The beta-agonist clenbuterol in mane and tail hair of horses.

REASONS FOR PERFORMING STUDY: The beta2-agonist clenbuterol is commonly administered for therapeutic purposes in the horse, but its use an an anabolic agent is illegal. Clenbuterol can be detected in blood and urine for a relatively short period after administration and detection in hair could enhance the analytical range and be used to determine the history of clenbuterol application. HYPOTHESIS: That detection in mane or tail hair is possible over an extended period. METHODS: Four horses received 0.8 microg clenbuterol hydrochloride/kg bwt b.i.d. for 10 days. Four other horses were used as untreated controls. Blood, urine, mane and tail hair samples were taken on Day 0 (before) and 5, 10, 30, 35, 40, 60, 90, 120, 150 and 360 days after start of treatment. Gas chromotography/high resolution mass spectrometry (GC/HRMS) was developed for clenbuterol analysis: limit of detection was 0.2 pg/mg; intra-assay repeatability limit r = 0.06 (confidence level 95%); interassay repeatability limit r = 0.03 (confidence level 95%). Prior to treatment, clenbuterol was absent from all samples analysed. RESULTS: Clenbuterol was detectable as early as Day 5 in tail and mane hair of Segment 1 (0-20 mm from the roots) and was maximal on Day 90. However, as time progressed, shift into lower 20 mm segments was observed. On Day 360, the maximum concentration (up to 21 pg/mg) was located in Segment 13, i.e. 26-28 cm from roots of hair. Clenbuterol was not detectable in blood or urine after Day 30. Mane and tail hair results were very similar. CONCLUSIONS: The study showed that the beta-agonist clenbuterol can be found in mane and tail hair of horses after extended periods. POTENTIAL RELEVANCE: It will be possible to detect clenbuterol in breeding and show horses where anabolic drugs have been used illegally to improve conformation. This method may also be helpful to monitor therapeutic clenbuterol treatment.

Potential parameters for the detection of hGH doping.

The aim of our hGH application study with non-competitive athletes was the investigation of selected serum parameters from different processes affected by hGH. Fifteen athletes (age 21-33, mean 24) were treated with 0.06 IU hGH/kg BW per day or placebo (10 hGH, 5 placebo) respectively for 14 days. Blood samples were taken prior to, during and until 10 weeks after treatment. The concentrations of the following markers were determined in relevant serum samples: IGF-I, IGFBP-3, ALS, PIIINP, PINP, osteocalcin, and leptin. The IGF-I concentration increased rapidly within the hGH treatment group and showed significantly higher levels compared to baseline even 3 days after application. The response of the IGFBP-3 to the hGH applications was lower in comparison to IGF-I. The hGH group showed an increasing IGFBP-3 compared to baseline from day 4 till day 15. The response of PIIINP to hGH is clearly delayed compared to the IGF-I axis, but the PIIINP concentration remains on an increased level for a longer period (from day 4 until day 21). The time course and the extent of response varied strongly interindividually. PINP and osteocalcin showed only a small response to hGH applications. These parameters are characterised by a strong scattering of base values compared with the small response. In the hGH treatment group very different leptin concentrations were found at the beginning of the study, but after treatment decreasing leptin levels were observed in all cases. The determination of only one parameter will not be sufficient for detection of hGH abuse. A combination of markers by mathematical methods can be helpful to distinguish between placebo and hGH-treated athletes. By using the suggested discriminant function the data sets of hGH and placebo-treated athletes could be separated without false positive results.

Determination of cannabinoids by gas chromatography-mass spectrometry and large-volume programmed-temperature vaporiser injection using 25 microl of biological fluid.

This paper presents a GC-MS confirmation method, based on large-volume programmed-temperature vaporisation (PTV) injection, for the determination of cannabinoids in plasma samples (or whole blood) with deuterium-labelled internal standards using only 25 microl of biological fluid. The analytes, Delta(9)-tetrahydrocannabinol (THC), 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC) and 11-nor-9-carboxy-Delta 9-tetrahydrocannabinol (THC-COOH), were enriched by means of solid-phase extraction cartridges containing octadecyl-bonded silica and were, subsequently, methylated. A 20 microl aliquot of an extract in hexane was injected into a PTV in solvent split mode. Method development and the results of the analyses of standard reference material and real samples are presented and discussed. This micro-method is precise and sensitive enough to assess relevant cannabinoid levels in human blood for forensic investigations as well as for clinical applications.

Introduction to the application of capillary gas chromatography of performance-enhancing drugs in doping control.

Performance-enhancing drugs banned by antidoping rules are detected in doping control preferably by hyphenated chromatographic techniques, capillary gas chromatography in particular. Based on the prohibited classes of substances and on the general aspects of sample collection and preparation, a survey is given about the usual procedures of screening, identification and confirmation of the most important doping agents: stimulants, narcotics, anabolics, diuretics, beta-blockers. In addition to gas chromatography itself, the application of various MS techniques doping is outlined.

[Fatal propane-butane poisoning]. / Tödliche Intoxikationen durch Propan-Butan.

Two lethal poisonings by butane and propane are described, and the corresponding concentrations in the body fluids and organ tissues are evaluated. One case appeared to be an accident after deliberate inhalation for butane, one was a suicide. The mechanism of the inhalation could be reconstructed in both cases. The concentrations in the biological material agreed well with observations in similar cases.

[Comparison of the body burden of the population of Leipzig and Munich with the heavy metals cadmium, lead and mercury--a study of human organ samples]. / Vergleich der Belastung der Bevölkerung im Leipziger und Münchner Raum mit den Schwermetallen Kadmium, Blei und Quecksilber--eine Untersuchung an menschlichem Organmaterial.

In the former GDR it was almost impossible to perform studies on environmental pollution. Therefore, a short time after the opening of the German interior border the authors started an investigation on the heavy metal burden of humans in the former District of Leipzig (Saxonia). In 1990/91 tissues from 57 deceased were collected from this region. The concentrations of cadmium were determined in specimens from the liver and renal cortex, of mercury in liver, renal cortex and grey matter of the cerebrum and of lead in samples of the pelvic bone and the cortical part of the femur. After sample pretreatment, the heavy metal concentrations were determined by GF-AAS or CV-AAS. The results were compared with studies recently performed by the authors in the region of Munich (southern Bavaria, FRG) and with values from the literature. It was found that the burden with cadmium was similar in both regions, whereas on the average, the bone lead concentrations in Leipzig were 10 times (!) higher than in Munich. Considering dental amalgam as main factor for the burdening with inorganic mercury, the mercury concentrations in the liver and the renal cortex were of the same order of magnitude in both regions. In contrast to this, significantly higher mercury concentrations were found in the brain samples from Leipzig than from Munich. Possible negative health effects of these elevated lead and mercury burden in the Leipzig area are discussed.

Influence of the status of the renin-angiotensin system on the effect of cilazapril on neointima formation after vascular injury in rats.

BACKGROUND: Angiotensin converting enzyme (ACE) inhibition has been shown to prevent neointima formation after vascular injury in rats. However, clinical results evaluating restenosis after angioplasty have been negative. The goal of the present study was to evaluate the influence of the renin-angiotensin system (RAS) status on the effect of ACE inhibition on neointima formation. METHODS AND RESULTS: Arterial injury was produced by ballooning the left carotid artery of rats, and neointima formation was evaluated by morphometry 2 weeks after ballooning. The effects of cilazapril were assessed in four experimental groups: normotensive rats, spontaneously hypertensive rats, hypertensive rats with a renal artery stenosis induced by clipping (two-kidney, one-clip rats), and hypertensive rats with uninephrectomy, high salt intake, and administration of deoxycorticosterone (DOCA). In parallel groups of rats, measurement of plasma renin activity was made in order to characterize (at least at the plasma level) the status of the RAS. As expected, renal artery stenosis markedly increased plasma renin activity, and DOCA decreased it to undetectable levels. Cilazapril had a marked preventive effect on neointima formation in normotensive rats, spontaneously hypertensive rats, and two-kidney, one-clip rats but was ineffective in DOCA rats. CONCLUSIONS: We conclude that the status of the RAS has a major influence on the effect of cilazapril on neointima formation after vascular injury.

[The environment and health. Environmental pollution and its health effects]. / Umwelt und Gesundheit. Umweltschäden und ihre gesundheitlichen Auswirkungen.

Both environment and health are terms of far-reaching meaning, which impedes a complete survey of their interactions. Originating from considerations about global phenomena, as e.g. the extinction of biological species, of the so called "forest dying", or of the extensive consumption of energy and material resources, on the hierarchy of effects on health of environmental damages on one hand or on the undisputable adaptivity of man in particular on the other, only actual examples are outlined. The groups of dioxins, asbestos and radon are outlined, considering them as representatives for the vast number of substances potentially harmful to the environment and for the complexity of the toxicological and oecological interactions with oecosphere, biosphere and man. By the examples, the principles of toxicological/oecological thinking are explained, finally never resulting in yes/no alternatives, but in compromises by sober balances of risk and benefit. The basically correct vigilance of the public against avoidable risks may not lead to hysteric reactions, impeding the concentration onto necessary and practicable solutions.

[Matrix effects from the thanatochemical viewpoint]. / Matrixeffektive thanatochemisch betrachtet.

The predominating hydrophilic physiological body constituents are not interfering severely during the toxicological analysis for organic poisons in biological matrices, whereas coextracted lipids are usually well distinguishable from xenobiotics. But interfering substances increase strongly with autolysis, and some of them behave like toxicologically relevant compounds to be detected by the respective analytical methods. Attempts are reaching from the STAS' isolation procedure through the ptomaines to our chromatographical epoche, to phenomenologically compensate the matrix effects--increasing in the course of putrefaction--by the determination and generalisation of according analytical signals. The paper outlines on the background of Systematic Toxicological Analysis how far a systematic thanatochemical concept should be considered more closely for the futural more effective analytical elimination of such matrix effects.

Role of angiotensin II in injury-induced neointima formation in rats.

Angiotensin converting enzyme inhibition markedly suppresses neointima formation in response to balloon catheter-induced vascular injury of the rat carotid artery. To determine whether this effect was mediated through the vasoactive peptide angiotensin II (Ang II), two approaches were followed. First, the balloon model was used to compare the effects of continuous infusion of Ang II, with and without concurrent converting enzyme inhibition by cilazapril; second, the effects of the orally active nonpeptidic Ang II receptor antagonist DuP 753 were analyzed. Morphometric analysis was performed at 14 days after balloon injury. Animals that received continuous infusion of Ang II (0.3 micrograms/min/rat) were found to have significantly greater neointima formation in response to balloon injury than controls. Animals treated with cilazapril (10 mg/kg/day) had markedly reduced neointima formation, but in animals receiving infusion of Ang II, treatment with cilazapril did not suppress development of neointimal lesions. In the second group of experiments, DuP 753 (10 mg/kg twice daily) was as effective to prevent neointima formation as cilazapril. These data support the conclusions that converting enzyme inhibition prevents neointima formation after vascular injury through inhibition of Ang II generation.

Heparin and cilazapril together inhibit injury-induced intimal hyperplasia.

Both heparin and the angiotensin converting enzyme inhibitor cilazapril inhibit intimal thickening in rat carotid arteries injured by the passage of a balloon catheter. The purpose of this study was to determine if combinations of the two drugs were more effective than either drug alone and whether the effect could be accounted for by inhibition of smooth muscle cell proliferation. Heparin (0.1-0.3 mg/kg/hr) administered by continuous intravenous infusion with or without cilazapril (0-25 mg/kg/day p.o.) produced a dose-dependent inhibition of smooth muscle accumulation at 14 days after rat carotid ballooning. At the lower doses, the inhibitory effects of heparin and cilazapril were additive when the drugs were used together. This overall effect on growth was reflected in decreased smooth muscle cell proliferation at 2 and 7 days. A 7-day course of heparin combined with cilazapril, a regimen that might be applicable in the clinical setting, produced an 80% inhibition of intimal thickening at 28 days. These results provide evidence that heparin and cilazapril together might prove to be more effective than either drug alone in the control of intimal hyperplasia after arterial injury.

Cardiovascular effect of low-dose epinephrine infusions in relation to the extent of preoperative beta-adrenoceptor blockade.

The relationship between the extent of preoperative beta-adrenoceptor blockade and the hemodynamic properties of epinephrine was investigated in patients scheduled for elective myocardial revascularization during the immediate preoperative period under steady-state hemodynamic and anesthetic conditions. Twenty patients had been treated with beta-adrenoceptor blocking drugs for at least 3 weeks before the study; 11 unblocked patients served as control group. The extent of clinical beta-adrenoceptor blockade was quantified using the isoproterenol sensitivity test. The dose of isoproterenol required to increase heart rate by 25 beats per min was defined as the chronotropic dose 25 (CD25), representing the degree of beta-adrenoceptor blockade. Geometric mean CD25 per 70 kg was 3.0 micrograms in the control group and 21.8 micrograms in the patients receiving beta-adrenoceptor blocking drugs. The authors found a significant inverse relationship between CD25 values and changes in cardiac index in response to three epinephrine infusion rates (0.01, 0.02, and 0.04 micrograms.kg-1.min-1), the correlation coefficients being -0.71, -0.81, and -0.86, respectively. Compared to unblocked patients, almost no change, or even a decrease, of the cardiac index was observed at greater degrees of clinical beta-adrenoceptor blockade, particularly in patients receiving nonselective blockers. Moreover, there was a significant linear correlation (r = 0.76-0.86) between CD25 values and the effects of epinephrine on systemic vascular resistance index (SVRI); i.e., SVRI significantly decreased in control patients but markedly increased in patients with high degrees of preoperative beta-adrenoceptor blockade. This unmasked vasoconstrictive response to low doses of epinephrine was observed despite the fact that the majority of our patients had received cardioselective adrenergic blocking drugs.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of the vascular response to injury: the role of angiotensin-converting enzyme inhibitors.

Smooth muscle cell proliferation and formation of extracellular matrix are parts of the repair process after vascular injury. Similar processes occur after coronary angioplasty and, in approximately 33% of vessels, lead to intimal hyperplasia and vascular restenosis within 6 months after angioplasty. In a rat model of balloon catheterization, the proliferative response to balloon injury was reduced by 70% and the area of vascular wall covered by lesion formation was decreased by 45% in rats treated with the angiotensin-converting enzyme inhibitor cilazapril. Other antihypertensive agents were much less active when tested for suppression of intimal hyperplasia after balloon injury: verapamil 0%, minoxidil 4% and hydralazine 34%. For cilazapril at the dose of 10 mg/kg per day, approximately 20% greater suppression of intimal hyperplasia was seen when the treatment was started 6 days before balloon injury. Treatment of rats from the time of balloon catheterization with both cilazapril (10 mg/kg per day) and heparin infusion (0.3 mg/kg per h) resulted in essentially complete (greater than 90%) inhibition of intimal hyperplasia. These data indicate that the angiotensin-converting enzyme inhibitor cilazapril specifically inhibits the proliferative response to balloon injury and that heparin and cilazapril inhibit intimal hyperplasia through different mechanisms. The data also suggest that the use of pharmacologic combinations may have therapeutic usefulness to prevent late restenosis after coronary angioplasty.

Vascular protection with cilazapril.

The hypertrophy of the media of coronary arteries associated with hypertension reduces cross-sectional area and limits vascular reserve. Cilazapril 10 mg/kg daily decreased cardiac hypertrophy, and decreased minimal coronary vascular resistance by 40% when administered to spontaneously hypertensive rats (SHR) at the onset of hypertension. After hypertension had developed, cilazapril restored arterial pressure to normal and increased the maximal coronary blood flow in isolated perfused hearts by 96%, which was probably a result of a marked decrease in medial hypertrophy of the coronary arteries. Similarly, cilazapril improved cerebral vascular reserve in the mesenteric and renal arteries of SHR. In the rat model of vascular injury produced by ballooning, cilazapril 10 mg/kg daily demonstrated a marked preventive effect on the myointimal proliferation that resulted in untreated controls, a phenomenon responsible for restenosis in humans after arterial angioplasty. Although this effect occurred with usual antihypertensive dosages in rats, it appeared to be independent of the decrease in arterial pressure since effective antihypertensive dosages of verapamil did not prevent neointima formation. In view of the clinical potential for preventing restenosis after coronary angioplasty, 2 multicentre trials of cilazapril are ongoing to test this hypothesis.

[Blood alcohol in automobile drivers--a comparison between Saarland and West Saxony]. / Blutalkohol bei Verkehrsteilnehmern--Ein Vergleich zwischen dem Saarland und Westsachsen.

The Saarland and Saxony have not only been located at the western respectively at the eastern border of Germany (or of the then separated both German states). Different law regulations and lifestyles seemed to be an additional reason for different incidences of blood alcohol. Therefore, the blood alcohol cases of the university institutes for legal medicine of both provinces were statistically compared for 1989. Beyond some difficulties in the comparison itself due to different definitions and managements, equal or similar patterns dominated by far against discrepancies. The slightly different regulations for quality assurance were also compared with the expectation of their equalisation during the next future.

Cilazapril suppresses myointimal proliferation after vascular injury: effects on growth factor induction in vascular smooth muscle cells.

Smooth muscle cell proliferation and formation of extracellular matrix in the intima of muscular arteries after vascular injury can lead to severe intimal hyperplasia and stenosis. Cilazapril reduces intimal hyperplasia induced by balloon catheterization of the rat carotid artery by 80%, and significantly decreases the surface area covered by proliferative lesions. We investigated the effects of angiotensin II (A II) on SMC proliferation in cell culture and A-II induction of selected growth factor or growth-related genes in SMC in culture: PDGF A chain, TGF-beta, thrombospondin, c-myc and c-fos, and compared the influence of cilazapril on these responses to A II. A-II induced SMC proliferation, stimulated mRNAs for c-myc and c-fos after 30 min, and stimulated mRNAs for PDGF A chain, TGF-beta, and thrombospondin somewhat later. The ACE inhibitor did not have detectable independent effects on the A-II induced proliferation or gene expression. Thus, these data support the conclusion that cilazapril suppresses SMC proliferation in vivo through the block of conversion of A I to A II, and that A II has a critical and central role in the control of the proliferative response after balloon catheter-induced vascular injury.

The proliferative response to vascular injury is suppressed by angiotensin-converting enzyme inhibition.

Smooth muscle cell (SMC) proliferation and formation of extracellular matrix in the intima of muscular arteries are major processes that can lead to vascular stenosis in arteriosclerosis or after coronary angioplasty. These processes are also seen in the proliferative response to balloon catheter-induced vascular injury of the rat carotid artery, and result in marked neointima formation by 14 days after catheterization. We have shown recently that the angiotensin-converting enzyme (ACE) inhibitor cilazapril strongly suppressed this development of neointima. In this report, we show that the beneficial effects on neointima formation persist for at least 8 weeks after stopping treatment with cilazapril, and that continuous treatment may have additional inhibitory effects during the late phases of vascular remodeling after injury. To investigate further the possible mechanisms, we examined several vasoactive compounds in this model. Another ACE inhibitor of a different chemical class, captopril, reduced neointima formation as strongly as cilazapril (67 and 78%, respectively), but the calcium antagonist verapamil was not active as an inhibitor of neointima formation, despite similar lowering of blood pressure. Hydralazine and a new calcium antagonist, Ro 40-5967, partially suppressed neointima formation (36%, p less than 0.005 and 33%, p less than 0.05, respectively). In vitro, neither cilazapril nor its active metabolite, cilazaprilate, had any effect on SMC proliferation in response to serum or PDGF. To characterize further the role of angiotensin II (Ang II), we tested in cell culture the effects of Ang II and cilazaprilate on mRNA levels of several proteins potentially involved in regulating the SMC response.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibitors of angiotensin-converting enzyme prevent myointimal proliferation after vascular injury.

The role of a local angiotensin system in the vascular response to arterial injury was investigated by administering the angiotensin-converting enzyme (CE) inhibitor cilazapril to normotensive rats in which the left carotid artery was subjected to endothelial denudation and injury by balloon catheterization. In control animals, by 14 days after balloon injury, the processes of smooth muscle cell (SMC) proliferation, migration of SMCs from the media to the intima, and synthesis of extracellular matrix produced marked thickening of the intima, with reduction of the cross-sectional area of the lumen. However, in animals that received continuous treatment with the CE inhibitor, neointima formation was decreased (by about 80 percent), and lumen integrity was preserved. Thus, the angiotensin-converting enzyme may participate in modulating the proliferative response of the vascular wall after arterial injury, and inhibition of this enzyme may have therapeutic applications to prevent the proliferative lesions that occur after coronary angioplasty and vascular surgery.

Pharmacological profile of moclobemide, a short-acting and reversible inhibitor of monoamine oxidase type A.

The novel antidepressant moclobemide is a reversible inhibitor of monoamine oxidase (MAO), preferentially of type A. Moclomide was active in three animal models considered predictive for antidepressant activity: 1) it prevented dose-dependently akinesia and blepharospasm induced in mice and rats by Ro 4-1284, a short-acting amine releasing agent. Prevention of akinesia by moclobemide also depended upon the dose of Ro 4-1284. For comparison also, effects of cimoxatone, harmaline, tranylcypromine and clorgyline are presented: 2) in cats, it selectively and dose-dependently suppressed rapid eye movement sleep without disturbing the sleep-wakefulness cycle; and 3) in the behavioral despair test in mice, it decreased the immobility score to a similar degree as amitriptyline or imipramine. In addition, moclobemide potentiated 5-hydroxytryptophan-induced stereotypies in rats with a potency similar to cimoxatone and with a duration of action of less than 24 hr. Moclobemide had almost no effect on the spontaneous behavior in mice, rats, cats and monkeys. Only in higher doses, marginal sedation and slight impairment in motor performance were seen. Moclobemide did not prevent pilcarpine-induced salivation in mice, demonstrating the absence of anticholinergic activity. Blood pressure and heart rate of freely moving, spontaneously hypertensive rats were only slightly decreased for less than 3 hr. Moclobemide moderately potentiated the pressor effect of p.o. tyramine in rats. In conclusion, the reversible MAO inhibitor moclobemide is active in animal models sensitive to all major drugs used in the treatment of depression. In contrast to imipramine-like antidepressants, it lacks anticholinergic activity and it differs from classic MAO inhibitors by potentiating only weakly the pressor effect of p.o. tyramine.