The relationship between fat and progesterone, estradiol, and chorionic gonadotropin levels in Quebec cow's milk.

PURPOSE: The majority of milk in industrialized countries is obtained from pregnant cows, which contains increased levels of estrogen and progesterone compared to non-pregnant cows. The aim of this study was to quantify the amount of hormones present in milk with different fat content because previous studies on humans have shown potential effects of increased milk consumption on serum and urine hormone levels as well as on sperm parameters. However, it is unclear whether consumption of milk at the currently recommended levels would lead to systemic effects. METHODS: Samples of cow's milk of varying fat concentrations (0, 1, 2, 3.25, 10, and 35%) were analyzed via competitive ELISA assays. RESULTS: Progesterone concentrations were significantly correlated to increasing fat content of milk (r = 0.8251, p = 0.04). CONCLUSIONS: Research on conditions in which additional progesterone may have an effect on human health should consider inclusion of limitation of milk intake and its effects. Further studies are needed to determine the concentration of progesterone in milk of different fat content in other regions and countries and to quantify the potential pathophysiologic role.

Quebec public funding facilitates fertility preservation for male cancer patients.

BACKGROUND: Sperm cryopreservation remains the only clinically feasible option to preserve male fertility. The quality of counselling provided by the treating physicians and the cost of sperm cryopreservation can both influence a patient's decision about whether to preserve sperm. On 5 August 2010, the Quebec government introduced provincial coverage of assisted reproductive technologies, with sperm cryopreservation included as a covered service. The aim of the present study was to evaluate whether and how such a program affects the behaviour of cancer patients with respect to sperm cryopreservation. METHODS: We analyzed the database derived from male patients undergoing sperm cryopreservation from August 2008 to August 2012 at our centre. The retrieved data included patient age, male infertility or oncologic diagnosis, sperm quality parameters, and details about the number of visits for sperm cryopreservation. RESULTS: The number of cancer patients who cryopreserved sperm before and after the policy change did not differ significantly, but a marked increase in the number of non-cancer patients was observed. Further analysis revealed that, after implementation of the public funding program, the total number of sperm cryopreservation sessions per patient increased significantly in cancer patients but not in non-cancer patients. CONCLUSIONS: It appears that cancer patients who are willing to freeze sperm are keen to return for more sessions of sperm banking when no fees are associated with the service. Those findings suggest that cost reduction is an important factor for improving delivery of fertility preservation services to male cancer patients.

A national study of the provision of oncology sperm banking services among Canadian fertility clinics.

The purpose of this study was to survey the current state of oncology sperm banking services provided by fertility clinics across Canada. A total of 78 Canadian fertility facilities were invited to complete a questionnaire related to the availability, accessibility, affordability and utilisation of sperm banking services for cancer patients. The total response rate was 59%, with 20 (69%) in vitro fertilisation clinics and 26 (53%) other fertility centres returning the survey. A total of 24 responding facilities accepted oncology sperm banking referrals. The time frame to book the first banking appointment for 19 (79%) facilities was within 2 days. Inconsistent practice was found regarding the consent process for cancer patients who are of minority age. Eight (33%) facilities did not provide any subsidy and charged a standard banking fee regardless of patients' financial situations. Overall, the utilisation of oncology sperm banking services was low despite its availability and established efficacy, suggesting that Canadian cancer patients are notably underserved. The study has highlighted some important issues for further consideration in improving access to sperm banking services for cancer patients, especially for adolescents. Better collaboration between oncology and reproductive medicine to target healthcare providers would help to improve sperm banking rates.

ICSI outcomes using testicular spermatozoa in non-azoospermic couples with recurrent ICSI failure and no previous live births.

BACKGROUND: The use of testicular over ejaculated spermatozoa for ICSI has been presented as an alternative to overcome infertility in men with poor semen parameters or high levels of sperm DNA fragmentation. OBJECTIVE: To evaluate the efficacy of testicular ICSI outcomes in couples with no previous live birth and recurrent ICSI failure using ejaculated spermatozoa by comparison to the outcomes of couples with similar history of recurrent ICSI using ejaculated spermatozoa only. MATERIALS AND METHODS: A total of 145 couples undergoing ejaculated or testicular ICSI cycles with no previous live births and with at least two previous failed ICSI cycles with ejaculated spermatozoa were evaluated retrospectively. ICSI was performed either with ejaculated (E-ICSI) or with testicular (T-ICSI) spermatozoa. Semen parameters and sperm DNA quality were assessed prior to the oocyte collection day. Primary outcomes included cumulative live birth and pregnancy rates. Secondary analysis included percentage of DNA fragmentation in ejaculated spermatozoa (SCSA® and TUNEL). RESULTS: Patients undergoing T-ICSI (n = 77) had a significantly higher clinical pregnancy rate/fresh embryo transfer (ET) (27.9%; 17/61) and cumulative live birth rate (23.4%; 15/64) compared to patients using E-ICSI (n = 68) (clinical pregnancy rate/fresh ET: 10%; 6/60 and cumulative live birth rate: 11.4%; 7/61). Further, T-ICSI yield significantly better cumulative live birth rates than E-ICSI for men with high TUNEL (≥36%) (T-ICSI: 20%; 3/15 vs. E-ICSI: 0%; 0/7, p < 0.025), high SCSA® (≥25%) scores (T-ICSI: 21.7%; 5/23 vs. E-ICSI: 9.1%; 1/11, p < 0.01), or abnormal semen parameters (T-ICSI: 28%; 7/25 vs. E-ICSI: 6.7%; 1/15, p < 0.01). CONCLUSIONS: The use of testicular spermatozoa for ICSI in non-azoospermic couples with no previous live births, recurrent ICSI failure, and high sperm DNA fragmentation yields significantly better live birth outcomes than a separate cohort of couples with similar history of ICSI failure entering a new ICSI cycle with ejaculated spermatozoa.

Impact of government health coverage for ART: The results of a 5-year experience in Quebec.

An analysis of national registry data for 5 years of in-vitro fertilization (IVF) funding in Quebec, Canada was compared with the previous complete year of non-funded IVF cycles, as well as the first complete year following the end of funding. The number of cycles, livebirth rates, age group of patients treated, use of donor gametes, multiple pregnancy rates and cycle cancellation rates were assessed. The total number of IVF cycles performed increased dramatically during the funded period, averaging over 10,000 cycles per year. There was no change in the age group distribution of patients treated, but less egg donation was performed. Interestingly, funding was also associated with an increase in the IVF cycle cancellation rate (17.0% versus 34.4%, P < 0.001), a dramatic decline in the multiple pregnancy rate (25.6% versus 4.9%, P < 0.001), and a decline in the livebirth rate per fresh embryo transfer in stimulated IVF cycles (32.3% versus 25.5%, P < 0.001). Although the livebirth rate for stimulated IVF declined, over 9000 babies were born as a result of the coverage. Lessons learned from this experience could help develop a more fiscally responsible programme that still facilitates access to IVF care.

Excisional surgery versus ablative surgery for ovarian endometriomata.

BACKGROUND: Endometriomata are endometriotic deposits within the ovary. The surgical management of these blood filled cysts is controversial. The laparoscopic approach to the management of endometriomata is favoured over a laparotomy approach as it offers the advantage of a shorter hospital stay, faster patient recovery and decreased hospital costs. Currently the commonest procedures for the treatment of ovarian endometriomata are either excision of the cyst capsule or drainage and electrocoagulation of the cyst wall. OBJECTIVES: The objective of this review was to determine the most effective technique of treating an ovarian endometrioma; either excision of the cyst capsule or drainage and electrocoagulation of the cyst wall. The end-points assessed were the relief of pain, recurrence of the endometrioma, recurrence of symptoms and in women desiring to conceive the subsequent pregnancy rate, either spontaneous or as part of fertility treatment. SEARCH STRATEGY: The reviewers searched the Cochrane Menstrual Disorders and Subfertility Group specialised register of trials (searched 3rd March 2007), the Cochrane Register of Controlled Trials (The Cochrane Library, Issue 3, 2007), MEDLINE (1966-August 2007), EMBASE (1980- March 2007) and reference lists of articles, the handsearching of relevant journals and conference proceedings and by contacting leaders in the field of endoscopic surgery throughout the world. The Cochrane Menstrual Disorders and Subfertility Group Trials Register is based on regular searches of MEDLINE, EMBASE, CINHAL and CENTRAL. SELECTION CRITERIA: Randomised controlled trials of excision of the cyst capsule versus drainage and electrocoagulation of the cyst in the management of ovarian endometriomata. DATA COLLECTION AND ANALYSIS: Reviewers assessed eligibility and trial quality. MAIN RESULTS: No randomised studies of the management of endometriomata by laparotomy were found. Two randomised studies of the laparoscopic management of ovarian endometriomata of greater than 3cm in size, for the primary symptom of pain were included. Laparoscopic excision of the cyst wall of the endometrioma was associated with a reduced recurrence rate of the symptoms of dysmenorrhea (OR 0.15 CI 0.06-0.38), dyspareunia (OR 0.08 CI 0.01-0.51) and non-menstrual pelvic pain (OR 0.10 CI 0.02-0.56), a reduced rate of recurrence of the endometrioma (OR 0.41 CI 0.18-0.93) and with a reduced requirement for further surgery (OR 0.21 CI 0.05-0.79) than surgery to ablate the endometrioma. For those women subsequently attempting to conceive it was also associated with a subsequent increased spontaneous pregnancy rate in women who had documented prior sub-fertility (OR 5.21 CI 2.04-13.29). A further randomised study was identified that demonstrated an increased ovarian follicular response to gonadotrophin stimulation for women who had undergone excsional surgery when compared to ablative surgery (WMD 0.6 CI 0.04-1.16). There is insufficient evidence to favour excisional surgery over ablative surgery with respect to the chance of pregnancy after controlled ovarian stimulation and intra-uterine insemination (OR 1.40 CI 0.47-4.15) . AUTHORS' CONCLUSIONS: There is good evidence that excisional surgery for endometriomata provides for a more favourable outcome than drainage and ablation with regard to the recurrence of the endometrioma, recurrence of pain symptoms, and in women who were previously subfertile, subsequent spontaneous pregnancy . Consequently this approach should be the favoured surgical approach. However in women who may subsequently may undergo fertility treatment insufficient evidence exists to determine the favoured surgical approach.

Does using testicular sperm retrieval rather than ejaculated spermatozoa improve reproductive outcomes in couples with previous ART failure and poor ovarian response? A case-controlled study.

The objective of this study was to assess whether testicular-retrieved spermatozoa improve reproductive outcomes compared to fresh ejaculate in women with poor ovarian response and a history of previous ART failure. The study was performed as a retrospective case-control study at a university-based reproductive center in Montreal, Quebec, Canada. Eighteen poor-responder patients were matched 3 : 1 with 54 controls. Poor responders were defined as those with ≤3 oocytes retrieved at oocyte pickup. Cases were identified as poor responders, and only those with previous IVF failure(s) as an indication for testicular-retrieved spermatozoa were included. Controls were age and cycle attempt number matched. All patients were included only once. From January 1, 2009 to December 31, 2015, all patients and controls underwent an IVF cycle using ICSI with either testicular spermatozoa or ejaculated spermatozoa, respectively. Outcomes included live birth rate, pregnancy rate, miscarriage rate, oocyte number, and embryo transfer (ET) day. The results showed live birth rates, pregnancy rates, and miscarriage rates were similar. There were fewer day 2 ETs (8.5% vs. 48.6%, p = 0.01) and more day 5 blastocyst transfers (25.0% vs. 5.4%, p = 0.05) in the testicular sperm retrieval group compared to controls and thus an overall suggestion of better embryo quality in the testicular sperm group. Overall, however, the use of testicular sperm retrieval appears to add little. Women with poor ovarian response typically have a poor prognosis with respect to live birth rates, and this is further supported in this study. The suggestion of better embryo quality in the testicular-retrieved sperm group would need to be further assessed in a larger multicentered study.

Ultrasound versus 'clinical touch' for catheter guidance during embryo transfer in women.

BACKGROUND: Many women undergoing an Assisted Reproductive Technology (ART) cycle will not achieve a live birth. Failure at the embryo transfer stage may be due to poor embryo quality, lack of uterine receptivity, or the transfer technique itself. Numerous methods, including the use of ultrasound guidance for proper catheter placement in the endometrial cavity, have been suggested as a means of improving the technique of embryo transfer. This review evaluates the effectiveness of ultrasound (UGET) in comparison with 'clinical touch' embryo transfer (CTET) the traditional method of embryo transfer. OBJECTIVES: :To determine whether ultrasound guidance influences treatment outcomes in women undergoing embryo transfer (ET) during assisted reproductive technology (ART) cycles. SEARCH STRATEGY: All electronic databases were searched on 20 th August 2006. We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched August 2006), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2006), MEDLINE (1970-2006), EMBASE (1985-2006), BIO Extracts (1980-2006). Relevant conference proceedings were also hand searched (ASRM, ESHRE and FIGO). SELECTION CRITERIA: Only randomised controlled trials were included. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed eligibility and quality of trials and extracted data from those selected. MAIN RESULTS: Thirteen out of fifteen identified studies were eligible for analysis. No study reported live births, however, personal communication resulted in data relating to this outcome being obtained in two of the studies. Six studies reported on ongoing pregnancies. The live birth/ ongoing pregnancies per woman randomised associated with UGET (452/1376) was significantly higher than for clinical touch (353/1338) OR 1.40, 95%CI 1.18 to 1.66, P<0.0001). This means, for example, that for a population of women with a 25% chance of pregnancy using clinical touch this would be increased to 32% (28% to 46%) by using UGET. There were no statistically significant differences in the incidence of adverse events between the two comparison groups with the exception of blood on the catheter. AUTHORS' CONCLUSIONS: The studies are limited by their quality with only one of the thirteen studies reporting details of both computerised randomisation techniques and adequate allocation concealment. Ultrasound guidance does appear to improve the chances of live/ongoing and clinical pregnancies compared with clinical touch methods. The quality of future studies should be improved with adequate reporting of randomisation, allocation concealment, and power calculations. The primary outcome measure of future studies should be the reporting of live births per woman randomised.

Excisional surgery versus ablative surgery for ovarian endometriomata.

BACKGROUND: Endometriomata are endometriotic deposits within the ovary. The surgical management of these blood filled cysts is controversial. The laparoscopic approach to the management of endometriomata is favoured for as it offers the advantage of a shorter hospital stay, faster patient recovery and decreased hospital costs. Currently the commonest procedures for the treatment of ovarian endometriomata are either excision of the cyst capsule or drainage and electrocoagulation of the cyst wall. OBJECTIVES: The objective of this review was to determine the most effective technique of treating an ovarian endometrioma; either excision of the cyst capsule or drainage and electrocoagulation of the cyst wall, with regard to relief of pain, recurrence of the endometrioma, recurrence of symptoms and the subsequent spontaneous pregnancy rate. SEARCH STRATEGY: The reviewers searched the Cochrane Menstrual Disorders and Subfertility Group specialised register of trials (searched 15 Nov 2004), the Cochrane Register of Controlled Trials (The Cochrane Library, Issue 4, 2004), MEDLINE (1966-Nov 2004), EMBASE (1980- Nov 2004) and reference lists of articles, the handsearching of relevant journals and conference proceedings and by contacting leaders in the field of endoscopic surgery throughout the world. SELECTION CRITERIA: Randomised controlled trials of excision of the cyst capsule versus drainage and electrocoagulation of the cyst in the management of ovarian endometriomata. DATA COLLECTION AND ANALYSIS: Reviewers assessed eligibility and trial quality. MAIN RESULTS: No randomised studies of the management of endometriomata by laparotomy were found. Two randomised studies of the laparoscopic management of ovarian endometriomata of greater than 3cm in size were included. Laparoscopic excision of the cyst wall of the endometrioma was associated with a reduced rate of recurrence of the endometrioma (OR 0.41 CI 0.18-0.93), reduced requirement for further surgery (OR 0.21 CI 0.05-0.79), reduced recurrence rate of the symptoms of dysmenorrhoea (OR 0.15 CI 0.06-0.38), dyspareunia OR 0.08 CI 0.01-0.51) and non-menstrual pelvic pain (OR 0.10 CI 0.02-0.56). It was also associated with a subsequent increased rate of spontaneous pregnancy women who had documented prior sub-fertility (OR 5.21 CI 2.04-13.29). AUTHORS' CONCLUSIONS: There is some evidence that excisional surgery for endometriomata provides for a more favourable outcome than drainage and ablation, with regard to the recurrence of the endometrioma, recurrence of symptoms and subsequent spontaneous pregnancy in women who were previously subfertile. Consequently this approach should be the favoured surgical approach. However we found no data as to the effect of either approach in women who subsequently undergo assisted reproductive techniques.

Decreased 5-HT2 but not 5-HT1 receptor binding in cortex of rat after chronic administration of dothiepin. Application of the Woolf plot to analysis of binding parameters.

Prolonged administration of the antidepressant drug, dothiepin hydrochloride (30 mg/kg orally twice daily for 24 days), resulted in a significant decrease in the population of serotonin2 (5-HT2) binding sites in the frontal cortex of rats whereas serotonin1 (5-HT1) binding sites remained unaltered. No significant differences in affinity constants for either ligand-binding site interaction were observed. Analyses of the binding parameters was performed using linear transformation methods of the specific binding isotherms according to Scatchard (1949) [Ann. N.Y. Acad. Sci. 51: 660-672] or Woolf (see Haldane, 1957: Nature 179: 832). The resulting parameter estimates generated in each analysis were compared. Although both methods demonstrated the decreased Bmax for 5-HT2 binding sites with no change in 5-HT1 sites after prolonged administration of dothiepin, Woolf analyses gave reliably better estimates of the binding parameters as judged by examination of the respective correlation coefficients for best fit linear regression lines.

A new and highly sensitive method for measuring 3-methoxytyramine using HPLC with electrochemical detection. Studies with drugs which alter dopamine metabolism in the brain.

3-Methoxytyramine (3-MT) is a minor metabolite of dopamine which is suggested to reflect the turnover and utilization of dopamine. A novel, isocratic HPLC method has been developed which can be used to analyse 3-MT in homogenates of rat brain without the need for additional purification procedures. Furthermore, the coulometric electrochemical detection system is sensitive enough to measure 3 pg of 3-MT (equivalent to 0.6 ng/g tissue wet weight). 3-Methoxytyramine was measured in the striatum and n. accumbens after decapitation and rapid freezing, using 3-methoxy-4-hydroxybenzylamine as the internal standard. The effects of dopaminergic and other drugs on this metabolite were examined using this method. alpha-Methyl-p-tyrosine (200 mg/kg i.v.) produced parallel linear decreases in dopamine and 3-MT in naive rats, but not those pretreated with tranylcypromine (5 mg/kg i.p.). Methamphetamine (0.3-10 mg/kg i.p.) and amphetamine (0.3-10 mg/kg i.p.) both dose-dependently increased 3-MT in naive and tranylcypromine-pretreated rats. In naive animals, 3-MT was not altered by intraperitoneal injection of the dopamine reuptake inhibitors, bupropion (10 mg/kg) and nomifensine (10 mg/kg) or by sibutramine HCl (3 mg/kg), amitriptyline (10 mg/kg), desipramine (10 mg/kg) and zimeldine (10 mg/kg). 3-Methoxytyramine was decreased by apomorphine (5 mg/kg i.p.) and also by large doses of the selective D2 antagonist, BRL 34778 (5 mg/kg i.p.) or L-DOPA (50 mg/kg i.p.). The selective D1 antagonist, SCH 23390 (0.1 or 5 mg/kg i.p.) was without effect. In tranylcypromine-pretreated rats, 3-MT was dose-dependently reduced and increased by apomorphine (0.01-5 mg/kg i.p.) and BRL 34778 (0.1-5 mg/kg i.p.), respectively. The drug SCH 23390 (0.1-5 mg/kg i.p.) produced much smaller increases in 3-MT which were probably mediated through the striatonigral pathway. Overall, the data suggest that measurement of 3-MT, after inhibition of monoamine oxidase, is a useful index of the release and utilization of dopamine. However, after substantial and prolonged depletion of dopamine, levels of 3-MT in naive animals are a better index. Also, the formation of 3-MT in naive rats rats provides a sensitive method for distinguishing between dopamine releasing agents and reuptake inhibitors.

The contribution of metabolites to the rapid and potent down-regulation of rat cortical beta-adrenoceptors by the putative antidepressant sibutramine hydrochloride.

Sibutramine HCl is an inhibitor of the reuptake of monoamines with a pharmacological profile in rodents indicative of antidepressant activity. The secondary (BTS 54 354) and primary (BTS 54 505) amine metabolites of the tertiary amine sibutramine HCl exhibit similar in vivo pharmacological activity to the parent compound. Thus, each compound displays potent activity in acute behavioural models predictive of antidepressant effects and a comparable ability to inhibit the uptake of monoamines in vivo. In addition, BTS 54 354 and BTS 54 505 induce an equally rapid and potent down-regulation of cortical beta-adrenoceptors in the rat as sibutramine HCl. The secondary and primary amines are, however, considerably more active than sibutramine HCl as inhibitors of the uptake of noradrenaline, dopamine and 5-hydroxytryptamine in vitro. The potent inhibition of the reuptake of noradrenaline by the secondary and primary amine metabolites probably contributes to the rapid and potent down-regulation of beta-adrenoceptors in the rat, induced by the putative antidepressant sibutramine HCl.

[3H]paroxetine binding in rat frontal cortex strongly correlates with [3H]5-HT uptake: effect of administration of various antidepressant treatments.

Paroxetine is a selective and potent inhibitor of 5-hydroxytryptamine (5-HT) uptake into serotonergic neurones. [3H]Paroxetine binding to rat frontal cortex was of high affinity with a high percentage of specific binding. The binding data of both competition and saturation studies fitted a single site binding model. [3H]Paroxetine binding was potently inhibited by the selective 5-HT uptake inhibitors. In addition, a very good correlation was demonstrated between the ability of twenty-three compounds to inhibit [3H]paroxetine binding to rat frontal cortical membranes and [3H]5-HT uptake into rat frontal cortical synaptosomes. These data support the view that [3H]paroxetine binds to a single site which corresponds to the 5-HT uptake site. Using this ligand, the effects of repeated administration of antidepressant drugs with a wide range of pharmacological actions and electroconvulsive shock on 5-HT reuptake sites were examined. [3H]Paroxetine binding parameters (Kd and Bmax) were unaltered by all treatments. It would, therefore, appear that antidepressant therapy does not produce adaptive changes in 5-HT uptake sites.

Biochemical and in vivo voltammetric evidence for differences in striatal dopamine levels in inbred strains of mice.

High performance liquid chromatography with electrochemical detection and differential pulse voltammetry were used to provide a direct measurement of tissue content of dopamine and its metabolites and extracellular dopamine levels, respectively, in the striata of BALB/c and CBA inbred strains of mice. We found that levels of striatal dopamine and its metabolite, dihydroxyphenylacetic acid, were significantly higher in the CBA strain than in the BALB/c strain, whereas levels of homovanillic acid were not significantly different between the strains. Levels of the dopamine metabolite 3-methoxytyramine, on the other hand, were higher in the BALB/c mice. Dopamine turnover rates were significantly higher in the CBA strain when the homovanillic acid/dopamine ratio was used as an index of dopamine activity. Voltammetric recording showed that the local infusion of K+ in pargyline-treated mice resulted in the immediate appearance of a peak at +85 mV, which has been shown to correspond to extracellular dopamine in the rat. The mean height of this peak detected in vivo following K+ stimulation corresponds to in vitro dopamine concentrations of 25 +/- 8 microM for BALB/c mice and 7 +/- 2 microM for CBA mice. K(+)-stimulated dopamine release in the BALB/c mice could be evoked every 10-15 min with similar magnitude. In contrast, very little dopamine release in CBA mice could be evoked after the first stimulation. Since striatal dopamine levels are higher in CBA mice, these data suggest that (a) BALB/c strain may have more dopamine in the readily releasable pool, whereas the CBA mice have a larger storage pool of dopamine, and/or (b) that dopamine uptake in the CBA mice is much more avid than in BALB/c.

Local anaesthetic and antiarrhythmic properties of an aminosteroid: 3alpha-dimethyl-amino-5alpha-androstan-2beta-ol-17-one (Org. NA 13).

1. The aminosteroid Org. NA13 (3alpha-dimethylamino-5alpha-androstan-2beta-ol-17-one) was shown to be a more potent local anaesthetic than lignocaine in rats and guinea-pigs. 2. Experimental arrhythmias induced in mice by chloroform, in rats by aconitine and in dogs by coronary artery ligation were corrected by Org. NA13 at doses from 10 to 50 mg/kg intravenously. 3. In contrast to lignocaine, other local anaesthetics and beta-adrenoceptor blocking drugs, Org. NA 13 did not show any activity against the arrhythmias induced by ouabian in dogs. 4. The acute toxicity in whole animals and myocardial toxicity in the rabbit isolated atrium appeared to be less than that observed with lignocaine.

Determination of the role of noradrenergic and 5-hydroxytryptaminergic neurones in postsynaptic alpha 2-adrenoceptor desensitization by desipramine and ECS.

1. Experiments were conducted to determine the respective roles which noradrenergic and 5-hydroxytryptaminergic neurones play in the down-regulation of postsynaptic alpha 2-adrenoceptors by desipramine and electroconvulsive shock (ECS). The functional status of these receptors was monitored by use of clonidine-induced mydriasis in conscious mice. 2. Mydriasis to clonidine (0.1 mg kg-1, i.p.) was markedly attenuated by administration of either desipramine (10 mg kg-1, i.p.) for 14 days or ECS (200 V, 2s) given five times over ten days confirming our previous observations. 3. The neurotoxin, DSP-4 (100 mg kg-1, i.p. X 2), reduced brain noradrenaline levels by 64% and abolished the mydriasis induced by the noradrenaline releasing agent and reuptake inhibitor, methamphetamine, without significantly altering the response to clonidine, confirming our earlier results. This lesion prevented the attenuation of clonidine mydriasis by repeated administration of desipramine, but not ECS. 4. Lesioning of central 5-hydroxytryptaminergic neurones with 5,7-dihydroxytryptamine (75 micrograms, i.c.v.) had no influence on the reduction in clonidine mydriasis produced by repeated administration of either desipramine or ECS. 5. Since noradrenergic neurones are essential for the desensitization of postsynaptic alpha 2-adrenoceptors by desipramine, it indicates that this effect is probably the result of increased synaptic noradrenaline levels. This mechanism is not responsible for the change induced by ECS because this adaptation is independent of an intact noradrenergic input. 5-HT-containing neurones do not play a permissive role in the down-regulation of postsynaptic alpha 2-adrenoceptors by either antidepressant treatment.

Measurement of 3-methoxy-4-hydroxyphenylglycol (MHPG) in mouse brain by h.p.l.c. with electrochemical detection, as an index of noradrenaline utilisation and presynaptic alpha 2-adrenoceptor function.

1. A novel method for measurement of 3-methoxy-4-hydroxyphenylglycol (MHPG) in mouse brain by use of high performance liquid chromatography (h.p.l.c.) with electrochemical detection is described. This technique incorporates an ethyl acetate purification procedure and uses 3-hydroxy-4-methoxyphenylglycol (iso-MHPG) as the internal standard. 2. Inhibition of monoamine oxidase by injection of tranylcypromine (5 and 10 mg kg-1) or pargyline (50 and 100 mg kg-1) markedly decreased brain MHPG concentrations. After injection of the tyrosine hydroxylase inhibitor, alpha-methyl-p-tyrosine (200 mg kg-1), there were time-dependent linear decreases in the concentrations of noradrenaline and MHPG in mouse brain. In addition, a very good correlation (r = 0.95, n = 30; P less than 0.001) was found between the concentrations of noradrenaline and MHPG present in the brains of the same mice after alpha-methyl-p-tyrosine treatment. 3. Mouse brain MHPG concentrations were dose-dependently reduced after administration of the alpha 2-adrenoceptor agonist, clonidine (1-3000 micrograms kg-1), and elevated by the antagonists, idazoxan (1 and 5 mg kg-1), and yohimbine (1 and 5 mg kg-1). Intracerebroventricular injection of the alpha 1-adrenoceptor agonist, phenylephrine (5-50 micrograms) dose-dependently increased MHPG levels. The alpha 1-adrenoceptor antagonist, prazosin, had no effect at the moderate dose of 1 mg kg-1, but increased MHPG concentrations at 5 mg kg-1. The beta-adrenoceptor agonist, clenbuterol (10-1000 micrograms kg-1) and the antagonist, pindolol (1 and 5 mg kg-1), were both without effect. 4. The decrease in brain MHPG concentrations induced by clonidine (100 micrograms kg-1) was prevented by prior injection of 1 mg kg-1 of idazoxan or yohimbine, but not by prazosin or pindolol. 5. MHPG levels were decreased after administration of the noradrenaline reuptake inhibitor desipramine (5 and 10 mg kg-1) and the non-selective monoamine reuptake inhibitors, sibutramine HCl (BTS 54 524; 1 and 3 mg kg-1) and amitryptyline (5 mg kg-1). However, the selective 5-hydroxytryptamine reuptake inhibitor, zimeldine (5 and 10 mg kg-1), was without effect. Dexamphetamine (1 and 5 mg kg-1) and methamphetamine (1 and 5 mg kg-1) both decreased brain MHPG concentrations in a dose-related fashion. 6. Overall the data show that MHPG can be used as a functional index of both presynaptic alpha 2-adrenoceptor activity and noradrenaline turnover and utilisation.

Sex-related differences in central adrenergic function and responsiveness to repeated administration of desipramine or electroconvulsive shock.

1. Clonidine induces hypoactivity in rodents. Male rats were found to be markedly more susceptible to the sedative effects of this alpha 2-adrenoceptor agonist than females. Thus to obtain identical hypoactivity responses for subsequent experiments, clonidine was administered to male and female rats at doses of 0.2 and 0.5 mg kg-1, respectively. 2. The clonidine-induced hypoactivity response of female rats was not affected by the oestrous cycle. 3. Repeated injection of desipramine (DMI; 5 mg kg-1 b.d.) for up to 14 days progressively attenuated clonidine-induced hypoactivity in both male and female rats. However, in males the attenuation was more rapid in onset and a greater overall reduction was obtained. This alpha 2-adrenoceptor-mediated response was also progressively reversed by repeated daily administration of an electroconvulsive shock (ECS; 110 V, 1 s). In this case, although the maximum decrease was greater in males, the time of onset was identical in both sexes. 4. There were no sex-related differences in either the number or affinity of alpha 2- and beta-adrenoceptors in rat cortex. Cortical alpha 2-adrenoceptors were decreased by 14 days of DMI injection or 10 days of ECS treatment (ECS x 10) and these effects were identical in both sexes. These receptors were not altered by 2 days administration of DMI or ECS. Cortical beta-adrenoceptors were reduced in male and female rats by 2 and 14 days of DMI injection and by ECS x 10, but not ECS x 2. 5. Viewed overall, the data show differences in alpha 2-adrenoceptor function between the sexes, as determined by clonidine-induced hypoactivity and the responsiveness of this paradigm to repeated administration of DMI and ECS. In contrast, no differences were observed in complementary alpha 2- and beta-adrenoceptor binding experiments using rat cortical tissue.

A comparison of the effects on central 5-HT function of sibutramine hydrochloride and other weight-modifying agents.

1. Effects on 5-HT function of sibutramine and its active metabolites, BTS 54 354 and BTS 54 505, were compared with fluoxetine, (+)-fenfluramine and (+)-amphetamine. 2. In vitro sibutramine weakly inhibited [3H]-5-HT uptake into brain synaptosomes. BTS 54 354, BTS 54 505 and fluoxetine were powerful [3H]-5-HT uptake inhibitors, whereas (+)-fenfluramine and (+)-amphetamine were very much weaker. Conversely, whilst sibutramine, its metabolites and fluoxetine did not release [3H]-5-HT from brain slices at < or = 10(-5)M, (+)-fenfluramine and (+)-amphetamine concentration-dependently increased [3H]-5-HT release. 3. Sibutramine and fluoxetine had no effect on 5-hydroxytryptophan (5-HTP) accumulation in either frontal cortex or hypothalamus at doses < 10 mg kg(-1). In contrast, (+)-amphetamine ( > or = 3 mg kg(-1)) reduced 5-HTP in hypothalamus, whilst (+)-fenfluramine (> or =1 mg kg(-1)) decreased 5-HTP in both regions. 4. Sibutramine (10 mg kg(-1) i.p.) and fluoxetine (10 mg kg(-1) i.p.) produced slow, prolonged increases of extracellular 5-HT in the anterior hypothalamus. In contrast, (+)-fenfluramine (3 mg kg(-1) i.p.) and (+)-amphetamine (4 mg kg(-1) i.p.) induced rapid, short-lasting increases in extracellular 5-HT. 5. Only (+)-fenfluramine (10 mg kg(-1)) altered 5-HT2A receptors in rat frontal cortex when given for 14 days, producing a 61% reduction in receptor number and a 18% decrease in radioligand affinity. 6. These results show that sibutramine powerfully enhances central 5-HT function via its secondary and primary amine metabolites; this effect, like that of fluoxetine, is almost certainly mediated through 5-HT uptake inhibition. By contrast, (+)-fenfluramine enhances 5-HT function predominantly by increasing 5-HT release. (+)-Amphetamine, though weaker than (+)-fenfluramine, also enhances 5-HT function by release.

Evaluation of BTS 67 582, a novel antidiabetic agent, in normal and diabetic rats.

1. The effect of BTS 67 582, a novel antidiabetic agent, has been evaluated on plasma glucose and plasma insulin in normal and streptozotocin-induced diabetic rats. 2. BTS 67 582 (3 to 300 mg kg-1, p.o.) caused a dose- and time-dependent reduction in plasma glucose and an increase in plasma insulin in both fasted and glucose-loaded normal rats. The ED50 for the glucose lowering effect of BTS 67 582 in fasted rats was 37.6, 18.4 and 18.5 mg kg-1 at 1, 2 and 4 h after administration respectively. 3. In streptozotocin-induced (50 mg kg-1, i.v.) diabetic rats, BTS 67 582 (37-147 mg kg-1, p.o.) caused significant reductions of plasma glucose following a glucose load, whereas glibenclamide (100 mg kg-1, p.o.) was ineffective. BTS 67 582 significantly increased plasma insulin compared to controls whereas glibenclamide did not. 4. BTS 67 582 did not displace [3H]-glibenclamide from its binding sites in rat brain, guinea-pig ventricle or the HIT-T15 insulinoma beta-cell line. BTS 67 582 does not therefore appear to modulate its action via an effect on the 'sulphonylurea' receptor. 5. In fasted rats, the glucose lowering effect of BTS 67 582 (100 mg kg-1 p.o.) and glibenclamide (1 mg kg-1, p.o.) were antagonized by diazoxide (30 mg kg-1, i.p.). In addition BTS 67 582, like glibenclamide, caused a dose-dependent rightward shift of cromakalim-induced relaxation of noradrenaline precontracted rat aortic strips, suggesting the involvement of KATP channels. 6. In summary, BTS 67 582 produces a blood glucose-lowering effect in normal and streptozotocin-induced diabetic rats associated with increased insulin concentrations. This effect appears to be due to a blockade of ATP-sensitive potassium channel activity via a different binding site to that of glibenclamide.