric acid (GABA) participates in the regulation of the secretion of many adenohypophyseal hormones [2, 9]. In addition, GABAergic mechanisms may be involved in the regulation of testosterone-dependent aggressive [5] and sexual [8] behavior. A substantial number of studies suggest that GABA and its receptors are capable of participating in the regulation of the secretions of luteinizing hormone (LH). However, its role in this process is not entirely clear, since according to the data of various authors, GABA exerts both inhibitory and activating influences on the secretion of LH [3, 12]. Still less is known of the role of GABA and its receptors in the regulation of the secretion of LH by the negative feedback mechanism, which has been studied in bilaterally castrated rats [3]. However, such a model offers the possibility of investigating only a separate link of this mechanism which regulates the hypothalamohypophyseotesticular complex (HHTC). With regard to the study of the neurochemical regulation of the integral negative feedback system, the use of unilaterally castrated rats is more appropriate for this purpose. In such animals the compensation of the insufficiency of androgens is determined by negative feedback stimulation, and not by the administration of exogenous steroids. In addition, the level of testosterone in the peripheral blood more adequately reflects the state of this mechanism than the level of the gonadotropins [7]. However, the role of GABA and its receptors in the regulation of the integral negative feedback mechanism of the HHTC, so far as we know, remains entirely unstudied. This was in fact the purpose of the present study.

A revised critical period for the sexual differentiation of the sexually dimorphic nucleus of the preoptic area in the rat.

The volume of the sexually dimorphic nucleus of the preoptic area (SDN-POA) of the rat is several times larger in males than in females. Several studies have established the importance of gonadal steroids perinatally in the sexual differentiation of the SDN-POA as well as a critical period for the permanent influences of exogenous androgen on the volume of the nucleus. Recent preliminary evidence from this laboratory had suggested, however, that the critical period for the effects of the removal of endogenous gonadal steroids on SDN-POA volume may not match that for the administration of exogenous gonadal steroids. A series of experiments was designed to examine further the effects of the removal of endogenous gonadal steroids on adult SDN-POA volume by castrating male rats at various ages. In spite of a rather clear definition of a postnatal critical period for the effects of exogenous steroid administration, the results of this study indicate that the volume of the SDN-POA is sensitive to the removal of endogenous gonadal steroids for a prolonged period of time, extending through at least day 29 postnatally. The data suggest that there may be multiple critical periods for the sexual differentiation of the SDN-POA and reinforce the concept that these critical periods are distinct from those for other sexually differentiated parameters.

Uterine oxytocin gene expression. II. Induction by exogenous steroid administration

Uterine oxytocin gene expression. II. Induction by exogenous steroid administration

Uterine oxytocin gene expression. II. Induction by exogenous steroid administration.

As we have recently shown, the gene encoding the hypothalamic nonapeptide oxytocin (OT) is expressed in the rat endometrial epithelium during late pregnancy and the estrous phase of the estrous cycle. To investigate the role of ovarian steroids in the regulation of uterine OT gene expression, Silastic capsules containing estradiol or progesterone were implanted into immature ovariectomized rats. Exposure to estradiol alone for 2 days caused a significant rise in OT mRNA. Administration of progesterone alone was without effect. However, a strong synergism was observed when the two hormones were applied together; progesterone potentiated the effect of estradiol by a factor of 7. In animals treated with steroids for 4 days, the removal of either the estradiol or progesterone capsule after day 2 led to a decrease in the total amount of OT mRNA accumulation, implying that the continued action of both steroids was required to achieve maximal OT mRNA levels. Immunocytochemical analysis demonstrated that the main site of steroid-induced uterine OT gene expression is the endometrial epithelium, the same site where endogenously induced OT gene expression occurs at the end of pregnancy. The OT mRNA levels achieved after 4 days of treatment with both steroids were comparable to those achieved at estrus or during pseudopregnancy, but corresponded to less than 20% of the levels present in the uterus on day 21 of pregnancy. These data suggest that in the uterus, the synergistic action of ovarian steroids represents an important, but probably not exclusive, regulator of OT gene expression.

Recovery from Facial Paralysis Following Crush Injury of the Facial Nerve in Hamsters: Differential Effects of Gender and Androgen Exposure

In recent studies, we have shown that administration of androgens to male hamsters enhances functional recovery from facial paralysis induced by facial nerve crush at the level of the stylomastoid foramen. Furthermore, we have established that the mechanism behind this enhancement of regeneration involves an acceleration of the rate of regeneration, without a shortening in the delay of sprout formation. From those studies, several unexpected findings of inherent sex differences emerged. First, intact (nongonadectomized) females have a faster facial nerve regeneration rate than males and, second, testosterone has a less dramatic effect on the rate of regeneration in females compared to males. In the present study, we explored these novel findings of sex differences in the response of motor neurons to injury. Adult intact female hamsters were subjected to right facial nerve crush axotomy at the level of stylomastoid foramen and either implanted with two or four silastic capsules containing 5α-dihydrotestosterone, or sham-implanted for controls. A group of adult intact male hamsters was also subjected to right facial nerve crush axotomy. Animals were observed daily, beginning on Day 1 postoperatively and continuing throughout a 3-week recovery period for signs of functional recovery from facial paralysis. The average day of return of each of four behavioral components (semi-blink, blink reflex, full vibrissae movement, and complete recovery) was calculated for all four experimental groups. The results indicate that intact females recover functional return of movement following crush injury significantly faster than intact males. In contrast to our previous findings in male hamsters, administration of exogenous steroids does not accelerate recovery from facial paralysis in adult female hamsters. Why these sex differences in both inherent recovery from peripheral nerve injury and in the ability of androgens to augment regeneration occur is unknown, but will be interesting to explore from a molecular perspective in future studies.

Necrotizing Enterocolitis: A Review of Pathogenetic Mechanisms and Implications for Prevention

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of premature neonates that accounts for 3000 to 4000 deaths each year in the United States. The pathogenesis is not well understood, however theories suggest that prematurity, enteral feeding, bacterial colonization, and intestinal ischemia contribute to the intestinal injury. Furthermore, recent studies have shown that platelet activating factor and perhaps other inflammatory mediators mediate bowel necrosis in animals and possibly in humans. Although no specific intervention for NEC treatment exists, preventive therapy using either enteral IgA supplementation, breast milk feeding, antibiotic prophylaxis, or exogenous steroid administration have reduced the incidence of this overwhelming disease in small randomized trials. These modalities and perhaps PAF antagonists or other inflammatory mediator inhibitors may reduce the incidence or severity of NEC in the next several years.

Hormonal control of polymorphic and sexually dimorphic coloration in the lizard sceloporus undulatus erythrocheilus

This study investigated the influence of sex steroids on the expression of seasonally labile and sexually dimorphic coloration in the red-lipped plateau lizard. The responses of ventral blue and polymorphic facial coloration to exogenous steroid administration were assessed. Though facial color is usually dimorphic in nature, males and females did not differ in the degree to which they expressed facial coloration following administration of testosterone (T). Both sexes developed significantly more ventral blue coloration than controls, but a fundamental dimorphism in intensity, favoring males, was maintained throughout the experiment. These results indicate that facial coloration is under activational influence of T. The ventral blue coloration is probably organized at sexual maturation, thus manifesting the more vivid expression in males. Males of this subspecies are polymorphic for facial coloration. Administration of T did not cause any lizards to change hue, whether their color morph was yellow or orange or lacked the facial pigments altogether. The difference among color morphs is probably not controlled by differences in circulating steroid concentrations and is hypothesized to be under genetic control.