Differential Regulation of Human Serotonin Receptor Type 3A by Chanoclavine and Ergonovine.

Irritable bowel syndrome (IBS) is a chronic disease that causes abdominal pain and an imbalance of defecation patterns due to gastrointestinal dysfunction. The cause of IBS remains unclear, but intestinal-brain axis problems and neurotransmitters have been suggested as factors. In this study, chanoclavine, which has a ring structure similar to 5-hydroxytryptamine (5-HT), showed an interaction with the 5-HT3A receptor to regulate IBS. Although its derivatives are known to be involved in neurotransmitter receptors, the molecular physiological mechanism of the interaction between chanoclavine and the 5-HT3A receptor is unknown. Electrophysiological experiments were conducted using a two-electrode voltage-clamp analysis to observe the inhibitory effects of chanoclavine on Xenopus oocytes in which the h5-HT3A receptor was expressed. The co-application of chanoclavine and 5-HT resulted in concentration-dependent, reversible, voltage-independent, and competitive inhibition. The 5-HT3A response induced by 5-HT was blocked by chanoclavine with half-maximal inhibitory response concentration (IC50) values of 107.2 µM. Docking studies suggested that chanoclavine was positioned close F130 and N138 in the 5-HT3A receptor-binding site. The double mutation of F130A and N138A significantly attenuated the interaction of chanoclavine compared to a single mutation or the wild type. These data suggest that F130 and N138 are important sites for ligand binding and activity. Chanoclavine and ergonovine have different effects. Asparagine, the 130th amino acid sequence of the 5-HT3A receptor, and phenylalanine, the 138th, are important in the role of binding chanoclavine, but ergonovine has no interaction with any amino acid sequence of the 5-HT3A receptor. The results of the electrophysiological studies and of in silico simulation showed that chanoclavine has the potential to inhibit the hypergastric stimulation of the gut by inhibiting the stimulation of signal transduction through 5-HT3A receptor stimulation. These findings suggest chanoclavine as a potential antiemetic agent for excessive gut stimulation and offer insight into the mechanisms of 5-HT3A receptor inhibition.

Diagnosis of coronary artery spasm by ergonovine provocation test of radial artery.

We investigated the sensitivity, specificity and safety of ergonovine provocation test of radial artery in the diagnosis of coronary artery spasm (CAS). The patients who came to our hospital for chest pain from January to June 2020 as well as had coronary stenosis < 50% and no radial artery stenosis, were enrolled in this study. These patients were divided into CAS group and control group after intracoronary ergonovine provocation test. All patients underwent ergonovine provocation test of radial artery, the inner diameter (D0 and D1) and the peak systolic velocities (PSV0 and PSV1) of the radial artery were measured by ultrasound before and after ergonovine provocation. The predictive value of ergonovine provocation test of radial artery for the diagnosis of CAS was analyzed using receiver operator characteristic (ROC) curve. There were 19 patients in the CAS group and 28 patients in the control group. Low density lipoprotein cholesterol and smoking rate were significantly higher in the CAS group than in the control group (all P < 0.05), but there were no significant differences in other items (P > 0.05) between the two groups. In the ergonovine provocation test of radial artery, degree of radial artery stenosis was significantly higher in the CAS group [41.50% (35.60%, 50.00%)] than in the control group [11.25% (5.15%, 23.00%)] (P = 0.000), but there were no siginificant differences in D0, PSV0 and PSV1 between the two groups (P > 0.05). The area under ROC curve of ergonovine (120 µg) provocation test of radial artery for the diagnosis of CAS was 0.912 with 95%CI: 0.792-0.975, P = 0.001, cut-off of 31%, specificity of 92.86% and sensitivity of 84.21%. The ergonovine (120 µg) provocation test of radial artery did not cause any adverse reactions. We concluded that the ergonovine provocation test of radial artery has high sensitivity, specificity and safety in the diagnosis of CAS.

Transitional changes of acetylcholine spasm provocation test procedures.

Intracoronary acetylcholine (ACh) testing has become popular in the world as a spasm provocation test as well as an ergonovine test. Intracoronary ACh test based on the Japanese Circulation Society guidelines is necessary to insert a temporary pace maker (PM). We analyzed the ACh spasm provocation test procedures retrospectively. We performed 1829 ACh spasm provocation testing during 28 years. We investigated the procedural approach sites of artery and vein. Femoral artery and vein approach, brachial artery and femoral vein approach, brachial artery and vein approach, radial artery and brachial vein approach, radial artery and femoral vein approach were performed in 292 patients (16.0%), 498 patients (27.2%), 589 patients (32.2%), 252 patients (13.8%), and 175 patients (9.6%), respectively. We could perform the ACh testing by the femoral artery and brachial artery in all patients, while the success rate of radial artery approach was 97.1%. We could also insert the temporary PM by the brachial vein in 94.8% (841/887) of the study patients, whereas we could insert the temporary PM in all femoral vein approach [100% (965/965)]. We experienced the pulmonary embolism by the femoral artery and vein approach in two patients, while we also had the arterio-venous fistula necessary for surgical repair in two patients by the brachial artery and vein approach. Although there was no difference about the procedure-related major complications among the various procedures, we had no pulmonary embolism or arterio-venous fistula by the radial artery and brachial vein approach. Considering the disinfection with povidone iodine, procedural performance or procedure-related complications by the ACh testing, we recommend that radial artery and brachial vein approach is more comfortable method of the future ACh testing not only for patients but also for operators.

Effects of maternal parity on response of human myometrium to oxytocin and ergometrine in vitro.

OBJECTIVE: The aim of this study was to compare the effects of oxytocin and ergometrine on the intrinsic contractile parameters of human uterine smooth muscle at term between primiparous and multiparous women. STUDY DESIGN: Myometrial biopsies were obtained from women undergoing planned caesarean section at term. The biopsies were dissected into eight uniform strips and mounted in tissue baths for isometric recording. The strips were challenged with increasing concentrations of oxytocin and ergometrine. Parameters of contractile activity, including mean contractile force (MCF) and maximum amplitude of contractions (MAMP) were recorded and analysed. Results were compared between primiparous (Group 1) and multiparous (Group 2) women. RESULTS: Myometrial biopsies were obtained from n = 11 donors (88 tissue strips), of which n = 5 were Group 1 and n = 6 were Group 2. In relation to oxytocin, the MAMP value observed was significantly greater in Group 2 than in Group 1 (151 ±â€¯18mN vs 67 ±â€¯14mN, P < 0.01). Regarding ergometrine, the MCF response was greater in Group 2 samples (24 ±â€¯10 mN) than that in Group 1 (18 ±â€¯2mN) (P < 0.05). CONCLUSION: Our findings highlight that women in a first pregnancy have a decreased response to both oxytocin and ergometrine in an in vitro setting when compared with women in a subsequent pregnancy, and this may have clinical implications regarding the management of postpartum haemorrhage in this cohort.

Differential incidence and morphology of provoked spasm between intracoronary acetylcholine and ergonovine testing: recommendation of supplementary use.

When cardiologists diagnose patients with coronary spastic angina, Japanese Circulation Society (JCS) guidelines recommend the intracoronary injection of acetylcholine (ACh) and ergonovine (ER) as class I. However, the pharmacological difference between ACh and ER is controversial in the clinic. We performed both ACh and ER tests in the same 528 patients during 26 years. We investigated the provoked spasm configuration, spasm site, and clinical characteristics of provoked spasm between ACh and ER, retrospectively. We defined positive spasm as ≥90% luminal narrowing. Provoked positive spasm was observed in 161 right coronary arteries (RCA) including 83 ACh just positive, 35 ER just positive, and 43 both positive. In contrast, positive spasm was documented in 172 left coronary arteries (LCA) including 94 ACh just positive, 28 ER just positive, and 50 both positive. ACh provoked spasm more distally and diffusely, while ER induced spasm more proximally and totally or focally in the RCA. In the LCA, ACh provoked spasm more proximally, whereas ER induced spasm more distally. ER testing after the negative ACh tests of RCA and LCA documented new positive spasms in 10.3% (35/340) and 7.4% (28/376), respectively. Coronary artery trees may each have a sensitive receptor on each segment. We recommend the supplementary use of ACh and ER to document coronary artery spasm in the cardiac catheterization laboratory.

[Coronary spasm a diagnostic and therapeutic challenge]. / Angor spastique : un défi diagnostique et thérapeutique.

Vasospastic angina is a clinical and physio-pathological entity, which has been documented for many years, but its diagnosis is under-estimated despite the fact that though inadequately considered and investigated. This condition is potentially serious and can sometimes trigger severe arrhythmia resulting in ventricular fibrillation and sudden death. This pathology has a higher incidence in Asia, where it is, therefore, better documented with provocative testing being carried out more frequently, while in France, these tests are not sufficiently performed probably due to the fact that they often produce negative findings. Provocative tests with Ergonovine injection should be performed via intra-coronary to improve its sensibility. Should this test become more sensitive and more routinely performed, this condition, which often responds well to medical treatment, could regain appropriate recognition as a coronary disease.

Development of a high-throughput fluorescence polarization assay for the discovery of EZH2-EED interaction inhibitors.

Aberrant activity of enhancer of zeste homolog 2 (EZH2) is associated with a wide range of human cancers. The interaction of EZH2 with embryonic ectoderm development (EED) is required for EZH2's catalytic activity. Inhibition of the EZH2-EED complex thus represents a novel strategy for interfering with the oncogenic potentials of EZH2 by targeting both its catalytic and non-catalytic functions. To date, there have been no reported high-throughput screening (HTS) assays for inhibitors acting at the EZH2-EED interface. In this study, we developed a fluorescence polarization (FP)-based HTS system for the discovery of EZH2-EED interaction inhibitors. The tracer peptide sequences, positions of fluorescein labeling, and a variety of physicochemical conditions were optimized. The high Z' factors (>0.9) at a variety of DMSO concentrations suggested that this system is robust and suitable for HTS. The minimal sequence requirement for the EZH2-EED interaction was determined by using this system. A pilot screening of an in-house compound library containing 1600 FDA-approved drugs identified four compounds (apomorphine hydrochloride, oxyphenbutazone, nifedipine and ergonovine maleate) as potential EZH2-EED interaction inhibitors.

A Role for Adrenergic Receptors in the Uterotonic Effects of Ergometrine in Isolated Human Term Nonlaboring Myometrium.

BACKGROUND: Ergometrine is a uterotonic agent that is recommended in the prevention and management of postpartum hemorrhage. Despite its long-standing use, the mechanism by which it acts in humans has never been elucidated fully. The objective of this study was to investigate the role of adrenoreceptors in ergometrine's mechanism of action in human myometrium. The study examined the hypothesis that α-adrenoreceptor antagonism would result in the reversal of the uterotonic effects of ergometrine. METHODS: Myometrial samples were obtained from women undergoing elective cesarean delivery. The samples were then dissected into strips and mounted in organ bath chambers. After the generation of an ergometrine concentration-response curve (10 to 10 M), strips were treated with increasing concentrations of ergometrine (10 to 10 M) alone and ergometrine (10 to 10 M) in the presence of phentolamine (10 M), prazosin (10 M), propranolol (10 M), or yohimbine (10 M). The effects of adding ergometrine and the effect of drug combinations were analyzed using linear mixed effects models with measures of amplitude (g), frequency (contractions/10 min), and motility index (g×contractions/10 min). RESULTS: A total of 157 experiments were completed on samples obtained from 33 women. There was a significant increase in the motility index (adding 0.342 g × counts/10 min/µM; 95% confidence interval [CI], 0.253-0.431, P < .001), amplitude (0.078 g/µM; 95% CI, 0.0344-0.121, P = 5e-04), and frequency (0.051 counts/10 min/µM; 95% CI, 0.038-0.063, P < .001) in the presence of ergometrine. The α-adrenergic antagonist phentolamine and the more selective α1-adrenergic antagonist prazosin inhibited the ergometrine mediated increase in motility index, amplitude, and frequency (-1.63 g × counts/10 min/µM and -16.70 g × counts/10 min/µM for motility index, respectively). CONCLUSIONS: These results provide novel evidence for a role for α-adrenergic signaling mechanisms in the action of ergometrine on human myometrial smooth muscle in the in vitro setting. Information that sheds light on the mechanism of action of ergometrine may have implications for the development of further uterotonic agents.

Effects of the KIR7.1 Blocker VU590 on Spontaneous and Agonist-Induced Contractions of Human Pregnant Myometrium.

KIR7.1, an inwardly rectifying K+ channel, plays a critical role in regulating uterine excitability during pregnancy and has been suggested as a potential new target for the treatment of conditions arising from dysfunctional uterine contractility, for example, atonic postpartum hemorrhage. The aim of this study was to investigate the effects of the selective KIR7.1 blocker, VU590, on both spontaneous and agonist-stimulated contractions of human pregnant myometrium in vitro. At a concentration of 20 µmol/L, VU590 significantly increased the mean contractile force and the frequency of spontaneous contractions ( P < 0.05) when compared to vehicle-treated tissues. However, there was a significant ( P < 0.0001) monoexponential decay in amplitude with time of exposure. When VU590 was coadministered with EC50 concentration of the uterotonics oxytocin, ergometrine, or carboprost, the only significant changes were an immediate decrease in the amplitude of oxytocin- and carboprost-induced contractions and a delayed reduction in amplitude and an increase in the frequency of ergometrine-induced contractions. Amplitude to all 3 agents in the presence of VU590 showed a monoexponential decay with time of exposure ( P < 0.0001). We conclude that VU590 modifies the contractility of pregnant human myometrium in support of a role for KIR7.1 in regulating that process. However, VU590 in vitro does not produce the types of contraction, either alone or in combination with other uterine stimulants that would suggest its usefulness as a first- or second-line clinical uterotonic agent.

Overview of the pharmacological spasm provocation test: Comparisons between acetylcholine and ergonovine.

The spasm provocation tests of ergonovine and acetylcholine have been employed in the cardiac catheterization laboratory. Ergonovine acts through the serotogenic receptors, while acetylcholine acts through the muscarinic cholinergic receptors. Different mediators may have the potential to cause different coronary responses. However, there are few reports concerning the coronary response between ergonovine and acetylcholine in the same patients. Acetylcholine is supersensitive for females; spasm provoked by ergonovine is focal and proximal, whereas provoked spasm by acetylcholine is diffuse and distal. We should use both tests as supplementary in the clinic because ergonovine and acetylcholine have self-limitations to induce coronary spasms during daily life. The maximal pharmacological doses, administration methods, and the angiographical positive definition are remarkably different for each institution in the world. We recommend the pharmacological spasm provocation tests as Class I in the guidelines in patients with vasospastic angina throughout the world.

The Quality of Selected Essential Medicines Sold in Accredited Drug Dispensing Outlets and Pharmacies in Tanzania.

INTRODUCTION: The purpose of this study was to investigate the quality of a select group of medicines sold in accredited drug dispensing outlets (ADDOs) and pharmacies in different regions of Tanzania as part of an in-depth cross-sectional assessment of community access to medicines and community use of medicines. METHODS: We collected 242 samples of amoxicillin trihydrate, artemether-lumefantrine (ALu), co-trimoxazole, ergometrine maleate, paracetamol, and quinine from selected ADDOs and pharmacies in Mbeya, Morogoro, Singida, and Tanga regions. The analysis included physical examination and testing with validated analytical techniques. Assays for eight of nine products were conducted using high-performance thin-layer chromatography (HPTLC). For ALu tablets, we used a two-tiered approach, where tier 1 was a semi-quantitative Global Pharma Health Fund-Minilab® method and tier 2 was high-performance liquid chromatography (HPLC) as described in The International Pharmacopoeia's monograph for artemether-lumefantrine. RESULTS AND DISCUSSION: The physical examination of samples revealed no defects in the solid and oral liquid dosage forms, but unusual discoloration in an injectable solution, ergometrine maleate. For ALu, the results showed that of 38 samples, 31 (81.6%) passed tier 1 testing and 7 (18.4%) gave inconclusive drug content results. The inconclusive ALu samples were submitted for tier 2 testing and all met the quality standards. The pass rate using the HPTLC and TLC/HPLC assays was 93.8%; the failures were the ergometrine maleate samples purchased from both ADDOs and pharmacies. The disintegration testing of the solid dosage forms was conducted in accordance with US Pharmacopeia monographs. Only two samples of paracetamol, 1.2% of the solid dosage forms, failed to comply to standards. The study revealed a high overall rate of 92.6% of samples that met the quality standards. Although the overall failure rate was 7.4%, it is important to note that this was largely limited to one product and likely due to poor distribution and storage rather than poor manufacturing practices. CONCLUSIONS: Over 90% of the medicines sold in ADDOs and pharmacies met quality standards. Policy makers need to reconsider ergometrine maleate's place on the list of medicines that ADDOs are allowed to dispense, by either substituting a more temperature-stable therapeutically equivalent product or requiring those sites to have refrigerators, which is not a feasible option for rural Tanzania.

Uterotonics for Non-emergent Caesarean Section: Protocol Change During UK-Licensed Drug Shortage.

The aim was to assess the efficacy of Syntometrine ® (500 micrograms ergometrine with 5 units oxytocin) as an appropriate alternative first-line uterotonic for use in elective caesarean section (CS) during a national shortage of UK-licensed IV oxytocin from April-June 2014. An observational study was performed involving 2 groups of 22 women undergoing elective CS in a UK DGH during this period. Primary endpoints included mean estimated blood loss (EBL), haemoglobin drop post-operatively and transfusion requirement. Secondary endpoints were use of antiemetics and mean post-operative nausea and vomiting (PONV) score. Results for Syntometrine ® groups and syntocinon groups respectively: mean EBL (ml) 527.3 vs. 550.0 (p=0.5820), mean haemoglobin drop (g/dL) 0.977 vs. 0.982 (p=0.98), blood transfusion 1/22 vs. 0/22 (p=1). Intra-operative antiemetics 20/22 vs. 6/22 (p=<0.001), post-operative antiemetics 2/22 vs. 2/22 (p=1), mean PONV score 11.5 vs. 3.5 (p=0.099). As no significant difference in primary endpoints or PONV scores was observed between regimes, we conclude Syntometrine ® was a safe first-line haemostatic agent for elective CS during oxytocin shortage.

Clinical implications of low-dose aspirin on vasospastic angina patients without significant coronary artery stenosis; a propensity score-matched analysis.

BACKGROUND: High-dose aspirin has been reported to exacerbate coronary artery spasm in patients with vasospastic angina. We investigated clinical implications of low-dose aspirin on vasospastic angina patients without significant coronary artery stenosis. METHODS: We included patients without significant coronary artery stenosis on coronary angiography (CAG) and with positive results on intracoronary ergonovine provocation test between January 2003 and December 2014. A total of 777 patients were divided into two groups according to prescription of low-dose aspirin at discharge: aspirin group (n=321) and non-aspirin group (n=456). The major adverse cardiovascular events (MACE), defined as composite outcomes of cardiac death, acute myocardial infarction, revascularization, or rehospitalization requiring CAG or medication change due to recurrent angina were compared. RESULTS: The aspirin group had significantly higher incidence of MACE (22.8% versus 12.1%; p=0.04) and had higher tendency for rehospitalization (20.6% versus 11.2%; p=0.08). All-cause mortality and cardiac death were similar between the two groups. After propensity score matching, the aspirin group had greater risk of MACE (hazard ratio [HR] 1.54; 95% confidence interval [CI], 1.04-2.28; p=0.037) and rehospitalization requiring CAG (HR, 1.33; 95% CI, 1.13-4.20; p=0.03), and a higher tendency for rehospitalization (HR, 1.40; 95% CI, 0.94-2.09; p=0.12). CONCLUSION: In vasospastic angina without significant coronary artery stenosis, patients taking low-dose aspirin are at higher risk of MACE, driven primarily by tendency toward rehospitalization. Low-dose aspirin might be used with caution in vasospastic angina patients without significant coronary artery stenosis.

High susceptibility of atherosclerotic coronary arteries to the onset of vasospasm and angina pectoris-like symptoms due to coronary spasm in WHHLMI rabbits.

We examined the relationship between atherosclerosis and the provocation of coronary spasm as well as the influence of coronary spasm on the onset of acute ischemic myocardial disease. Coronary spasm was provoked in anesthetized normal Japanese white (JW) rabbits and myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits, an animal model for coronary atherosclerosis and myocardial infarction, by injecting ergonovine during the infusion of norepinephrine through a marginal ear vein. A decrease in contrast flow in the left circumflex artery was observed on coronary angiograms. Ischemic changes were observed on the electrocardiograms of 29% (2/7) of JW and 79% (27/34, P=0.007) of WHHLMI rabbits. The frequency of coronary spasm was significantly high in rabbits with severe coronary plaques showing diffuse lesions. Left ventricle motility in vasospasm-positive rabbits, which was evaluated with echocardiograms, was decreased by 29% following the ergonovine injection (P<0.001), and every serum ischemic marker markedly increased 4 h after the provocation of vasospasm. These results demonstrate that atherosclerotic coronary arteries are positively related to the provocation of vasospasm, and vasospasm in severe atherosclerotic coronary segments evokes angina pectoris-like findings and/or non-fatal myocardial infarction. WHHLMI rabbits may be a novel animal model for angina pectoris and acute ischemic heart disease.

Increased circulating malondialdehyde-modified low-density lipoprotein levels in patients with ergonovine-induced coronary artery spasm.

OBJECTIVE: Coronary endothelial dysfunction is thought to underlie the development of coronary artery spasms. Malondialdehyde-modified low-density lipoprotein (MDA-LDL) was suggested as a marker of endothelial damage. This study investigated the diagnostic impact of MDA-LDL on ergonovine-induced coronary spasms. METHODS: We included 152 patients with suspected coronary spastic angina. MDA-LDL levels were measured before an ergonovine provocation test. Coronary spasm was defined as total or subtotal occlusion, compared to the relaxed state after nitroglycerin, associated with ischemic ECG changes and concurrent chest pain. Changes in vessel diameter in response to ergonovine were evaluated with quantitative coronary angiography. RESULTS: Coronary spasms were observed in 41 patients (27%). MDA-LDL levels were significantly higher in patients with spasms compared to those without spasms (139.9 ± 45.9 U/L vs. 109.6 ± 36.6 U/L, p<0.01). Univariate logistic regression analyses indicated significant relationships between coronary spasms and MDA-LDL (per 10 U/L, odds ratio (OR): 1.20; p<0.01), high-density lipoprotein (per 10 mg/dL, OR: 0.76; p=0.03), smoking (OR: 3.04; p<0.01), and male gender (OR: 3.51; p<0.01). In the multivariate model, MDA-LDL (per 10 U/L, OR: 1.17; p<0.01) remained a significant predictor of coronary spasm. Regression analysis showed a positive correlation between MDA-LDL levels and coronary luminal diameter changes induced by ergonovine (r=0.57, p<0.01). The optimal MDA-LDL threshold for predicting coronary spasm was 121.3 U/L, identified with a receiver operating characteristic curve. CONCLUSIONS: Increased circulating MDA-LDL levels were associated with ergonovine-induced coronary artery spasm.

The Contractile Effects of Oxytocin, Ergonovine, and Carboprost and Their Combinations: an In Vitro Study on Human Myometrial Strips.

BACKGROUND: The objective of this study was to compare the in vitro contractile effects of the combination of oxytocin (low dose and high dose) with either ergonovine or carboprost in myometrial strips from women undergoing cesarean delivery (CD), and to study the effect of oxytocin pretreatment on these contractions. We hypothesized that the use of ergonovine or carboprost in combination with oxytocin would improve contractility compared with oxytocin alone. METHODS: Myometrial samples obtained from women undergoing elective CD were pretreated in organ bath chambers with either oxytocin 10 M (experimental) or physiological salt solution (control) for 2 hours. They were then washed and subjected to dose-response testing with oxytocin, ergonovine, or carboprost (10 to 10 M), either alone or in combination with a fixed low-dose (10 M) (LDOx) or high-dose (10 M) (HDOx) oxytocin. The amplitude, frequency, area under the curve, and motility index (amplitude × frequency) of contractions during the dose-response period were analyzed with linear regression models, and compared among the groups. The primary outcome was the motility index across the study groups. RESULTS: One hundred sixty-nine experiments were done in samples obtained from 56 women. The mean square root of the motility index [standard error] (√g·contractions/10 min) of oxytocin was significantly higher in the control (3.40 [0.24]) versus experimental group (2.02 [0.15]) (P < 0.001). When all control groups were compared, the motility index of oxytocin (3.21 [0.25]) was higher than that of ergonovine (2.13 [0.30], P < 0.001 [multiple comparisons adjusted P value, P < 0.001]), carboprost (1.88 [0.10], P < 0.001 [P < 0.001]), ergonovine + LDOx (2.07 [0.15], P < 0.001 [P < 0.001]), and carboprost + LDOx (1.82 [0.15], P < 0.001 [P < 0.001]) and was not different than that of ergonovine + HDOx (3.39 [0.32], P = 0.68 [P = 0.99]) and carboprost + HDOx (2.68 [0.30], P = 0.20 [P = 0.60]). However, in oxytocin-pretreated groups, carboprost + LDOx (motility index: 2.53 [0.08], P = 0.001 [multiple comparisons adjusted P value, P = 0.002]) and ergonovine + HDOx (2.82 [0.15], P < 0.001 [P < 0.001]) exhibited significantly superior contractility response compared with oxytocin alone, while ergonovine + LDOx (2.47 [0.13], P = 0.01 [P = 0.08]) and carboprost + HDOx (2.51 [0.20], P = 0.05 [P = 0.24]) showed higher mean contractility response compared with oxytocin alone but failed to reach statistical significance in adjusted analyses. CONCLUSIONS: The attenuation of oxytocin-induced contractility in oxytocin-pretreated myometrial strips is in keeping with the previously established oxytocin-receptor desensitization phenomenon. Oxytocin is the most effective of the uterotonics tested if the myometrium is not preexposed to oxytocin. However, in the oxytocin-pretreated myometrium, a synergistic response is evident, and the combination of oxytocin with either ergonovine or carboprost produces superior response compared with oxytocin alone. Further in vivo studies in humans are necessary to determine whether these differences identified in vitro are clinically significant.

Alkaloid variation among epichloid endophytes of sleepygrass (Achnatherum robustum) and consequences for resistance to insect herbivores.

Epichloid endophytes are well known symbionts of many cool-season grasses that may alleviate environmental stresses for their hosts. For example, endophytes produce alkaloid compounds that may be toxic to invertebrate or vertebrate herbivores. Achnatherum robustum, commonly called sleepygrass, was aptly named due to the presence of an endophyte that causes toxic effects to livestock and wildlife. Variation in alkaloid production observed in two A. robustum populations located near Weed and Cloudcroft in the Lincoln National Forest, New Mexico, suggests two different endophyte species are present in these populations. Genetic analyses of endophyte-infected samples revealed major differences in the endophyte alkaloid genetic profiles from the two populations, which were supported with chemical analyses. The endophyte present in the Weed population was shown to produce chanoclavine I, paspaline, and terpendoles, so thus resembles the previously described Epichloë funkii. The endophyte present in the Cloudcroft population produces chanoclavineI, ergonovine, lysergic acid amide, and paspaline, and is an undescribed endophyte species. We observed very low survival rates for aphids feeding on plants infected with the Cloudcroft endophyte, while aphid survival was better on endophyte infected plants in the Weed population. This observation led to the hypothesis that the alkaloid ergonovine is responsible for aphid mortality. Direct testing of aphid survival on oat leaves supplemented with ergonovine provided supporting evidence for this hypothesis. The results of this study suggest that alkaloids produced by the Cloudcroft endophyte, specifically ergonovine, have insecticidal properties.

Comparative efficacy of uterotonic agents: in vitro contractions in isolated myometrial strips of labouring and non-labouring women.

PURPOSE: To compare the in vitro contractile responses to oxytocin, ergonovine, prostaglandin F2 alpha (PGF2α), and misoprostol in isolated myometrium from non-labouring and labouring pregnant women. METHODS: Myometrial strips obtained from labouring (with or without oxytocin augmentation) and non-labouring women undergoing Cesarean deliveries were subjected to a dose-response testing with oxytocin, ergonovine, PGF2α, or misoprostol (10(-10) M to 10(-5) M). The amplitude and frequency of contractions, motility index (MI) (amplitude × frequency), and area under the curve during the dose-response period were recorded. The primary outcome was the motility index. Data were analyzed using linear regression models. RESULTS: We performed 130 experiments in myometrial strips obtained from 46 women. The overall MI (√gram·contractions·10 min(-1) [√g·c·10 min(-1)]) was greatest for oxytocin (mean 5.10 √g·c·10 min(-1); 95% confidence interval [CI] 4.70 to 5.50) than for ergonovine (mean 3.46 √g·c·10 min(-1); 95% CI 3.13 to 3.80; P < 0.001), PGF2α (mean 2.64 √g·c·10 min(-1); 95% CI 2.40 to 2.87; P < 0.001), and misoprostol (2.52 √g·c·10 min(-1); 95% CI 2.22 to 2.82; P < 0.001). The MI for oxytocin was significantly lower in augmented labour (mean 4.11 √g·c·10 min(-1); 95% CI 3.48 to 4.73) than in non-augmented labour (mean 5.19 √g·c·10 min(-1); 95% CI 4.39 to 6.00; P = 0.04) or in absence of labour (mean 5.80 √g·c·10 min(-1); 95% CI 5.36 to 6.24; P < 0.001). Nevertheless, in augmented labour, oxytocin still produced superior contractions compared with other uterotonic drugs. Responses to ergonovine, PGF2α, and misoprostol were unaffected by labour or prior exposure to oxytocin. CONCLUSION: Oxytocin induces superior myometrial contractions compared with ergonovine, PGF2α, and misoprostol. The effect of oxytocin is reduced in myometrium of women with oxytocin-augmented labour; however, it is still superior to the other uterotonics. This trial was registered at ClinicalTrials.gov: NCT01689311.

A comparison of prophylactic intramuscular ergometrine and oxytocin for women in the third stage of labor.

OBJECTIVE: To compare the efficacy and adverse effects of ergometrine and oxytocin given intramuscularly for the prevention of postpartum hemorrhage during the third stage of labor. METHODS: The study included women with a singleton pregnancy of at least 28 weeks' gestation who had a vaginal delivery. High-risk pregnancies were excluded. Oxytocin (10 IU) or ergometrine (0.5mg) were administered intramuscularly in a blinded pattern immediately after delivery of the infant. An intention-to-treat analysis was performed. RESULTS: Postpartum blood loss (301.8 ± 109.2 mL versus 287.1 ± 84.4 mL, P=0.011) and packed cell volume (30.7 ± 1.7% versus 31.6 ± 2.0%; Z=0.00; P=0.008) were considerably reduced among parturients who received intramuscular ergometrine. The rates of therapeutic oxytocics use, blood transfusion, placental retention, and manual removal of the placenta were significantly higher in the oxytocin group. No significant differences between the groups were observed in terms of adverse effects, with the exception of diastolic hypertension, which was more common in the ergometrine group (odds ratio, 0.00; 95% confidence interval, 0.00-0.75; P=0.007). CONCLUSION: Intramuscular ergometrine is superior to intramuscular oxytocin in averting postpartum hemorrhage during the third stage of labor. There are no significant risks of adverse effects except for diastolic hypertension.

Vasospasm of atherosclerotic coronary arteries precipitates acute ischemic myocardial damage in myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits.

OBJECTIVE: This study tested the hypothesis that vasospasm can trigger coronary plaque injury and acute ischemic myocardial damage. APPROACH AND RESULTS: Myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits received an intravenous bolus of ergonovine maleate (0.45 µmol/kg) during intravenous infusion of norepinephrine (12 nmol/kg per minute) to provoke coronary spasm in vivo. After this treatment, coronary angiography demonstrated vasospasm, and the ECG showed ischemic abnormalities (ST depression/elevation and T-wave inversion) in 77% of animals (23/30). These changes normalized after nitroglycerin injection. In rabbits that demonstrated these ECG findings for >20 minutes, echocardiograms showed left ventricular wall motion abnormality. Serum levels of heart-type fatty acid-binding protein, cardiac troponin-I, and myoglobin increased markedly 4 hours after spasm provocation. In coronary lesions of myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits with provoked coronary spasm, we observed intimal injury in 60.9% in the form of endothelial cell protrusions (39.1%), denudation (30.4%), and macrophage extravasation (56.5%). Plaque disruption with luminal thrombus, however, was only seen in 2 of 23 animals (8.7%), and mural microthrombus was rarely observed (4.3%). CONCLUSIONS: These observations show that provocation of vasospasm in myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits associates with subsequent ischemic myocardial damage. Although treatment with spasmogens altered aspects of plaque morphology, for example, endothelial protrusion and macrophage emigration, thrombosis was rare in these animals with chronic atherosclerotic disease.