Ergodic Research Articles

Levodopa attenuates the feed intake reduction caused by ergot alkaloids in cattle.

Consumption of ergot alkaloids from endophyte-infected tall fescue results in losses to the livestock industry in many countries and a means to mitigate these losses is needed. The objective of this study was to evaluate intra-abomasal infusion of the dopamine precursor, levodopa (L-DOPA), on dopamine metabolism, feed intake, and serum metabolites of steers exposed to ergot alkaloids. Twelve Holstein steers (344.9 ± 9.48kg) fitted with ruminal cannula were housed with a cycle of heat challenge during the daytime (32 °C) and thermoneutral at night (25 °C). The steers received a basal diet of alfalfa cubes containing equal amounts of tall fescue seed composed of a mixture of endophyte-free (E-) or endophyte-infected tall fescue seeds (E+) equivalent to 15 µg ergovaline/kg body weight (BW) for 9d followed by intra-abomasal infusion of water (L-DOPA-) or levodopa (L-DOPA+; 2mg/kg BW) for an additional 9d. Afterward, the steers were pair-fed for 5d to conduct a glucose tolerance test. The E+ treatment decreased (P = 0.005) prolactin by approximately 50%. However, prolactin increased (P = 0.050) with L-DOPA+. Steers receiving E+ decreased (P < 0.001) dry matter intake (DMI); however, when supplemented with L-DOPA+ the decrease in DMI was less severe (L-DOPA × E, P = 0.003). Also, L-DOPA+ infusion increased eating duration (L-DOPA × E, P = 0.012) when steers were receiving E+. The number of meals, meal duration, and intake rate were not affected (P > 0.05) by E+ or L-DOPA+. The L-DOPA+ infusion increased (P < 0.05) free L-DOPA, free dopamine, total L-DOPA, and total dopamine. Conversely, free epinephrine and free norepinephrine decreased (P < 0.05) with L-DOPA+. Total epinephrine and total norepinephrine were not affected (P > 0.05) by L-DOPA+. Ergot alkaloids did not affect (P > 0.05) circulating free or total L-DOPA, dopamine, or epinephrine. However, free and total norepinephrine decreased (P = 0.046) with E+. Glucose clearance rates at 15 to 30min after glucose infusion increased with L-DOPA+ (P < 0.001), but not with E+ (P = 0.280). Administration of L-DOPA as an agonist therapy to treat fescue toxicosis provided a moderate increase in DMI and eating time and increased plasma glucose clearance for cattle dosed with E+ seed.

Effect of continuous or intermittent feeding of ergot contaminated grain in a mash or pelleted form on the performance and health of feedlot beef steers.

This study evaluated the effect of feeding ergot contaminated grain continuously or intermittently through backgrounding (BG) and finishing (FN) in a mash or pelleted supplement on the growth performance, health and welfare parameters, and carcass characteristics of feedlot beef steers. Sixty black Angus steers (300 ± 29.4kg BW) were used in a complete randomized 238-d study. Steers were stratified by weight and randomly assigned to four different diets (15 steers/treatment) and individually housed. Treatments included: (1) control [CON; no added ergot alkaloids (EA)], (2) continuous ergot mash (CEM; fed continuously at 2mg total EA/kg of DM), (3) intermittent ergot mash (IEM; fed at 2mg total EA/kg of DM, during the first week of each 21-d period and CON for the remaining 2wk, this feeding pattern was repeated in each period), and (4) intermittent ergot pellet (IEP; fed at 2mg of total EA/kg of DM as a pellet during the first week of each 21-d period and CON for the remaining 2wk as described for IEM). Steers were fed barley based BG diets containing 40% concentrate:60% silage (DM basis) for 84 d (four 21-d periods), transitioned over 28 d (no ergot fed) to an FN diet (90% concentrate:10% silage DM basis) and fed for 126 d (six 21-d periods) before slaughter. In the BG phase, steer DMI (P < 0.01, 7.45 vs. 8.05kg/d) and ADG (P < 0.01) were reduced for all EA diets compared to CON. The CEM fed steers had lower ADG (P < 0.01, 0.735 vs. 0.980kg) and shrunk final BW (P < 0.01, 350 vs. 366kg) than CON. CEM had lower gain:feed (P < 0.07, 0.130 vs. 0.142) than CON. In the FN phase, steer DMI (P < 0.01, 9.95 vs. 11.05kg/d) and ADG (P = 0.04) were also decreased for all EA fed steers compared to CON. Total shrunk BW gain (P = 0.03, 202.5 vs. 225.2kg), final BW (P = 0.03, 617.9 vs. 662.2kg), and carcass weight (P = 0.06) decreased for all EA fed steers compared to CON. The percentage of AAA carcasses decreased for all EA fed steers (P < 0.01, 46.7 vs. 93.3%) compared to CON. EA fed steers had increased rectal temperatures (P < 0.01, 39.8 vs. 39.4 °C) compared to CON. Pelleting ergot contaminated grain did not reduce the impact of ergot alkaloids on any of the measured parameters during BG or FN. Continuously or intermittently feeding ergot contaminated diets (2mg total EA/kg of DM) significantly reduced intake, growth performance, and carcass weight, with minimal impact on blood parameters in feedlot steers. Pelleting was not an effective method of reducing ergot toxicity.

Risks for animal health related to the presence of ergot alkaloids in feed.

The European Commission requested EFSA to provide an update of the 2012 Scientific Opinion of the Panel on Contaminants in the Food Chain (CONTAM) on the risks for animal health related to the presence of ergot alkaloids (EAs) in feed. EAs are produced by several fungi of the Claviceps and Epichloë genera. This Opinion focussed on the 14 EAs produced by C. purpurea (ergocristine, ergotamine, ergocornine, α- and β-ergocryptine, ergometrine, ergosine and their corresponding 'inine' epimers). Effects observed with EAs from C. africana (mainly dihydroergosine) and Epichloë (ergovaline/-inine) were also evaluated. There is limited information on toxicokinetics in food and non-food producing animals. However, transfer from feed to food of animal origin is negligible. The major effects of EAs are related to vasoconstriction and are exaggerated during extreme temperatures. In addition, EAs cause a decrease in prolactin, resulting in a reduced milk production. Based on the sum of the EAs, the Panel considered the following as Reference Points (RPs) in complete feed for adverse animal health effects: for pigs and piglets 0.6 mg/kg, for chickens for fattening and hens 2.1 and 3.7 mg/kg, respectively, for ducks 0.2 mg/kg, bovines 0.1 mg/kg and sheep 0.3 mg/kg. A total of 19,023 analytical results on EAs (only from C. purpurea) in feed materials and compound feeds were available for the exposure assessment (1580 samples). Dietary exposure was assessed using two feeding scenarios (model diets and compound feeds). Risk characterisation was done for the animals for which an RP could be identified. The CONTAM Panel considers that, based on exposure from model diets, the presence of EAs in feed raises a health concern in piglets, pigs for fattening, sows and bovines, while for chickens for fattening, laying hens, ducks, ovines and caprines, the health concern related to EAs in feed is low.

Ergot alkaloid consumption alters serotonin receptor-induced vasoactivity in ovine umbilical vasculature.

Consumption of ergot alkaloids during the second half of gestation has been shown to decrease umbilical artery vasoactivity resulting in decreased birth weights. Negative vascular effects of ergot alkaloids are mediated predominantly through serotonergic and adrenergic receptors in other tissues. Vasoactivity of serotonin (5-HT) receptors 5-HT2A and 5-HT1B/1D in umbilical artery and vein from ewes receiving endophyte-infected seed (E + 1.77mg ergovaline/hd/d) or a control total mixed ration (CON; 0mg ergovaline/hd/d) tall fescue seed at d-110 and d-133 of gestation was evaluated. Gravid reproduction tracts were collected from ewes. Two-mm sections of umbilical artery and vein were exposed to increasing concentrations of a 5-HT1B/1D agonist and 5-HT2A agonist. The 5-HT1B/1D agonist did not stimulate a contractile response in artery or vein or either gestation time point. 5-HT2A agonist caused large responses in artery with greatest occurring at d-110 and decreasing in magnitude as days of gestation increased (p < 0.05). On d-110 and 133 of gestation, arteries from CON ewes had greater contractile response than arteries collected from E+ ewes (p < 0.05). Veins responded to increasing concentrations of the 5-HT2A agonist. Maximal d-110 vein response was greater than d-133 when exposed to 5-HT2A agonist (p < 0.05). Unlike the artery, veins from E+ ewes had greater d-133 contractile response than CON (p < 0.05). Vascular contractions of umbilical artery and vein are induced by 5-HT2A receptor activity and not 5-HT1B/1D. Umbilical artery 5-HT2A receptor activity was more sensitive to seed treatment and could be responsible for ergot alkaloid-induced intra-uterine growth restriction.

Ergodic measures with infinite entropy

Ergodic measures with infinite entropy

Ergot alkaloids as pharmaceuticals: Status and prospects of commercial cultivation of ergot crop for natural alkaloids

Ergot is a plant disease symptom induced by a fungal pathogen of the genus Claviceps in grains of cereal crops, wherein the ergot alkaloids are produced in the cereal grains which are transformed into ergot sclerotia. The natural occurrence of ergot grains in cereal crops is dependent on the environmental factors conducive to ergot development. Under natural fungal infection, the ergot percent varies from 1.2 to 3.3 in the infected crops which hamper the yield or recovery of natural ergot alkaloids. Ergot alkaloids are specific pharmaceutical alkaloids used to treat certain ailments like migraines, induction of childbirth, and the control of postpartum bleeding in humans. Ergot sclerotia contain about 0.15% to 0.5% alkaloids, with medicinally useful compounds. Annual world production of ergot alkaloids has been estimated at 5,000-8,000 kg of all ergopeptines (peptide ergot alkaloids) and 10,000-15,000 kg of lysergic acid, the latter being mainly used in the manufacture of semisynthetic derivatives. The greater part of this production occurs as a result of fermentation (around 60%) while field cultivation of triticale (a hybrid of wheat and rye) accounts for the balance. This is because the artificial cultivation of ergot sclerotia on a host crop plant is lacking as a business module. Due to the low recovery of ergot grains and ergot alkaloids under natural crop production conditions, commercial cultivation for ergot grains is discussed in this paper.

Ruminal ergovaline and volatile fatty acid dynamics: Association with poor performance and a key growth regulator in steers grazing toxic tall fescue

Fescue toxicosis (FT) is produced by an ergot alkaloid (i.e., ergovaline [EV])-producing fungus residing in toxic fescue plants. Associations between EV, decreased weight gain and ruminal volatile fatty acids are unclear. Feces, rumen fluid, and blood were collected from 12 steers that grazed non-toxic (NT) or toxic (E +) fescue for 28 days. The E + group exhibited decreased propionate (P), increased acetate (A), and increased ruminal A:P ratio, with similar trends in feces. Plasma GASP-1 (G-Protein-Coupled-Receptor-Associated-Sorting-Protein), a myostatin inhibitor, decreased (day 14) only in E + steers. Ergovaline was present only in E + ruminal fluid and peaked on day 14. The lower ruminal propionate and higher A:P ratio might contribute to FT while reduced GASP-1 might be a new mechanism linked to E + -related weight gain reduction. Day 14 ergovaline zenith likely reflects ruminal adaptations favoring EV breakdown and its presence only in rumen points to local, rather than systemic effects.

Endophyte genomes support greater metabolic gene cluster diversity compared with non-endophytes in Trichoderma.

Trichoderma is a cosmopolitan genus with diverse lifestyles and nutritional modes, including mycotrophy, saprophytism, and endophytism. Previous research has reported greater metabolic gene repertoires in endophytic fungal species compared to closely-related non-endophytes. However, the extent of this ecological trend and its underlying mechanisms are unclear. Some endophytic fungi may also be mycotrophs and have one or more mycoparasitism mechanisms. Mycotrophic endophytes are prominent in certain genera like Trichoderma, therefore, the mechanisms that enable these fungi to colonize both living plants and fungi may be the result of expanded metabolic gene repertoires. Our objective was to determine what, if any, genomic features are overrepresented in endophytic fungi genomes in order to undercover the genomic underpinning of the fungal endophytic lifestyle. Here we compared metabolic gene cluster and mycoparasitism gene diversity across a dataset of thirty-eight Trichoderma genomes representing the full breadth of environmental Trichoderma's diverse lifestyles and nutritional modes. We generated four new Trichoderma endophyticum genomes to improve the sampling of endophytic isolates from this genus. As predicted, endophytic Trichoderma genomes contained, on average, more total biosynthetic and degradative gene clusters than non-endophytic isolates, suggesting that the ability to create/modify a diversity of metabolites potential is beneficial or necessary to the endophytic fungi. Still, once the phylogenetic signal was taken in consideration, no particular class of metabolic gene cluster was independently associated with the Trichoderma endophytic lifestyle. Several mycoparasitism genes, but no chitinase genes, were associated with endophytic Trichoderma genomes. Most genomic differences between Trichoderma lifestyles and nutritional modes are difficult to disentangle from phylogenetic divergences among species, suggesting that Trichoderma genomes maybe particularly well-equipped for lifestyle plasticity. We also consider the role of endophytism in diversifying secondary metabolism after identifying the horizontal transfer of the ergot alkaloid gene cluster to Trichoderma.

Cartan subalgebras in von Neumann algebras associated with graph product groups

We completely classify the Cartan subalgebras in all von Neumann algebras associated with graph product groups and their free ergodic measure preserving actions on probability spaces.

Geometric interpretation of the entropy of so c systems

We consider a geometric approach to the notion of metric entropy. We justify the possibility of this approach for the class of Borel invariant ergodic probability measures on so c systems, which is the rst result of such generality for non-Markovian systems.

Development, in-house validation and application of a method using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) for the quantification of 12 ergot alkaloids in compound feeds.

Ergot alkaloids (EAs) are toxic substances naturally produced by Claviceps fungi. These fungi infest a wide range of cereals and grasses. When domestic animals are exposed to EAs through contaminated feeds, it is detrimental to them and leads to significant economic losses. For that reason, it is important to monitor feed for the presence of EAs, especially with methods enabling their determination in processed materials. Ergot alkaloids were extracted with acetonitrile, and dispersive solid phase extraction (d-SPE) was used for clean-up of the extracts. After evaporation, the extracts were reconstituted in ammonium carbonate and acetonitrile and subjected to instrumental analysis using high-performance liquid chromatography with fluorescence detection. The developed method was validated in terms of linearity, selectivity, repeatability, reproducibility, robustness, matrix effect, limits of quantification and detection and uncertainty. The EA content of 40 compound feeds was determined. All the assessed validation parameters fulfilled the requirements of Regulation (EU) 2021/808. At least one of the monitored alkaloids was determined in 40% of the samples. The EAs with the highest incidence rate were ergocryptine, ergometrinine and ergocornine. The total concentrations of EAs ranged from under the limit of quantification to 62.3 μg kg-1. The results demonstrated that the developed method was suitable for simultaneously determining twelve EAs in compound feed and could be used for routine analysis.

ERG Is a New Predisposition Gene for Bone Marrow Failure and Hematological Malignancy

There remain gaps in our knowledge of hereditary and sporadic causes of hematological malignancy (HM) and bone marrow failure (BMF) that prevent optimal diagnosis, disease surveillance and treatment. Here we report the discovery of ERG as a novel predisposition gene for BMF and HM. ERG is a known oncogene, typically via gene-fusions, leading to dysregulated ERG overexpression in blood and solid cancers. We identified a germline ERG ETS domain variant p.Y373C segregating with thrombocytopenia in a mother, who progressed to AML (27 yr) and then therapy-related MDS (35 yr), and in her 2 sons. All three showed copy neutral loss of heterozygosity of all or part of chromosome 21q, including the ERG locus, with the oldest son showing at least 2 somatic genetic rescue (SGR) events. The possibility of causal RUNX1 variants were ruled out, with the smallest somatic cnLOH event beginning within the RUNX1 gene, but not encompassing the RUNT domain where the majority of pathogenic missense variants are located. ERG, a highly constrained gene (LOEUF &amp;lt;0.33), is critical for definitive hematopoiesis, adult hematopoietic stem cell (HSC) function and platelet maintenance. An identical corresponding heterozygous germline variant (p.Y343C) in ERG’s closest gene by homology, FLI1, causes platelet-type bleeding disorder-21 (BDPLT21, OMIM #617443). Through global collaborations, we have identified 15 heterozygous variants in the ERG gene, 13 of which are missense and 2 truncating variants, in 17 individuals with cytopenia and/or HM (mainly myeloid) or lymphedema (Table). Onset of hematological symptoms ranged from birth to 38 years for truncating and constrained ETS domain variants. Of these 15 variants, 12 have been confirmed germline including 2 de novo. Only 4 meiotic transmissions are observed. None of the missense variants in the highly conserved ETS domain of ERG which mediates DNA binding, protein-protein interactions and nuclear localization, are present in gnomAD. We have functionally characterized 19 ERG variants, 12 potentially pathogenic, 1 known mouse pathogenic variant and 3 population controls demonstrating that most ETS domain missense variants display loss-of-function (LOF) characteristics disrupting transcriptional transactivation (Figure), DNA-binding and/or nuclear localization in vitro. Robust preliminary data from ex vivo models of ERG overexpression in mouse fetal liver cells in tissue culture (cytokine-independence), a mouse transplant assay and previous germline mutant Erg mouse models are concordant with ETS domain missense variants being LOF compared to wildtype ERG and benign controls. Together, these data provide clinical, in vitro and ex vivo functional studies implicating LOF variants in hematological disease predisposition. LOF ERG mutations also occur in sporadic cases of HM. Recently, as part of a Genomics England Research Consortium population study, 4 truncating ERG variants were described in 7 individuals across 4 families with 3 meiotic transmissions and a de novo case with primary lymphedema (1) and we add 2 novel missense variants here. One patient showed SGR across the ERG locus in blood. Blood phenotypes were not described. Our results demonstrate that germline ERG variants predispose to diverse cytopenia, BMF and HM in both children and adults. In our family mentioned above, the mother received an unrelated alloHSCT due to t-MDS while her 2 sons with cytopenias continue to be monitored. The natural history of this new syndrome will require careful identification of germline lesions with additional longitudinal studies in more patients and families needed. This ERG syndrome parallels GATA2 deficiency syndrome (HM and lymphedema) and RUNX1 Familial Platelet disorder-myeloid malignancy (thrombocytopenia and HM). Like the well-known disease genes GATA2 and RUNX1, ERG is also a member of the transcription factor heptad involved in HSC maintenance and differentiation. ERG adds to a growing list of genes whose unregulated expression contributes to HM and other cancers. Identification of causal germline ERG variants like those outlined in this study, has direct clinical implications for patient and family management including diagnosis, counselling, surveillance and treatment strategies such as selection of bone marrow transplant donors and potential for targeted therapies including gene and cell therapy. Reference 1. Greene D et al. Nat.Med. 29:679-688 2023

Biological studies of clavine alkaloids targeting CNS receptors

In contrast to well established psychedelics such as lysergic acid diethylamide (LSD) and psilocybin, ergot alkaloids of the clavine subclass have not been thoroughly investigated, in spite of their broad occurrence in nature and their well-established potent physiological effects. This study presents the current knowledge on the biological properties of clavine alkaloids, draws comparisons to the pharmacology of ergolines and related psychedelics, and demonstrates opportunities to develop novel structure–activity relationship (SAR) profiles. The latter could usher in a new stage of medicinal chemistry studies that enable an expansion of the currently structurally limited portfolio of psychedelic therapeutics.

Development and Application of Isotope Labelled Internal Standards in a Sum Parameter Method for Ergot Alkaloid Screening of Food

Ergot alkaloids are a group of toxic compounds, formed by fungi on infested grasses. In 2022, the European Commission set into effect maximum levels for the sum of the twelve major ergot alkaloids in multiple foods. To facilitate the laborious and costly individual quantification of the twelve major ergot alkaloids by HPLC–MS/MS or -FLD, we recently reported a sum parameter method (SPM) for ergot alkaloid quantification. Here, derivatization to lysergic acid hydrazide—a derivative of the mutual ergoline backbone in all ergot alkaloids—allowed simplified determination of all ergot alkaloids in flour via HPLC-FLD. For the measurement of more complex matrices like processed foods, we now developed a MS/MS-based SPM. Two internal standards (IS), isotopically labelled at different positions of the molecule, were synthesized and employed in the MS/MS-measurements. Method performance using either the 13CD3-labelled or the 15N2-labelled IS was evaluated on naturally contaminated rye and wheat flour samples as well as on processed food matrices. Employing the 13CD3-labelled IS leads to lower variances and better consistency with the reference data (obtained by the FLD-based SPM) in flour samples compared to the 15N2-labelled IS. The novel method significantly improves the measurement of ergot alkaloids in complex food matrices, due to their increased selectivity and thus lower interferences. Furthermore, the application of isotope labelled IS obviates the need for time-consuming steps like the determination of recovery rate based, matrix specific correction factors as described in the MS/MS-based European standard method for ergot alkaloid quantification (EN 17425).

Conditional intermediate entropy and Birkhoff average properties of hyperbolic flows

AbstractKatok [Lyapunov exponents, entropy and periodic points of diffeomorphisms. Publ. Math. Inst. Hautes Études Sci.51 (1980), 137–173] conjectured that every $C^{2}$ diffeomorphism f on a Riemannian manifold has the intermediate entropy property, that is, for any constant $c \in [0, h_{\mathrm {top}}(f))$ , there exists an ergodic measure $\mu $ of f satisfying $h_{\mu }(f)=c$ . In this paper, we obtain a conditional intermediate metric entropy property and two conditional intermediate Birkhoff average properties for basic sets of flows that characterize the refined roles of ergodic measures in the invariant ones. In this process, we establish a ‘multi-horseshoe’ entropy-dense property and use it to get the goal combined with conditional variational principles. We also obtain the same result for singular hyperbolic attractors.

Amenable wreath products with non almost finite actions of mean dimension zero

Almost finiteness was introduced in the seminal work of Kerr [J. Eur. Math. Soc. (JEMS) 22 (2020), pp. 3697–3745] as an dynamical analogue of Z \mathcal {Z} -stability in the Toms-Winter conjecture. In this article, we provide the first examples of minimal, topologically free actions of amenable groups that have mean dimension zero but are not almost finite. More precisely, we prove that there exists an infinite family of amenable wreath products that admit topologically free, minimal profinite actions on the Cantor space which fail to be almost finite. Furthermore, these actions have dynamical comparison. This intriguing new phenomenon shows that Kerr’s dynamical analogue of Toms-Winter conjecture fails for minimal, topologically free actions of amenable groups. The notion of allosteric group holds a significant position in our study. A group is allosteric if it admits a minimal action on a compact space with an invariant ergodic probability measure that is topologically free but not essentially free. We study allostery of wreath products and provide the first examples of allosteric amenable groups.

213 Effect of Continuous Or Intermittent Feeding of Ergot Contaminated Grain in a Mash Or Pelleted Form on the Performance and Health Parameters of Finishing Beef Steers

Abstract This study evaluated the effect of feeding pelleted or mash ergot contaminated grain fed continuously or intermittently on the growth performance, blood serum variables, and carcass quality of finishing beef steers. Sixty black angus steers (442 ± 36.7 kg) were used in a complete randomized finishing (90% concentrate:10% barley silage DM basis) 126-d study. Steers were randomly assigned to 4 different treatments and individually housed. Treatments included: 1) control ration [CON; no added ergot alkaloids (EA)], 2) continuous ergot mash (CEM; fed continuously at 2 ppm total EA), 3) intermittent ergot mash (IEM; fed at 2 ppm EA during the first week of each 21-d period and control diet for the remaining 2 weeks), and 4) intermittent ergot pellet (IEP; fed at 2 ppm EA incorporated into a pelleted supplement during the first week of each 21-d period and control diet for the other 2 weeks). Steers were weighed every 21 d and blood samples were collected on day 0, 42, 84, and 126. Steer DMI (P &amp;lt; 0.01, 9.95 vs. 11.05 kg/day) and ADG (P = 0.04) decreased for all EA treatments compared with the CON. Total shrunk BW gain (P = 0.03, 202.5 vs. 225.2 kg), final BW (P = 0.03, 617.9 vs. 662.2 kg), and carcass weight (P = 0.06) decreased for all EA steers compared with the CON steers. No treatment effects (P &amp;gt; 0.05) were observed for carcass dressing percentage, ribeye area, marbling score, or liver abscess. The percent of carcasses graded AAA decreased for all EA steers compared CON steers (P &amp;lt; 0.01, 46.7 vs. 93.3%). Steers fed EA had increased rectal temperature compared with CON steers (P &amp;lt; 0.01, 39.8 vs. 39.4 °C). Hair cortisol concentrations were less in steers fed IEP (P = 0.05, 1.23 vs. 1.76 pg/mg) than CON. No treatment effects (P &amp;gt; 0.05) were observed for complete blood count, and serum prolactin, haptoglobin, albumin, alkaline phosphatase, alanine transaminase, amylase, calcium, creatine, glucose, lipase, total bilirubin, total protein, or globulin. Blood urea nitrogen was less for EA steers compared with CON (P = 0.01, 3.48 vs. 4.10 mmol/L). The IEM steers had decreased concentrations of serum gamma-glutamyl transferase compared with IEP steers (P = 0.04, 23.4 vs. 28.5 IU). Pelleting ergot contaminated grain did not reduce the impact of ergot alkaloids on any of the measured parameters. Results suggest that continuously or intermittently feeding an ergot contaminated diet (2 ppm EA) can significantly reduce intake, growth performance, and carcass weight, with minimal impact on blood serum variables in finishing steers. Pelleting was not an effective method of reducing ergot toxicity.

286 Evaluation of Serotonin as a Vasorelaxant in Ovine Saphenous Artery and Vein

Abstract Herbivores that consume ergot alkaloids frequently suffer from vasoconstriction that can result in a myriad of symptoms that can range from necrosis of peripheral tissues to fetal intra-uterine growth restriction. As part of a larger study screening compounds that may mitigate the vasoconstrictive effects of ergot alkaloids, the objective of this experiment was to evaluate serotonin (5-HT) as vasorelaxant in the ovine saphenous artery and vein. Blood vessels were collected from a total mixed breed market rams (n = 16; approximate BW = 58 kg) at slaughter, cleaned of surrounding adipose and connective tissue, sliced into 2-mm cross-sections, and mounted in a multimyograph. Artery and vein cross-sections were equilibrated to 1 g tension in continuously gassed (95% O2/5% CO2) Krebs-Henseleit buffer (pH 7.4; 37.5 °C) for 90 min, precontracted with 0.0001 M phenylephrine for 15 min, exposed to concentrations of 5-HT that ranged from 1 x 10-9 to 1 x 10-4 M for a 5-min interval. Response data were normalized to the 0.0001 M phenylephrine response and were analyzed as a completely randomized design in SAS. The lateral saphenous vein (n = 5 lambs) relaxed to increasing concentrations of 5-HT (P &amp;lt; 0.05) with 65 to 75 % relaxation occurring at 1 x 10-7 M through 1 x 10-4 5-HT. Conversely, the lateral saphenous artery (n = 6 lambs) contracted in response to increasing concentrations of 5-HT (P &amp;lt; 0.05) resulting in a 255% increase from the phenylephrine response by the 1 x 10-4 M addition. In a subsequent experiment, saphenous veins from the remaining lambs (n = 5) were treated the same, but in place of increasing concentrations of 5-HT, saphenous veins were exposed to increasing concentrations of selective 5-HT receptor agonists to determine the receptor subtypes involved in the previously observed vasorelaxation. Agonists for receptors 5-HT2B (BW 723C86; α-methyl-5-(2-thienylmethoxy)-1H-indole-3-ethanamine hydrochloride), 5-HT4 (BIMU-8; 2,3-Dihydro-N-[(3-endo)-8-methyl-8-azabicyclo[3.2.1]oct-3-yl]-3-(1-methylethyl)-2-oxo-1H-benzimidazole-1-carboxamide hydrochloride), and 5-HT7 (LP44; 4-[2-(methylthio)phenyl]-N-(1,2,3,4-tetrahydro-1-naphthalenyl)-1-piperazinehexanamide, monohydrochloride) were used. These 5-HT receptor subtypes were selected based on their association with vascular smooth muscle relaxation. While all three 5-HT receptor subtypes resulted in vasorelaxation (P &amp;lt; 0.05), the 5-HT2B agonist only stimulated a maximal relaxation of 32% compared with the agonists for 5-HT4 and 5-HT7 that resulted in maximal relaxation of 68% and 50%, respectively. The agonist for 5-HT4 produced the greatest relaxation in the ovine lateral saphenous vein and should be targeted in subsequent research. It is likely that the combined effect of binding multiple receptor subtypes contributes to the overall effect of 5-HT. The focus on development of ergot alkaloid mitigation strategies should consider the divergent responses of arteries and veins to serotonin in peripheral tissues.

412 Awardee Talk: New Insights into Mechanisms of Serotonin Receptor-Mediated Vasoactivity and Complex Interactions with Ergot Alkaloids in Bovine Vasculature

Abstract Ergovaline (ERV), produced in toxic endophyte-infected tall fescue, causes potent vasoconstriction of bovine vasculature by interacting with serotonin (5-HT) receptors. Ergovaline acts as a partial agonist of 5-HT2A-mediated vasoconstriction. The duration of ERV exposure affects 5-HT-mediated vasoactivity of mesenteric blood vessels. If ERV and 5-HT exposure occur simultaneously, ERV can increase 5-HT-mediated vasoconstriction. If 5-HT exposure occurs after blood vessels have had prior ERV exposure, increasing levels of 5-HT can induce vasorelaxation of blood vessels. To better understand mechanisms of 5-HT-mediated vasorelaxation, lateral saphenous veins from steers (n = 5) were assessed for vasoactivity in response to increasing concentrations of selective 5-HT receptor agonists Isolated vessel segments were suspended in chambers of a multi-myograph containing 5 mL of continuously oxygenated Krebs-Henseleit buffer and equilibrated to 1 g tension for 90 min. Vessels were pre-contracted with 1×10-4 M phenylephrine and exposed to increasing concentrations of 5-HT or 5-HT receptor agonists that were selective for 5-HT1B, 5-HT2B, 5-HT4, and 5-HT7. Vasoactive response data were normalized as a percentage of the maximum contractile response induced by the phenylephrine pre-contraction. Increasing concentrations of 5-HT resulted in divergent vasoconstriction and vasorelaxation responses that were dose-dependent. Serotonin caused an 86.3% increase (P &amp;lt; 0.01) in relaxation activity at 1×10-7 M and 5-HT caused a 166% increase (P &amp;lt; 0.01) in contraction activity at 1x10-4 M. Increasing concentrations of the selective 5-HT1B agonist did not result in any vasoactive response. Increasing concentrations of agonists selective for 5-HT2B, 5-HT4, or 5-HT7 resulted in a 27.3%, 91.6%, or 43.9% (P &amp;lt; 0.01) increase in maximal vasorelaxation activity. Of these 5-HT receptor agonists, the selective 5-HT4 receptor agonist resulted in the lowest -log IC50 value (6.30) compared with 5-HT2B and 5-HT7 receptor agonists (4.21 and 4.66, respectively). To confirm the involvement of 5-HT4 in 5-HT-mediated vasorelaxation, blood vessels were exposed to either DMSO (control), a selective 5-HT2A antagonist (1×10-5M), or selective antagonists of 5-HT2A and 5-HT4 simultaneously for 5-min before the pre-contraction with phenylephrine and additions of 5-HT. Antagonism of the 5-HT2A receptor did not result in increased vasorelaxation activity compared with control. Antagonism of the 5-HT2A receptor and 5-HT4 receptor simultaneously inhibited vasorelaxation activity and increased (P &amp;lt; 0.01) the maximal contractile response occurring at 1×10-4 M by 47% compared with control. Approximately 84% of the maximal vasorelaxation activity occurring in response to 5-HT could be accounted for through 5-HT4. These data provide strong evidence that 5-HT4 is the primary receptor involved with 5-HT-mediated vasorelaxation in bovine lateral saphenous vein. More research is needed to determine if 5-HT4-mediated vasorelaxation is responsible for relaxation responses observed in blood vessels with prior ERV exposure. This will aid in the development of strategies for alleviating symptoms of sustained vasoconstriction that occur during fescue toxicosis in ruminants.

Preparation and characterization of vaginal suppository of semisynthetic derivatives of ergot alkaloids cabergoline

BackgroundThere is evidence that vaginal cabergoline can help to prevent ovarian hyperstimulation syndrome. Therefore, the vaginal suppository may be a good choice because it can be administered directly into the vagina and has no adverse effects on the stomach. In this regard we developed a cabergoline suppository as an alternative to cabergoline tablets. Design-Expert was used to determine the most suitable concentrations of PEG 6000/400, and Tween 80 to obtain a stable suppository. Specific ratios of PEG6000/400 and Tween 80 were entered as factors, and release, melting time, and hardness were evaluated as responses. In addition, the final formulation was evaluated for weight changes, pH, drug content, degradation time, deformation time, in vitro drug release, DSC analysis, infrared spectroscopy, and stability properties. ResultsThe suppositories were all smooth and white. They all had a weight that averaged less than 5 %. The formulations showed a pH between 6 and 6.5. The active ingredient content ranged between 79.666 ± 8.54 % and 99.67 ± 6.55 %. Suppository stiffness was between 2.74 ± 0.04 and 4.20 ± 0.03. The decomposition time of the suppositories varied between 11.25 ± 0.15 to 20.19 ± 0.08 min. The deformation time was between 26.11 ± 0.06 to 38.59 ± 0.47 min. Cabergoline content was released over 45 min from formulations of F10 (∼46 %), F2 (∼64 %), F6 (∼69 %), F4 (∼79 %), F1 (∼88 %), and F7 (∼93 %). However, other formulations released more than 95 % within 45 min. ConclusionsAll variables except melting time significantly affected our responses. In vitro studies have indicated that the optimized cabergoline formula could be an excellent alternative to cabergoline oral formulations.