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د. غريب عمر حمد الشويعر Dr. Ghareeb O. Alshuwaier

Assistant Professor

رئيس قسم فسيولوجيا الجهد البدني - ماجستير-تغــذية الـرياضــيين أنجلترا - دكتوراه-تغذية الرياضيين أسكتلندا (جامعة جلاسكو) Sport Nutrition-MSc, PhD, Head of Exercise Physiology Department

كلية علوم الرياضة والنشاط البدني
قسم فسيولجي الجهد البدني المبنى 069 المكتب 115
publication
Journal Article
2019

Development of a Derivatization Method for Investigating Testosterone and Dehydroepiandrosterone Using Tandem Mass Spectrometry in Saliva Samples from Young Professional Soccer Players Pre- and Post-Training

Alshuwaier, Ghareeb O . 2019

testosterone; dehydroepiandrosterone; epitestosterone; 2-hydrazino-1-methylpyridine; liquid chromat

In the last decade, high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) combined with electrospray ionization (ESI) has been widely used for determining low concentrations of steroids, and derivatization has often been employed to enhance detection. In the present study, endogenous steroids were extracted using a Strata-XL polymeric reverse phase cartridge. The isolated steroids were reacted with 2-hydrazino-1-methylpyridine (HMP) at 50 °C for 30 min. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used in a positive mode with multiple reaction monitoring (MRM) for the quantification of testosterone (T) and its precursor, dehydroepiandrosterone (DHEA), in saliva samples collected from twenty young Saudi professional soccer players. The analytes were separated on an ACE Ultracore 2.5 Superphenylhexyl column (150 × 3.0 mm id). The extraction recovery during the pre-treatment was >89% and gave <±20% for inter- and intra-assay precision and accuracy. The limits of quantification (LOQ) were found to be 20 pg/mL for (T and DHEA) and 50 pg/mL for Epitestosterone (EPI). The results showed no significant variation in the concentration of T between pre and post training, whereas DHEA was significantly increased after short-term exercise. These results could indicate that there is no correlation between T and its precursor DHEA level following short term physical activity. EPI concentrations could not be detected with a LOQ of 50 pg/mL in the saliva samples

Publication Work Type
ورقة علمية
Volume Number
87
Issue Number
11
Magazine \ Newspaper
Scientia Pharmaceutica
Pages
1 - 16
more of publication
publications

Abstract: Background: The Capability Assessment for Diet and Activity (CADA) is a questionnaire
that was developed in English and designed to measure the practical barriers and opportunities…

by Jwaher Haji Alhaji , Ghareeb O. Alshuwaier, Nouf Sahal Alharbi, Abdulrahman I. Alaqil, Nora Majed BinSultan, Wadi B. Alonazi
2021
Published in:
Int. J. Environ. Res. Public Health
publications

Aim: to estimate 24-hour urinary sodium concentration in young Saudi professional soccer players by using a single spot urine. Method: a cross sectional study design, conducted during the official…

by Ghareeb O. Alshuwaier
2021
Published in:
International Journal of Sport, Exercise and Health Research
publications

Abstract: Purpose: to assess urinary potassium concentration level among young professional Saudi soccer players. Method: a cross sectional study design, conducted during the official Saudi Soccer…

by Ghareeb O. Alshuwaier
2022
Published in:
Journal of Sport Sciences and Physical Education