Research group - Lena Ekström

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We are performing studies on doping and drug metabolism.

Doping: We study how genetic variations, gender, different doses and administration routes, diseases and co-medications can affect the results of doping tests. For example we have shown that individuals that are devoid of the UGT2B17 gene cannot excrete testosterone in the urine and are therefore not tested positive when tested for testosterone doping. Elite athletes are now being tested by individual longitudinal sampling rather than population based cut-off values by using athlete biological passport (ABP) approach. We are now conducting studies how different diseases, pregnancy and drug use may affect the individual ABP profile. The research is in collaboration with Anti-Doping lab situated at Division of Clinical Pharmacology. Moreover, we are studying side effects (cardiovascular and endocrine) of anabolic-androgenic steroids. This is done in healthy volunteers (low, single doses of AAS) and in AAS users, in collaboration with Anti-Doping hotline at Division of Clinical Pharmacology.

Drug metabolism: Lipophilic drugs needs to be metabolized to more hydrophilic metabolites before can be excreted in the urine. This is normally done by different enzyme systems where CYPs, UGTs and SULTs are playing major roles. The expression and activity of these enzymes differ throughout the development. We have characterized the expression profile of several of these enzyme families in the first trimester and are in progress of study the phase II metabolism during the first 12 years of age and also during/after a pregnancy. We are studying how drug use in neonates may interact with the metabolism of different endobiotic compounds important for endothelial function.  The enzyme activity in many of these enzymes is highly dependent on genetic variation. We have for example seen that genetics can influence how we respond to statin treatment (cholesterol lowering effects and adverse side effects such as muscle pain). We are also study if miRNAs and methylation may be epigenetic regulators for enzyme activity/drug effect. 

Research group leader Lena Ekström

Senior lecturer

Lena Ekström

Phone: 08-524 876 54
Organizational unit: Division of Clinical Pharmacology

Group members

Annica BörjessonGraduate Student
Jenny MullenPhD student
Lena EkströmSenior lecturer

Research techniques

  • Genotyping
  • Quantitative PCR
  • Western blot
  • HPLC
  • Cell culturing
  • Transfections
  • Epigenetic studies

External funding

World anti-doping agency (WADA), Swedish National Centre for Research in Sports, Partnership for clean competition (PCC).

Teaching assignments

  • Pharmacology and drug management 3 Credits, semester 2, Nurses (Campus and Distance)
  • Disease specific pharmacology 3hp, semester 3, Nurses (Campus and Distance)
  • Pharmacology, 7.5 Credits, semester 5, BMA

Selected publications

Androgens and doping tests: genetic variation and pit-falls.
Rane A, Ekström L
Br J Clin Pharmacol 2012 Jul;74(1):3-15

Single dose testosterone increases total cholesterol levels and induces the expression of HMG CoA reductase.
Gårevik N, Skogastierna C, Rane A, Ekström L
Subst Abuse Treat Prev Policy 2012 Mar;7():12

Bioavailability of testosterone enanthate dependent on genetic variation in the phosphodiesterase 7B but not on the uridine 5'-diphospho-glucuronosyltransferase (UGT2B17) gene.
Ekström L, Schulze J, Guillemette C, Belanger A, Rane A
Pharmacogenet. Genomics 2011 Jun;21(6):325-32

Beneficial vasoactive endothelial effects of fluvastatin: focus on prostacyclin and nitric oxide.
Skogastierna C, Luksha L, Kublickiene K, Eliasson E, Rane A, Ekström L
Heart Vessels 2011 Nov;26(6):628-36

Non-steroidal anti-inflammatory drugs interact with testosterone glucuronidation.
Sten T, Finel M, Ask B, Rane A, Ekström L
Steroids 2009 Nov;74(12):971-7