Hormonal intervention: "buffer hormones" or "state dependency". The role of dehydroepiandrosterone (DHEA), thyroid hormone, estrogen and hypophysectomy in aging

Nongenomic bronchodilating action elicited by dehydroepiandrosterone (DHEA) in a guinea pig asthma model

Primates secrete large amounts of the precursor steroid dehydroepiandrosterone (DHEA); in humans, its levels are low during childhood and start declining after the fourth decade. It has been postulated that the progressive decline in DHEA levels may be related with the severity of asthma associated with age. To determine whether DHEA may regulate the airway smooth muscle (ASM) activity, isolated tracheal rings with and without epithelium from male guinea pigs were isometrically recorded to characterize the response of ASM to DHEA at different concentrations on KCl- and carbachol (CCh)-induced contraction as well as on ovalbumin (OVA)-induced contraction in sensitized guinea pigs. Additionally, we used barometric plethysmography in sensitized guinea pigs in order to compare changes of the lung resistance increased by the antigen challenge to OVA in the absence and presence of different doses of DHEA. DHEA concentration-dependently abolished the contraction to KCl, CCh and OVA, and no differences were found in preparations with and without epithelium. DHEA-induced relaxation was not modified by the suppression of protein synthesis or transcription, pharmacological inhibition of nitric oxide (NO) synthase, nor by antagonist of β2-adrenergic receptors or an inhibitor of the 3β-HSD enzyme. Likewise, Ca(2+)-induced contraction in Ca(2+)-free depolarized tissues was antagonized by DHEA, and the contraction to the L-type voltage-dependent calcium channel activator (Bay K 8644) was inhibited by DHEA. Furthermore, DHEA prevented OVA-induced increases in lung resistance. These results indicate that DHEA-induced relaxation in ASM is a nongenomic (membrane) action and is not produced after its bioconversion. The data suggest that DHEA-induced relaxation is an epithelium- and NO-independent mechanism that involves a blockade of voltage-dependent calcium channels and possible non-selective cation channels.

Self-rated mental stress and exercise training response in healthy subjects

Purpose: Individual responses to aerobic training vary from almost none to a 40% increase in aerobic fitness in healthy subjects. We hypothesized that the baseline self-rated mental stress may influence to the training response. Methods: The study population included 44 healthy sedentary subjects (22 women) and 14 controls. The laboratory controlled training period was 2 weeks, including five sessions a week at an intensity of 75% of the maximum heart rate for 40 min/session. Self-rated mental stress was assessed by inquiry prior to the training period from 1 (low psychological resources and a lot of stressors in my life) to 10 (high psychological resources and no stressors in my life), respectively. Results: Mean peak oxygen uptake (VO2peak) increased from 34 ± 7 to 37 ± 7 ml kg⁻¹ min⁻¹ in training group (p < 0.001) and did not change in control group (from 34 ± 7 to 34 ± 7 ml kg⁻¹ min⁻¹). Among the training group, the self-rated stress at the baseline condition correlated with the change in fitness after training intervention, e.g., with the change in maximal power (r = 0.45, p = 0.002, W/kg) and with the change in VO2peak (r = 0.32, p = 0.039, ml kg⁻¹ min⁻¹). The self-rated stress at the baseline correlated with the change in fitness in both female and male, e.g., r = 0.44, p = 0.039 and r = 0.43, p = 0.045 for ΔW/kg in female and male, respectively. Conclusion: As a novel finding the baseline self-rated mental stress is associated with the individual training response among healthy females and males after highly controlled aerobic training intervention. The changes in fitness were very low or absent in the subjects who experience their psychological resources low and a lot of stressors in their life at the beginning of aerobic training intervention.

Dehydroepiandrosterone sulfate linked to physiologic response against hot spring immersion

The steroid dehydroepiandrosterone sulfate (DHEA-S) is associated with longevity and adaptation against external stress in humans. The aim of the study was to investigate the acute effect of a 30-min hot spring immersion at 41 degrees C on insulin resistance measures of 16 male subjects, in relation to DHEA-S level. To elucidate the role of DHEA-S in the coping against the heat stress, all subjects were evenly divided into lower and upper halves according to their baseline DHEA-S concentrations. The levels of glucose, insulin, blood pressure, and stress hormones (growth hormone, testosterone, and cortisol) in both groups were compared before and after hot spring immersion. The result shows that hot spring immersion significantly increased heart rate and reduced diastolic blood pressure, both of which were paralleled with a drop of DHEA-S concentration. Homeostasis model assessment for insulin resistance (HOMA-IR) and area under curve of glucose (GAUC) of oral glucose tolerance test were significantly increased by the hot spring immersion only in the Low DHEA-S group. Likewise, hot spring immersion caused an opposing effect on cortisol changes for the Low and High DHEA-S groups (+95% vs. -33%, p<0.05), respectively. In conclusion, hot spring bathing induced insulin resistance confined only to those Low DHEA-S individuals. This response may be associated with a stress response such as increased cortisol levels.

DHEA metabolism in prostate: For better or worse?

Dehydroepiandrosterone (DHEA) is commonly used in the USA as a nutritional supplement for antiaging, metabolic support or other uses. Investigations into understanding the effects of DHEA on human prostate cancer progression have posed more questions than answers and highlight the importance of communications between stromal and epithelial tuoitiuot elements within the prostate that contribute to the regulation of DHEA metabolism. Intracrine metabolism of DHEA to androgens (A) and/or estrogens (E) may occur in one cell compartment (stromal) which may release paracrine hormones or growth/inhibitory factors to the epithelial cells. Alternatively no metabolism of DHEA may occur, resulting in no harmful consequences of high levels of DHEA in prostate tissues. We herein review the tissue components involved and interactions with the prohormone, DHEA and/or resulting metabolites, including dihydrotestosterone (DHT) or 17beta-estradiol (E(2)) in an in vitro model of endocrine-immune-paracrine interactions within the prostate. This work raises questions and hypotheses concerning the role of DHEA in prostate in normal tissues, vs. preneoplastic tissues.

Human prostate stromal cells stimulate increased PSA production in DHEA-treated prostate cancer epithelial cells

Dehydroepiandrosterone (DHEA) is commonly used as a dietary supplement and may affect prostate pathophysiology when metabolized to androgens and/or estrogens. Human prostate LAPC-4 cancer cells with a wild type androgen receptor (AR) were treated with DHEA, androgens dihydrotestosterone (DHT), T, or R1881), and E2 and assayed for prostate specific antigen (PSA) protein and gene expression. In LAPC-4 monocultures, DHEA and E2 induced little or no increase in PSA protein or mRNA expression compared to androgen-treated cells. When prostate cancer-associated (6S) stromal cells were added in coculture, DHEA stimulated LAPC-4 cell PSA protein secretion to levels approaching induction by DHT. Also, DHEA induced 15-fold more PSA mRNA in LAPC-4 cocultures than in monocultures. LAPC-4 proliferation was increased 2-3-fold when cocultured with 6S stromal cells regardless of hormone treatment. DHEA-treated 6S stromal cells exhibited a dose- and time-dependent increase in T secretion, demonstrating stromal cell metabolism of DHEA to T. Coculture with non-cancerous stroma did not induce LAPC-4 PSA production, suggesting a differential modulation of DHEA effect in a cancer-associated prostate stromal environment. This coculture model provides a research approach to reveal detailed endocrine, intracrine, and paracrine signaling between stromal and epithelial cells that regulate tissue homeostasis within the prostate, and the role of the tumor microenvironment in cancer progression.

Increased antioxidant capacity in healthy volunteers taking a mixture of oral antioxidants versus vitamin C or E supplementation

The objectives of this study were (1) to evaluate the capacity of human plasma that had been obtained from healthy adult volunteers before and after they ingested vitamin E or C to inhibit induced lipoperoxidation in vitro (antioxidant capacity of plasma [ACP]), and (2) to compare the efficiency of these vitamins with that of a commercial mixture of antioxidant vitamins, cofactors, and minerals (MAOx). Seventy-nine healthy individuals between 19 and 23 y of age were randomly assigned to 1 of 4 groups. Each received a daily dose of antioxidants for 7 d: vitamin C (n=18; 500 mg), vitamin E (n=21; 400 IU), vitamins C and E (n=19), or MAOx (n=21; 1.2 g). ACP and plasma malondialdehyde were measured at 4 and 24 h and 7 d. ACP increased significantly (P<.05) in all 4 groups within 4 h of antioxidant intake, and this effect was sustained throughout supplementation. Plasma ACP increased significantly over basal values in the group taking MAOx; relative increases were 42%, 44%, and 55% at 4 h, 24 h, and 7 d, respectively (P<.001). Smaller increases in plasma ACP were observed in the vitamin C group (25%, 32%, and 36%) and, specifically, in the vitamin E group (17%, 24%, and 28%) (P<.05). The mixture of vitamins and minerals was comparatively more efficient than vitamin C or E alone, presumably because MAOx contains various antioxidant compounds with different redox potentials, leading to the possible development of chain reactions.

A possible link between exercise-training adaptation and dehydroepiandrosterone sulfate- an oldest-old female study

The purpose of this study was to determine the association between the level of salivary dehydroepiandrosterone sulfate (DHEA-S) and the magnitude of adaptation to exercise training in insulin sensitivity for aged females. A group of 16 females, aged 80-93 years old, was divided into 2 groups according to their baseline DHEA-S levels: Lower Halves (N = 8) and Upper Halves (N = 8), and participated in a 4-month exercise intervention trial. Insulin response with an oral glucose tolerance test (OGTT), cholesterol, blood pressure (BP), motor performance, and DHEA-S were determined at baseline and 4 months after the training program. Glucose tolerance and body mass index (BMI) remained unchanged with training for both groups. Insulin, fasted cholesterol, diastolic blood pressure, reaction time, and locomotive function were significantly lowered by training only in the Upper Halves group. Changes in the area under curve of insulin (IAUC) were negatively correlated with the baseline DHEA-S level (R= - 0.60, P < 0.05). The current study provides the first evidence that oldest-old subjects with low DHEA-S level appear to be poor responders to exercise-training adaptations.

Effect of resistance exercise on dehydroepiandrosterone sulfate concentrations during a 72-h recovery: Relation to glucose tolerance and insulin response

Serum dehydroepiandrosterone sulfate (DHEA-S) concentration is known to be associated with the whole-body insulin sensitivity. The main purpose of the study was to investigate the effect of resistance exercise on DHEA-S concentration during a 72 h post-exercise recovery, and its relation to glucose tolerance and insulin sensitivity. Morning fasted serum samples was obtained from 19 male volunteers (aged 21.1+/-0.4 years) 24 h before the onset of exercise and 24 h, 48 h, and 72 h following exercise for measurements of DHEA-S, cortisol, and TNF-alpha. Oral glucose tolerance test (OGTT) and insulin response were determined 24 h before and 48 h after exercise. We found that resistance exercise causes a delayed suppression in serum DHEA-S levels during recovery (48 h and 72 h). This exercise challenge did not affect glucose tolerance, but insulin response during OGTT was significantly elevated. The increased insulin level was not associated with serum levels of cortisol and TNF-alpha. In conclusion, the present study found that resistance exercise has a DHEA-S lowering effect that persisted for 72 h. This change could be related to the elevated insulin concentrations during OGTT.

The vasodepressor effect of androgens in pithed rats: potential role of calcium channels

Estrogens induce vasodilatation and/or hypotension in several experimental models, probably by a blockade of calcium currents. However, very little is known about the potential cardiovascular effects of androgens. We have previously shown that 5 beta-reduced androgens are more potent vasorelaxants than their precursors (delta 4-3 keto), 5-reduced progestins and 17beta-estradiol. The present study set out to investigate if this vasorelaxant effect of 5-reduced androgens is operative in vivo in the analysis of the potential vasodepressor effect of these compounds in vagosympathectomized, pithed rats. After increasing diastolic blood pressure (DBP) by a continuous infusion of norepinephrine (0.059 micromol x kg(-1)min(-1)), i.v. bolus injections of 3 alpha-hydroxy-5 beta-androstan-17-one (etiocholanolone), 5 beta-dihydrotestosterone (5 beta-DHT), and its isomer 5 alpha-dihydrotestosterone (5 alpha-DHT) (5-25 micromol x kg(-1) each) produced, separately, dose-dependent vasodepressor responses. These responses were biphasic: an immediate fall in DBP (reaching the nadir within 1.7 min) was followed by a further slow decrease that reached a maximum between 80 and 100 min after steroid administration. The order of potency of androgens in decreasing DBP was: 5 beta-DHT>5 alpha-DHT=etiocholanolone for the short-lasting response and 5 alpha-DHT>5 beta-DHT>or=etiocholanolone for the longer lasting response. Importantly, the same doses of these compounds produced no significant changes in heart rate. Moreover, 5 beta-DHT significantly antagonized the vasopressor responses to methyl 1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluromethylphenyl)-pyridine-5-carboxylate (Bay K 8644) with a blocking profile similar to that of nifedipine (NIF). This finding suggests that a blockade of voltage-operated calcium channels may be involved in androgen-induced hypotension.

Hypercholesterolemia treatment: a new hypothesis or just an accident?

A new hypothesis concerning the association of low levels of steroid hormones and hypercholesterolemia is proposed. This study presents data that concurrent restoration to youthful levels of multiple normally found steroid hormones is able to normalize or improve serum total cholesterol (TC). We evaluated 20 patients with hypercholesterolemia who received hormonorestorative therapy (HT) with natural hormones. Hundred percent of patients responded. Mean serum TC was 263.5 mg/dL before and 187.9 mg/dL after treatment. Serum TC dropped below 200 mg/dL in 60.0%. No morbidity or mortality related to HT was observed. In patients characterized by hypercholesterolemia and sub-youthful serum steroidal hormones, our findings support the hypothesis that hypercholesterolemia is a compensatory mechanism for life-cycle related down-regulation of steroid hormones, and that broadband steroid hormone restoration is associated with a substantial drop in serum TC in many patients.

Administration of dehydroepiandrosterone suppresses experimental allergic encephalomyelitis in SJL/J mice

Experimental allergic encephalomyelitis (EAE) is a Th1-mediated inflammatory demyelinating disease in the CNS, an animal model of multiple sclerosis. We have examined the effect of dehydroepiandrosterone (DHEA) on the development of EAE in mice. The addition of DHEA to cultures of myelin basic protein-primed splenocytes resulted in a significant decrease in T cell proliferation and secretion of (pro)inflammatory cytokines (IFN-gamma, IL-12 p40, and TNF-alpha) and NO in response to myelin basic protein. These effects were associated with a decrease in activation and translocation of NF-kappaB. In vivo administration of DHEA significantly reduced the severity and incidence of acute EAE, along with a decrease in demyelination/inflammation and expressions of (pro)inflammatory cytokines in the CNS. These studies suggest that DHEA has potent anti-inflammatory properties, which at least are in part mediated by its inhibition of NF-kappaB activation.

Stimulation of Th2 response by high doses of dehydroepiandrosterone in KLH-primed splenocytes

Although dehydroepiandrosterone (DHEA) has long been considered as a precursor for steroid hormones, it has also been shown to have regulatory effects in immune homeostasis. We have examined the effect of high DHEA doses on T cell proliferation, differentiation, and cytokine secretion patterns following stimulation with mitogens and soluble antigens. DHEA profoundly inhibited T cell receptor-mediated T cell proliferation in the upstream of IL-2R signaling. Addition of DHEA to KLH-primed splenocytes stimulated Th2 response, indicated by an increase of IL-4 or a decrease of IFN-gamma production in the cultures. Further studies showed that DHEA enhanced IL-4, but inhibited IL-12-mediated T cell proliferation and IL-12 production in antigen-presenting cells (APCs). Our data demonstrated that supraphysiologic levels of DHEA favored Th2 immune responses in vitro by inhibition of IL-12 production from APCs and/or stimulation of Th2 proliferation during the interactions of T cells with APCs.

The effect of 7-oxo-DHEA acetate on memory in young and old C57BL/6 mice

7-Oxo-dehydroepiandrosterone, which can be formed from dehydroepiandrosterone (DHEA) by several mammalian tissues, is more effective than its parent steroid as an inducer of thermogenic enzymes when administered to rats. Using the Morris water maze procedure, we tested DHEA and its 7-oxo-derivative for their ability to reverse the memory abolition induced by scopolamine in young C57BL/6 mice, and for their effect on memory in old mice. A single dose of 7-oxo-DHEA-acetate at 24 mg/kg b.w. completely reversed the impairment caused by 1 mg of scopolamine per kg b.w. (P < 0.001). DHEA (20 mg/kg) was also effective (P < 0.01). In old mice given the same single doses followed by feeding 0.05% of the respective steroid in the diet, memory of the water maze training was retained through a four week test period in mice receiving 7-oxo-DHEA-acetate (P < 0.05) but not in the control or DHEA-treated groups. When old mice were not tested until five weeks after being trained 7-oxo-DHEA exerted a slight, but statistically insignificant, improvement in memory retention. The possible effect of 7-oxo-DHEA in human memory problems deserves investigation.

Dehydroepiandrosterone (DHEA) facilitates liver regeneration after partial hepatectomy in rats

In this study we investigated whether or not liver regeneration is facilitated by dehydroepiandrosterone (DHEA) after partial (70%) hepatectomy in rats. Treatment with DHEA (300 mg/kg body weight) did not cause any significant increase in the expression ratio of proliferating cell nuclear antigen (PCNA) in sham-operated controls; however, in partially hepatectomized rats it caused a significant increase in the ratio in hepatocytes 24 and 36 hr after hepatectomy. In partially hepatectomized rats, DHEA treatment significantly accelerated the restoration of liver 48, 60, and 72 hr after partial hepatectomy. The restoration rate in DHEA-treated hepatectomized rats at 72 hr was 1.3-fold greater than in partially hepatectomized controls. Treatment with androstenedione (300 mg/kg body weight), the first metabolite of DHEA, did not cause any significant increase in the expression of PCNA in either sham-operated controls or partially hepatectomized rats. These results indicate that DHEA itself promotes the liver regenerative process after partial hepatectomy in rats.

Polyelectroylte complex composed of chitosan and sodium alginate for wound dressing application

Drug-impregnated polyelectrolyte complex (PEC) sponge composed of chitosan and sodium alginate was prepared for wound dressing application. The morphological structure of this wound dressing was observed to be composed of a dense skin outer layer and a porous cross-section layer by scanning electron microscopy (SEM). Equilibrium water content and release of silver sulfadiazine (AgSD) could be controlled by the number of repeated in situ PEC reactions between chitosan and sodium alginate. The release of AgSD from AgSD-impregnated PEC wound dressing in PBS buffer (PH = 7.4) was dependent on the number of repeated in situ complex formations for the wound dressing. The antibacterial capacity of AgSD-impregnated wound dressing was examined in agar plate against Pseudomonas aeruginosa and Staphylococcus aureus. From the behavior of antimicrobial release and the suppression of bacterial proliferation, it is thought that the PEC wound dressing containing antimicrobial agents could protect the wound surfaces from bacterial invasion and effectively suppress bacterial proliferation. In the cytotoxicity test, cellular damage was reduced by the controlled released of AgSD from the sponge matrix of AgSD-medicated wound dressing. In vivo tests showed that granulation tissue formation and wound contraction for the AgSD plus dihydroepiandrosterone (DHEA) impregnated PEC wound dressing were faster than any other groups.

The role of dehydroepiandrosterone in diabetes mellitus

Much has been written in the lay literature regarding potential benefits of dehydroepiandrosterone (DHEA). Although it was removed from the over-the-counter market in 1985, the Dietary Supplement Health Education Act of 1994 allowed the drug to be marketed as a food supplement. Because DHEA no longer falls under the scrutiny of the Food and Drug Administration, many unverified claims have been put forth in the press espousing its therapeutic value. This barrage of "infomercials" has left the average American consumer (and health care professional) curious about DHEA and its possible therapeutic utility. One focus of recent research is to define the role of DHEA in diabetes mellitus. Although it has been claimed that decreased levels of endogenous DHEA are associated with diabetes, impaired glucose tolerance, hyperglycemia, and insulin resistance, much of the information is based on cross-sectional studies. Other claims correlate decreased endogenous DHEA levels with adverse cardiovascular effects. Some information is contradictory and indicates high doses of exogenous DHEA may produce adverse cardiovascular effects, an undesirable outcome in patients with diabetes mellitus. At this time, its administration in patients with diabetes is not warranted. Long-term trials evaluating the role of exogenous DHEA and its effect on patients with diabetes should be conducted.

Possible role of Ca2+ channels in the vasodilating effect of 5beta-dihydrotestosterone in rat aorta

It has previously been shown that the androgen, 5beta-dihydrotestosterone (17beta-hydroxy-5beta-androstan-3-one, 5beta-DHT), is able to produce an endothelium-independent vasodilating effect in rat aorta. The present study analyzed the mechanisms underlying the above vasodilator effect of 5beta-dihydrotestosterone, with particular emphasis on verifying a possible interaction with GABA(A) receptors, beta-adrenoceptors and Ca2+ channels. Rat aortic rings without endothelium were isometrically recorded. 5Beta-dihydrotestosterone produced a concentration-dependent relaxation on the contractions induced by noradrenaline (NA; 0.3 microM) or K+ (KCl; 60 mM), with the latter being more sensitive to 5beta-dihydrotestosterone-induced relaxation than the former; the concentration-response curves showed that 5beta-dihydrotestosterone is significantly more potent than 17beta-estradiol(1,3,5(10)-estratrien-3,17beta-diol) to induce vasodilatation. The vasodilating effect of 5beta-dihydrotestosterone on noradrenaline-induced contraction was resistant to blockade by the GABA(A) receptor antagonists, picrotoxin or bicuculline, and the beta-adrenoceptor antagonist, propranolol, a finding that excludes an interaction of the steroid with GABA(A) receptors and beta-adrenoceptors. Interestingly, the contractions evoked by calcium in depolarized tissues were substantially inhibited by 5beta-dihydrotestosterone, implying that this steroid could be an endogenous calcium channel blocker; consistent with this finding, 5beta-dihydrotestosterone was able to relax tissues precontracted with the calcium channel opener, Bay K 8644. Moreover, although the rings precontracted with noradrenaline and potassium were almost equipotently relaxed by 5beta-dihydrotestosterone. Nifedipine was more potent than 5beta-dihydrotestosterone to block the potassium-induced contraction, but the steroid was more effective than nifedipine to prevent noradrenaline-induced contraction. The above results suggest that 5beta-dihydrotestosterone causes relaxation of rat aorta by acting directly on the membrane of smooth muscle cells; this non-genomic action may be explained in terms of a blockade of voltage- and receptor-dependent calcium channels, a mechanism that restricts the availability of extracellular calcium in the contractile machinery.

The importance of being dehydroepiandrosterone sulfate (in the blood of primates): a longer and healthier life?

The general aging sequence in tissues of healthy human beings is proposed to be: capillary endothelial cell damage --> arteriosclerosis --> decreased blood flow --> metabolic dysregulation --> secondary tissue damage. Molecular O2 is an obligatory substrate for the successive syntheses of 17alpha-OH pregnenolone and dehydroepiandrosterone (DHEA) by cytochrome P450c17 in the zona reticularis of the adrenal cortex, in which it is suggested that arteriosclerosis --> decreased blood flow --> O2 and glucose deficit --> decreased O2-requiring synthesis of DHEA --> eventual decrease in number of DHEA-synthesizing cells. Aging changes in the zona reticularis synergize with those in the hypothalamo-hypophyseal machinery that controls it neurally and hormonally, with ACTH-evoked pulsatile floods of cortisol coming from the adrenal zona fasciculata, with the onslaught of free radicals generated by the metabolism of catecholamines released from interdigitating cells of the adrenal medulla, and with age-correlated disabilities of erythrocytes to bind and release O2 to decrease the viability of the DHEA and dehydroepiandrosterone sulfate (DHEAS)-forming cells. One of the chief functions of serum DHEAS in the male may be to act as an allosteric facilitator of the binding of testosterone (T) to serum albumin, thereby helping target T to specific receptors and to allosteric sites for rapid and efficient action at the cellular level. There is reason to consider combining O2 therapy with appropriate administration of DHEA and T to optimize steroid functionality in the healthy aging male, and thus, possibly, to alleviate some of the age-related cognitive and physical decrements that occur.

An acute oral gavage study of 3beta-acetoxyandrost- 5-ene-7,17-dione (7-oxo-DHEA-acetate) in rats

The present study was done to assess the tolerance of rats for 3-acetoxyandrost-5-ene-7,17-dione (7-oxo-DHEA-acetate, 7-ODA) when administered as a single oral gavage dose. Five groups of Sprague-Dawley rats (Crl:CD (SD) BR VAF/Plus) (five/sex/group) were treated with 7-ODA at a dose level of 0 (control), 250, 500, 1000, or 2,000 mg/kg of body weight in a dose volume of 10 ml/kg. Food and water were provided ad libitum. All animals survived in good health to the scheduled sacrifice on Day 15. The single oral administration of 7-ODA had no apparent effects on body weight. Food consumption was significantly higher for all female treated groups during week two; however, the statistically significant differences were not considered to be of clinical consequence. Treatment caused no apparent changes of gross or microscopic anatomical structures of nine different organs. This study demonstrated that the no-observable adverse effect level for a single oral dose of 7-ODA in male and female rats was 2,000 mg/kg.

Adrenal function in preterm infants: ACTH may not be the sole regulator of the fetal zone

The fetal zone of the adrenal gland is known to persist after preterm birth, but there is uncertainty as to how long adrenal fetal zone steroid production continues and how it is regulated. The purpose of this study was to test two hypotheses. First, that the urinary excretion of 3beta-OH-5-ene steroids persists until term, and then declines, as it does in full-term infants. Second, that the persistence of the fetal zone is due to continuing ACTH stimulation. A longitudinal observational study was undertaken in 22 preterm infants of 24-31-wk gestation. Sequential measurements were made of urinary 3beta-OH-5-ene steroids (fetal zone steroid metabolites), plasma dehydroepiandrosterone sulfate (DHEAS), and ACTH. Excretion of urinary 3beta-OH-5-ene steroids was 1500-2000 microg kg(-1) d(-1), persisting until term, and declining abruptly at approximately 42 wk postconceptional age (PCA), to levels comparable to term infants at the same PCA. Median plasma ACTH levels rose from <7.6 pg mL(-1) at 25-wk PCA to 34.5 pg mL(-1) at 46-wk PCA. Urinary 3beta-OH-5-ene steroids were highest when ACTH levels were lowest, and were declining when ACTH was rising. In four infants given dexamethasone, urinary excretion of 3beta-OH-5-ene steroids and plasma DHEAS were not suppressed fully, when plasma ACTH and cortisol, and urinary cortisol metabolites were. These data suggest that ACTH is not the sole regulator of the adrenal fetal zone steroid synthesis and that involution of the fetal zone is related to gestation rather than birth.

The steroid hormone dehydroepiandrosterone (DHEA) breaks intranasally induced tolerance, when administered at time of systemic immunization

The induction of intranasal tolerance might be dependent on specific characteristics of mucosal, nose-draining lymph nodes. Such a specific characteristic might lie in the metabolism of the steroid hormone DHEA. Conversion of the prohormone DHEAS into DHEA is dependent on DHEAS-sulphatase activity in lymph nodes. This activity is low in mucosa-draining lymph nodes compared to peripheral lymph nodes, leading to differences in microenvironment. However, administration of DHEA before the induction of intranasal tolerance, could not change tolerance induction. We next determined the effect of DHEA after the induction of intranasally induced tolerance and demonstrated that the steroid hormone and some of its derivatives are able to break tolerance, when administered at time of systemic immunization. These findings might have implications for the regulation of intranasal tolerance and the use of DHEA.

Combined effects of dehydroepiandrosterone and EM-800 on bone mass, serum lipids, and the development of dimethylbenz(A)anthracene-induced mammary carcinoma in the rat

Although treatment with dehydroepiandrosterone (DHEA) and the antiestrogen EM-800 alone decreased dimethylbenz(A)anthracene (DMBA)-induced mammary tumor incidence from 95% to 57% and 38%, respectively, approximately 9 months after DMBA administration, only two tumors developed in the group of animals that received the combination of DHEA and EM-800, and these two tumors disappeared before the end of the experiment (P < 0.01 vs. DHEA or EM-800 alone). Average tumor number per tumor-bearing animal as well as average tumor area per tumor-bearing animal were further decreased in animals that received the combination therapy compared with the effect of each treatment alone (P < 0.01). DHEA induced 6.9% (P < 0.01), 10.6% (P < 0.05), and 8.2% (P < 0.01) increases in bone mineral density of total skeleton, lumbar spine, and femur, respectively. The addition of EM-800 to DHEA did not affect the enhancing effect of DHEA on bone mass. The combination of the two drugs had important inhibitory effects on the urinary excretion of calcium and phosphorus as well as on the urinary hydroxyproline/creatinine ratio. Serum total alkaline phosphatase was stimulated by DHEA. Treatment with EM-800 decreased both serum triglyceride and cholesterol levels, whereas DHEA had an inhibitory effect on serum triglycerides. Although treatment with EM-800 caused a marked atrophy of the mammary gland, DHEA alone reduced lobular hyperplasia seen in aged intact rats while causing an androgen-specific stimulation of the same structures in animals already receiving the antiestrogen EM-800. The combination of DHEA and EM-800 lowered ovarian weight by 24% (P < 0.01) and decreased serum estradiol concentrations to intact control levels, whereas each compound alone had no effect on ovarian weight and stimulated serum estradiol levels by 45% (P < 0.05) and 46% (P < 0.05), respectively. Treatment with EM-800 caused a marked inhibition of uterine and vaginal weight. The present data show the additive inhibitory effects of DHEA and EM-800 on the development of DMBA-induced mammary carcinoma in the rat, thus suggesting the potential benefits of such a combination for the prevention of breast cancer in women while preserving or even increasing bone mass and maintaining a favorable lipid profile.

Effect of dehydroepiandrosterone on bone mass, serum lipids, and dimethylbenz(a)anthracene-induced mammary carcinoma in the rat

The present study investigated the effect of dehydroepiandrosterone (DHEA) on bone mass and serum lipids in the rat with dimethylbenz(a)anthracene (DMBA)-induced mammary carcinoma. The animals received DHEA once daily, percutaneously, at the dose of 5, 10, or 20 mg for 9 months following a single dose of 20 mg DMBA at 50-52 days of age. Bone mineral content (BMC) and bone mineral density (BMD) of total skeleton, lumbar spine, and femur were measured by dual energy x-ray absorptiometry. A 9-month treatment with DHEA increased BMC and BMD of total skeleton by 14.2% to 14.5% (all P < 0.01) and 6.7% to 8.3% (all P < 0.01), respectively. Similarly, femoral BMC and BMD were stimulated by 13.6% to 14.7% (all P < 0.05) and by 8.1% to 9.5% (all P < 0.01), respectively. In addition, BMD of lumbar spine was increased by 10.4% to 10.8% (all P < 0.05), whereas the 9.4% to 11.1% increment in BMC of lumbar spine was not statistically significant. Treatment with DHEA led to 26% (NS), 60% (P < 0.01), and 62% (P < 0.01) decreases in serum triglyceride levels at the same doses. On the other hand, no significant change in serum cholesterol concentrations was observed. Two hundred and seventy-nine days after DMBA administration, the incidence of mammary carcinoma had decreased from 95% in control animals to 73% (P < 0.05), 57% (P < 0.01), and 38% (P < 0.01) at the daily percutaneous doses of 5, 10, and 20 mg of DHEA, respectively. Moreover, the mean tumor number per tumor-bearing animal and the mean tumor area per tumor-bearing animal were also reduced by the same treatments. DHEA increased serum total alkaline phosphatase activity and decreased urinary calcium excretion, but had no effect on the urinary ratio of hydroxyproline to creatinine and urinary phosphorus excretion. These data show that DHEA exerts a stimulatory effect on bone mass and an inhibitory effect on serum triglycerides, as well as a preventive effect on the development of mammary carcinoma induced by DMBA in the rat. Such data suggest that while decreasing the risk of breast cancer, DHEA replacement therapy could also exert beneficial effects on the bone and lipid metabolism in women receiving DHEA replacement therapy.

Immune enhancing effects of dehydroepiandrosterone and dehydroepiandrosterone sulphate and the role of steroid sulphatase

Steroid hormones, such as glucocorticoids (GC), influence immune and inflammatory responses through their suppressive actions. Recent evidence suggests that another steroid hormone, dehydroepiandrosterone (DHEA), provides an immunostimulatory influence opposing the effect of GC. DHEA circulates in its inactive sulphated form, DHEAS, requiring conversion to DHEA by a steroid sulphatase (SS) enzyme for biological activity. Therefore, inhibition of SS activity may affect immune responses, allowing endogenous GC effects to predominate. We have shown that administration of DHEA and DHEAS in contact sensitization (CS) augments ear swelling by 39 and 46% respectively (P < 0.001). DHEAS at doses of 0.5, 5 and 50 mg/kg reverses the inhibitory effect of corticosterone (5 mg/kg) (P < 0.01). In CS, CT2251 (SS inhibitor) at 10 and 0.1 mg/kg inhibited ear swelling by 61 and 38% (P < 0.05) respectively. In addition, it inhibited DHEAS-augmented responses by 49 and 35% respectively (P < 0.05), with no effect on DHEA-augmented responses. DHEAS reversed CT2251 inhibition of the CS response with complete reversal at 50 mg/kg (P < 0.05). DHEAS and CT2251 appear to affect cellular infiltration into the ear, since DHEAS increased the number of lymphocytes by 63.8% and macrophages by 107% (P < 0.001), whereas CT2251 at 0.1 mg/kg decreased the number of lymphocytes by 65% (P < 0.001) and macrophages by 80% (P < 0.001). DHEAS, CT2251 and dexamethasone had no effect on oedema in the ear. From our data we have shown that steroid hormones, such as DHEA, have the potential to act as immunostimulatory factors in vivo. Inhibiting the conversion of DHEAS to DHEA by SS enzyme leads to an anti-inflammatory effect.

Photoaffinity labeling of peroxisome proliferator binding proteins in rat hepatocytes; dehydroepiandrosterone sulfate- and bezafibrate-binding proteins

To detect the cellular sites which directly interact with peroxisome proliferators (PPs) and mediate their inducing effect on peroxisomal enzymes in rat hepatocytes, two kinds of radiolabeled ligands, AD12 (7alpha-N-(4-azido-2-hydroxy-5-iodo[125I]benzyl)-aminomethyl-5-and rostene-3beta-ol-17-one-O-3-sulfate) and BZ5 (2-[p-[2-(4'-azido-3',5'-diiodo[125I]benzamido-2'-hydroxy)ethyl]phenoxy] -2-methylpropionic acid), were developed for photoaffinity labeling. These compounds were derivatives of dehydroepiandrosterone sulfate (DHEAS) and bezafibrate, respectively, with an azido group as the photoreactive functional group. Upon UV-irradiation following incubation with rat liver cytosol and nuclei, both the ligands effectively radiolabeled several proteins analyzed by SDS-polyacrylamide gel electrophoresis/radioluminography. When [125I]AD12 was used at a concentration of 0.2 microM, two cytosolic proteins with molecular masses of 55 and 28 kDa and a nuclear protein of 40 kDa were specifically labeled, as coincubation with a 1000-fold excess of DHEAS inhibited labeling. Photoaffinity labeling of the cytosolic 28-kDa protein was also affected by Wy-14,643, but not by unsulfated dehydroepiandrosterone or androsterone sulfate, consistent with our previous findings obtained in competitive binding studies of [3H]DHEAS-binding detected in rat liver cytosol (Yamada et al. (1994) Biochim. Biophys. Acta 1224, 139-146). On the other hand, [125I]BZ5 specifically labeled a cytosolic protein of 31 kDa, which was inhibited by coincubation with bezafibrate, clofibric acid and Wy-14,643, but not with DHEAS. Thus, [125I]AD12 and [125I]BZ5 labeled several proteins which recognized DHEAS and bezafibrate, respectively, in rat liver cytosol and nuclei, providing a useful means to investigate PP-binding proteins.

Pregnenolone sulfate enhances post-training memory processes when injected in very low doses into limbic system structures: the amygdala is by far the most sensitive

Immediate post-training, stereotactically guided, intraparenchymal administration of pregnenolone sulfate (PS) into the amygdala, septum, mammillary bodies, or caudate nucleus and of PS, dehydroepiandrosterone sulfate, and corticosterone into the hippocampus was performed in mice that had been weakly trained in a foot-shock active avoidance paradigm. Intrahippocampal injection of PS resulted in memory enhancement (ME) at a lower dose than was found with dehydroepiandrosterone sulfate and corticosterone. Intraamygdally administered PS was approximately 10(4) times more potent on a molar basis in producing ME than when PS was injected into the hippocampus and approximately 10(5) times more potent than when injected into the septum or mammillary bodies. ME did not occur on injection of PS into the caudate nucleus over the range of doses tested in the other brain structures. The finding that fewer than 150 molecules of PS significantly enhanced post-training memory processes when injected into the amygdala establishes PS as the most potent memory enhancer yet reported and the amygdala as the most sensitive brain region for ME by any substance yet tested.

Effect of dehydroepiandrosterone on mitogen-induced lymphocyte proliferation and cytokine production in young and old F344 rats

The steroid hormone intermediate, dehydroepiandrosterone (DHEA), has been proposed as a therapeutic agent for the treatment of immunosenescence in mouse model. In the present study, the in vitro effect of DHEA on mitogen-induced lymphocyte proliferation and cytokine production was evaluated in a rat model. Spleen lymphocytes were isolated from young (4-6 months) and old (24-26 months) F344 rats and were incubated with DHEA for 30 min. The induction of lymphocyte proliferation, interleukin-2 (IL-2), and interferon-gamma (IFN-gamma) production by concanavalin A (Con A) was measured in a culture medium supplemented with either fetal calf serum (FCS) or with serum-free medium (Nutridoma-SR, N-SR). The induction of lymphocyte proliferation and IL-2 production by Con A decreased significantly with age, whereas induction of IFN-gamma increased with age. Treatment of lymphocytes with DHEA did not significantly alter Con A-induced proliferation or the production of IL-2 or IFN-gamma by spleen lymphocytes isolated from either young or old rats. These data indicate that in vitro DHEA treatment appears to have no immunomodulatory effect on the age-related changes in mitogen-induced proliferation or cytokine production in rat lymphocytes.

Key role for pregnenolone in combination therapy that promotes recovery after spinal cord injury

Controlled compressive injury to rat spinal cord was chosen to test therapies that might attenuate the progression of tissue destruction and locomotor deficits that characteristically occur after spinal injury. A highly significant reduction of damage was achieved by immediate postinjury treatment with a combination of the following: an antiinflammatory substance, indomethacin; a stimulator of cytokine secretion, bacterial lipopolysaccharide; and the parent steroid, from which all other steroids arise, pregnenolone. This treatment reduced histopathological changes, spared tissue from secondary injury, and increased restoration of motor function. Remarkably, 11 of 16 of the animals treated with the above combination were able to stand and walk at 21 days after injury, 4 of them almost normally. The results were far superior to those obtained in controls or in animals to which the substances were given separately or in combination of two. This approach may prove to be applicable to nervous system injury, in general, and to injury in other tissues.

Dehydroepiandrosterone protects mice inoculated with West Nile virus and exposed to cold stress

The protective effect of pretreatment with dehydroepiandrosterone (DHEA) on stress-enhanced viral encephalitis was studied in mice exposed to cold following inoculation with West Nile virus (WNV). Exposure of WNV-inoculated mice to cold water (1 +/- 0.5 degrees C, 5 minutes/day for 8 days) resulted in a mortality rate of 83% as compared to 50% in nonstressed mice (p < 0.05). The effect of cold stress was more pronounced when mice were inoculated with WN-25, a noninvasive neurovirulent variant of WNV. Mice infected with WN-25 showed no mortality, whereas cold stressed mice inoculated with the same virus had a mortality rate of 67% (p < 0.05). The administration of DHEA (serial injections of 10-20 mg/kg with or without a loading dose of 1 gm/kg) resulted in a significant reduction in the mortality rate of stressed mice inoculated with either virus (p < 0.05). Virus levels in the blood and brain of the DHEA-treated mice, were significantly lower than in the control groups. DHEA also prevented the involution of lymphoid organs in stressed mice. The present study provides direct evidence of the protective effects of DHEA as an "anti-stress" agent. Its ability to prevent mortality associated with WNV or WN-25, and involution of lymphoid organs caused by stress-induced immunosuppression, supports the notion that its activity is based on the modulation of the host response.

Dehydroepiandrosterone protects mice from endotoxin toxicity and reduces tumor necrosis factor production

Recent reports have demonstrated an immunomodulating activity of dehydroepiandrosterone (DHEA) different from that described for glucocorticoids. The present study was designed to test DHEA's activity in endotoxic shock and to investigate its effect on endotoxin-induced production of tumor necrosis factor (TNF). Mortality of CD-1 mice exposed to a lethal dose of lipopolysaccharide (LPS; 800 micrograms per mouse) was reduced from 95 to 24% by treatment with a single dose of DHEA, given 5 min before LPS. LPS administration resulted in high levels of TNF, a response that was significantly blocked by DHEA, both in vivo and in vitro. DHEA treatment also reduced LPS-induced increments in serum corticosterone levels, a parameter considered not to be mediated by TNF. In another experimental model, mice sensitized with D-galactosamine, followed by administration of recombinant human TNF, were subjected to 89% mortality rate, which was reduced to 55% in DHEA-treated mice. These data show that DHEA protects mice from endotoxin lethality. The protective effect is probably mediated by reduction of TNF production as well as by effecting both TNF-induced and non-TNF-induced phenomena.

Dehydroepiandrosterone prevents dexamethasone-induced hypertension in rats

Dehydroepiandrosterone (DHEA) is an endogenous steroid having a wide variety of biological and biochemical effects. In the present study, we have examined the role of DHEA on various rodent models of experimental hypertension. Sprague-Dawley rats were given subcutaneous injections of 1.5 mg dexamethasone every alternate day, resulting in an increase in systolic blood pressure within 1 wk. Interestingly, administration of a pharmacological dose of 1.5, 3, or 7.5 mg DHEA along with dexamethasone prevented dexamethasone-induced hypertension in a dose-dependent manner. DHEA had no effect on the hypertension induced by deoxycorticosterone acetate (DOCA)-salt administration using uninephrectomized rats or on the genetic model of spontaneously hypertensive rats. Dexamethasone administration resulted in a significant weight loss in rats, which was not prevented by simultaneous administration of DHEA. These results indicate that dexamethasone-mediated weight loss may involve mechanisms separate from its hypertensive action. Dexamethasone treatment resulted in a significant decrease in food consumption that was not reversed by DHEA. It is concluded that DHEA at doses above physiological levels when given subcutaneously has no effect on DOCA-salt or a genetic model of hypertension but has a beneficial effect on dexamethasone-induced hypertension.

Memory-enhancing effects in male mice of pregnenolone and steroids metabolically derived from it

Immediate post-training intracerebroventricular administration to male mice of pregnenolone (P), pregnenolone sulfate (PS), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), androstenedione, testosterone, dihydrotestosterone, or aldosterone caused improvement of retention for footshock active avoidance training, while estrone, estradiol, progesterone, or 16 beta-bromoepiandrosterone did not. Dose-response curves were obtained for P, PS, DHEA, and testosterone. P and PS were the most potent, PS showing significant effects at 3.5 fmol per mouse. The active steroids did not show discernible structural features or known membrane or biochemical effects that correlated with their memory-enhancing capacity. The above, together with the findings that DHEA acted even when given at 1 hr after training and that P, PS, and DHEA improved retention over a much wider dose range than do excitatory memory enhancers, led to the suggestion that the effects of the active steroids converge at the facilitation of transcription of immediate-early genes. P and PS, for which receptors have not yet been demonstrated, may exert their effects by serving as precursors for the formation of a panoply of different steroids, ensuring near-optimal modulation of transcription of immediate-early genes required for achieving the plastic changes of memory processes. Low serum levels of P in aging and the increases of cancer and behavioral disorders in individuals receiving drugs that block synthesis of cholesterol, the immediate precursor of P, suggest possible clinical utility for P.

Characteristics of dehydroepiandrosterone as a peroxisome proliferator

Treatment of rats with dehydroepiandrosterone (300 mg/kg body weight, per os, 14 days) caused a remarkable increase in the number of peroxisomes and peroxisomal beta-oxidation activity in the liver. The activities of carnitine acetyltransferase, microsomal laurate 12-hydroxylation, cytosolic palmitoyl-CoA hydrolase, malic enzyme and some other enzymes were also increased. The increases in these enzyme activities were all greater in male rats than in female rats. Immunoblot analysis revealed remarkable induction of acyl-CoA oxidase and enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase bifunctional enzyme in the liver and to a smaller extent in the kidney, whereas no significant induction of these enzymes was found in the heart. The increase in the hepatic peroxisomal beta-oxidation activity reached a maximal level at day 5 of the treatment of dehydroepiandrosterone and the increased activity rapidly returned to the normal level on discontinuation of the treatment. The increase in the activity was also dose-dependent, which was saturable at a dose of more than 200 mg/kg body weight. All these features in enzyme induction caused by dehydroepiandrosterone correlate well with those observed in the treatment of clofibric acid, a peroxisome proliferator. Co-treatment of dehydroepiandrosterone and clofibric acid showed no synergism in the enhancement of peroxisomal beta-oxidation activity, suggesting the involvement of a common process in the mechanism by which these compounds induce the enzymes. These results indicate that dehydroepiandrosterone is a typical peroxisome proliferator. Since dehydroepiandrosterone is a naturally occurring C19 steroid in mammals, the structure of which is novel compared with those of peroxisome proliferators known so far, this compound could provide particular information in the understanding of the mechanisms underlying the induction of peroxisome proliferation.

Regulation of murine lymphokine production in vivo. III. The lymphoid tissue microenvironment exerts regulatory influences over T helper cell function

We investigated the capacity of murine T lymphocytes, isolated from various lymphoid organs of normal or antigen-primed donors, to produce IL-2 or IL-4 after activation with anti-CD3 or specific antigen. Our results established that T cells resident within lymphoid organs being drained by nonmucosal tissue sites (e.g., axillary, inguinal, brachial lymph nodes, or spleen) produced IL-2 as the predominant T cell growth factor (TCGF) after activation. Conversely, activated T cells from lymphoid organs being drained by mucosal tissues (Peyer's patches, and cervical, periaortic, and parathymic lymph nodes) produced IL-4 as the major species of TCGF. Analysis of the lymphoid tissues obtained from adoptive recipients of antigen-primed lymphocytes provided by syngeneic donors provided evidence that direct influences were being exerted on T cells during their residence within defined lymphoid compartments. These lymphoid tissue influences appeared to be responsible for altering the potential of resident T cells to produce distinct species of TCGF. Steroid hormones, known transcriptional enhancers and repressors of specific cellular genes, were implicated in the controlling mechanisms over TCGF production. Glucocorticoids (GCs) were found to exert a systemic effect on all recirculating T cells, evidenced by a marked dominance in IL-4 production by T cells obtained from all lymphoid organs of GC-treated mice, or after a direct exposure of normal lymphoid cells to GCs in vitro before cellular activation with T cell mitogens. Further, the androgen steroid DHEA appeared to be responsible for providing an epigenetic influence to T cells trafficking through peripheral lymphoid organs. This steroid influence resulted in an enhanced potential for IL-2 secretion after activation. Anatomic compartmentalization of the DHEA-facilitated influence appears to be mediated by differential levels of DHEA-sulfatase in lymphoid tissues. DHEA-sulfatase is an enzyme capable of converting DHEA-sulfate (inactive) to the active hormone DHEA. We find very high activities of this enzyme isolated in murine macrophages. The implications of our findings to immunobiology are very great, and indicate that T cells, while clonally restricted for antigen peptide recognition, also appear to exhibit an extreme flexibility with regards to the species of lymphokines they produce after activation. Regulation of this highly conservative mechanism appears to be partially, if not exclusively, controlled by cellular influences being exerted by distinct species of steroid hormones, supplied in an endocrine or a paracrine manner where they mediate either systemic or tissue-localized influences, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Protection against acute lethal viral infections with the native steroid dehydroepiandrosterone (DHEA)

A significant protective effect of a native adrenal steroid, dehydroepiandrosterone (DHEA), was demonstrated in studies of two lethal viral infection models in mice: systemic coxsackievirus B4 and herpes simplex type 2 encephalitis. The steroid was active either by long-term feeding or by a single subcutaneous injection. A closely related steroid, etiocholanolone, was not protective in these models. Histopathological analysis, leukocyte counts, and numbers of spleen antibody forming cells in the coxsackievirus B4 model suggests that DHEA functions by maintaining or potentiating the immune competence of mice otherwise depressed by viral infection. DHEA was not effective in genetically immunodeficient HRS/J hr/hr mice and did not demonstrate antiviral activity in vitro. While the molecular basis for DHEA's effect on the immune system is not known, studies by others suggest that it may counteract the stress related immunosuppressive effects of glucocorticoids stimulated by viral infection. Because DHEA is a native steroid that has been used clinically with minimal side effects, the utility of DHEA in the therapeutic modulation of acute and chronic viral infections including the acquired immune deficiency syndrome deserves intensive study.