Biomedical subjects

K Larsson

Publications and source records attributed to K Larsson.

At least 55 records · Page 3Linked to original sources

PubMed2001

Comparison of airway conductance and FEV(1) as measures of airway responsiveness to methacholine. Discrimination of small differences in bronchial responsiveness with Gaw and FEV(1).

When defining bronchial responsiveness in healthy, non-asthmatic, subjects exposed in different working situations, it is not clear whether different outcome measures yield similar results. Therefore, the concentration and dose of methacholine that caused a 20% decrease in forced expiratory volume in 1 s (FEV(1)) (PC20(FEV(1)) and PD20(FEV(1))), the corresponding change in Gaw and the relationship between the dose-response slope (DRS) for FEV(1) and Gaw was studied in different working populations and healthy control subjects (n=1038). The two outcome measures were compared in groups of subjects in whom differences in bronchial responsiveness could be anticipated [atopics (n=72) and non-atopics (n= 207) and subjects exposed (n=54) and not exposed (n=32) to saw dust]. A bronchial challenge was also made before and after exposure in a swine confinement building, an exposure known to increase bronchial responsiveness (n=37). PD20(FEV(1)) was 1.7 mg in atopics and 4.9 mg in non-atopics, 7.1 mg in saw dust exposed and >20 mg in non-exposed subjects and 5.3 mg before and 0.79 mg after exposure to organic dust. There was a correlation between DRS(FEV(1)) and DRS(Gaw), r=0.87 (P<0.001). In subjects who were highly sensitive to methacholine a 20% change in FEV(1) corresponded to <40% change in Gaw, while a 20% decrease in FEV1 corresponded to none or a minor decrease in Gaw in subjects with less methacholine-sensitive airways. The ability to detect differences in bronchial responsiveness between groups, or to detect changes in bronchial responsiveness following exposure was approximately the same for FEV(1) and Gaw. The reproducibility was similar for both variables and a second measurement was within one doubling of the methacholine concentration of the first provocation in approximately 95% of all measurements (n=41). In conclusion, with our methacholine provocation method, FEV(1) and Gaw had similar sensitivity in detecting small differences in bronchial responsiveness in healthy subjects.

Adolescent↗

PubMed2001

Quality of life in primary care asthma.

In primary care, asthma is usually assessed by means of the patients' history regarding symptoms and simple lung-function testing. These outcomes may, however, not be related to other estimates of asthma control such as quality of life. In the present study quality of life was studied in relation to symptoms (visual analogue scale, VAS) and lung function in adult patients with asthma in a primary-care setting. In a healthcare centre in Stockholm, 405 individuals diagnosed as having asthma were identified. Out of this number, 120 patients completed the study. Patients were categorized into four groups according to lung function and their response to a question regarding asthma symptoms on the VAS. Quality of life was evaluated with the Asthma Quality of Life Questionnaire (AQLQ) and current treatment was recorded. Quality of life differed significantly between the groups with regard to all domains and overall score; overall score was 6.0 (0.12)--(mean SEM) in group A (VAS < or = 2, normal FEV1), 5.4 (0.24) in group B (VAS < or = 2, low FEV1), 4.8 (0.25) in group C (VAS > 2, normal FEV1) and 4.6 (0.24) in group D (VAS > 2, low FEV1) (P < 0.0001). In general a gradient, with group A having the highest and group D the lowest score, was detected. Experience of symptoms (VAS > 2) was highly related to lower scores in the environmental domain (P < 0.0001). The correlation between FEV1 and quality of life was generally low whereas there was a fairly good correlation between VAS and quality of life (P < 0.0001 for all domains). Patients without steroid treatment had higher quality of life scores than patients treated with steroids. The majority of asthma patients in primary care have high quality of life scores, indicating a low prevalence of symptoms and only slight activity limitations. Evaluation of quality of life enables a more careful grading of asthma status. Furthermore, this measure provides information concerning asthma control that is not revealed by spirometry and simple questions regarding symptoms.

Administration, Topical↗

PubMed2001

Incidence of physician-diagnosed asthma in adults--a real incidence or a result of increased awareness? Report from The Obstructive Lung Disease in Northern Sweden Studies.

Only limited data are available about the incidence of asthma based on longitudinal prospective studies. Further, the results from different studies on incidence vary considerably depending on the age composition of the cohorts under study, the used methods and the criteria for disease. Also among adults high incidence rates have been reported during recent years. The aim of this study was to examine to what extent the incidence of physician-diagnosed asthma could be explained by a real incidence of the disease, and to what extend by an increased diagnostic activity or altered diagnostic praxis. Another aim was to study risk factors for asthma based on incident cases. Three cross-sectional surveys have been performed in the same population sample living in the northern-most province of Sweden, Norrbotten. The first survey was performed in 1986, and 5698 subjects, 86% of those invited, responded to a postal questionnaire. Of these, 4754 subjects (83%) participated at the third survey in 1996. After exclusion of all subjects who had reported that they had asthma in 1986, or had been classified as having asthma in 1986, 68 men and 98 women (P=0.02) reported in 1996 that they had been diagnosed as having asthma by a physician. Thus, the cumulative incidence for the 10-year period was 3.2% among men and 4.5% among women. After correction for subjects who already in 1986 had reported symptoms common in asthma, or had been classified as having chronic bronchitis, 97 subjects with incident asthma remained, which corresponded to an annual incidence rate among men of 1.7 and among women of 2.9/1000 persons year(-1) (P=0.1). Clinical examinations confirmed asthma in a large majority of these 97 subjects. Significant risk factors were family history of asthma, both ex- and current smoking, and female sex. The socio-economic groups manual workers and assistant non-manual employees were associated with incident asthma, although not significantly. The increasing prevalence of asthma among adults during recent 10-20 years may to a considerable extent be explained by an increased diagnostic activity or altered diagnostic praxis. Use of different methods when measuring incidence may in part explain the extremely diverging incidence rates of asthma found in different studies.

Aged↗

PubMed2001

Prevention of adhesions by surfactants and cellulose derivatives in mice.

OBJECTIVE: To evaluate the efficacy of hydrophobically modified ethyl (hydroxyethyl) cellulose (cellulose), sodium hyaluronate (hyaluronate) and phosphatidylglycerol, in the reduction of adhesion formation. DESIGN: Controlled study. SETTING: Experimental academic unit, Sweden. MATERIAL: NMRI mice. Solutions: (1) cellulose, (2) hyaluronate, (3) phosphatidylglycerol, (4) phosphatidylglycerol and cellulose, and (5) phosphatidylglycerol, cellulose and hyaluronate. INTERVENTIONS: A standard lesion was created in the parietal peritoneum in mice. One of the viscous solutions to be tested, or saline, was given intraperitoneally. MAIN OUTCOME MEASURES: Amount of adhesions found one week postoperatively. RESULTS: Cellulose; phosphatidylglycerol and cellulose; and phosphatidylglycerol, cellulose and hyaluronate all significantly reduced the amount of adhesions (p=0.0002, p=0.002, p < 0.0001), as did the hyaluronate alone (p < 0.05). Phosphatidylglycerol alone did not reduce the amount of adhesions. Combining cellulose with phosphatidylglycerol, or with hyaluronate, did not improve efficacy. CONCLUSION: Cellulose and hyaluronate were effective in reducing the formation of adhesions. Combining cellulose with hyaluronate or phosphatidylglycerol or both did not improve efficacy.

Animals↗

PubMed2001

Sex dependent differences in physiological ageing in the immune system of lower airways in healthy non-smoking volunteers: study of lymphocyte subsets in bronchoalveolar lavage fluid and blood.

BACKGROUND: Age related changes in the immune system have been studied frequently but a possible relation to sex has not, to our knowledge, previously been examined. The effect of age and sex on the composition of lymphocyte subsets in bronchoalveolar lavage (BAL) fluid and peripheral blood was therefore examined. METHODS: Bronchoscopy with lavage was performed in 32 healthy non-atopic, non-smoking volunteers (16 women aged 26-63 years (mean 44) and 16 men aged 23-63 years (mean 39)). Cytospin preparations for differential counts of BAL fluid cells and surface antigen expression of lymphocytes from BAL fluid and blood were analysed by flow cytometry. RESULTS: Most parameters in the BAL fluid changed with age in women. The percentage of CD4+ lymphocytes increased with age from a mean of 48 (SD10)% in women aged < or =40 years to 69 (11)% in women aged >43 years (p=0.001). The percentage of CD8+ lymphocytes tended to decrease with age and the CD4/CD8 ratio was 5.8 (1.2) in women aged >43 years compared with 2.1 (0.7) in those aged < or =40 years (p<0.0001). Women aged >43 years differed from men aged >43 years as well as from younger subjects of both sexes with respect to CD4+ cells and CD4/CD8 ratio, and from younger women with respect to CD8+ cells. There was no age related change in the CD4/CD8 ratio in blood. No sex related differences were seen in the blood or BAL fluid of adults below the age of 40 years. CONCLUSIONS: The composition of lymphocytes with different phenotypes in the lower respiratory tract changes with age in women but not in men. This may have implications for some clinical conditions such as chronic dry cough which are observed predominantly in women.

Adult↗

PubMed2001

Worsening of asthma in children allergic to cats, after indirect exposure to cat at school.

Exposure to cat allergen at school might exacerbate symptoms in asthmatic children with cat allergy. To study this, we identified 410 children, 6-12 yr of age, who were being treated for asthma (inhaled steroids and beta-agonists), were allergic to cats, and had no cat at home. Peak expiratory flow (PEF), asthma symptoms, medication, fever and/or sore throat, and contact with furred pets were recorded twice daily during the last week of summer holidays and the second and third weeks of school. The number of cat owners in each class was recorded. Ninety-two children with asthma reported no contact with furred pets. Among these, children who attended classes with > 18% (median value) cat owners reported significantly decreased PEF, more days with asthma symptoms, and increased use of medication after school started. Those in classes with < or = 18% cat owners reported no change. Children in classes with many cat owners ran a 9-fold increased risk of exacerbated asthma after school start compared with children in classes with few cat owners, after adjusting for age, sex, and fever and/or sore throat. Thus, asthma symptoms, PEF, and the use of asthma medication in children with cat allergy may be affected by indirect cat exposure at school.

Adolescent↗

PubMed2001

Hyperhomocysteinemia and changed plasma thiol redox status in chronic obstructive pulmonary disease.

Reduced and total homocysteine, cysteine, glutathione and cysteinylglycine in plasma were investigated in 19 patients with chronic obstructive pulmonary disease and in 29 healthy subjects. The purpose was to examine the influence of pro-oxidant activity caused by the lung disease on the metabolism of homocysteine and other plasma thiols. We observed a decreased concentration of reduced glutathione and a decreased ratio of reduced/total glutathione in the patients compared to the healthy individuals, which supports the hypothesis of an association between free radicals and pathogenesis in some lung diseases. We also observed an increased total plasma homocysteine. The influence of a possible extracellular pro-oxidant activity on the concentration of total plasma homocysteine is discussed.

Aged↗

PubMed2001

beta2-Adrenoceptor desensitization in human alveolar macrophages induced by inhaled terbutaline in vivo is not counteracted by budesonide.

In vitro studies suggest that glucocorticoids may counteract beta-agonist-induced desensitization of beta-adrenoceptors by actions at the transcriptional level, but the clinical relevance of such findings is not clear. Oral terbutaline treatment decreases beta-adrenoceptor sensitivity in alveolar macrophages in vivo. This effect is not counteracted by inhaled or orally taken steroids. We therefore examined whether inhaled terbutaline elicited a similar effect on beta(2)-adrenoceptor sensitivity in alveolar macrophages, and if co-treatment with an inhaled steroid, budesonide, would prevent such down-regulation. Bronchoalveolar lavage (BAL) and lung function tests, including bronchodilator responses to inhaled terbutaline, were performed before and after 2 weeks of regular inhalation of terbutaline, 0.5 mg three times daily, and budesonide, 400 microg twice daily, or placebo, in 24 healthy volunteers. Four untreated subjects served as controls. A marked, approx. 90%, decrease in isoprenaline-induced cAMP accumulation in alveolar macrophages was found in both treatment groups after 2 weeks, with no difference between placebo and budesonide (P = 0.45). In the untreated control group, cAMP responses to both isoprenaline and prostaglandin E(1) tended to be lower on the second occasion. A limited, non-specific desensitization of adenylate cyclase activity thus contributed to the marked desensitization elicited by terbutaline inhalations. The bronchodilator response to inhaled terbutaline did not change after treatment in any of the three groups (F = 0.9, P = 0.50). In conclusion, inhalation of a beta-agonist induced marked down-regulation of beta(2)-adrenoceptor sensitivity in alveolar macrophages in vivo without influencing the bronchodilator response to a beta(2)-agonist in healthy subjects. Co-treatment with an inhaled steroid failed to counteract the desensitization of alveolar macrophage beta(2)-adrenoceptors.

Administration, Topical↗

PubMed2000

SGD1 encodes an essential nuclear protein of Saccharomyces cerevisiae that affects expression of the GPD1 gene for glycerol 3-phosphate dehydrogenase.

We here report the identification of the previously uncharacterized SGD1 gene, encoding a 102.8-kDa protein containing a leucine zipper region and a bipartite nuclear localization signal. Deletion of SGD1 results in loss of cell viability, while an increased dosage of SGD1 partially suppresses the osmosensitivity of pbs2 delta and hog1 delta mutants that are defective in the osmosignaling high osmolarity glycerol (HOG) mitogen-activated protein kinase pathway. The rescued mutants display a partially re-established transcriptional control of the osmostress-induced expression of GPD1, a target gene of the HOG pathway encoding NAD(+)-dependent glycerol 3-phosphate dehydrogenase, and a partially recovered hyperosmolarity-induced production of glycerol. Consistent with Sgd1p affecting the transcriptional control of GPD1, a functional green fluorescent protein tagged Sgd1p is localized to the cell nucleus.

Cell Division↗

PubMed2000

Design and dosimetry characteristics of a soft-docking system for intraoperative radiation therapy.

PURPOSE: The design concept and the dosimetric characteristics of an applicator system for intraoperative radiation therapy (IORT) with special emphasis on alignment methods, the effect of a plastic scatterer in the beam, radiation leakage, and misalignment dosimetry, are presented in this paper. MATERIALS AND METHODS: A soft-docking system for a linear accelerator, which enables collimation of electron beams (4-22 MeV) for IORT has been developed. The system includes twenty-one circular polymethylmethacrylate (PMMA) treatment cones of different lengths, diameters and end angles. All in-water measurements are made using p-type silicon diode detectors. RESULTS: The effect of introducing a PMMA scatterer in the therapeutic beam includes increased surface dose values (above 83% for all nominal electron energies and for all cones) and improved dose homogeneity within the therapeutic range. Electrons scattered from the inside wall of the cone result in dose profile horns at depth of dose maximum always lower than 109%. The radiation leakage outside the cone is less than 13%. Large changes in the dose profiles occur if the intraoperative cone is misaligned more than 0.5. CONCLUSION: The alignment procedure of the soft-docking system is easy to handle and the applicator design provides adequate collimation of electron beams for IORT.

Combined Modality Therapy↗

PubMed2000

Nucleus pulposus inhibits the axonal outgrowth of cultured dorsal root ganglion cells.

Although it is well established that nucleus pulposus cells may induce structural and functional changes in adjacent nerve roots when placed epidurally, it is not known whether this is due to direct neurotoxic effects or whether the nerve roots are affected indirectly by reduction of nutrition and inflammatory/immunologic mechanisms. In the present study we assessed the effects of various tissues on cultured dorsal root ganglions from newborn rats. Nucleus pulposus was found to have a toxic effect on the axons by blocking axonal outgrowth, but no similar effects on the nerve cell bodies (extra-ganglionic nerve cell density, nerve cell arborisation) were found as compared to the series with only culture medium. Sterile water for 1 or 24 h (positive controls) induced significant effects by all four criteria, whereas medium without nerve growth factor, fat and frozen nucleus pulposus had no statistically significant effects. The study thus showed that there are direct axonotoxic effects induced by the nucleus pulposus, and since frozen nucleus pulposus did not have any effects, it may be assumed that the mechanisms are related to substances produced by the nucleus pulposus cells. The presented model allows for future studies on the neurotoxic properties of nucleus pulposus cell-derived candidate substances.

Animals↗

PubMed2000

Influence of fluticasone and salmeterol on airway effects of inhaled organic dust;an in vivo and ex vivo study.

Inhalation of dust from swine confinement buildings induces airway inflammation with an increase in both inflammatory cell numbers and secretion of proinflammatory cytokines in the lungs. It is not known whether anti-asthma drugs, which influence airway inflammation in asthma, also influence the airway reaction to inhaled organic dust. In the present study we examined the effects of a ss2-agonist (salmeterol) and an inhaled steroid (fluticasone) on the swine dust-induced cell and cytokine content of the lower airways, and cytokine release in cultured alveolar macrophages. Healthy volunteers were pretreated with inhaled salmeterol (n = 8), fluticasone propionate (n = 8) or placebo (n = 8) for about 2 weeks and exposed to dust in a pig house. Bronchoalveolar lavage was performed both before medication and after dust exposure. Cell differential counts and cytokine analyses in bronchoalveolar lavage fluid (BALF) were examined. Alveolar macrophages were cultured and cytokine release was studied, both in unstimulated cells and after lipopolysaccharide (LPS) stimulation. Unstimulated alveolar macrophages from swine dust-exposed individuals released less IL-6, IL-8 and tumour necrosis factor-alpha (TNF-alpha) after, than before, exposure (P < 0.01). Medication did not influence basal cytokine production. Fluticasone inhibited LPS-induced IL-6 and IL-8 release (P < 0.05). There was no significant difference between the groups. There was a large and significant increase (P < 0.05) in alveolar macrophage, granulocyte, lymphocyte numbers, and IL-6 and TNF-alpha content in BALF in all three groups following dust exposure, with no significant difference between the groups. These findings suggest that drugs which are known to influence and control airway inflammation in asthma do not have major effects on airway inflammation induced by the inhalation of organic dust.

Adrenergic beta-Agonists↗

PubMed2000

The salt output of a nebulizer--a comparison between two nebulizer types.

The output of a nebulizer is generally defined as its weight loss during 1 min of nebulization. This mass output includes the weight loss due to evaporation of the solution required to moisten the dry air that is fed through the nebulizer. In order to compare results obtained from studies using different nebulizers we introduce the salt output as the amount of the solution that actually leaves the liquid phase as droplets and not by evaporation. The performance characteristics of a standard jet nebulizer (MA2) and a Sidestream jet neublizer were compared. Mass output was determined at different methacholine concentrations. Salt output was assessed by analysing the remaining salt in the nebulizers after 1 min of nebulization. Overall system performance in terms of forced expiratory volume in 1 sec (FEV1) reduction after 1 min of exposure to individually selected concentrations of methacholine were studied in 15 healthy, non-smoking subjects. Both nebulizer types showed a moderate linear increase of mass output with methacholine concentration. The efficiency coefficient, the quotient between salt output and mass output, was found to be 0.93 and 0.75 for the MA2 and Sidestream nebulizer respectively. These findings were explained by differences in airflow through, and temperature inside, the nebulizers. The salt output of the nebulizers proved to be better correlated to the FEV1-reduction following methacholine inhalation than did the mass output. The relative amount of the salt output that adhered to the acrylic walls of the Sidestream nebulizer drying tower was found to be 9%. We conclude that it is more appropriate to use salt output than mass output as a nebulizer performance descriptor. The study also shows the importance of determining nebulizer system performance under conditions as similar to true provocations as possible.

Equipment Design↗

PubMed2000

T-cell activation by organic dust in vitro.

Inhalation of swine dust causes intense airway inflammation with a multifold increase of inflammatory cells and lymphocyte activation as assessed by bronchoalveolar lavage. To further investigate the mechanism for lymphocyte activation the present in vitro study focuses on the lymphocyte response to swine dust in whole blood. Various concentrations of phytohaemagglutinin (PHA) (final concentrations: 3.16, 10.0, 3.16 and 100 microg ml(-1)) and swine dust (final concentrations: 10.0, 31.6, 100 and 316 microg ml(-1)) were added to heparinized whole blood from healthy donors. The blood samples were incubated in duplicate, using the homologous unstimulated blood as control, for 4, 24, 48 and 72 h in a water bath at 37 degrees C. The cells were stained with fluorochrome conjugated monoclonal antibodies. For analysis of T-cell activation CD3 was double-stained together with the activation markers CD69, CD25 and HLADR. Cell count percentages were analysed by flow cytometry. Soluble IL-2sRalpha in plasma was analysed using commercial sandwich ELISA technique. At baseline CD69, CD25 and HLA-DR were expressed in < 1%, approx 5% and < 1% of the T-cells respectively. We found a dose response relationship between swine dust exposure and the expression of all three T-cell activation markers which appeared at different time-points. Maximal expression of CD69 (8%, P<0.05) and CD25 (15%, P<0.001) was found after 24h of activation. HLA-DR was significantly expressed after 48h (8%) and maximally expressed after 72 h of activation (13%, P<0.05). The soluble IL-2sRalpha in plasma was maximally expressed after 24-48 h (1200 pg ml(1) and 1500 pg ml(-1), respectively. In conclusion, T-cells were activated by swine dust in vitro. Thus, our previous findings of T-cell activation following swine dust exposure, in vivo may be an effect of the dust either directly on T-cells or on other cells which in turn contribute to the T-cell activation.

Adult↗

PubMed2000

Airway reactivity and exhaled NO following swine dust exposure in healthy volunteers.

Short-time exposure to swine dust causes an intense inflammation of upper and lower airways and induces increased bronchial responsiveness to methacholine in previously non-exposed healthy volunteers. The objective to this study was to investigate the nasal inflammatory response and mucosal reactivity to swine dust exposure and whether nitric oxide metabolism is involved in the inflammatory process. Nitric oxide in expired air, nasal histamine test (NH), nasal lavage (NAL) and bronchial histamine challenges were studied before and after a 3 h exposure to swine dust in a swine confinement building in 17 non-smoking healthy subjects not previously exposed to farm dust. To detect any interference between NAL and NH, the subjects were divided into two groups: in group 1, NAL was performed after NH and in group 2, NAL preceded NH. Nasal histamine response increased significantly in group 1, but not in group 2 (P=0.012). Albumin levels in NAL were higher before as well as after dust exposure in group 1 compared to group 2 (P=0.036 and 0.015 respectively). Bronchial histamine responsiveness increased following exposure (P= 0.045). Nitric oxide in expired air decreased following bronchial histamine challenge at baseline (P=0.013) but was otherwise unaltered. Short-time exposure to swine dust increases non-specific reactivity of both nose and bronchi. Nasal lavage procedure interferes with nasal histamine test when performed with connection to each other. The inflammatory reaction may involve NO metabolism.

Adolescent↗

PubMed2000

Different response to doubling and fourfold dose increases in methacholine provocation tests in healthy subjects.

RATIONALE: In a modified methacholine provocation test that was used to study changes in airway responsiveness to occupational irritants or sensitizers in healthy subjects, two protocols were used: a long protocol (doubling methacholine concentrations between dose steps) or a short protocol (fourfold increases in concentration). This modified methacholine provocation allows measurements of the provocative dose causing 20% decrease in FEV(1) (PD(20)) in a high proportion of a normal population. METHODS: The distribution of PD(20) was investigated in healthy nonatopic men without history of allergy or asthma symptoms using the long protocol (n = 101) or the short protocol (n = 309). In addition, 30 healthy subjects underwent methacholine provocation tests using both protocols. RESULTS: PD(20) was defined in 79% of subjects with the long protocol and in 48% of subjects with the short protocol. The provocative concentration of methacholine causing a 20% decline in FEV(1) (PC(20)) and PD(20) were significantly lower using the long protocol: long-protocol PC(20) (median [25th to 75th percentile]), 19.9 mg/mL (3.9 to > 32 mg/mL) compared with short-protocol PC(20), > 32 mg/mL (8.7 to >32 mg/mL; p < 0.0001); long-protocol PD(20), 4.2 mg (1.6 to 20 mg) compared with short-protocol PD(20), > 13.7 (2.6 to > 13.7 mg; p = 0. 006). The differences in PD(20) using short and long protocols were confirmed in a randomized trial of 30 healthy subjects tested with both protocols. CONCLUSION: Using doubling concentrations, PC(20) and PD(20) could be defined in a higher proportion of healthy subjects than a protocol using fourfold dose increases. Furthermore, the doubling protocol results in a PD(20) estimate that is less than half the value obtained when using a protocol with fourfold concentrations between dose steps. The difference remains, whether the methacholine effect is regarded as cumulative or noncumulative. The explanation for the difference between the protocols is unclear.

Adult↗

PubMed2000

Stimulation of the medical preoptic area facilitates sexual behavior but does not reverse sexual satiation.

The aim of the present study was to establish whether electrical and/or drug stimulation of the medial preoptic area/anterior hypothalamus (mPOA/AH) surmounts the sexual behavior inhibition that results from copulation to exhaustion. Thus, intermittent electrical stimulation of the mPOA/AH (alone or combined with the systemic injection of yohimbine or apomorphine, at doses that were subthreshold for reversing sexual exhaustion) or intrapreoptic treatments to block GABAergic transmission were applied to sexually satiated rats. The results suggest that the mPOA/AH is not responsible for male sexual behavior inhibition or for the pharmacologically induced sexual behavior expression in satiated rats. Data are discussed in terms of the roles ascribed to the mPOA/AH, both in the control of sexual behavior expression and in the regulation of the postejaculatory interval.

Animals↗

PubMed1999

Synergistic actions of the 5-HT1A receptor antagonist WAY-100635 and citalopram on male rat ejaculatory behavior.

The selective serotonin re-uptake inhibitor citalopram (0-40 mg kg(-1), s.c., - 60 min) did not affect the male rat ejaculatory behavior, and there were no statistically significant effects of the 5-HT1A receptor antagonist N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexane carboxamide 3HCl (WAY-100635) (0.04-0.08 mg kg(-1), s.c., - 30 min). When combined, there was a marked, and statistically significant, prolongation of the ejaculation latency in comparison with saline treated controls, as well as in comparison with either drug by itself. This citalopram (10.0)/WAY-100635 (0.04)-induced effect was fully antagonized by the administration of the 5-HT1B receptor antagonist isamoltane (4.0 mg kg(-1)). There were no consistent effects on other aspects of the male rat sexual behavior, i.e., number of mounts and intromissions preceding ejaculation and the post-ejaculatory interval. Finally, the intromission latency was also markedly enhanced in animals receiving both citalopram and WAY-100635, and at the higher dose of WAY-100635 (0.08 mg kg(-1)) 7 out of 18 animals failed to initiate copulation. It is suggested that blockade of inhibitory 5-HT1A autoreceptors discloses inhibitory effects of the selective serotonin re-uptake inhibitor citalopram on male rat ejaculatory behavior mediated via stimulation of 5-HT1B receptors.

Adrenergic beta-Antagonists↗