Orally administered progesterone enhances sensitivity to triazolam in postmenopausal women

Diazepam Tolerance Effects on Vestibular Function Testing, Part I: Saccadic Parameters during Electronystagmography

Objectives:

Benzodiazepines, particularly diazepam (DZ), are used in clinical practice to suppress acute vestibular symptoms. There have been limited studies looking at the effects of tolerance to DZ on parameters designed to measure the integrity of the vestibular system and its interaction with the oculomotor and balance systems.

Methods:

In a double-blinded, repeated-measures design, we randomized 30 young healthy men into one of two treatment groups (diazepam and placebo) and assessed with electro-oculography the effects of clinical divided doses of DZ on saccadic eye movements and sedation over 16 days.

Results:

Only sedation and saccadic latency were significant (p < .05) for treatment group, indicating selective effects on different central nervous system mechanisms. No significant effect for time was seen in any of the variables measured. Bonferroni t-test comparisons of the DZ group among 3 days were significant (p < .017) between baseline and day 3 for saccadic latency and accuracy and between day 3 and day 16 for self-ratings of sedation.

Conclusions:

Saccadic latency and accuracy and sedation ratings appear to be more sensitive to changes over time and less affected by subject variability than saccadic eye velocity. It remains questionable whether patients who have been on DZ for acute or extended periods of time need to discontinue the drug 48 hours before testing.

Depression, Anxiety, and Anger in Patients with Polycystic Ovary Syndrome

INTRODUCTION

Polycystic Ovary Syndrome (PCOS) is a syndrome of heterogeneous nature, affecting multiple systems, particularly the endocrine system. We propose to investigate the possible relationships among hormonal changes, levels of anxiety, depression, and anger in patients with PCOS.

METHOD

Forty-four female patients with PCOS and 44 body mass index (BMI )-matched healthy women participated in this study. We measured the sociodemographic features, some serum hormonal levels (insulin, gonadotropins, prolactin, dehydroepiandrosterone sulfate (DHEAS), thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), 17 OH-progesterone, and total and free testosterone), and some other biochemical parameters of the participants. Also, all participants completed the Trait Anger-Anger Expression Scale (STAS), Beck Depression, and Beck Anxiety Inventories. We evaluated the psychiatric scale scores obtained from PCOS patients and control subjects. We used the independent-samples t-test for parametric data to evaluate normal distribution, and Mann-Whitney U-test was used for both abnormally distributed and nonparametric data. We used Pearson correlation analysis to evaluate the potential connection between the two groups' data.

RESULTS

The mean ages of the patients with PCOS and control subjects who participated in this study were 27.3±5.6 and 27.4±6.1 years, respectively. The measures of BMI, insulin, luteinizing hormone (LH), DHEAS, and total testosterone serum levels in the patient group were significantly higher than in the control group (p<.05). There was a statistically significant positive correlation between Beck anxiety scores and serum DHEAS levels (Pearson r=.4366, P=.0001). We found significant differences between the two groups in terms of trait anger, anger control, outward and inward anger, anxiety level, and depression scores (P<.05).

CONCLUSION

Anxiety symptoms indicate a stronger relationship compared to depression with DHEAS serum levels via the autonomic nervous system, considering the gamma-aminobutyric acid (GABA)-antagonistic effect of DHEAS. Obesity, hirsutism, and infertility may reduce self-confidence and create depressive symptoms in patients with PCOS. In addition, changes in hormonal levels may lead to anxiety directly. Possibly, depressive symptoms are a secondary reflection of these changes.

Progesterone effects on the discriminative stimulus, subjective and performance effects of triazolam in healthy, premenopausal women

There is accumulating evidence that sex plays a critical role in drug abuse. Female sex hormones have been shown to affect central nervous system function and modulate the effects of drugs of abuse. For example, γ-aminobutyric acid type A (GABA(A)) receptor function is positively modulated by progesterone metabolites. There is evidence from preclinical in-vitro and in-vivo studies as well as some clinical research suggesting that progesterone and its metabolites may enhance the behavioral effects of benzodiazepines, which also serve as positive modulators of GABA(A) receptors. The purpose of this experiment was to determine the independent and combined discriminative stimulus, subjective and psychomotor effects of progesterone and triazolam in healthy adult premenopausal women. Oral micronized progesterone (100 mg), triazolam (0.06, 0.12 and 0.25 mg/70 kg) and placebo were administered to healthy, premenopausal women (n=9) under conditions of low circulating sex hormones. Triazolam alone functioned as a discriminative stimulus and produced prototypical sedative-like effects (e.g., performance impairment, enhanced reports of sedative effects). Progesterone alone produced sedative-like effects on several subjective and performance measures, and the dose combination effects of progesterone and triazolam on several subjective measures of drug effect were similar to the summation of the two drug effects in isolation. Progesterone did not substitute for or modify the discriminative stimulus effects of triazolam. These results suggest that the parent hormone, progesterone, and triazolam have discordant neuropharmacological mechanisms of action. Additional research is necessary to determine the degree to which neurosteroids influence sex differences in benzodiazepine use and abuse.

Physiological doses of progesterone potentiate the effects of triazolam in healthy, premenopausal women

RATIONALE

Gender plays a critical role in the effects of drugs and drug abuse liability. Biological factors, including ovarian hormones, may contribute to gender differences in drug abuse. Preclinical and some clinical research suggests that progesterone and its metabolites have activity at the GABA(A) receptor and may enhance the effect of GABAergic compounds (e.g., benzodiazepines). Because women are exposed to varying levels of progesterone from puberty until menopause, and appear more sensitive to the negative consequences of benzodiazepine use, it is important to understand the impact of progesterone on GABAergic drug effects.

OBJECTIVES

The purpose of this experiment was to characterize the behavioral effects of progesterone, alone and in combination with the short-acting benzodiazepine, triazolam, to determine if progesterone potentiates the behavioral effects of triazolam.

METHODS

Oral micronized progesterone (0, 100, and 200 mg) and oral triazolam (0.00, 0.12, and 0.25 mg/70 kg) were administered to healthy, premenopausal women (n = 11) under conditions of low circulating sex hormones. The subjective, performance and physiological effects of progesterone, alone and in combination with triazolam, were assessed.

RESULTS

Triazolam alone produced prototypical sedative-like effects. Progesterone alone also engendered some sedative effects, although the time course of the effects was more limited than that of triazolam. Progesterone increased and extended the duration of triazolam effects and delayed the onset of triazolam peak effects, most notably at the 0.12 mg/70 kg dose.

CONCLUSIONS

Progesterone potentiates the behavioral effects of benzodiazepines and may contribute to benzodiazepine use and abuse among women.

Modulation of the discriminative stimulus effects of triazolam across the menstrual cycle phase in healthy pre-menopausal women

Pre-clinical studies indicate that changes in progesterone levels across menstrual cycle phases modulate the behavioral effects of sedative drugs acting at GABA(A) receptor sites. In this study, seven healthy women learned to discriminate triazolam (0.25 mg/70 kg) from placebo. After acquiring the discrimination, a range of triazolam doses (0.00, 0.06, 0.12 and 0.25 mg/70 kg) was tested during the early follicular and mid-luteal menstrual cycle phases. During the mid-luteal phase, when progesterone levels were elevated, 0.12 mg/70 kg triazolam was identified as the active triazolam training dose (0.25 mg/70 kg), whereas 0.12 mg/70 kg triazolam was identified as placebo during the early follicular phase, when progesterone levels were low. Triazolam engendered prototypical sedative effects on subjective effect, performance and cardiovascular measures that were generally independent of cycle phase. These results suggest that the discriminative stimulus effects of the positive GABA(A) modulator, triazolam, are sensitive to menstrual cycle phase in healthy adult women.

Decreasing Pain and Anxiety Associated with Patient-Activated Atrial Shock: A Placebo-Controlled Study of Adjunctive Sedation with Oral Triazolam

INTRODUCTION

Implantable atrial defibrillators (IADs) have proved to be safe and effective in the management of atrial fibrillation. A potential limitation of self-activated IAD therapy is patient-reported pain and anxiety. The main objective of the present study was to determine whether triazolam improved patient perception of the shock experience or altered patient memory of shock discomfort relative to placebo.

METHODS AND RESULTS

A total of 15 men and women (mean age: 59 +/- 6 years) were enrolled in this double-blind, placebo-controlled, crossover study of triazolam. Randomized study medication was administered orally 75 minutes prior to scheduled atrial shock delivery. Patient perception of the shock experience was assessed along with sedation, memory, anxiety, and mood. Triazolam reduced mean pre-shock anxiety (t= 2.98, df = 14, P = 0.01) and shock-related pain (t= 2.74, df = 13, P = 0.01) and intensity (t= 2.64, df = 13, P = 0.018) relative to placebo. Similarly, participants recalled less discomfort the morning after shock with triazolam than with placebo (t= 2.82, df = 11, P = 0.017).

CONCLUSIONS

This study was the first to investigate the use of an oral benzodiazepine administered prior to patient-activated shock delivery with an IAD. Our data indicate that oral triazolam is beneficial in decreasing pain and anxiety associated with self-activated atrial defibrillation. If triazolam provides a similar benefit in the community to that which has been reported here, this medication could be offered to patients as an adjunct to intermittent IAD therapy.

Gender differences in response to lorazepam in a human drug discrimination study

Gender differences in the discriminative stimulus properties of drugs of abuse have sometimes been reported, although we have previously found no differences in subjective or discriminative responses in human subjects acquiring an alcohol discrimination. The aim of the present work was to determine if there were gender differences in the effects of lorazepam, a benzodiazepine-receptor agonist which substituted for the alcohol stimulus in trained social drinkers. Volunteers who had already acquired an alcohol (0.2g/kg) placebo discrimination were administered (double-blind) either placebo (nine females, nine males) or lorazepam 2mg (six females, six males). They then sampled a series of five drinks and rated each one for likeness to the training stimulus (the generalization response). In addition they completed rating scales for subjective effects and the Digit Symbol Substitution Test (DSST). Lorazepam substituted for the alcohol stimulus equally in both sexes and increased associated scores for lightheadedness. Females however, showed a much greater DSST performance impairment following lorazepam, compared with males. This effect was independent of body weight differences and sedation. These results are discussed in the light of current knowledge of gender differences in response to drugs of abuse and suggest that the stimulus and cognitive effects of benzodiazepine-receptor agonists are modulated by different brain mechanisms.

Estradiol and the addition of progesterone increase the sensitivity to a neurosteroid in postmenopausal women

The aim of this study was to compare the pharmacodynamic response to a neuroactive steroid, pregnanolone, before and during different hormonal settings of postmenopausal hormone replacement therapy (HRT), using natural progesterone. A second aim was to investigate whether the response to pregnanolone was associated with cyclicity in negative mood symptoms during treatment. Twenty six postmenopausal women with climacteric symptoms were administered HRT in a randomized, double blinded, placebo-controlled, crossover study. The women received 2 mg oral estradiol (E(2)) continuously during two 28-day cycles and 800 mg of vaginal progesterone or placebo sequentially for the last 14 days of each treatment cycle. Pharmacodynamic response to pregnanolone was assessed before treatment, and during the last week of each treatment cycle, by comparing the effects of intravenous pregnanolone (3alpha-hydroxy-5beta-pregnan-20-one) on saccadic eye velocity (SEV), saccade acceleration, saccade latency and self-rated sedation. Throughout the study daily symptom rating scales were kept. According to the daily symptom rating scales, patients were divided into two groups; one group who displayed a significant variance in negative mood symptoms during HRT (cyclicity) and one group with no cyclical changes in negative mood symptoms during treatment. During treatment with either E(2) alone or E(2)+progesterone the response in saccadic eye movement parameters and in self-rated sedation to pregnanolone was enhanced compared to pretreatment values. The SEV, saccade acceleration and sedation responses to pregnanolone was also increased in women expressing cyclicity in negative mood symptoms compared to women with no cyclical changes in negative mood during HRT. In conclusion, during treatment with either E(2) alone, or E(2)+progesterone, pregnanolone sensitivity was increased. Women expressing cyclicity in negative mood symptoms were more sensitive to pregnanolone than women without symptom cyclicity during HRT.

Effects of progesterone treatment on cocaine responses in male and female cocaine users

We recently reported that progesterone treatment attenuated some of the subjective effects of smoked cocaine in female cocaine users. In this study, we further examined the interaction between progesterone and cocaine in both male and female cocaine users using subjective, physiological and behavioral outcomes. A total of 10 subjects, 6 male and 4 female cocaine users, had two experimental sessions. Before each session, participants received either two oral doses of 200 mg of progesterone or placebo. Two hours after the second dose of medication treatment, the participants received a 0.3 mg/kg dose of cocaine intravenously and started the self-administration period, in which five optional doses of cocaine were available. Progesterone treatment attenuated the cocaine-induced diastolic blood pressure increases without affecting the systolic blood pressure and heart rate increases. Progesterone treatment also attenuated the subjective ratings of high and feel the effect of last dose in response to cocaine but did not affect cocaine self-administration behavior. These results suggest that progesterone attenuates some of the physiological and subjective effects of cocaine in both male and female participants. The effects of progesterone treatment on cocaine dependence need to be further studied in controlled trials.

Olanzapine and progesterone have dose-dependent and additive effects to enhance lordosis and progestin concentrations of rats

There is evidence that actions of both progesterone (P) and its metabolite, 5alpha-pregnane-3alpha-ol-20-one (3alpha,5alpha-THP), are important for sexual behavior of estradiol (E(2))-primed rodents. Olanzapine, an atypical antipsychotic, dose-dependently increases 3alpha,5alpha-THP in the cortex of male rats. These experiments investigated the effects of olanzapine administration on female sexual behavior and progestin concentrations. In Experiment 1, ovariectomized (ovx) rats (N=128) were primed with estradiol benzoate (EB) at Hour 0 and were administered P (0, 50, 100, or 200 microg sc) at Hour 44 and olanzapine (0.0, 2.5, 5.0, or 10.0 mg/kg ip) at Hour 47. At Hour 48, rats were tested for sexual receptivity with a stimulus male. Administration of 10.0 mg/kg of olanzapine, irrespective of P, significantly increased the occurrence (lordosis quotients, LQs) and the intensity (lordosis ratings, LRs) of lordosis compared to all other dosages. Administration of 2.5 or 5.0 mg/kg of olanzapine, irrespective of P, increased LQs and LRs compared to vehicle administration. Olanzapine without P dose-dependently increased LQs and LRs. As expected, administration of P without olanzapine also dose-dependently increased LQs and LRs. In Experiment 2, ovx rats (N=44, n=4 per group) received EB (0 or 10 microg sc), P (0 or 200 microg sc), and/or olanzapine (0.0, 2.5, 5.0, or 10.0 mg/kg ip). The same pattern of effects seen for lordosis was observed on progestin concentrations. Whole brain and plasma P and 3alpha,5alpha-THP concentrations were increased with olanzapine or P dosing and were greatest with coadministration. Together, these data demonstrate that olanzapine and P have independent effects to increase lordosis, P, and 3alpha,5alpha-THP concentrations of adult rats and additive effects in combination, suggesting complimentary mechanisms of action.

Role of allopregnanolone in regulation of GABA(A) receptor plasticity during long-term exposure to and withdrawal from progesterone

Here we summarize recent data from our laboratory pertaining to the effects of fluctuations in the brain concentrations of the progesterone (PROG) metabolite allopregnanolone (3alpha,5alpha-TH PROG) on the expression and function of gamma-aminobutyric acid type A (GABA(A)) receptors. The effects of long-term exposure to progesterone and of its sudden withdrawal on the activity of GABA(A) receptors and on the abundance of receptor subunit mRNAs were examined in cultured rat cerebellar granule cells and cortical neurons. The effects of a persistent reduction in the brain concentration of 3alpha,5alpha-TH PROG on GABA(A) receptor function and gene expression were examined in vivo in rats subjected to long-term administration of oral contraceptives. Our results demonstrate that long-lasting changes in the exposure of GABA(A) receptors to this PROG metabolite induce marked effects on receptor structure and function. These effects of 3alpha,5alpha-TH PROG appear to be mediated through modulation of GABA(A) receptor signaling mechanisms that control the expression of specific receptor subunit genes. Furthermore, the specific outcomes of such signaling appear to differ among neurons derived from different regions of the brain. Neuroactive steroids such as 3alpha,5alpha-TH PROG might thus exert differential actions on GABA(A) receptor plasticity in distinct neuronal cell populations, likely accounting for some of the physiological effects induced by these compounds.

Increased expression of the neuropeptide Y receptor Y(1) gene in the medial amygdala of transgenic mice induced by long-term treatment with progesterone or allopregnanolone

The neurosteroid allopregnanolone, a reduced metabolite of progesterone, induces anxiolytic effects by enhancing GABA(A) receptor function. Neuropeptide Y (NPY) and GABA are thought to interact functionally in the amygdala, and this interaction may be important in the regulation of anxiety. By using Y(1)R/LacZ transgenic mice, which harbour a fusion construct comprising the promoter of the mouse gene for the Y(1) receptor for NPY linked to the lacZ gene, we previously showed that long-term treatment with benzodiazepine receptor ligands modulates Y(1) receptor gene expression in the medial amygdala. We have now investigated the effects of prolonged treatment with progesterone or allopregnanolone on Y(1)R/LacZ transgene expression, as determined by quantitative histochemical analysis of beta-galactosidase activity. Progesterone increased both the cerebrocortical concentration of allopregnanolone and beta-galactosidase expression in the medial amygdala. Finasteride, a 5alpha-reductase inhibitor, prevented both of these effects. Long-term administration of allopregnanolone also increased both the cortical concentration of this neurosteroid and transgene expression in the medial amygdala. Treatment with neither progesterone nor allopregnanolone affected beta-galactosidase activity in the medial habenula. These data suggest that allopregnanolone regulates Y(1) receptor gene expression through modulation of GABA(A) receptor function, and they provide further support for a functional interaction between GABA and neuropeptide Y in the amygdala.

Effects of acute progesterone administration in healthy postmenopausal women and normally-cycling women

The goal of this study was to investigate the behavioral and subjective effects of single doses of progesterone (intramuscular) in post-menopausal women and in women with normal menstrual cycles. Although certain metabolites of progesterone (e.g., allopregnanolone) are known to bind to GABA(A) receptors and produce sedative-like effects in laboratory animals, few studies have examined the acute effects of these neurosteroids in humans. Postmenopausal women (N=10) received progesterone (25, 50, 100 mg im) or placebo at weekly intervals, and women with normal menstrual cycles (N=8) received progesterone (100 mg im) or placebo once a month during the early follicular phase. Dependent measures included plasma levels of progesterone and allopregnanolone, self-report measures of mood and subjective effects and psychomotor performance. Plasma concentrations of progesterone and allopregnanolone increased in a time and dose-dependent manner, with relatively little variability. The concentrations were similar in both groups, although the ratio of allopregnanolone to progesterone was higher in cycling women at certain time points. Contrary to expectations, progesterone produced only modest behavioral or subjective effects. In the cycling women, it produced mild sedative-like effects (i.e., decreases in ratings of Vigor and Friendliness). In the post-menopausal women, only the highest dose (100 mg) slightly increased ratings of feeling "sluggish". These results suggest that progesterone and its metabolites, at concentrations well beyond those attained during the normal menstrual cycle, produce only marginal sedative-like effects. These findings suggest that brief (i.e., several hours) increases in plasma levels of allopregnanolone do not have direct effects on mood.

Inhibiting progesterone metabolism in the hippocampus of rats in behavioral estrus decreases anxiolytic behaviors and enhances exploratory and antinociceptive behaviors

Blocking progesterone's metabolism to 5 alpha-pregnan-3 alpha-ol-20-one (3 alpha,5 alpha-THP) with finasteride, a 5 alpha-reductase inhibitor, and effects on anxiolytic, exploratory, and antinociceptive behaviors of rats in behavioral estrus were examined. Rats in behavioral estrus received finasteride systemically (SC), to the hippocampus, or to control implant sites, the nucleus accumbens (NA) or ventral tegmental area (VTA), and were tested in horizontal crossing, open-field, elevated plus-maze, emergence, holeboard, social interaction, tailflick, pawlick, and defensive freezing tasks. Finasteride, SC or intrahippocampally, reduced 3 alpha,5 alpha-THP in the hippocampus relative to vehicle implants or finasteride to the NA or VTA. Systemic or intrahippocampal finasteride decreased central entries in the open field and open-arm time on the elevated plus-maze and increased freezing in response to shock relative to vehicle. Finasteride to the hippocampus decreased emergence latencies and increased social interaction, pawlick, and tailflick latencies relative to all other groups. Finasteride to the hippocampus of rats in behavioral estrous decreased anxiolysis and enhanced exploration and analgesia. In summary, these data demonstrate that decreases in anxiolytic behavior of behavioral estrous rats can be produced by reductions in 3 alpha,5 alpha-THP in the hippocampus, which suggest that elevations in 3 alpha,5 alpha-THP in the hippocampus may give rise to anxiolysis seen during behavioral estrus.

Sensitivity to a neurosteroid is increased during addition of progestagen to postmenopausal hormone replacement therapy

The aim of this study was to compare the pharmacodynamic response to a neuroactive steroid, pregnanolone, before and during different hormonal settings of postmenopausal hormone replacement therapy (HRT). Twenty-seven postmenopausal women with climacteric symptoms were administered HRT in a randomized, double-blinded, placebo-controlled crossover study. The women received 2 mg estradiol (E2) continuously during four 28-day cycles and 10 mg medroxyprogesterone acetate (MPA), 1 mg norethisterone acetate (NETA) or placebo sequentially for the last 14 days in each cycle. The pharmacodynamic response to pregnanolone was assessed before treatment and during the last week of each treatment, by comparing the effects of intravenous pregnanolone (3alpha-hydroxy-5beta-pregnan-20-one) on saccadic eye velocity (SEV), saccade deceleration, saccade latency and self-rated sedation. Throughout the study daily symptom rating scales were kept. During the progesta gen phase of the treatment cycles, negative mood symptoms and physical symptoms were increased, whereas positive mood symptoms were decreased. Compared to pretretreatment conditions, E2 alone did not change the responsiveness to pregnanolone. During progestagen addition to E2, the responsiveness to pregnanolone was increased. The sedation response increased compared to pretreatment conditions during both E2 + MPA and E2 + NETA treatment. Compared to E2 treatment alone, addition of MPA increased the postpregnanolone effect on saccade deceleration, whereas the SEV response to pregnanolone was increased during E2 + NETA treatment. It is concluded that pregnanolone sensitivity increases together with deterioration in mood symptoms during addition of progestagen to HRT.

Progesterone treatment during the early follicular phase of the menstrual cycle: effects on smoking behavior in women

The goals of this study were (1) to examine the feasibility of administering progesterone to women during the early follicular phase when the endogenous estradiol and progesterone levels are low, and (2) to investigate the effects of oral progesterone treatment on smoking behavior in female smokers. Twelve subjects had two experimental sessions, within 3-9 days after the beginning of their menses. In each experimental session, subjects received a single 200-mg dose of progesterone or placebo, orally. Two and a half hours after the medication treatment, subjects were assessed for subjective response to two puffs of a cigarette and then started the self-administration period in which they had the option to exchange their token for two puffs of cigarette, 15 min apart. Subjects had low levels of estradiol and progesterone before the first and second sessions. Plasma progesterone levels peaked in 2 h following progesterone treatment. Progesterone treatment attenuated the craving for and subjective effects from smoking. Under progesterone treatment, there was a trend for decreased smoking behavior. These preliminary results suggest that the early follicular phase of the menstrual cycle may be a useful interval to investigate the effects of exogenous progesterone in female smokers. The effects of progesterone on nicotine dependence need to be studied further.

Estrous cycle and sex differences in performance on anxiety tasks coincide with increases in hippocampal progesterone and 3alpha,5alpha-THP

Sex differences and estrous cycle variations in anxiolytic-like behaviors and progestin concentrations were examined. Proestrous (n=22), estrous (n=19), diestrous (n=20), and male (n=18) Long-Evans rats were tested in horizontal crossing, open field, elevated plus-maze, emergence, holeboard, social interaction, tailflick, pawlick, and defensive burying tasks. Concentrations of plasma and hippocampal progesterone and 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP) were measured by radioimmunoassay in behaviorally tested (proestrus n=11, estrus n=8, diestrus n=9, male n=7) and yoked non-tested rats (proestrus n=11, estrus n=8, diestrus n=10, male n=8). Proestrous females exhibited more anxiolytic-like behavior than all other groups on the elevated plus-maze, social interaction, and defensive burying tasks. Proestrous females had significantly shorter latencies to emerge from a cylinder than did estrous and diestrous females, but not males. Proestrous and estrous females entered significantly more peripheral and total squares in a brightly-lit open field than did males. While proestrous females had a tendency to make more beam breaks than did males in the horizontal crossing task, there were no differences between groups on the holeboard task. There was a tendency for proestrous females to have longer tailflick latencies than diestrous and male rats; however, on the pawlick task there were no differences among the groups. Plasma and central progesterone and 3alpha,5alpha-THP of tested and non-tested rats were not different. Proestrous females had significantly higher plasma and hippocampal progesterone and 3alpha,5alpha-THP levels than all other groups. These data demonstrate that proestrous increases in anxiolytic-like behavior coincide with elevated circulating and hippocampal progestin concentrations.

Dehydroepiandrosterone sulfate and psychiatric measures in a frail, elderly residential care population

BACKGROUND

Previous reports have found low levels of dehydroepiandrosterone sulfate (DHEA-S) in association with physical illness, and with frailty in the elderly. In a preliminary study, we also found low DHEA-S associated with increased disability and number of pain sites. However, we found the opposite relationship between DHEA-S and cognitive impairment. Therefore, we conducted a study of a second sample to confirm this unexpected finding and the expected inverse correlations between DHEA-S levels and increased disability and number of pain sites.

METHODS

Psychiatric symptoms and disorders were correlated with DHEA-S and related steroid levels in a second convenience sample in the nursing home population.

RESULTS

This sample confirmed the previous finding of a positive association of cognitive impairment with higher DHEA-S levels but the inverse association of DHEA-S levels with the numbers of pain sensations did not reach statistical significance. Cognitive impairment was also positively associated with higher dehydroepiandrosterone (DHEA) and estradiol levels (women only). Cortisol levels were inversely associated with depressive symptoms.

CONCLUSIONS

The anomalous positive correlation between cognitive dysfunction and DHEA-S levels, and the inverse correlation between cortisol levels and depressive symptoms, suggests that the relationships between psychiatric symptomatology and levels of steroids that are part of the hypothalamic-pituitary adrenal axis are different in the frail elderly population from that of younger and heartier populations.

Effects of triazolam at three phases of the menstrual cycle

This study investigated the subjective and behavioral effects of a commonly used benzodiazepine, triazolam, in healthy women at three phases of the menstrual cycle: follicular, periovulatory, and luteal. Ovarian hormones or their metabolites have direct and indirect actions on neuronal receptors, which may affect responses to psychoactive drugs acting on the same central nervous system receptors. This study explored the effect of menstrual cycle phase on the mood-altering and performance effects of a single oral dose of the benzodiazepine triazolam. Twenty women received triazolam (0.25 mg orally) or placebo at the follicular, periovulatory, and luteal phases of their menstrual cycles in a within-subject design. Dependent measures included self-reported mood states, psychomotor performance, and plasma levels of triazolam, estradiol, progesterone, and allopregnanolone. After administration of triazolam, most subjects reported the expected increases in fatigue and decreases in arousal and psychomotor performance. Neither plasma levels nor mood and performance effects of triazolam differed across the three phases. This study illustrates a useful methodology for assessing responses to psychoactive drugs in normally cycling women and shows that the effects of this drug were highly stable across the cycle.

Physiological modulation of GABA(A) receptor plasticity by progesterone metabolites

The possible functional relation between changes in brain and plasma concentrations of neurosteroids and the plasticity of gamma-aminobutyric acid type A (GABA(A)) receptors in the brain during pregnancy and after delivery was investigated in rats. The concentrations in the cerebral cortex and plasma of pregnenolone as well as of progesterone and its neuroactive derivatives allopregnanolone (3alpha-hydroxy-5alpha-pregnan-20-one) and allotetrahydrodeoxycorticosterone (5alpha-hydroxy-3alpha,21-diol-20-one) increased during pregnancy, peaking around day 19, before returning to control (estrus) values immediately before delivery (day 21). In the postpartum period, steroid concentrations in plasma and brain did not differ from control values. The densities of [3H]GABA, [3H]flunitrazepam, and t-[35S]butylbicyclophosphorotionate (TBPS) binding sites in the cerebral cortex also increased during pregnancy, again peaking on day 19 and returning to control values on day 21; receptor density was decreased further 2 days after delivery and again returned to control values within 7 days. These changes were accompanied by a decrease in the apparent affinity of the binding sites for the corresponding ligand on day 19 of pregnancy. The amount of the gamma2L subunit mRNA decreased progressively during pregnancy, in the cerebral cortex and hippocampus, returned to control value around the time of delivery and did not change in the postpartum period. On the contrary, the amount of alpha4 subunit mRNA was not modified during pregnancy both in the cerebral cortex and hippocampus whereas significantly increased 7 days after delivery only in the hippocampus. No significant changes were apparent for alpha1, alpha2, alpha3, beta1, beta2, beta3 and gamma2S subunit mRNAs. Administration of finasteride, a specific 5alpha-reductase inhibitor, to pregnant rats from days 12 to 18 markedly reduced the increases in the plasma and brain concentrations of allopregnanolone and allotetrahydrodeoxycorticosterone as well as prevented both the increase in the densities of [3H]flunitrazepam and [35S]TBPS binding sites and the decrease of gamma2L mRNA normally observed during pregnancy. The results demonstrate that the changes in the plasticity of GABA(A) receptors that occur in rat brain during pregnancy and after delivery are related to the physiological changes in plasma and brain concentrations of neurosteroids.

Influence of endogenous progesterone on alprazolam pharmacodynamics

The results of a recently completed study demonstrated that postmenopausal women were more sensitive to triazolam-induced psychomotor performance impairment when progesterone was administered concomitantly. That clinical evidence agrees with the emerging in vitro information regarding the rapid membrane effects of a progesterone metabolite that positively modulates the gamma-aminobutyric acid-A-benzodiazepine receptor complex. The objective of this study in premenopausal women was to determine whether the response to a benzodiazepine is altered when endogenous progesterone concentrations are high (luteal phases of a menstrual cycle) compared with when progesterone concentrations are low (follicular phases of a menstrual cycle). The pharmacokinetics and pharmacodynamics of oral alprazolam were evaluated in twelve healthy, normally menstruating women who were not receiving oral contraceptive agents. On two separate occasions, once during each phase of the menstrual cycle, the women randomly received an oral alprazolam 2-mg dose. Blood samples were collected, and psychomotor performance tests were conducted at selected times before and after dosing. These data show that fluctuations of endogenous progesterone across the menstrual cycle do not influence alprazolam pharmacodynamics. Despite endogenous progesterone concentrations being significantly higher during the midluteal than during the midfollicular drug administrations, no differences were observed in either the digit-symbol substitution test, card sorting by suit, or sedation scores on these two occasions. No pharmacokinetic differences were observed between the two menstrual cycle-phase drug administrations. In conclusion, the lack of changes during the menstrual cycle in demonstrable cognitive impairment and pharmacokinetics after alprazolam administration is reassuring. This implies that a dose adjustment made on the basis of menstrual timing is not required.

Role of brain allopregnanolone in the plasticity of gamma-aminobutyric acid type A receptor in rat brain during pregnancy and after delivery

The relation between changes in brain and plasma concentrations of neurosteroids and the function and structure of gamma-aminobutyric acid type A (GABAA) receptors in the brain during pregnancy and after delivery was investigated in rats. In contrast with plasma, where all steroids increased in parallel, the kinetics of changes in the cerebrocortical concentrations of progesterone, allopregnanolone (AP), and allotetrahydrodeoxycorticosterone (THDOC) diverged during pregnancy. Progesterone was already maximally increased between days 10 and 15, whereas AP and allotetrahydrodeoxycorticosterone peaked around day 19. The stimulatory effect of muscimol on 36Cl- uptake by cerebrocortical membrane vesicles was decreased on days 15 and 19 of pregnancy and increased 2 days after delivery. Moreover, the expression in cerebral cortex and hippocampus of the mRNA encoding for gamma2L GABAA receptor subunit decreased during pregnancy and had returned to control values 2 days after delivery. Also alpha1, alpha2, alpha3, alpha4, beta1, beta2, beta3, and gamma2S mRNAs were measured and failed to change during pregnancy. Subchronic administration of finasteride, a 5alpha-reductase inhibitor, to pregnant rats reduced the concentrations of AP more in brain than in plasma as well as prevented the decreases in both the stimulatory effect of muscimol on 36Cl- uptake and the decrease of gamma2L mRNA observed during pregnancy. These results indicate that the plasticity of GABAA receptors during pregnancy and after delivery is functionally related to fluctuations in endogenous brain concentrations of AP whose rate of synthesis/metabolism appears to differ in the brain, compared with plasma, in pregnant rats.

Patients with premenstrual syndrome have decreased saccadic eye velocity compared to control subjects

BACKGROUND

Prior neurophysiological studies on patients with premenstrual syndrome (PMS) have revealed sleep electroencephalographic alterations in both cycle phases. We report on a study evaluating saccadic eye movements in PMS patients.

METHODS

Saccadic eye movements were examined in 21 women with and 21 women without PMS on two occasions in the midfollicular and late luteal phase, respectively. On each occasion, plasma levels for estradiol, progesterone, and neuroactive progesterone metabolites were determined.

RESULTS

PMS patients had decreased saccadic eye velocity (SEV) compared to control subjects. This finding was most evident in the luteal phase, whereas the difference between groups approached significance in the follicular phase. Saccade accuracy and saccade latency were not different between the two groups. Control subjects increased their SEV in the luteal phase compared to the follicular phase, whereas PMS patients did not. PMS patients rated themselves more sedated than control subjects on the testing days in both phases of the menstrual cycle. Plasma levels of gonadal hormones and neuroactive steroids did not differ between the study groups.

CONCLUSIONS

The findings of a decreased SEV in PMS patients could be due to poor sleep and consequently increased sedation, but might also indicate that gamma-aminobutyric acidergic inhibition is different in patients with premenstrual syndrome.

Do alprazolam-induced changes in saccadic eye movement and psychomotor function follow the same time course?

The purpose of this study was to determine whether short-term tolerance develops to GABA-agonist-induced changes in saccadic eye movements (SEMs), and whether the time course for GABA-agonist induced onset and offset of impairment is similar for SEMs and for psychomotor function. An additional goal was to determine whether there are differences in sensitivity between SEMs and psychomotor function. Six healthy volunteers participated in this balanced double-blind, three-way crossover, single-dose study of placebo and two different dosage forms of the GABA-agonist alprazolam: a rapidly absorbed oral 1.5-mg compressed tablet (CT) and a 3.0-mg sustained release (SR) tablet. Treatments were separated by a 7-day washout period. Peak concentrations did not differ between CT and SR treatments, although area under the concentration-time curve (AUC) of alprazolam was greater after administration of SR than after CT, because plateau concentrations were attained after SR. Both SEM and psychomotor tests showed time-dependent responses consistent with the development of tolerance. SEMs discriminated the differences in rate of drug input of the CT and SR formulations, with impairment evident at low concentrations during absorption. SEM impairment also persisted longer than did psychomotor impairment. Peak saccade velocity is a more sensitive indicator of pharmacologic effects mediated by the GABA-benzodiazepine receptor complex than are psychomotor responses. This is probably the result of the very high GABA dependency of SEMs, along with their limited sensitivity to motivation.

Patients with premenstrual syndrome have a different sensitivity to a neuroactive steroid during the menstrual cycle compared to control subjects

We have evaluated the functional sensitivity to a neuroactive steroid in 12 women with and 12 women without premenstrual syndrome (PMS) at two stages of the menstrual cycle, by comparing the effects of three increasing doses of intravenous pregnanolone (3alpha-hydroxy-5beta-pregnan-20-one) on saccadic eye velocity (SEV) and self-rated sedation. Control subjects in the follicular and luteal phase showed a significant reduction in SEV after pregnanolone injections compared to vehicle. In PMS patients, pregnanolone injections induced a significant dose-related decrease in SEV compared to vehicle only in the follicular phase, not in the luteal phase. After pregnanolone injections, sedation scores increased significantly from vehicle among control subjects in the luteal phase but not among PMS patients in either cycle phase. High-severity PMS patients responded with less decrease in SEV and less increase in sedation scores following pregnanolone injections compared to low-severity patients. Control subjects increased their SEV response to pregnanolone in the luteal phase compared to the follicular phase, whereas PMS patients did not. These findings are compatible with a decreased GABAA-receptor sensitivity in brain areas controlling saccadic eye movements among PMS patients in the late luteal phase.

Effect of neuroactive steroids on [3H]flumazenil binding to the GABAA receptor complex in vitro

Modulation of benzodiazepine receptor ligand binding to the GABAA receptor complex by the neuroactive steroids 3 alpha-hydroxy-dihydroprogesterone (3 alpha-OH-DHP) and 3 alpha-hydroxycorticosterone (3 alpha- THDOC) was assessed in an in vitro binding assay with the benzodiazepine antagonist [3H]flumazenil using rat cortical membranes. Neuroactive steroids, pentobarbital, GABA and bicuculline did not significantly affect flumazenil binding. However, the addition of neuroactive steroids significantly decreased the Ki of benzodiazepine agonists, including alprazolam, diazepam and clonazepam, indicating an increase in agonist affinity. Only the addition of 3 beta-OH-DHP, an inactive stereoisomer had no effect on the Ki of these agonists. The binding of the benzodiazepine inverse agonist FG 7142 was not significantly affected by these steroids, but the addition of GABA significantly increased the Ki of FG 7142 indicating a decrease in inverse agonist affinity. High concentrations of GABA or bicuculline were able to occlude the 3 alpha-THDOC mediated decrease in alprasolam Ki, indicating a GABA dependent mechanism of binding enhancement. An advantage of using [3H]flumazenil is that neither the Ki nor the Bmax change in the presence of allosteric site modulators, permitting the simple and direct assessment of alterations in benzodiazepine ligand affinity for the GABAA receptor complex by neuroactive steroids.

Time-dependent sensitization to triazolam? An observation in three studies

Evidence of time-dependent sensitization (TDS) to triazolam was observed in three separate clinical studies. Study 1 was conducted in 12 normal-weight and 12 obese men; an intravenous bolus dose of triazolam, 0.5 mg, was administered on two occasions. Study 2 was a balanced crossover of three 0.25-mg oral doses and one 0.20-mg oral dose of triazolam in 11 men. Study 3 was a balanced crossover of one placebo, one 0.5-mg, and two 0.4-mg oral doses of triazolam. In all three studies, treatments were separated by 6 days and included serial blood sampling for characterization of pharmacokinetics. Psychomotor response was assessed with the Digit Symbol Substitution Test and the Continuous Performance Test (CPT). Sedation was rated by an observer. For each measure, an effect ratio was calculated as the area under the effect curve divided by the area under the triazolam concentration curve; this parameter relates the extent of response relative to drug concentration in plasma. Effect ratios increased progressively by week for CPT; the percentage increase ranged from 31.9% in the study 1 normal subjects (week 1 to week 2; p = 0.08) to 631% in study 2 (week 1 to week 4; p = 0.0013). Similar increases were observed for other responses. Overall, the effect ratio data demonstrate increasing responsiveness per unit of triazolam concentration when triazolam was administered as a single dose at 1-week intervals. This observation was incidental to the original objectives of the studies. However, the data suggest that definitive studies to verify the occurrence of this phenomenon need to be conducted.(ABSTRACT TRUNCATED AT 250 WORDS)