Triiodothyronine and estradiol increase the serum level of androstanediol glucuronide but do not influence androgen UDP-glucuronyl transferase activity in the female rat

In this study, adult female rats were treated with either estradiol, testosterone or triiodothyronine (T3). The mean +/- SD for serum levels of androstane-3 alpha,17 beta-diol glucuronide (ADIOL-G) in rats injected with estradiol (31.1 +/- 6.1 nmol/l) and T3 (28.7 +/- 6.1 nmol/l) increased three-fold in comparison to the controls (9.2 +/- 3.6 nmol/l; p < 0.01). There was no significant increase in ADIOL-G levels in rats injected with testosterone (12.0 +/- 3.4 nmol/l) even though serum testosterone levels increased more than 17-fold (1.2 +/- 0.3 nmol/l; p < 0.01). Testosterone levels remained below the detection level of the assay (0.07 nmol/l) in the control and the estradiol and T3 treatment groups. Androgen UDPGT activity in liver microsomes was not altered by treatment with testosterone, estradiol or T3. However, the UDPGT activity for p-nitrophenol increased two-fold in estradiol and T3-treated females (p < 0.01), but was not significantly altered by testosterone treatment. These results suggest that the activity of androgen UDPGT in liver is not the limiting factor in the increased serum levels of ADIOL-G observed on treatment with estradiol and T3.

The clinical usefulness of 3 alpha-androstanediol glucuronide in premenopausal women with hirsutism

A biochemical parameter correlating with the clinical assessment of the severity of hirsutism and changing appropriately with the clinical response to treatment would be extremely useful. Preliminary reports of androstanediol glucuronide indicated that it was a peripherally-derived androgen and had a high correlation with clinical gradings of hirsutism. More recent reports have cast doubts on this association. This paper presents an evaluation of the clinical usefulness of androstanediol in 121 consecutive premenopausal patients with hirsutism. Androstanediol had a positive correlation with the clinical grading of hirsutism (p < 0.02) and the BMI (p < 0.01) but a negative correlation with age (p < 0.01). After adjustment for the effects of age and BMI there was no significant association between the degree of hirsutism and the level of androstanediol.

Assessment of 5 alpha-reductase activity in hirsute women: comparison of serum androstanediol glucuronide with urinary androsterone and aetiocholanolone excretion

OBJECTIVE

Recent evidence suggests that androstanediol glucuronide (AG), a metabolite of dihydrotestosterone (DHT) formed in skin, is frequently elevated in hirsute women, presumably reflecting enhanced 5 alpha-reductase activity. An alternative method of demonstrating 5 alpha-reductase activity is the androsterone (A)/aetiocholanolone (E) ratio in urine. A and E are the 5 alpha- and 5 beta-reduced metabolites, respectively, of androstenedione, which is the principal metabolite of dehydroepiandrosterone (D). Although serum AG and the urinary A/E ratio have both been considered valid methods for assessing 5 alpha-reductase activity, the two have not been previously compared in hirsute women. The present study was undertaken to assess 5 alpha-reductase activity in hirsute patients as determined by these two different methods.

PATIENTS AND MEASUREMENTS

We surveyed 47 untreated women (ages 17-33) with various degrees of hirsutism. Serum testosterone, bioavailable testosterone, dehydroepiandrosterone sulphate, and AG were determined. Additionally, A, E and D were measured in 24-hour collections of urine.

RESULTS

For the 47 women, 37 had elevated blood levels of AG (17.4 +/- 2.2, mean +/- SEM; normal < 8 nmol/l), but only 18 of these had an increased urinary A/E ratio (> 1.5). All but one of the remainder had elevated urinary and/or serum androgen levels. Overall, no significant correlation between AG and A/E was observed. There was a highly significant correlation between AG in serum and A in urine (r = 0.82, P < 0.001). AG was also positively related to dehydroepiandrosterone sulphate (r = 0.64; P < 0.005), bioavailable testosterone (r = 0.6; P < 0.001), aetiocholanolone (r = 0.58; P < 0.001) and total testosterone (r = 0.52; P < 0.01). In contrast, A/E was not significantly related to androgen production.

CONCLUSIONS

There is a poor correlation between AG and the A/E ratio in hirsute women. Although AG may be raised by increased 5 alpha-reductase activity, it is probably also affected by the presence of elevated androgens regardless of 5 alpha-reductase activity.

Longitudinal study of maternal plasma bioavailable testosterone and androstanediol glucuronide levels during pregnancy

OBJECTIVE

The aim of this study to evaluate during normal pregnancy plasma bioavailable testosterone and androstanediol glucuronide levels.

MEASUREMENTS

Bioavailable testosterone, androstanediol glucuronide and SHBG levels were evaluated every 4 weeks from week 6 to week 38 in 10 normal pregnant women. We also measured plasma oestradiol, oestriol, delta 4-androstenedione, 17-hydroxyprogesterone, progesterone and testosterone.

RESULTS

The mean bioavailable testosterone levels were within the range of non-pregnant women but with an increasing trend until delivery. Androstanediol glucuronide had increased at weeks 6 and 8, decreased at week 14, remained low at week 30, and increased again at week 34. SHBG was significantly correlated with testosterone, oestradiol and oestriol. No correlation could be established between androstanediol glucuronide and any other parameter.

DISCUSSION

Bioavailable testosterone (non-SHBG bound testosterone) represents the sum of free testosterone plus albumin bound testosterone. The increase in testosterone concentrations with decreased albumin levels during pregnancy, could suggest reduced metabolic clearance of testosterone throughout pregnancy. No correlation was established between the decrease in androstanediol glucuronide and increase in progesterone, suggesting that the decrease in androstanediol glucuronide is not a consequence of the inhibitory effect of progesterone on 5 alpha-reductase activity.

Adrenal androgens and testosterone as coronary risk factors in the Helsinki Heart Study

We investigated the role of adrenal androgens, cortisol, testosterone and sex-hormone binding globulin (SHBG) as coronary risk factors using a nested case-control design. The study population consisted of 62 cases with cardiac end-points and 97 controls on placebo during the last 4 years in the Helsinki Heart Study. Serum concentrations of dehydroepiandrosterone, dehydroepiandrosterone sulfate (DHEAS), androstenedione, androstanediol glucuronide, cortisol, testosterone, and SHBG at the first annual visit of the 5-year study period were determined by radioimmunoassays. The only significant difference was found in DHEAS, with cases having higher levels than controls (P < 0.04). DHEAS levels were positively associated with smoking (P < 0.001), alcohol consumption (P < 0.04) and triglyceride levels (P < 0.002) and with systolic (P < 0.04) and diastolic (P < 0.006) blood pressures, and negatively associated with age (P < 0.01) and HDL-cholesterol (P < 0.03). The association between DHEAS and the CHD risk was studied using logistic regression analyses with the classical risk factors--age, smoking, blood pressure, and lipid levels--as covariates in the models. Studies of the joint effects of age and DHEAS disclosed that the risk associated with elevated DHEAS was confirmed to older men (odds ratio (OR) 7.3, 95%, CI 2.3-23.3). A similar analysis with smoking revealed that the DHEAS-related risk was mainly found in smokers (OR 3.4, 95% CI 1.5-8.2). One possible explanation for these results is that some form of mild steroid biosynthetic defect of the adrenals or functional adrenal hyperplasia associated with high DHEAS levels increases the CHD risk in this population.

[Unidentified steroid hormone of Cushing's syndrome and disease]

A previously unknown HPLC peak was recently observed in urine samples from patients with Cushing's syndrome and disease. We analysed dansylated derivatives of 17keto steroid glucuronides in urine samples from patients with Cushing's syndrome, Cushing disease and from healthy subjects using high-performance liquid chromatography (HPLC) on reversed-phase Cap Cell PakC8. All urine samples from patients with Cushing's syndrome caused by adrenal adenoma and Cushing's disease showed an unknown large peak at the point between [110HE-G] and [110HA-G] peaks and at a retention time of 25.4 min. The same unknown peak was also observed in urine samples from a patient with asymptomatic cortisol-producing adrenal adenoma and two patients with ectopic ACTH-producing tumor, though the peak height was low for the former and one of the latter but high for the second of the two patients. In contrast, healthy male and female urine only showed a very small peak at the same retention time. Urine samples from a Cushing disease treated with op'DDD and Cushing's syndrome bilaterally adrenalectomized and treating with cortisol showed no such peak. The retention time of this unknown peak is clearly different from that of seven 17keto steroid standard glucuronide conjugates. The structure of this substance may be closely related to [110HE-G] or [110HA-G].

Two different pathogenetic mechanisms may play a role in acne and in hirsutism

OBJECTIVE

Acne is one of the most common skin disorders. Androgens are known to play an important and possibly central role. Androgens secreted from ovaries and adrenal glands (androstenedione, dehydroepiandrosterone and its sulphate, testosterone) and target tissue-produced androgens (testosterone and its 5 alpha-reduced metabolite, dihydrotestosterone) have been implicated. Although the sebaceous gland and the hair follicle form a single morphological entity, the pilosebaceous unit, acne and hirsutism do not always appear concomitantly, thus leading to the supposition that these two structures may have different degrees of sensitivity to similar androgenic stimulation.

DESIGN AND PATIENTS

To determine whether acne and hirsutism are the clinical expression of a different androgen metabolism at target tissue levels we studied 90 randomly selected patients who came to our Out-patient Department for diagnosis and treatment during the last 2 years with isolated acne of mild to severe degree and 52 patients with idiopathic hirsutism without acne or history of acne. Twenty-four women without acne or hirsutism and without a history of endocrine disease were studied as controls.

MEASUREMENTS

In both groups of patients, plasma levels of sex hormone binding globulin, of dihydrotestosterone, and of 3 alpha-androstanediol and of its glucuronide were evaluated. In all patients the percentage of free testosterone and the testosterone/sex hormone binding globulin ratio were also calculated.

RESULTS

Patients with acne and those with isolated hirsutism showed significantly decreased sex hormone binding globulin plasma levels. The values of the percentage free testosterone and those of the testosterone/sex hormone binding globulin ratio were, on the contrary, higher with respect to the controls, although there were no statistically significant differences between the two groups. Significantly increased plasma levels of dihydrotestosterone with respect to the controls were observed in patients with acne or in those with hirsutism. However, while all patients with hirsutism showed increased plasma values of 3 alpha-androstanediol and its glucuronide, all patients with acne showed plasma levels within the normal range, independently of the precursor plasma levels.

CONCLUSIONS

Our results demonstrate that dihydrotestosterone is further reduced to 3 alpha-androstanediol and its glucuronide only in hirsute patients but not in acne patients. These results suggest that dihydrotestosterone may undergo different metabolic pathways at skin levels and support the hypothesis that the two clinical manifestations may be the expression of the different metabolic fate of dihydrotestosterone itself. Moreover, our results demonstrate that 3 alpha-androstanediol and its glucuronide cannot be used as plasma markers of target-tissue produced androgens in all hyperandrogenic conditions.

Androgen metabolism in men receiving finasteride before prostatectomy

Oral administration of finasteride, a 5 alpha-reductase inhibitor, affects intraprostatic androgens by suppressing dihydrotestosterone and increasing testosterone. This study was designed to determine the correlation of these effects of finasteride with changes in serum dihydrotestosterone, testosterone and androstanediol glucuronide. In a double blind, placebo-controlled study, 27 men with symptomatic benign prostatic hyperplasia were treated with placebo or 1 or 5 mg. per day finasteride for 6 to 8 weeks before transurethral resection of the prostate. There was no significant change in serum testosterone in any group, or in serum dihydrotestosterone or androstanediol glucuronide in the placebo group. There was a decrease in serum dihydrotestosterone by 66 +/- 4% and 70 +/- 8% (p = 0.32), and of serum androstanediol glucuronide by 78 +/- 3% and 86 +/- 3% (p = 0.012) in the 1 and 5 mg. finasteride groups, respectively. Intraprostatic dihydrotestosterone in the placebo group decreased from 18.6 +/- 1.4 nmol./kg. to 3.8 +/- 1.0 nmol./kg. and 1.7 +/- 0.7 nmol./kg. with 1 mg. and 5 mg. finasteride, respectively (p = 0.049 between 1 mg. and 5 mg. finasteride). Intraprostatic testosterone in the placebo group increased from 1.1 +/- 0.2 nmol./kg. to 7.6 +/- 1.0 nmol./kg. and 8.3 +/- 0.7 nmol./kg. with 1 mg. and 5 mg. finasteride, respectively (no significant difference between 1 mg. and 5 mg. finasteride). Serum and intraprostatic dihydrotestosterone correlated (p = 0.002). There was no correlation between intraprostatic dihydrotestosterone and serum androstanediol glucuronide. We conclude that 5 mg. of finasteride cause greater inhibition of intraprostatic 5 alpha-reductase than 1 mg. and that serum dihydrotestosterone is a better marker of intraprostatic dihydrotestosterone than androstanediol glucuronide.

Insulin-like growth factor-1 (IGF-1) and dehydroepiandrosterone sulphate in obese women

Severe obesity is known to reduce either dehydroepiandrosterone circulating levels or growth hormone (GH) and insulin-like growth factor-1 (IGF-1) secretion. The present study was undertaken to evaluate the possibility of a relationship between the circulating levels of IGF-1 and those of dehydroepiandrosterone sulphate (DHEAS) in 25 fertile obese women. A logarithmic transformation of the values of non-normally distributed variables was performed before statistical analysis. We found a significant positive correlation between DHEAS and IGF-1 (r = 0.615, P < 0.01). In addition, stepwise multiple regression analysis showed that IGF-1 maintained a strong positive relationship with DHEAS (P < 0.01) when adjusted for other variables such as age, body mass index (BMI), waist:hip ratio (WHR) and insulin levels (adjusted R2 = 0.373; P < 0.01). These findings suggest that IGF-1 may independently influence the DHEAS circulating levels. ADG (5 alpha-androstan-3 alpha, 17 beta-diol-glucuronide) was also positively correlated to IGF-1 (r = 0.436, P < 0.05). However, when ADG concentrations were adjusted for DHEAS levels, this metabolite was not significantly correlated with IGF-1, thus excluding a direct influence of IGF-1 on the 5-alpha-reductase activity. Therefore, although our data represent only a preliminary study, they seem to suggest a possible influence of IGF-1 on circulating levels of DHEAS in obese women.

Androstanediol glucuronide production in human liver, prostate, and skin. Evidence for the importance of the liver in 5 alpha-reduced androgen metabolism

Androstanediol glucuronide (Adiol G) has been reported to be a marker of peripheral androgen metabolism and action. It consists of two isomers, Adiol 3-G and Adiol 17-G. Adiol G is formed from unconjugated precursors by the enzyme glucuronyl transferase. To determine the likely source of Adiol G formation in man, we developed a glucuronyl transferase assay and measured the activity of this enzyme in human liver, abdominal and scalp skin, and prostate. In human liver, glucuronyl transferase activity was linear with respect to time (up to 120 min) and tissue concentration (up to 1 mg/ml). Apparent Michaelis-Menten constant Km (micromolar) and maximum velocity (Vmax) (picomoles per mg/30 min) were 5.6 and 140 for dihydrotestosterone, 8.9 and 1300 for androstanediol, and 3.1 and 46 for androsterone, respectively. Conversion of androstanediol to Adiol G (/0.5 mg tissue.30 min) was 5.8-13.2%. Over 80% of the Adiol G formed in human liver was Adiol 17-G, similar to what has been previously found in human serum. Glucuronyl transferase activity was present at low levels in human prostate (conversion of androstanediol to Adiol G was 0.04-4.6%/50 mg tissue.120 min). Analogous conversion rates (/50 mg tissue.120 min) for human scalp skin were 0.2-0.4% and for human abdominal skin were 0.07-0.14%. Although dihydrotestosterone may be converted to androstanediol in peripheral tissues such as skin and prostate, our results suggest that the principal site of androgen conjugation to glucuronic acid is the liver. The present results cast doubt upon the role of androstanediol glucuronide as a specific marker of cutaneous androgen metabolism.

Plasma 3 alpha-androstanediol glucuronide in precocious adrenarche

The aim was to study 3 alpha-androstanediol glucuronide (3AG) plasma levels and its relationship with 5-ene and 4-ene steroids in children with the benign form of precocious pubarche (precocious adrenarche). Sixty-five children with precocious adrenarche (PA), aged 3.6-8.2 yr (55 girls and 10 males) and 15 normal age-matched children were studied. We evaluated plasma androstenedione (A), dehydroepiandrosterone (DHA), its sulfate (DHA-S), testosterone (T), dihydrotestosterone (DHT), its glucuronide (DHTG), 3 alpha-androstanediol (3Ad) and its glucuronide (3AG) in all subjects. All androgens are expressed as mean +/- SD. We found significantly higher plasma levels not only in glandular androgens but also in peripheral androgens (A, 2.4 +/- 1.5 nM vs 0.79 +/- 0.46 nM, p < 0.001; DHA, 9.8 +/- 4.9 vs 2.7 +/- 0.76 ng/dl, p < 0.001; DHA-S, 3.4 +/- 2 microM vs 2.4 +/- 0.65 microM, p < 0.05; T, 0.74 +/- 0.5 nM vs 0.4 +/- 0.1 nM, p < 0.001; DHT, 0.36 +/- 0.13 nM vs 0.12 +/- 0.05 nM, p < 0.001; 3Ad, 0.13 +/- 0.1 nM vs 0.054 +/- 0.03 nM, p < 0.001; DHTG, 0.5 +/- 0.3 nM vs 0.26 +/- 0.09 nM p < 0.01). As far as the plasma 3AG levels are concerned we found significantly higher values in PA with respect to controls (1.17 +/- 0.7 nM vs 0.61 +/- 0.04 nM, p < 0.01), suggesting that 3AG may be considered a marker of skin androgen utilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of plasma androgen glucuronide levels after percutaneous or peroral androgen treatment in men: evidence for important splanchnic contribution to plasma 17 beta-hydroxyandrogen glucuronides

To investigate whether glucuronides of 17 beta-hydroxyandrogens are formed mainly in peripheral tissues or in splanchnic tissues, we compared androstanediol (AD) glucuronide (ADG) and dihydrotestosterone (DHT) glucuronide (DHTG) levels as well as the ratios of glucuronides over free steroids after transcutaneous DHT gel administration to levels and ratios found after oral administration of testosterone undecanoate. Whereas DHT and AD plasma levels were much higher after transcutaneous DHT gel administration, ADG and DHTG levels as well as glucuronide/free androgen ratios were an order of a magnitude higher after oral TU. This indicates that 17 beta-hydroxyandrogen glucuronides cannot be considered specific metabolites of androgen target tissues and are formed to a large extent in the splanchnic circulation.

Cutaneous application of an androstenedione gel as an in vivo test of 5 alpha-reductase activity in women

OBJECTIVE

Assessment of an in vivo test for 5 alpha-reductase activity using serum markers, 5 alpha-androstane-3 alpha,17 beta-diol glucuronide and androsterone glucuronide, after the cutaneous application of androstenedione (A).

DESIGN

An A gel was applied for 6 days to the skin of normal women, male volunteers, and hirsute and nonhirsute patients with polycystic ovarian syndrome (PCOS). Blood samples were obtained at baseline and on day 6 of the A gel application. Blood samples were assayed for A, 5 alpha-androstane-3 alpha,17 beta-diol glucuronide, and androsterone glucuronide. In three hirsute women, the protocol was followed before and after receiving an oral contraceptive (OC) and spironolactone 200 mg/d for 3 months.

SETTING

The study was performed in the outpatient clinic of the Division of Reproductive Endocrinology and Infertility, Women's Hospital of the Los Angeles County and University of Southern California Medical Center in Los Angeles, California.

PATIENTS, PARTICIPANTS

A total of eight nonhirsute patients with PCOS, seven hirsute patients with PCOS, and six male volunteers were enrolled in the study. Five normal women served as a control group.

MAIN OUTCOME MEASURE

Serum A increased after 6 days by a similar magnitude in all groups. Serum androsterone glucuronide showed a significant increase from baseline only in the hirsute group (P < 0.03), whereas the increase in 5 alpha-androstane-3 alpha,17 beta-diol glucuronide was not statistically significant.

RESULTS

The ratio of the increases in serum androsterone glucuronide over serum A was significantly higher in the hirsute group (P < 0.02). In the three hirsute patients who were placed on an OC and spironolactone, serum 5 alpha-androstane-3 alpha,17 beta-diol glucuronide and androsterone glucuronide decreased after 3 months and did not increase with application of the gel for another 6 days.

CONCLUSION

The cutaneous application of A provides a useful assessment of in vivo 5 alpha-reductase activity. However, because we found that A absorption varied considerably (30% to 62%), we suggest that this in vivo test may not provide more information than baseline determinations of 5 alpha-androstane-3 alpha,17 beta-diol glucuronide and androsterone glucuronide. It may, however, be useful as a parameter for assessing the effectiveness of various treatment regimens for hirsutism.

Studies on anabolic steroids. 10. Synthesis and identification of acidic urinary metabolites of oxymetholone in a human

Two major unconjugated acidic metabolites of oxymetholone (17 beta-hydroxy-2-hydroxymethylene-17 alpha-methyl-5 alpha-androstan-3-one, 1), namely, 17 beta-hydroxy-17 alpha-methyl-2,3-seco-5 alpha-androstane-2,3-dioic acid (2) and 3 alpha,17 beta-dihydroxy-17 alpha-methyl-5 alpha-androstane-2 beta-carboxylic acid (6a), were detected by gas chromatography/mass spectrometry in urine samples collected after oral administration of 1 to a human volunteer. Reference steroid 2 was synthesized and identified. The identification of urinary metabolite 6a was based on the synthesis of its stereoisomers and the isomerization of the methyl ester 6b to its 2-epimer, 3 alpha,17 beta-dihydroxy-17 alpha-methyl-5 alpha-androstane-2 alpha-carboxylic acid methyl ester (9b). The mechanisms accounting for the formation of these acidic metabolites are discussed.

3 alpha-Androstanediol and 3 alpha-androstanediol glucuronide. Maternal and umbilical cord plasma concentrations in normal pregnancy

Concentrations of 3 alpha-androstanediol (A) and 3 alpha-androstanediol glucuronide (AG) were measured with a radioimmunoassay in pregnancy plasma samples collected from the mother in the first trimester (first, n = 18) and second trimester (second, n = 20) and at term (n = 14). At term, along with the maternal samples, matching cord plasma samples were also obtained (n = 14). Throughout pregnancy the levels of A and AG were significantly higher than in normally menstruating women. Although the total concentration of A and AG did not change significantly throughout pregnancy, the levels of A in the second and at term were significantly higher than in the first. In contrast, AG concentrations in the second were significantly lower than in the first and at term. As compared to the maternal concentrations at term, the cord levels of AG and A plus AG were not significantly different. However, the levels of A in the cord were significantly lower than those in the maternal circulation at term. Significant correlations were observed between the term maternal and cord levels of AG and A plus AG. No sex-related differences in the plasma levels of A and AG were noted. The results show that levels of A and AG increase significantly in the first trimester and remain elevated throughout pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Newer neuromuscular blocking drugs. An overview of their clinical pharmacology and therapeutic use

Four new nondepolarising muscle relaxants, pipecuronium bromide, doxacurium chloride, mivacurium chloride and Org 9426 (rocuronium) offer alternatives to the established agents atracurium besilate and vecuronium bromide. Pipecuronium and Org 9426 are steroidal compounds, the latter being a monoquaternary agent, whereas doxacurium and mivacurium are bisquaternary benzylisoquinolinium compounds. Pipecuronium and doxacurium have a relatively slow onset and a long duration of action. Pipecuronium produces maximum block in 3 to 6 min when given in a dose of 45 to 80 micrograms/kg, and a duration of clinical relaxation of between 40 and 110 min. Doxacurium is more potent, but is the least rapid and the longest acting relaxant currently available. When administered in doses of 37 to 80 micrograms/kg, it produces maximum block within 3.5 to 10 min, with a duration of clinical relaxation of 77 to 164 min. The advantage of both pipecuronium and doxacurium is their cardiovascular stability. Both agents are primarily eliminated via the kidneys and both have now been licensed for use in the US. Mivacurium is a muscle relaxant with a short duration of action. When administered in doses of 0.1 to 0.25 mg/kg it produces maximum block in 2 to 4 min, but the duration of clinical relaxation is less than 20 min. Higher doses which could induce a faster neuromuscular block are unfortunately associated with some histamine liberation. The drug is metabolised by plasma cholinesterase. Mivacurium has also been licensed for use in the US. Org 9426 is an agent with a rapid onset but an intermediate duration of action. A dose of 0.5 to 0.6 mg/kg induces maximum block in about 1.5 min and has a duration of clinical relaxation of about 30 min. The rapid onset of effect could be useful for early intubation as an alternative to suxamethonium chloride. However, much more clinical experience is needed with this agent, particularly with regard to duration of action of larger doses and occurrence of side effects. The drug is mainly eliminated via the liver.

Pipecuronium-induced neuromuscular blockade during nitrous oxide-fentanyl, enflurane, isoflurane, and halothane anesthesia in surgical patients

This study was designed to determine the capacity of several anesthetics to augment pipecuronium neuromuscular blockade. The potency of pipecuronium was determined with single-bolus administration of 20-50 micrograms/kg in 160 patients. Patients were anesthetized with N2O/O2 (60:40) supplemented with fentanyl (4-5 micrograms/kg), halothane (0.8%), isoflurane (1.2%), or enflurane (1.7%). Neuromuscular blockade was measured by an acceleration-responsive transducer (the Accelograph, Biometer International, Odense, Denmark). Responses were defined in terms of percent depression in first-twitch height and train-of-four response, and the dose-response curves were constructed after probit transformation of the responses. The dose-response curves were found to be parallel for both first twitch height and train-of-four responses. The dose-response lines for the enflurane and isoflurane groups were displaced significantly (P less than 0.01) to the left of the line for the fentanyl-N2O group. The calculated doses producing 50% depression of first twitch height were 21.9, 21.2, 18.9, and 17.8 micrograms/kg for the N2O-fentanyl, halothane, isoflurane, and enflurane groups, respectively. Corresponding calculated doses for 50% depression of train-of-four response were significantly smaller (15.5, 14.4, 13.7, 11.9 micrograms/kg, respectively). The enhancing effects of the volatile anesthetics were reflected by significant prolongation of the clinical duration of neuromuscular blockade by pipecuronium. It is concluded that the potency of pipecuronium is enhanced more by enflurane and isoflurane than halothane or fentanyl-N2O anesthesia.

Normal and elevated 3 alpha-androstanediol glucuronide concentrations in women with various causes of hirsutism and its correlation with degree of hirsutism and androgen levels

We investigated peripheral androgen metabolic activity in 54 hirsute females (HF) by evaluating the serum 3 alpha-androstanediol glucuronide (3AG) concentration, hirsutism score (HS), and etiology of hirsutism. Based on basal and ACTH-stimulated steroid profiles (1 h post-Cortrosyn, 0.25 mg, i.v. bolus), the causes of hirsutism were determined to be increased adrenal androgen production (greater than 2 SD above normal mean), increased ovarian testosterone (T) production (greater than 2 SD above normal mean basal T of ovarian source only), or idiopathic cause (normal steroid profile). Serum 3AG levels in each group of HF were significantly higher (P less than 0.01-0.001) than those in normal females [normal: 2.9 +/- 0.94 nmol/L (n = 28); HF: increased adrenal androgen production of undefined cause, 7.7 +/- 7.5 nmol/L (n = 14); 21-hydroxylase deficiency, 7.6 +/- 7.4 nmol/L (n = 5); increased ovarian T production 5.5 +/- 3.5 nmol/L (n = 18); idiopathic cause, 5.8 +/- 4.8 nmol/L (n = 17)]. However, normal 3AG levels (less than 5.2 nmol/L) were present in 50-67% of HF in each group. Collectively, 3AG levels in HF correlated significantly (P less than 0.01) with dehydroepiandrosterone (DHEA; r = 0.41) and DHEA sulfate (DS; r = 0.44), while the correlation with androstenedione (r = 0.15) or T (r = 0.19) was not significant. Serum 3AG and adrenal androgen levels decreased in all subjects after dexamethasone treatment (0.5-1 mg at hour of sleep; 2 mg/day for 3-5 days). The correlation between 3AG and HS was significant (r = 0.6-0.74; P less than 0.01-0.001) only in HF with increased adrenal androgen secretion and idiopathic cause, and was not significant (r = 0.42) in HF with increased ovarian T secretion. There was no significant correlation between androgen levels and HS. We conclude that the serum 3AG level was not consistently elevated in HF and did not differ significantly between the various causes. Significant correlations between 3AG and DHEA/DS levels, and the simultaneous decrease in 3AG and adrenal androgens after dexamethasone administration in HF suggest that adrenal androgens contribute significantly to 3AG production. The significant correlation between 3AG and HS in HF with increased adrenal androgen secretion and idiopathic cause indirectly suggests an adrenal androgen contribution to both 3AG production and hirsutism in these HF. The insignificant correlation between 3AG and HS in HF with increased ovarian T secretion may result from a confounding effect of ovarian T on hirsutism.

Effect of intravenous hypnotics on the actions of pipecuronium

Seventy-five ASA Grades I-III patients (18-85 years, 45-90 kg) were randomized into five groups. All patients received N2O/O2 (2/1) and alfentanil: loading dose (LD) 0.015 mg kg-1 and maintenance dose (MD) 0.045 mg kg-1 h-1 (groups 1-4). Group 1 received propofol (LD 2 mg kg-1 and MD 6 mg kg-1 h-1); Group 2 etomidate (LD 0.3 mg kg-1 and MD 0.6 mg kg-1 h-1); Group 3 midazolam (LD 0.2 mg kg-1 and MD 0.120 mg kg-1 h-1); Group 4 methohexitone (LD 1.5 mg kg-1 and MD 4 mg kg-1 h-1); Group 5 dehydrobenzperidol 0.05-0.23 mg kg-1 and alfentanil (LD 0.100 mg kg-1 and MD 0.060 mg kg-1 h-1). The neuromuscular block induced by pipecuronium (50 micrograms kg-1) was evaluated. No statistically significant differences were found between the five groups as concerned degree of block (expressed as % twitch amplitude in response to the first of the TOF stimuli (Ta1) at intubation, T1 minimum and recovery to Ta1 = 20%, 25% and 75%. Slightly faster intubation was possible when midazolam was used in comparison with propofol, methohexitone or NLA and when etomidate was used in comparison with propofol. A wide range of individual values of maximal neuromuscular blocking activity was found.

Lack of correlation between sex hormone binding globulin, adrenal and peripheral androgens in precocious adrenarche

Sex hormone binding globulin (SHBG) is a specific steroid-binding plasma glycoprotein regulated by several different factors. Sex steroids are currently considered to be the main physiological regulators of this protein. Testosterone (T) in adults seems to be the main hormone active in lowering SHBG. The role of dihydrotestosterone (DHT) in such regulation, particularly in the prepubertal age, is not well understood, and no data exist about the role of 3 alpha-androstanediol (3A alpha) and its glucuronide. In adulthood, in addition to T, 5-ene steroids seems to play a role in the regulation of SHBG plasma concentration. To assess the effect of adrenal and peripheral androgens in modulating SHBG levels in the prepubertal age, we studied subjects with precocious pubarche secondary to precocious adrenarche (PA). PA represents, in fact, a good model of study as it is characterized by an increased production and action of adrenal androgen in females under 8 yr of age and in males under 9. Sixty-five subjects (55 females and 10 males; chronologic age: 3.6 - 8.2 yr (6.9 +/- 1.3, SD); bone age: 3.6 - 11 yr (7.6 +/- 1.9); BMI 17.9 +/- 3 kg/m2) were studied. Fifteen age-matched normal children (BMI 15.2 +/- 0.8 kg/m2) were studied as controls. Androstenedione (A), dehydroepiandrosterone (DHA) and its sulphate (DHA-S), T, DHT, 3Ad and its glucuronide (3AG) and SHBG were evaluated in all subjects. In PA cases serum SHBG levels (50 +/- 27 nM) were significantly lower (p less than 0.05) with respect to normal prepubertal patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased free testosterone but normal 5 alpha-reduced testosterone metabolites in obese premenopausal women

OBJECTIVE

The aim of the study was to investigate whether the absence of increased 5 alpha-reductase activity explained the absence of hirsutism in premenopausal obese women with increased free testosterone (FT) levels.

DESIGN

As in hyperandrogenicity there generally exists evidence for increased 5 alpha-reductase activity, we measured, as parameters of 5 alpha-reductase activity, plasma levels of 5 alpha-androstane-3 alpha,17 beta-diol glucuronide (ADG) and androsterone glucuronide (ADTG) as well as their precursor levels in obese women without hirsutism, obese hirsute women, non-obese hirsute women, and non-obese, non-hirsute women.

PATIENTS

Eighty-two premenopausal women (20-45 years old) were studied, in four age matched groups: 39 controls, 18 obese without hirsutism, 11 non-obese hirsute and 14 obese hirsute women.

MEASUREMENTS

Blood samples were taken between days 5 and 7 of the menstrual cycle. Steroid hormone levels were measured by radioimmunoassay. Free testosterone levels were measured by equilibrium dialysis.

RESULTS

Compared to controls, mean free testosterone levels were increased (P less than 0.01) in obese, obese hirsute and hirsute patients, whereas mean DHEAS levels were increased in hirsute and obese hirsute (P less than 0.01), but not in obese, women. Mean androstanediol glucuronide levels were markedly increased in hirsute and obese hirsute patients (P less than 0.01), but not in obese women. Plasma androsterone glucuronide levels were increased in hirsute (P less than 0.01), in the normal range in obese hirsute, and decreased in obese women (P less than 0.01).

CONCLUSIONS

These results show that, despite the presence of higher free testosterone levels, neither 5 alpha-reductase activity (as suggested by normal androstanediol glucuronide levels) nor adrenal androgen precursor levels (DHEAS) are increased in obese women without hirsutism.

Pharmacokinetics and pharmacodynamics of pipecuronium bromide (Arduan) in elderly surgical patients

The neuromuscular response to pipecuronium bromide (Arduan), 70 micrograms/kg, was studied in 20 elderly (greater than 70 yr) and 10 younger patients (less than 60 yr) during nitrous oxide, fentanyl, and droperidol anesthesia. The adductor pollicis response to single 0.2-ms supramaximal pulses was recorded. Although all younger patients were completely paralyzed, 2 of 20 elderly patients did not attain 90% paralysis. Onset time in the elderly was prolonged (6.9 +/- 2.6 vs 4.3 +/- 1.5 min, P less than 0.02). Spontaneous recovery was similar in both groups, with 75% recovery occurring at 133 +/- 52 min in the elderly and 146 +/- 46 min in the younger patients. The pharmacokinetic variables were similar for the two groups, and pharmacodynamic analysis revealed a similar sensitivity at the neuromuscular junction. The pharmacologic actions of pipecuronium in otherwise healthy patients do not differ between young and elderly adults.