Ergot alkaloid mycotoxins: physiological effects, metabolism and distribution of the residual toxin in mice.

The complex ergot alkaloids, ergovaline and ergotamine, cause dysregulation of physiological functions, characterised by vasoconstriction as well as thermoregulatory and cardiovascular effects in grazing livestock. To assess the effect of the mycotoxins, blood pressure and heart rate of male mice were measured, and metabolite profiling undertaken to determine relative abundances of both ergotamine and its metabolic products in body and brain tissue. Ergotamine showed similar cardiovascular effects to ergovaline, causing elevations in blood pressure and reduced heart rate. Bradycardia was preserved at low-levels of ergovaline despite no changes in blood pressure. Ergotamine was identified in kidney, liver and brainstem but not in other regions of the brain, which indicates region-specific effects of the toxin. The structural configuration of two biotransformation products of ergotamine were determined and identified in the liver and kidney, but not the brain. Thus, the dysregulation in respiratory, thermoregulatory, cardiac and vasomotor function, evoked by ergot alkaloids in animals observed in various studies, could be partially explained by dysfunction in the autonomic nervous system, located in the brainstem.

Ergot alkaloid exposure during gestation alters: II. Uterine and umbilical artery vasoactivity1.

Previous research has shown that livestock exposed to ergot alkaloids results in decreased vasoactivity of gastrointestinal and peripheral vasculature. Little is known regarding the effect ergot alkaloid exposure during gestation may have on vasculature supporting the fetus. The objective of this study was to evaluate contractile responses of uterine and umbilical arteries collected from ewes consuming ergot alkaloids during gestation. On day 35 of gestation, 36 Suffolk ewes (78.24 ± 9.5 kg) were assigned to endophyte-infected (E+) or endophyte-free (E-) tall fescue seed treatments that were fed either throughout or switched on day 86 of gestation, creating four seed treatments E+E+, E+E-, E-E+, and E-E-. Ewes were fed E+ tall fescue seed to provide 1.77 mg of total ergovaline ⋅ hd-1 ⋅ d-1 with E- ewes receiving the same quantity of E- seed. Gestation was terminated on day 133, and sections of uterine artery and umbilical cord were surgically collected. Only collections from 28 ewes (n = 7/treatment) were of sufficient viability to proceed with the contractility experiments. Arteries were cleaned, sliced into 2-mm cross sections, and suspended in multi-myograph chambers containing 5 mL of continuously oxygenated Krebs-Henseleit buffer. Vessels were exposed to increasing concentrations (5 × 10-8 to 1 × 10-4 M) of norepinephrine, serotonin, ergotamine, and ergovaline (5 × 10-9 to 1 × 10-5M; extract of tall fescue seed) in 15-min intervals. Increasing concentrations of norepinephrine generated a contractile response by the uterine artery (P < 0.05), but no response in the umbilical artery. Increasing concentrations of serotonin resulted in negligible responses in uterine preparations, whereas umbilical artery preparations were responsive (P < 0.05) to serotonin. Ewes receiving E+E+ and E-E+ treatments had decreased vasoactivity in umbilical arteries to serotonin with a dextral shift in concentrations where the response curve initiated (P < 0.05). Interestingly, uterine arteries were not responsive to exposure to ergotamine or ergovaline, whereas umbilical arteries were responsive (P < 0.05). Umbilical arteries collected from ewes receiving E-E- and E+E- were more vasoactive to ergot alkaloids (P < 0.05) than other treatments. These findings indicate that maternal blood supply to the placenta appears protected from negative effects of ergot alkaloids; however, umbilical vasculature is not, and this could adversely influence fetal growth.

Insuficiencia arterial aguda severa vinculada a ergotismo / Severe acute arterial insufficiency linked to ergotism / Insuficiência arterial aguda severa vinculada a ergotismo

El ergotismo es un síndrome clínico poco frecuente pero potencialmente letal vinculado a la intoxicación aguda o crónica con el uso de alcaloides del ergot en el tratamiento de la migraña. Se caracteriza por un vasoespasmo severo generalizado que puede generar isquemia periférica o visceral y conducir a disfunción orgánica múltiple y muerte. Existen numerosos fármacos de metabolismo hepático que pueden alterar la metabolización de la ergotamina pudiendo alcanzar concentraciones tóxicas incluso a bajas dosis. Presentamos el caso de un paciente infectado con virus de la inmunodeficiencia humana bajo tratamiento antirretroviral que incluía inhibidores de la proteasa y que se había automedicado con ergotamina. El paciente presentó posteriormente sintomatología sensitivo motora deficitaria de miembros superiores e inferiores, acompañada de elementos de hipoperfusión distal severa. Se solicitó Doppler arterial que evidenció vasoespasmo de ejes arteriales de miembros. Se realizó diagnóstico de ergotismo secundario a la asociación de ergotamina - ritonavir, ingresando a cuidados intensivos. Se inició tratamiento en base a suspensión de ambos fármacos, vasodilatación arterial con nitroprusiato y antiagregación con ácido acetilsalicílico. En relación con este caso se presenta una revisión del mecanismo de toxicidad de la ergotamina, sus interacciones farmacológicas, así como diagnóstico y tratamiento disponibles para esta patología. (AU)

Ergotism is a rare but potentially lethal clinical syndrome linked to acute or chronic poisoning with the use of ergot alkaloids in the treatment of migraine. It is characterized by a severe generalized vasospasm that can generate peripheral or visceral ischemia and lead to multiple organ dysfunction and death. There are numerous drugs of hepatic metabolism that can alter the metabolism of ergotamine and can reach toxic concentrations even at low doses. We present the case of a patient infected with human immunodeficiency virus under antiretroviral treatment that included protease inhibitors and who had self-administered with ergotamine. The patient subsequently presented motor sensory deficit symptoms of upper and lower limbs, accompanied by elements of severe distal hypoperfusion. Arterial Doppler was requested, which showed vasospasm of the arterial axis of the limbs. A diagnosis of ergotism secondary to the ergotamine-ritonavir association was made, entering intensive care. Treatment was started based on suspension of both drugs, arterial vasodilatation with nitroprusside and antiaggregation with acetylsalicylic acid. In relation to this case, we present a review of the ergotamine toxicity mechanism, its pharmacological interactions, as well as the diagnosis and treatment available for this pathology. (AU)

O ergotismo é uma síndrome clínica pouco frequente, porém potencialmente letal vinculado à intoxicação aguda ou crônica pelo uso de alcalóides do Ergot no tratamento da enxaqueca. Caracteriza-se por um vaso espasmo severo generalizado que pode gerar isquemia periférica ou visceral e levar a disfunção orgânica múltipla e morte. Existem múltiplos fármacos de metabolismo hepático que podem alterar a metabolização da ergotamina podendo alcançar concentrações tóxicas inclusive em doses baixas. Apresentamos o caso de um paciente infectado com vírus da imunodeficiência humana recebendo tratamento antirretroviral que incluía inibidores da protease e que se automedicou com ergotamina. O paciente apresentou posteriormente sintomatologia sensitiva motora deficitária de membros superiores e inferiores, acompanhada de elementos de hipoperfusao distal severa. Solicitou-se Doppler arterial que mostrou vaso espasmo dos eixos arteriais de membros. Realizou-se diagnóstico de ergotismo secundário à associação ergotamina - ritonavir, e transferiu-se o paciente a cuidados intensivos. Iniciou-se tratamento com a suspensão de ambos os fármacos, vasodilatação arterial com nitroprussiato e antiagregaçao com ácido acetilsalicílico. Apresenta-se uma revisão do mecanismo de toxicidade da ergotamina, suas interações farmacológicas, seu diagnóstico e os tratamentos disponíveis para esta patologia. (AU)

Contractile Response of Bovine Lateral Saphenous Vein to Ergotamine Tartrate Exposed to Different Concentrations of Molecularly Imprinted Polymer.

Ergot alkaloids, in their active isomeric form, affect animal health and performance, and adsorbents are used to mitigate toxicities by reducing bioavailability. Adsorbents with high specificity (molecularly imprinted polymers: MIP) adsorb ergot alkaloids in vitro, but require evaluation for biological implications. Using ex vivo myography, synthetic polymers were evaluated for effects on the bioactivity of ergotamine tartrate (ETA). Polymers were first evaluated using isotherms. Lateral saphenous veins were collected from 17 steers for four independent studies: dose response of ETA, adsorbent dose response, validation of pre-myograph incubation conditions and MIP/ non-molecularly imprinted polymer (NIP) comparison. Norepinephrine normalized percent contractile response to increasing ETA exhibited a sigmoidal dose response (max: 88.47 and log of the effective molar concentration (EC50) (-log [ETA]) of 6.66 ± 0.17 M). Although sample preparation time affected contractile response (p < 0.001), pre-myograph incubation temperature (39 vs. 21 °C, 1 h) had no effect (p > 0.05). Isothermal adsorption showed a maximum adsorption of 3.27E-008 moles·mg-1 and affinity between 0.51 and 0.57 mg (R²: 0.83-0.92) for both polymers, with no significant difference between polymers (p > 0.05). No significant differences in maximum inhibitory (p = 0.96) and IC50 responses (p = 0.163) between MIP and NIP were noticed. Normalized percent contraction could be predicted from the in vitro adsorption data (R² = 0.87, p < 0.01), for both polymers. These studies indicate that synthetic polymers are potentially effective adsorbents to mitigate ergot toxicity caused by ergot alkaloids, with little evidence of significant differences between MIP and NIP in aqueous media.

Ergotism and factitious hypotension associated with interaction of ergotamine with CYP3A4 inhibitors.

BACKGROUND: Although uncommon, severe ergotism continues to occur. The purpose of this study is to describe causes and clinical effects of ergotism in recent years. METHODS: This is an observational case series with data obtained retrospectively from all patients with ergotism referred to Ramathibodi Poison Center in Bangkok, Thailand from January 2006 to August 2013. RESULT: Twelve cases of ergotism were identified. All cases involved ergotamine 1 mg/caffeine 100 mg combination tablets. Nine cases (75%) were precipitated by drug-drug interactions with CYP3A4 inhibitors. The other cases involved suicidal attempt (2 cases) and pediatric unsupervised ingestion (1 case). Ten patients (83%) had signs of peripheral vascular insufficiency. Five of these patients initially had factitiously low or unmeasurable blood pressure using non-invasive technique and had paradoxical increase following intravenous vasodilator administration. Two patients required partial foot amputations due to gangrene. Two patients, including a 15-month-old boy with an unsupervised ingestion, died. DISCUSSION: In this series, most cases of severe ergotism were associated with interaction with CYP3A4 inhibitors, which increase ergotamine bioavailability. Factitious low blood pressure in these cases was likely caused by severe vasospasm. CONCLUSION: Critical ergotism continues to occur in Thailand, most commonly associated with the drug-drug interactions.

Combined effects of fungal alkaloids on intestinal motility in an in vitro rat model.

Diarrhea is caused by factors that alter absorption and secretion of water and ions across the intestinal epithelium and disrupt motility. Parasitic infection, stress, poor nutrition, and exposure to plant or fungal toxins predispose livestock to noninfectious diarrhea. This is more prevalent in sheep that graze pastures infected with wild-type endophytic fungus, suggesting the involvement of fungal alkaloids. These increase smooth muscle contraction: ergovaline/ergotamine (ergot alkaloid) activates serotonin (5-HT) receptors, and lolitrem B (indole diterpene) inhibits large-conductance Ca2+-activated K+ (BK) channels. Because of their separate mechanisms of action the objective of this study was to investigate whether they act synergistically to increase smooth muscle contraction. Effects of ergotamine (1 µM) and lolitrem B (0.1 µM) on the tension and frequency of spontaneous contractions were investigated in a longitudinal preparation of isolated distal colon. The compounds were dissolved in 0.1% dimethyl sulfoxide (DMSO) and applied separately or together for 1 h. Ergotamine increased contractile tension compared to the pretreatment control (P<0.01) and produced a short-lived increase in frequency (P<0.001). Lolitrem B increased contractile tension (P<0.05) but had no effect on frequency. When applied together, the contractile tension was greater than the sum of the compounds applied separately (P<0.05). The frequency of contractions was increased (P<0.05) but was not significantly different from that for ergotamine alone. The increased contractile tension when both compounds were applied together indicates that ergotamine and lolitrem B acted synergistically to increase smooth muscle contraction, suggesting that they would alter motility in vivo.

Antagonism of lateral saphenous vein serotonin receptors from steers grazing endophyte-free, wild-type, or novel endophyte-infected tall fescue.

Pharmacologic profiling of serotonin (5HT) receptors of bovine lateral saphenous vein has shown that cattle grazing endophyte-infected (Neotyphodium coenophialum) tall fescue (Lolium arundinaceum) have altered responses to ergovaline, 5HT, 5HT2A, and 5HT7 agonists. To determine if 5HT receptor activity of tall fescue alkaloids is affected by grazing endophyte-free (EF), wild-type [Kentucky-31 (KY31)], novel endophyte AR542-infected (MAXQ), or novel endophyte AR584-infected (AR584) tall fescue, contractile responses of lateral saphenous veins biopsied from cattle grazing these different fescue-endophyte combinations were evaluated in presence or absence of antagonists for 5HT2A (ketanserin) or 5HT7 (SB-269970) receptors. Biopsies were conducted over 2 yr on 35 mixed-breed steers (361.5 ± 6.3 kg) grazing EF (n = 12), KY31 (n = 12), MAXQ (n = 6), or AR584 (n = 5) pasture treatments (3 ha) between 84 and 98 d (Yr 1) or 108 to 124 d (Yr 2). Segments (2 to 3 cm) of vein were surgically biopsied, sliced into 2- to 3-mm cross-sections, and suspended in a myograph chamber containing 5 mL of oxygenated Krebs-Henseleit buffer (95% O2/5% CO2; pH = 7.4; 37°C). Veins were exposed to increasing concentrations of 5HT, ergovaline, and ergovaline + 1 × 10(-5) M ketanserin or + 1 × 10(-6) M SB-269970 in Yr 1. In Yr 2, ergotamine and ergocornine were evaluated in presence or absence of 1 × 10(-5) M ketanserin. Contractile response data were normalized to a reference addition of 1 × 10(-4) M norepinephrine. In Yr 1, contractile response to 5HT and ergovaline were least (P < 0.05) in KY31 pastures and the presence of ketanserin greatly reduced (P < 0.05) the response to ergovaline in all pastures. However, presence of SB-269970 did not (P = 0.91) alter contractile response to ergovaline. In Yr 2, there was no difference in contractile response to ergotamine (P = 0.13) or ergocornine (P = 0.99) across pasture treatments, but ketanserin reduced (P < 0.05) the contractile response to both alkaloids. The 5HT2A receptor is involved in alkaloid-induced vascular contraction and alkaloid binding may be affected by exposure to different endophyte-fescue combinations.

Ergotamina e inhibidores de la proteasa: impacto clínico de las interacciones farmacológicas: presentación de dos casos / Ergotamine and protease inhibitors: clinical impact of drugs interactions: report of two cases

Las interacciones medicamentosas constituyen un factor relevante en lo que a la alteración de la terapéutica se refiere. Dicha importancia debería ser valorada de forma permanente y su detección y prevención deberían constituir dos de los ejes centrales de la actuación del equipo de salud en su ejercicio profesional. La polifarmacia y la automedicación son dos puntos a supervisar. A su vez, la subnotificación al ente regulatorio es una constante que impide la toma de medidas correctivas por parte del mismo. La difusión de alertas y la educación del paciente son medidas fundamentales en este aspecto. Se presentan dos casos que describen el impacto clínico de las interacciones en pacientes ambulatorios.

Drug interactions are a relevant factor as far as the alteration of therapy is concerned. Such an importance should be assessed on an ongoing basis and its detection and prevention should be two of the cornerstones of the health team's performance inpractice. Polypharmacy and self-medication are two points to be monitored. At the same time, the underreporting to the Regulating Entity is a constant that prevents it from taking corrective actions. Warnings dissemination and patient education are key steps at this point. Two cases are presented describing the clinical impact of the interactions on outpatients.

Ergotamina e inhibidores de la proteasa: impacto clínico de las interacciones farmacológicas: presentación de dos casos / Ergotamine and protease inhibitors: clinical impact of drugs interactions: report of two cases

Las interacciones medicamentosas constituyen un factor relevante en lo que a la alteración de la terapéutica se refiere. Dicha importancia debería ser valorada de forma permanente y su detección y prevención deberían constituir dos de los ejes centrales de la actuación del equipo de salud en su ejercicio profesional. La polifarmacia y la automedicación son dos puntos a supervisar. A su vez, la subnotificación al ente regulatorio es una constante que impide la toma de medidas correctivas por parte del mismo. La difusión de alertas y la educación del paciente son medidas fundamentales en este aspecto. Se presentan dos casos que describen el impacto clínico de las interacciones en pacientes ambulatorios.(AU)

Drug interactions are a relevant factor as far as the alteration of therapy is concerned. Such an importance should be assessed on an ongoing basis and its detection and prevention should be two of the cornerstones of the health teams performance inpractice. Polypharmacy and self-medication are two points to be monitored. At the same time, the underreporting to the Regulating Entity is a constant that prevents it from taking corrective actions. Warnings dissemination and patient education are key steps at this point. Two cases are presented describing the clinical impact of the interactions on outpatients.(AU)

Ergotamina e inhibidores de la proteasa: impacto clínico de las interacciones farmacológicas: presentación de dos casos / Ergotamine and protease inhibitors: clinical impact of drugs interactions: report of two cases

Las interacciones medicamentosas constituyen un factor relevante en lo que a la alteración de la terapéutica se refiere. Dicha importancia debería ser valorada de forma permanente y su detección y prevención deberían constituir dos de los ejes centrales de la actuación del equipo de salud en su ejercicio profesional. La polifarmacia y la automedicación son dos puntos a supervisar. A su vez, la subnotificación al ente regulatorio es una constante que impide la toma de medidas correctivas por parte del mismo. La difusión de alertas y la educación del paciente son medidas fundamentales en este aspecto. Se presentan dos casos que describen el impacto clínico de las interacciones en pacientes ambulatorios.(AU)

Drug interactions are a relevant factor as far as the alteration of therapy is concerned. Such an importance should be assessed on an ongoing basis and its detection and prevention should be two of the cornerstones of the health teams performance inpractice. Polypharmacy and self-medication are two points to be monitored. At the same time, the underreporting to the Regulating Entity is a constant that prevents it from taking corrective actions. Warnings dissemination and patient education are key steps at this point. Two cases are presented describing the clinical impact of the interactions on outpatients.(AU)

Solución del caso 24. Isquemia aguda de miembros inferiores secundaria a intoxicación crónica por ingesta de ergotamínicos / No disponible

No disponible

Ergovaline-induced vasoconstriction in an isolated bovine lateral saphenous vein bioassay.

Ergovaline has been proposed as a toxic component of endophyte-infected tall fescue. As many of the symptoms of fescue toxicosis are a result of compromised circulation, the objective of this study was to examine the vasoconstrictive potentials of ergovaline and a more documented ergopeptine, ergotamine, using a bovine, lateral (cranial branch) saphenous vein bioassay. Segments of the cranial branch of the lateral saphenous vein (2 to 3 cm) were collected from healthy, mixed breed cattle (n = 12 and n = 5 for the ergovaline and ergotamine experiments, respectively) at local abattoirs. The veins were trimmed of excess fat and connective tissue, sliced into 2- to 3-mm cross sections, and suspended in a myograph chamber containing 5 mL of a modified Krebs-Henseleit, oxygenated buffer (95% O2 + 5% CO2; pH = 7.4; 37 degrees C). The tissue was allowed to equilibrate at 1 g of tension for 90 min before of the addition of treatments. Increasing doses of ergovaline (1x10(-11) to 1 x10(-4) M) or ergotamine (1 x10(-11) to 1 x 10(-5) M) were administered every 15 min after buffer replacement. Contractile response data were normalized to a percentage induced by a reference dose of norepinephrine (1 x10(-4) M). Contractile responses of saphenous veins were similar for ergovaline and ergotamine. Initial contractile responses began at 1 x10(-8) M for both ergovaline and ergotamine (4.4 +/- 0.8% and 5.6 +/-1.1%, respectively). Vascular tension continued to increase as the alkaloid concentrations increased (maximums: 43.7 +/-7.1% at 1 x10(-5) M ergotamine; 69.6 +/- 5.3% at 1 x10(-4) M ergovaline). Interestingly, ergovaline-induced contractions (1 x10(-4) M) were not reversed by repeated buffer replacement over a 105-min period. As previously shown with ergotamine, these results confirm that ergovaline is a potent vasoconstrictor. The resistance of an ergovaline-induced contraction to relaxation over an extended period of time suggests a potential for bioaccumulation of this ergopeptine alkaloid and may aid in understanding its toxicity within the animal.

Embryo development and survival in beef cattle administered ergotamine tartrate to simulate fescue toxicosis.

Two experiments were performed to determine whether administration of ergotamine tartrate altered embryo development (Exp. 1) and uterine competency to establish pregnancy (Exp. 2) in beef cattle. Animals were fed daily either 0 (CON) or 40 mug/kg body weight of ergotamine tartrate (ERGOT). Following a 30-d period on respective diets, animals in Exp. 1 were artificial inseminated at estrus (d = 0) and single embryo recoveries performed on day 7; whereas, animals in Exp. 2 received two frozen-thawed embryos on day 7. As an indicator of ergotamine effects, prolactin was decreased throughout both experiments in ERGOT compared to CON animals (p<0.05). Furthermore, rectal temperature (RT) tended to increase during both experiments in ERGOT compared to CON (p= 0.06). In Exp. 1, embryo recovery (p=0.08) and the percentage of transferable embryos (p=0.09) tended to be greater for CON than for ERGOT. Percentage of embryos that developed to compacted morula or greater was increased for CON compared to ERGOT heifers (p<0.05). In Exp. 2, pregnancy rates of transferred embryos did not differ between treatment groups. Thus, administration of ERGOT to simulate fescue toxicosis altered developmental potential of embryos, but does not appear to affect uterine competency to establish pregnancy.

Effects of administration of ergotamine tartrate on fertility of yearling beef bulls.

Sixteen yearling bulls were utilized to investigate administration of ergotamine tartrate on semen parameters, fertilization, and endocrinology. Bulls were allotted to a control diet of cracked corn, corn silage, and soybean meal (CON, n = 8) or a diet supplemented daily with 40 microg/kg body weight of ergotamine tartrate (ET, n = 8). Blood samples, average daily gain, scrotal circumference and rectal temperatures were collected every 14 day. Semen samples were obtained every 60 day and evaluated for motility and morphology. Scrotal temperatures were obtained by thermography immediately before electroejaculation. Semen from a subset of bulls from each treatment was also evaluated for in vitro fertilization. Administration of ET increased rectal temperature and resulted in lower scrotal temperatures compared to CON bulls (P < 0.05). However, prolactin, scrotal circumference, testosterone, and semen motility and morphology did not differ between groups throughout the experimental period (224 day). Cleavage rates of embryos derived from in vitro fertilization (IVF) with semen of bulls, fed with ET, were reduced compared to CON (P < 0.05); however, development of cleaved embryos to blastocyst did not differ between treatments. In conclusion, extended exposure of bulls to ET appeared to reduce fertilization potential of sperm.

Valvulopatía por uso de ergotamina / Valvular heart disease associated with ergotamine

La ergotamina se usa para tratar o prevenir migrañas. Las reacciones adversas más comunes son náuseas, vómitos, mialgias, diarreas o xerostomía; su uso está contraindicado en la enfermedad vascular periférica por la producción de vasoespasmos o en enfermedades hepáticas por su metabolización en esta localización. La afección cardíaca es mucho menos frecuente y conocida. Describimos los casos de 2 pacientes con uso crónico de ergotamina con repercusión valvular cardíaca

Ergotamine is used to abort or prevent migraine. The most common adverse reactions are nausea, vomiting, myalgia, diarrhea or mouth dryness, and the contraindications are peripheral vascular disease because of its vasospastic effect, and liver disease because the drug is metabolized in this organ. Its effects on the heart are less frequent and less well known. We report two patients on long-term ergotamine treatment who developed valvular disorders

Ergot alkaloid transport across ruminant gastric tissues.

Ergot alkaloids cause fescue toxicosis when livestock graze endophyte-infected tall fescue. It is generally accepted that ergovaline is the toxic component of endophyte-infected tall fescue, but there is no direct evidence to support this hypothesis. The objective of this study was to examine relative and potential transport of ergoline and ergopeptine alkaloids across isolated gastric tissues in vitro. Sheep ruminal and omasal tissues were surgically removed and placed in parabiotic chambers. Equimolar concentrations of lysergic acid, lysergol, ergonovine, ergotamine, and ergocryptine were added to a Kreb's Ringer phosphate (KRP) solution on the mucosal side of the tissue. Tissue was incubated in near-physiological conditions for 240 min. Samples were taken from KRP on the serosal side of the chambers at times 0, 30, 60, 120, 180, and 240 min and analyzed for ergot alkaloids by competitive ELISA. The serosal KRP remaining after incubation was freeze-dried and the alkaloid species quantified by HPLC. The area of ruminal and omasal tissues was measured and the potential transportable alkaloids calculated by multiplying the moles of transported alkaloids per square centimeter of each tissue type by the surface area of the tissue. Studies were conducted to compare alkaloid transport in reticular, ruminal, and omasal tissues and to determine whether transport was active or passive. Ruminal tissue had greater ergot alkaloid transport potential than omasal tissue (85 vs 60 mmol) because of a larger surface area. The ruminal posterior dorsal sac had the greatest potential for alkaloid transport, but the other ruminal tissues were not different from one another. Alkaloid transport was less among reticular tissues than among ruminal tissues. Transport of alkaloids seemed to be an active process. The alkaloids with greatest transport potential were lysergic acid and lysergol. Ergopeptine alkaloids tended to pass across omasal tissues in greater quantities than across ruminal tissues, but their transport was minimal compared to lysergic acid and lysergol.

Physiological responses of Brahman and Hereford steers to an acute ergotamine challenge.

Research was conducted to evaluate the sensitivity of Bos indicus and Bos taurus cattle to a tall fescue ergopeptine alkaloid by assessing vital sign responses. Eight Polled Hereford and seven Red Brahman steers received bolus i.v. injections of ergotamine tartrate and saline vehicle in a simple cross-over design. Physiological traits measured 30 min and immediately before and 30, 60, and 90 min after treatment were respiration rate, rectal temperature, skin temperature at the tailhead and tail tip, systolic and diastolic blood pressure, and heart rate. Blood samples were collected immediately before and 105 min after treatments to determine plasma prolactin and cortisol concentrations. Steers were fed a fescue-free diet in drylot. Ambient temperature and relative humidity averaged 31 degrees C and 55%, respectively, during data collection. No breed x treatment x time interactions were apparent for vital signs. The treatment x time interaction was significant (P < .05) for blood pressure and skin temperature. Ergotamine increased (P < .01) blood pressure and decreased (P < .01) skin temperature. The breed x treatment x time interactions were significant for prolactin (P < .1) and cortisol (P < .01). Ergotamine decreased plasma (P < .01) prolactin and increased (P < .01) cortisol concentrations in both breeds, despite some breed variation. Across all traits, Brahman and Hereford steers responded similarly to acute ergotamine exposure, indicating that the breeds are alike in acute sensitivity to a systemically administered ergopeptine alkaloid associated with fescue toxicosis.

Increased proinflammatory cytokines production by ergotamine in male BALB/c mice.

The ergopeptine alkaloid ergotamine (ET) mimics the effects of ergopeptine alkaloids found in endophyte-infected (E+) fescue forage considered causative for fescue toxicosis. Altered immune capacity, compromised intake and thermoregulation, and inflammatory changes are observed in fescue toxicosis. Taken together, these suggest the cytokine pattern may be altered by ergot alkaloids. Thus, the objective of this study was to determine whether major splenocyte-derived cytokines--interleukin 2 (IL-2), interleukin 4 (IL-4), interferon gamma (IFN-gamma)--and macrophage-derived cytokines--interleukin 1beta, (IL-1beta), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-alpha)--were affected by ergotamine. Two sets of male BALB/c mice (n = 5/treatment) were treated with ergotamine tartrate (s.c.) for 10 d at doses of 0 (control), 0.4, 2, 10, or 50 mg/kg body weight. Twenty-four hours after the last treatment, splenocytes (S) were isolated from one set of animals and macrophages (Mphi) from the other set for determination of IL-2, IL-4, INF-gamma, and IL-1beta, IL-6, TNF-alpha, respectively. Following activation with 5 microg/ml concanavalin A (Con A) (S) and 10 microg/ml lipopolysaccharide (LPS) (Mphi), cells were incubated for 48 and 24 h, respectively, and supernatants were collected and assayed for respective cytokines by enzyme-linked immunosorbent assay (ELISA). Additionally, differential white blood cell (WBC) counts were performed and the neutrophil (N):lymphocyte (L) ratio calculated. Ergotamine treatment significantly increased IL-6 levels at the 2.0 mg/kg dose and greater and TNF-alpha at the highest dose. There was no treatment effect on IL-1beta, IL-2, IL-4, and IFN-gamma. Also, no effect was observed upon total and differential WBC counts as well as N:L ratio. Ergotamine affected the proinflammatory cytokine IL-6, and this increase may contribute to fescue tosicosis.

Evaluation of physiologic indices in mice vaccinated with protein-ergotamine conjugates and fed an endophyte-infected fescue diet.

OBJECTIVES: To assess effects of vaccination against fescue toxicosis on weight gain, serum prolactin and cholesterol concentrations, and alkaline phosphatase (ALP) activity in mice fed an endophyte-infected (EI) or endophyte-free (EF) fescue diet. ANIMALS: 50 six-week-old male BALB/c mice. PROCEDURE: Mice were randomly allocated to the following 5 groups: 1, vaccinated intraperitoneally with a bovine serum albumin-ergotamine (EG) conjugate and fed an EI fescue diet; 2, orally vaccinated with cholera toxin (CT) subunit B-EG conjugate mixed with free CT and fed an EI fescue diet; 3, not vaccinated and fed an EI fescue diet; 4, passively vaccinated with monoclonal antibodies specific for ergovaline (EV) and fed an EI fescue diet; and 5, not vaccinated and fed an EF fescue diet. RESULTS: Antibodies against EG and EV were in serum of mice of groups 1 and 4, respectively. Secretory IgA and IgG coproantibodies against EG were induced in mice of group 2. Weight increased in groups 1 and 2 and tended to be increased in group 4 versus group 3. Prolactin concentration was similar in all groups; cholesterol concentration was decreased in groups 1, 3, and 4, compared with group 5. Compared with that in group 5, serum ALP activity decreased in groups 1 and 4 and was further decreased in group 1, compared with that in groups 2 and 3; it was negatively correlated with anti-EG titer. CONCLUSIONS AND CLINICAL RELEVANCE: Induction of anti-EG antibodies and administration of EV monoclonal antibodies tended to increase short-term weight gain in this murine model of fescue toxicosis. However, systemic IgG antibodies against EG or EV antibodies were not protective against decreases in serum ALP activity and cholesterol concentrations. Clinical significance of decreased ALP activity associated with vaccination is unknown, but represents a worsening of a response often associated with fescue toxicosis in cattle.