Search results for "Agoni"

Antagonist mechanical contribution to resultant maximal torque at the ankle joint in young and older men.

2007

Abstract A recorded muscular torque at one joint is a resultant torque corresponding to the participation of both agonist and antagonist muscles. This study aimed to examine the effect of aging on the mechanical contributions of both plantar- and dorsi-flexors to the resultant maximal voluntary contraction (MVC) torques exerted at the ankle joint, in dorsi-flexion (DF) and plantar-flexion (PF). The estimation of isometric agonist and antagonist torques by means of an EMG biofeedback technique was made with nine young (mean age 24 years) and nine older (mean age 80 years) men. While there was a non-significant age-related decline in the measured resultant DF MVC torque (−15%; p =0.06), there…

Electrophysiological evidence for an inverse benzodiazepine receptor agonist in panic disorder.

1999

Abstract Inverse agonists of the GABA A receptor clearly decrease the amplitudes of the spontaneous EEG in the P-frequency range. Therefore, we tested the hypothesis that panic patients exhibit a reduction of the EEGs spectral power in the P-frequency band. Ten unmedicated patients with panic disorder and agoraphobia according to DSM-III-R criteria and 10 matched controls were investigated under baseline conditions, after hyperventilation and 30 min after hyperventilation. EEG recordings from the position P z and C z were performed under eyes closed conditions. At baseline conditions the patients suffering from panic disorder depicted a reduced P-power reaching statistically significance fo…

GnRH agonist versus recombinant HCG in an oocyte donation programme: a randomized, prospective, controlled, assessor-blind study.

2009

The use of gonadotrophin-releasing hormone (GnRH) agonists for triggering ovulation remains controversial. The primary objective of this study was to evaluate the incidence of ovarian hyperstimulation syndrome (OHSS) following GnRH agonist versus recombinant human chorionic gonadotrophin (HCG) as methods for triggering ovulation. A second aim was to compare the clinical outcome and embryo quality according to the two procedures. The cycle characteristics of 100 oocyte donors undergoing ovarian stimulation and IVF outcomes of their 100 oocyte recipients were analysed. Donors were prospectively randomized into two groups on the last day of ovarian stimulation: Group I received a single bolus …

Concomitant gonadotropin-releasing hormone agonist and menotropin treatment for the synchronized induction of multiple follicles.

1988

In an effort to overcome possible interference by endogenous gonadotropin-ovarian hormone dynamics, desensitization of the pituitary gonadotropins by a gonadotropin-releasing hormone agonist (GnRHa) was achieved in 12 women with repeatedly failed attempts at multiple follicular stimulation. Eight women were scheduled for in vitro fertilization (IVF) and embryo transfer (ET), and 4 for gamete intrafallopian transfer (GIFT). Stimulation failure was characterized by premature luteinization, poor estradiol (E2) response, or inadequate follicular growth. The agonist was administered by nasal spray 500 to 600 micrograms/day beginning on days 21 to 23 of the menstrual cycle. A rapid desensitizatio…

Similar endometrial development in oocyte donors treated with either high- or standard-dose GnRH antagonist compared to treatment with a GnRH agonist…

2005

Background This descriptive study evaluates the impact on endometrial development of standard and high doses of a GnRH antagonist in stimulated cycles compared with GnRH agonist and natural cycles. Methods Thirty-one oocyte donors were treated with a combination of rFSH and 0.25 mg/day ganirelix (standard dose), 2 mg/day ganirelix (high dose) or 0.6 mg/day buserelin (long protocol). Vaginal progesterone (200 mg/day) was administered in the luteal phase. Endometrial biopsies were performed 2 and 7 days after HCG administration. Additional biopsies were carried out in a subset of 12 subjects, 2 and 7 days following the LH peak of their previous natural cycle. Biopsies were evaluated histologi…

Chapter 9 Nicotinic acetylcholine receptors on hippocampal neurons: cell compartment-specific expression and modulatory control of channel activity

1996

Publisher Summary The neuronal nicotinic acetylcholine receptors (nAChRs) are differentially expressed on the somato-dendritic surface of hippocampal neurons. This chapter demonstrates that various ions and drugs play a crucial role in modulating the activity of neuronal nAChRs. Considering the diversity of the neurotransmitter receptors and their binding sites and the diversity of substances, which can act simultaneously as a primary agonist of one receptor and an allosteric modulator of a different receptor, an enormous variety of combinatorial possibilities can be achieved in the brain giving rise to very complex neuronal networks. The characterization of the diversity of many receptors …

0149: Agonistic anti β3-adrenoceptor antibodies do not affect the β1-adrenoceptor-mediated inotropy and the β3 adrenoceptor-mediated vasorelaxation i…

2014

Cardiac activity of autoantibodies (AABs) directed against β1-adrenoceptor (β1-AR) has been proposed to play an important role in the pathogenesis of dilated cardiomyopathy. Our previous work has shown that the immunization of rats with the second extracellular loop (ECII) of β1-AR induced endothelial dysfunction in aorta and mesenteric arteries. However, until now, no study has explored the cardiovascular effects of β3-AABs alone or combined with β1-AABs.AimTo evaluate whether β3-AABs possess β3-AR agonistic effect and whether active immunization producing β3-AABs and/or β1-AABs has deleterious effects on cardiac and vascular reactivity in Lewis rats.MethodsLewis rats were immunized for 3 …

The rxr agonist bexarotene in combination with rosuvastatin inhibits angiotensin-ii induced abdominal aortic aneurysm formation in apoliprotein -e-kn…

2014

Oxytocin receptors: ligand binding, signalling and cholesterol dependence

2008

The G protein coupled oxytocin receptor (OTR) reveals some specific molecular and physiological characteristics. Ligand-receptor interaction has been analysed by photoaffinity labelling, site-directed mutagenesis, the construction of receptor chimeras and molecular modelling. Major results of these studies will be summarized. The N-terminus of the OTR is mainly involved in agonist binding. Notably, antagonists that are derived from the ground structure of oxytocin, bind the receptor at distinct sites partly non-overlapping with the agonist binding site. OTRs are able to couple to different G proteins, with a subsequent stimulation of phospholipase C-beta isoforms. In dependence on G protein…

Prostacyclin receptor desensitization is a reversible phenomenon in human platelets.

1997

Background Long-term exposure of platelets to endogenous or exogenous prostacyclin or its analogues might result in desensitization of the platelet prostacyclin receptor in vitro and in vivo accompanied by a loss in receptor density on the platelet surface and a reduced sensitivity toward the inhibitory effects of prostacyclins. However, the reversibility of this process in platelets has not yet been investigated. Methods and Results Human platelets desensitized by the chemically stable prostacyclin analogue iloprost showed a significant reduction in [ 3 H]-iloprost binding sites that was reversed by saponin permeabilization. This indicates functionally active internalized prostacyclin rec…