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Maria Tsivou, Evangelia Giannadaki, Fiona Hooghe, Kris Roels, Wim Van Gansbeke, Flaminia Garribba, Emmanouil Lyris, Koen Deventer, Monica Mazzarino, Francesco Donati, Dimitrios G Georgakopoulos, Peter Van Eenoo, Costas G Georgakopoulos, Xavier de la Torre, Francesco Botrè
Urine collection containers used in the doping control collection procedure do not provide a protective environment for urine, against degradation by microorganisms and proteolytic enzymes. An in-house chemical stabilization mixture was developed to tackle urine degradation problems encountered in human sport samples, in cases of microbial contamination or proteolytic activity. The mixture consists of antimicrobial substances and protease inhibitors for the simultaneous inactivation of a wide range of proteolytic enzymes...
May 2017: Drug Testing and Analysis
P Ferro, G Krotov, I Zvereva, G Rodchenkov, J Segura
Growth hormone releasing peptides (GHRPs) could be widely used by cheating athletes because they produce growth hormone (GH) secretion, so may generate an ergogenic effect in the body. Knowledge of the essential amino acids needed in GHRP structure for interaction with the target biological receptor GHSR1a, the absorption through different administration routes, and the maintenance of pharmacological activity of potential biotransformation products may help in the fight against their abuse in sport. Several GHRPs and truncated analogues with the common core Ala-Trp-(D-Phe)-Lys have been studied with a radio-competitive assay for the GHSR1a receptor against the radioactive natural ligand ghrelin...
January 2017: Drug Testing and Analysis
Andreas Thomas, Christian Görgens, Sven Guddat, Detlef Thieme, Frank Dellanna, Wilhelm Schänzer, Mario Thevis
The analysis of low-molecular-mass peptides in doping controls has become a mandatory aspect in sports drug testing and, thus, the number of samples that has to be tested for these analytes has been steadily increasing. Several peptides <2 kDa with performance-enhancing properties are covered by the list of prohibited substances of the World Anti-Doping Agency including Desmopressin, LH-RH, Buserelin, Triptorelin, Leuprolide, GHRP-1, GHRP-2, GHRP-3, GHRP-4, GHRP-5,GHRP-6, Alexamorelin, Ipamorelin, Hexarelin, ARA-290, AOD-9604, TB-500 and Anamorelin...
January 2016: Journal of Separation Science
Ekaterina Semenistaya, Irina Zvereva, Grigory Krotov, Grigory Rodchenkov
Currently liquid chromatography - mass spectrometry (LC-MS) analysis after solid-phase extraction (SPE) on weak cation-exchange cartridges is a method of choice for anti-doping analysis of small bioactive peptides such as growth hormone releasing peptides (GHRPs), desmoporessin, LHRH, and TB-500 short fragment. Dilution of urine samples with phosphate buffer for pH adjustment and SPE on weak cation exchange microelution plates was tested as a means to increase throughput of this analysis. Dilution using 200 mM phosphate buffer provides good buffering capacity without affecting the peptides recoveries...
September 2016: Drug Testing and Analysis
Ekaterina Semenistaya, Irina Zvereva, Andreas Thomas, Mario Thevis, Grigory Krotov, Grigory Rodchenkov
Growth hormone releasing peptides (GHRPs) stimulate secretion of endogenous growth hormone and are listed on the World Anti-Doping Agency (WADA) Prohibited List. To develop an effective method for GHRPs anti-doping control we have investigated metabolites of GHRP-1, GHRP-2, GHRP-6, Hexarelin, and Ipamorelin in urine after nasal administration. Each compound was administrated to one volunteer. Samples were collected for 2 days after administration, processed by solid-phase extraction on weak cation exchange cartridges and analyzed by means of nano-liquid chromatography - high resolution mass spectrometry...
October 2015: Drug Testing and Analysis
David E Beck, W Brian Sweeney, Martin D McCarter
BACKGROUND: Postoperative ileus is a significant clinical challenge lacking effective management strategies. Ghrelin-receptor stimulation has promotility effects in the upper and lower gastrointestinal tract. OBJECTIVE: This proof-of-concept, phase 2, randomized study evaluated the safety and efficacy of the ghrelin-receptor agonist ipamorelin in the treatment of postoperative ileus following abdominal surgery ( NCT00672074). DESIGN: The design was a multicenter, double-blind, placebo-controlled, clinical trial...
December 2014: International Journal of Colorectal Disease
Mark Timms, Nikki Hall, Vita Levina, John Vine, Rohan Steel
The growth hormone releasing peptides (GHRPs) hexarelin, ipamorelin, alexamorelin, GHRP-1, GHRP-2, GHRP-4, GHRP-5, and GHRP-6 are all synthetic met-enkephalin analogues that include unnatural D-amino acids. They were designed specifically for their ability to stimulate growth hormone release and may serve as performance enhancing drugs. To regulate the use of these peptides within the horse racing industry and by human athletes, a method is presented for the extraction, derivatization, and detection of GHRPs from equine and human urine...
October 2014: Drug Testing and Analysis
Wai Him Kwok, Emmie N M Ho, Ming Yip Lau, Gary N W Leung, April S Y Wong, Terence S M Wan
In recent years, there has been an ongoing focus for both human and equine doping control laboratories on developing detection methods to control the misuse of peptide therapeutics. Immunoaffinity purification is a common extraction method to isolate peptides from biological matrices and obtain sufficient detectability in subsequent instrumental analysis. However, monoclonal or polyclonal antibodies for immunoaffinity purification may not be commercially available, and even if available, such antibodies are usually very costly...
March 2013: Analytical and Bioanalytical Chemistry
Andreas Thomas, Philippe Delahaut, Oliver Krug, Wilhelm Schänzer, Mario Thevis
New, potentially performance enhancing compounds have frequently been introduced to licit and illicit markets and rapidly distributed via worldwide operating Internet platforms. Developing fast analytical strategies to follow these new trends is one the most challenging issues for modern doping control analysis. Even if reference compounds for the active drugs are readily obtained, their unknown metabolism complicates effective testing strategies. Recently, a new class of small C-terminally amidated peptides comprising four to seven amino acid residues received considerable attention of sports drug testing authorities due to their ability to stimulate growth hormone release from the pituitary...
December 4, 2012: Analytical Chemistry
Andreas Thomas, Katja Walpurgis, Oliver Krug, Wilhelm Schänzer, Mario Thevis
In the present study, a screening assay was developed comprising 11 prohibited peptides (<1.5 kDa) that are sufficiently purified from urine using weak cation exchange with subsequent determination of all substances by means of nanoUHPLC separation coupled to high resolution tandem mass spectrometry. These peptides included Gonadorelin (LH-RH), Desmopressin and 9 growth hormone releasing peptides (GHRP-1, -2, -4, -5, -6, Hexarelin, Alexamorelin, Ipamorelin and a GHRP-2 metabolite); however, the procedure is expandable to further target analytes or metabolites...
October 12, 2012: Journal of Chromatography. A
Andreas Thomas, Sebastian Höppner, Hans Geyer, Wilhelm Schänzer, Michael Petrou, Dorota Kwiatkowska, Andrzej Pokrywka, Mario Thevis
A family of small peptides has reached the focus of doping controls representing a comparably new strategy for cheating sportsmen. These growth hormone releasing peptides (GHRP) are orally active and induce an increased production of endogenous growth hormone (GH). While the established test for exogenous GH fails, the misuse of these prohibited substances remains unrecognized. The present study provides data for the efficient extraction of a variety of known drug candidates (GHRP-1, GHRP-2, GHRP-4, GHRP-5, GHRP-6, alexamorelin, ipamorelin, and hexarelin) from human urine with subsequent mass spectrometric detection after liquid chromatographic separation...
August 2011: Analytical and Bioanalytical Chemistry
Kalina Venkova, William Mann, Richard Nelson, Beverley Greenwood-Van Meerveld
Ghrelin and ghrelin mimetics stimulate appetite and enhance gastric motility. The present study investigates whether ipamorelin, a selective growth hormone secretagogue and agonist of the ghrelin receptor, would accelerate gastrointestinal transit and ameliorate the symptoms in a rodent model of postoperative ileus (POI). Fasted male rats were subjected to laparotomy and intestinal manipulation. At the end of surgery, a dye marker was infused in the proximal colon to evaluate postsurgical colonic transit time, which was the time to the first bowel movement...
June 2009: Journal of Pharmacology and Experimental Therapeutics
Niels Kristian Aagaard, Thorbjørn Grøfte, Jacob Greisen, Kjell Malmlöf, Peter B Johansen, Henning Grønbaek, Hans Ørskov, Niels Tygstrup, Hendrik Vilstrup
OBJECTIVES: Growth hormone (GH) reduces the catabolic side effects of steroid treatment via effects on the amino-nitrogen metabolism. Ipamorelin is a synthetic peptide with GH releasing properties. We wished to study the metabolic effects of Ipamorelin and GH on selected hepatic measures of alpha-amino-nitrogen conversion during steroid-induced catabolism. DESIGN: Five groups of rats were included: (1) free-fed controls (2) pair-fed controls (3) prednisolone (delcortol, 4 mg x kg(-1) x day(-1)) (4) prednisolone and GH (1 mg x kg(-1) x day(-1)) (5) prednisolone and Ipamorelin (0...
October 2009: Growth Hormone & IGF Research
Chung-Man Yeung, Chi-Bun Chan, Norman Y S Woo, Christopher H K Cheng
Recent studies have indicated that ghrelin stimulates growth hormone release from the pituitary via the growth hormone secretagogue receptor (GHSR). We have previously isolated two GHSR subtypes from the pituitary of the black seabream Acanthopagrus schlegeli. In the present study, we have cloned and characterized ghrelin from the same fish species at both the cDNA and gene levels. The full-length seabream ghrelin cDNA, isolated from sea-bream stomach using a novel approach by exploiting a single conserved region in the coding region, was found to encode a prepropeptide of 107 amino acids, with the predicted mature ghrelin peptide consisting of 20 amino acids (GSSFLSPSQKPQNRGKSSRV)...
May 2006: Journal of Endocrinology
Ernest Adeghate, Abdul Samad Ponery
OBJECTIVE: To examine the effect of ipamorelin (IPA), a novel pentapeptide with a strong growth hormone releasing potency, on insulin secretion from pancreatic tissue fragments of normal and diabetic rats. MATERIALS AND METHODS: Diabetes mellitus was induced by streptozotocin (60 mg kg(-1)). Four weeks after the induction of diabetes, pancreatic tissue fragments of normal and diabetic rats were removed and incubated with different concentrations (10(-12) - 10(-6) M) of IPA...
December 2004: Neuro Endocrinology Letters
C B Chan, C K Fung, Wendy Fung, Margaret C L Tse, Christopher H K Cheng
The action of a number of growth hormone secretagogues (GHS) on growth hormone (GH) secretion and gene expression was studied in a primary culture of pituitary cells isolated from the black seabream Acanthopagrus schlegeli. The peptide GHS employed included growth hormone-releasing peptide (GHRP)-2, ipamorelin, and human ghrelin. The nonpeptide GHS employed included the benzolactam GHS L692,585 and the spiropiperidine GHS L163,540. Secreted GH was measured in the culture medium by an enzyme-linked immunosorbent assay (ELISA) method using a specific antibody against seabream GH...
October 2004: Comparative Biochemistry and Physiology. Toxicology & Pharmacology: CBP
Peter B Johansen, Yael Segev, Daniel Landau, Moshe Phillip, Allan Flyvbjerg
The growth hormone (GH) and insulin-like growth factor I (IGF-I) axis were studied in streptozotocin (STZ) diabetic and nondiabetic female mice following intravenous (IV) injection of the GH secretagogue (GHS) ipamorelin or saline. On day 14, blood samples were obtained before and 10 minutes after the injection. Livers were removed and frozen for determination of the mRNA expressions of the GH receptor, GH-binding protein, and IGF-I, and hepatic IGF-I peptide. Serum samples were analyzed for GH and IGF-I. Following ipamorelin injection, the GH levels were found to be 150 +/- 35 microg/L and 62 +/- 11 microg/L in the diabetic compared to the nondiabetic mice (P <...
April 2003: Experimental Diabesity Research
Bernd Peschke, Michael Ankersen, Michael Bauer, Thomas Kruse Hansen, Birgit Sehested Hansen, Karin Kramer Nielsen, Kirsten Raun, Lutz Richter, Lisbet Westergaard
In order to obtain more potent growth hormone secretagogues, a comparison of ipamorelin and NN703 suggested the addition of a polar group at the C-terminus of NN703. A study was conducted using constrained amines for this purpose. Here, substituted 4-piperidinylamino- and 4-dimethylaminopiperidino-substituents were found to give the most active compounds. A replacement of the 4-dimethylaminopiperidino-substituent with 4-hydroxypiperidino resulted in a series of compounds, which showed in vitro activity with EC(50) values in the low nanomolar range, and favourable kinetic properties, such as 40% oral bioavailability...
June 2002: European Journal of Medicinal Chemistry
L Jiménez-Reina, R Cañete, M J de la Torre, G Bernal
Growth hormone (GH) is secreted in the anterior pituitary gland by the somatotroph cells. Secretion is regulated by growth hormone releasing hormone (GHRH) and somatostatin. Morever, GH secretagogues (GHS) can exert a considerable effect on GH secretion. In order to determine the effects of chronic treatment with the GHS Ipamorelin on the composition of the somatotroph cell population and on somatotroph GH content, an in vitro analysis was performed of the percentage of somatotroph cells (% of total), the ratio of different GH cell types (strongly/weakly-staining) and individual GH content, in pituitary cell cultures obtained from young female rats receiving Ipamorelin over 21 days (Ipamorelin group) and the effects were compared with those of GHRH (GHRH group) or saline (saline group)...
2002: Histology and Histopathology
N B Andersen, K Malmlöf, P B Johansen, T T Andreassen, G Ørtoft, H Oxlund
The ability of the growth hormone secretagogue (GHS) Ipamorelin to counteract the catabolic effects of glucocorticoid (GC) on skeletal muscles and bone was investigated in vivo in an adult rat model. Groups of 8-month-old female rats were injected subcutaneously for 3 months with GC (methylprednisolone) 9 mg/kg/day or GHS (Ipamorelin) 100 microg/kg three times daily, or both GC and GHS in combination. The maximum tetanic tension of the calf muscles was determined in vivo in a materials testing machine. The maximum tetanic tension was increased significantly, and the periosteal bone formation rate increased four-fold in animals injected with GC and GHS in combination, compared with the group injected with GC alone...
October 2001: Growth Hormone & IGF Research
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