SwePub
Tyck till om SwePub Sök här!
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "L773:0306 4530 OR L773:1873 3360 ;pers:(Bäckström Torbjörn)"

Sökning: L773:0306 4530 OR L773:1873 3360 > Bäckström Torbjörn

  • Resultat 1-10 av 14
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  •  
2.
  •  
3.
  • Andréen, Lotta, et al. (författare)
  • Sex steroid induced negative mood may be explained by the paradoxical effect mediated by GABAA modulators
  • 2009
  • Ingår i: Psychoneuroendocrinology. - : Elsevier BV. - 0306-4530 .- 1873-3360. ; 34:8, s. 1121-1132
  • Tidskriftsartikel (refereegranskat)abstract
    • Certain women experience negative mood symptoms as a result of progesterone during the luteal phase of the menstrual cycle, progestagens in hormonal contraceptives, or the addition of progesterone or progestagens in sequential hormone therapy (HT). This phenomenon is believed to be mediated via the action of the progesterone metabolites on the GABA(A) system, which is the major inhibitory system in the mammalian CNS. The positive modulators of the GABA(A) receptor include allopregnanolone and pregnanolone, both neuroactive metabolites of progesterone, as well as benzodiazepines, barbiturates, and alcohol. Studies on the effect of GABA(A) receptor modulators have shown contradictory results; although human and animal studies have revealed beneficial properties such as anaesthesia, sedation, anticonvulsant effects, and anxiolytic effects, recent reports have also indicated adverse effects such as anxiety, irritability, and aggression. It has actually been suggested that several GABA(A) receptor modulators, including allopregnanolone, have biphasic effects, in that low concentrations increase an adverse, anxiogenic effect whereas higher concentrations decrease this effect and show beneficial, calming properties. The allopregnanolone increase during the luteal phase in fertile women, as well as during the addition of progesterone in HT, has been shown to induce adverse mood in women. The severity of these mood symptoms is related to the allopregnanolone serum concentrations in a manner similar to an inverted U-shaped curve. Negative mood symptoms occur when the serum concentration of allopregnanolone is similar to endogenous luteal phase levels, while low and high concentrations have less effect on mood. It has also been shown that progesterone/allopregnanolone treatment in women increases the activity in the amygdala (as measured with functional magnetic resonance imaging) in a similar way to the changes seen during anxiety reactions. However, it is evident that only certain women experience adverse mood during progesterone or GABA(A) receptor modulator treatments. Women with premenstrual dysphoric disorder (PMDD) have severe luteal phase related symptoms; in this phase, they show changes in GABA(A) receptor sensitivity and GABA concentrations that are related to the severity of the condition. These findings suggest that negative mood symptoms in women with PMDD are caused by the paradoxical effect of allopregnanolone mediated via the GABA(A) receptor. CONCLUSION: Progesterone and progestagens induce negative mood, most probably via their GABA(A) receptor active metabolites. In postmenopausal women treated with progesterone and animals treated with allopregnanolone, there is a bimodal association between serum allopregnanolone concentration and adverse mood, resembling an inverted U-shaped curve. In humans, the maximal effective concentration of allopregnanolone for producing negative mood is within the range of physiological luteal phase serum concentrations.
  •  
4.
  • Bengtsson, Sara K. S., et al. (författare)
  • Isoallopregnanolone antagonize allopregnanolone-induced effects on saccadic eye velocity and self-reported sedation in humans
  • 2015
  • Ingår i: Psychoneuroendocrinology. - : Elsevier BV. - 0306-4530 .- 1873-3360. ; 52, s. 22-31
  • Tidskriftsartikel (refereegranskat)abstract
    • Allopregnanolone (AP) is an endogenous neurosteroid. It modulates the effect of gamma-amino-butyric acid (GABA) on the GABA type A (GABA(A)) receptor, which leads to increased receptor activity. Since the GABA-system is mainly inhibitory, increased AP activity leads to modulation of neuronal activity. In vitro studies of GABA(A) receptor activity and in vivo animal studies of sedation have shown that AP-induced effects can be inhibited by another endogenous steroid, namely isoallopregnanolone (ISO). In this study we investigated if ISO can antagonize AP-induced effects in healthy female volunteers, via measurements of saccadic eye velocity (SEV) and self-rated sedation. With a single-blind cross-over design, 12 women were studied on three separate occasions; given AP alone or AP in combination with one of two ISO doses. Congruent with previous reports, AP administration decreased SEV and induced sedation and these effects were diminished by simultaneous ISO administration. Also, the ISO effect modulation was seemingly stronger for SEV than for sedation. These effects were observed already at an ISO dose exposure that was approximately half of that of AP. In conclusion, ISO antagonized AP-induced decrease in SEV and self-reported sedation, probably in a non-competitive manner.
  •  
5.
  • Bixo, Marie, et al. (författare)
  • Treatment of premenstrual dysphoric disorder with the GABA(A) receptor modulating steroid antagonist Sepranolone (UC1010)-A randomized controlled trial
  • 2017
  • Ingår i: Psychoneuroendocrinology. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0306-4530 .- 1873-3360. ; 80, s. 46-55
  • Tidskriftsartikel (refereegranskat)abstract
    • Context: Allopregnanolone is a metabolite from progesterone and a positive modulator of the GABA(A) receptor. This endogenous steroid may induce negative mood in sensitive women when present in serum levels comparable to the premenstrual phase. Its endogenous isomer, isoallopregnanolone, has been shown to antagonize allopregnanolone effects in experimental animal and human models.Objective: The objective was to test whether inhibition of allopregnanolone by treatment with the GABA(A) modulating steroid antagonist (GAMSA) Sepranolone (UC1010) during the premenstrual phase could reduce symptoms of the premenstrual dysphoric disorder (PMDD). The pharmacokinetic parameters of UC1010 when given as a subcutaneous injection were measured in healthy women prior to the study in women with PMDD.Design: This was an explorative randomized, double-blind, placebo-controlled study.Setting: Swedish multicentre study with 10 centers.Participants: Participants were 26 healthy women in a pharmacokinetic phase I study part, and 126 women with PMDD in a phase II study part. Diagnosis followed the criteria for PMDD in DSM-5 using Daily Record of Severity of Problems (DRSP) and Endicott's algorithm.Intervention: Subjects were randomized to treatment with UC1010 (10 or 16 mg) subcutaneously every second day during the luteal phase or placebo during one menstrual cycle.Outcome measures: The primary outcome measure was the sum of all 21 items in DRSP (Total DRSP score). Secondary outcomes were Negative mood score i.e. the ratings of the 4 key symptoms in PMDD (anger/irritability, depression, anxiety and lability) and impairment (impact on daily life).Results: 26 healthy women completed the pharmacokinetic phase I study and the dosing in the following trial was adjusted according to the results. 106 of the 126 women completed the phase II study. Within this group, a significant treatment effect with UC1010 compared to placebo was obtained for the Total DRSP score (p = 0.041) and borderline significance (p = 0.051) for the sum of Negative mood score. Nineteen participants however showed symptoms during the follicular phase that might be signs of an underlying other conditions, and 27 participants had not received the medication as intended during the symptomatic phase. Hence, to secure that the significant result described above was not due to chance, a post hoc sub-group analysis was performed, including only women with pure PMDD who completed the trial as intended (n =60). In this group UC1010 reduced Total DRSP scores by 75% compared with 47% following placebo; the effect size 0.7 (p = 0.006), and for sum of Negative mood score (p=0.003) and impairment (p =0.010) with the effect size 0.6. No severe adverse events were reported during the treatment and safety parameters (vital signs and blood chemistry) remained normal during the study.Conclusions: This explorative study indicates promising results for UC1010 as a potential treatment for PMDD. The effect size was comparable to that of SSRIs and drospirenone containing oral contraceptives. UC1010 was well tolerated and deemed safe.
  •  
6.
  • Bäckström, Torbjörn, et al. (författare)
  • A randomized, double-blind study on efficacy and safety of sepranolone in premenstrual dysphoric disorder
  • 2021
  • Ingår i: Psychoneuroendocrinology. - : Elsevier BV. - 0306-4530 .- 1873-3360. ; 133
  • Tidskriftsartikel (refereegranskat)abstract
    • Women with premenstrual dysphoric disorder (PMDD) experience mood symptoms related to the increase in progesterone and the neuroactive steroid allopregnanolone. Our hypothesis is that allopregnanolone is the symptom provoking factor. The rationale for the present study was to treat PMDD patients with the GABAA receptor modulating steroid antagonist, sepranolone (isoallopregnanolone). Patients (n = 206) with PMDD from 12 European centers were randomized in a parallel double-blind study and treated with placebo, sepranolone 10 mg and 16 mg. Patients administered sepranolone subcutaneously every 48 h during the 14 premenstrual days of three consecutive menstrual cycles. After obtaining informed consent, the PMDD diagnosis was confirmed according to DSM-5 and verified with two menstrual cycles of daily symptom ratings using the Daily Record of Severity of Problems (DRSP) scale in an eDiary. Inclusion and exclusion criteria stipulated that the women should be essentially healthy, not pregnant, have no ongoing psychiatric disorder or take interfering medications, and have regular menstrual cycles. The study's primary endpoint was the Total symptom score (Sum21, the score for all 21 symptom questions in the DRSP). In the prespecified statistical analysis the average score of the 5 worst premenstrual days in treatment cycles 2 and 3 were subtracted from the corresponding average score in the two diagnostic cycles. The treatment effects were tested using analysis of variance in a hierarchal order starting with the combined active sepranolone treatments vs. placebo. The prespecified analysis of Sum21 showed a large treatment effect of all three treatments but no statistically significant difference to placebo. However, the ratings of distress showed a significant treatment effect of sepranolone compared to placebo (p = 0.037) and the ratings of impairment showed a trend to greater treatment effect of sepranolone compared to placebo. Many women with PMDD had symptoms during a longer period than the late luteal phase. It has previously been shown that 9 premenstrual days may be more representative for comparison of PMDD symptom periods than the 5 worst premenstrual days. A post hoc analysis was undertaken in the per protocol population investigating the treatment effect during 9 premenstrual days in the third treatment cycle. The Sum21 results of this analysis showed that the sepranolone 10 mg was significantly better than placebo (p = 0.008). Similar significant treatment effects were found for the impairment and distress scores. A significantly larger number of individuals experienced no or minimal symptoms (Sum21 <42 points) with the 10 mg sepranolone treatment compared to placebo (p = 0.020). The results indicate that there is an attenuating effect by sepranolone on symptoms, impairment, and distress in women with PMDD especially by the 10 mg dosage. Sepranolone was well tolerated, and no safety concerns were identified.
  •  
7.
  • Bäckström, Torbjörn, et al. (författare)
  • Increased neurosteroid sensitivity - An explanation to symptoms associated with chronic work related stress in women?
  • 2013
  • Ingår i: Psychoneuroendocrinology. - : Pergamon Press. - 0306-4530 .- 1873-3360. ; 38:7, s. 1078-1089
  • Tidskriftsartikel (refereegranskat)abstract
    • Work related psychosocial stress can be accompanied by so called burnout syndrome with symptoms of mental exhaustion, physical fatigue, and cognitive dysfunction. Underlying mechanisms for acquiring burnout syndrome are not clear. Animal studies show that chronic stress is associated with altered release of GABA-A receptor modulating steroids (GAMS), altered composition of the GABA-A receptor and altered sensitivity to GAMS. In the present study we investigated if such changes occur in women with burnout syndrome. We further asked whether flumazenil (a benzodiazepine antagonist, but with positive modulating effects on GABA-A receptors with altered subunit composition) can block the effect of the GAMS allopregnanolone. Ten women with occupational psychosocial stress and burnout syndrome were compared with twelve healthy controls in an experimental setting. Saccadic eye velocity (SEV) was measured after an injection of allopregnanolone, followed by an injection of flumazenil and a second injection of allopregnanolone. The sensitivity to allopregnanolone was significantly higher in the patients compared to controls after the first injection (p = 0.04) and the difference increased when the response per allopregnanolone concentration unit was compared ( p = 0.006). Following the flumazenil injection the burnout patients (p= 0.016), but not controls, showed a decrease in SEV and flumazenil acted like a positive modulator that is agonistic. There was no significant difference between the groups after second allopregnanolone injection. In conclusion, patients with work related psychosocial stress and burnout syndrome show a different response to GABA-A receptor modulators than controls suggesting a changed GABA-A receptor function in these patients. More precisely we hypothesize that the alpha 4 and delta subunits are up-regulated elevating the responsiveness to allopregnanolone and change the effect of flumazenil, which provides a potential explanation to the burnout syndrome. Flumazenil does not block the effect of allopregnanolone.
  •  
8.
  • Das, Roshni, et al. (författare)
  • Medroxyprogesterone acetate positively modulates specific GABAA-receptor subtypes - affecting memory and cognition
  • 2022
  • Ingår i: Psychoneuroendocrinology. - : Elsevier. - 0306-4530 .- 1873-3360. ; 141
  • Tidskriftsartikel (refereegranskat)abstract
    • Medroxyprogesterone acetate (MPA) is a progestin widely used in humans as hormone replacement therapy and at other indications. Many progestin metabolites, as the progesterone metabolite allopregnanolone, have GABAA-receptor modulatory effects and are known to affect memory, learning, appetite, and mood. In women, 4 years chronic treatment with MPA doubles the frequency of dementia and in rats, MPA causes cognitive impairment related to the GABAergic system. Activation of the membrane bound GABAA receptor results in a chloride ion flux that can be studied by whole-cell patch-clamp electrophysiological recordings. The purpose of this study was to clarify the modulatory effects of MPA and specific MPA metabolites, with structures like known GABAA-receptor modulators, on different GABAA-receptor subtypes. An additional aim was to verify the results as steroid effects on GABA response in single cells taken from rat hypothalamus. HEK-293 cell-lines permanently expressing the recombinant human GABAA-receptor subtype α1β2γ2L or α5β3γ2L or α2β3γ2S were created. The MPA metabolites 3α5α-MPA,3β5α-MPA and 3β5β-MPA were synthesised and purified for electrophysiological patch-clamp measurements with a Dynaflow system. The effects of MPA and tetrahydrodeoxycorticosterone were also studied. None of the studied MPA metabolites affected the responses mediated by α1β2γ2L or α5β3γ2L GABAA receptors. Contrary, MPA clearly acted both as a positive modulator and as a direct activator of the α5β3γ2L and α2β3γ2S GABAA receptors. However, in concentrations up to 10 μM, MPA was inactive at the α1β2γ2L GABAA receptor. In the patch-clamp recordings from dissociated cells of the preoptic area in rats, MPA increased the amplitude of responses to GABA. In addition, MPA alone without added GABA, evoked a current response. In conclusion, MPA acts as a positive modulator of specific GABAA receptor subtypes expressed in HEK cells and at native GABA receptors in single cells from the hypothalamic preoptic area.
  •  
9.
  •  
10.
  • Kask, Kristiina, et al. (författare)
  • Lower levels of prepulse inhibition of startle response in pregnant women compared to postpartum women
  • 2008
  • Ingår i: Psychoneuroendocrinology. - : Elsevier BV. - 0306-4530 .- 1873-3360. ; 33:1, s. 100-107
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVE: During the postpartum period, estradiol and progesterone levels decline from very high levels during late pregnancy to low levels within 48h of parturition. This period is associated with dysphoric states such as the postpartum blues. Animal studies have suggested an enhanced acoustic startle response and deficient prepulse inhibition (PPI) of startle response following progesterone withdrawal and during the postpartum period. The aim of the current study was to compare acoustic startle response and PPI in healthy third trimester pregnant women and healthy postpartum women. METHODS: Twenty-eight healthy pregnant and 21 healthy postpartum women (examined between 48h and 1 week after delivery) were recruited for the study. In addition, to evaluate the time-course of postpartum changes 11 early postpartum women (examined within 48h following delivery) were included in the study. The eyeblink component of the acoustic startle reflex was assessed using electromyographic measurements of m. Orbicularis Oculi. Twenty pulse-alone trials (115dB 40ms broad-band white noise) and 40 prepulse-pulse trials were presented. The prepulse stimuli consisted of a 115dB 40ms noise burst preceded at a 100ms interval by 20ms prepulses that were 72, 74, 78 or 86dB. RESULTS: Pregnant women exhibited lower levels of PPI compared to late postpartum women, p<0.05. There was no difference between pregnant women and postpartum women examined within 48h of delivery. There was no difference in startle response or habituation to startle response between pregnant women and either of the two groups of postpartum women. CONCLUSION: Healthy women display lower levels of PPI during late pregnancy when estradiol and progesterone levels are high compared to the late postpartum period when ovarian steroid levels have declined.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 14

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy