Serotonin transporter binding of [123I]ADAM in bulimic women, their healthy twin sisters, and healthy women: a SPET study.

Abstract

BACKGROUND:

Bulimia Nervosa (BN) is believed to be caused by an interaction of genetic and environmental factors. Previous studies support the existence of a bulimia-related endophenotype as well as disturbances in serotonin (5-HT) transmission. We studied serotonin transporter (SERT) binding in BN, and to investigate the possibility of a SERT-related endophenotype for BN, did this in a sample of female twins. We hypothesized clearly reduced SERT binding in BN women as opposed to healthy women, and intermediate SERT binding in unaffected co-twins.

METHODS:

We studied 13 female twins with BN (9 with purging and 4 with non-purging BN) and 25 healthy women, including 6 healthy twin sisters of BN patients and 19 women from 10 healthy twin pairs. [123I]ADAM, a selective SERT radioligand for single photon emission tomography (SPET) imaging, was used to assess SERT availability in the midbrain and the thalamus.

RESULTS:

No differences in SERT binding were evident when comparing the BN women, their unaffected co-twins and the healthy controls (p = 0.14). The healthy sisters of the BN patients and the healthy control women had similar SERT binding in both brain regions. In a post hoc subgroup analysis, the purging bulimics had higher SERT binding than the healthy women in the midbrain (p = 0.03), but not in the thalamus.

CONCLUSION:

Our finding of increased SERT binding in the midbrain in the purging BN women raises the possibility that this subgroup of bulimics might differ in serotonergic function from the non-purging ones. The similarity of the unaffected co-twins and the healthy controls doesn't support our initial assumption of a SERT-related endophenotype for BN. Due to the small sample size, our results need to be interpreted with caution and verified in a larger sample.

• Authors: Anu K Koskela, Anna Keski-Rahkonen, Elina Sihvola, Tomi Kauppinen, Jaakko Kaprio, Aapo Ahonen, Aila Rissanen
• Journal: BMC psychiatry (BMC Psychiatry) Vol. 7 Pg. 19 (May 21 2007) ISSN: 1471-244X [Electronic] England
• PMID: 17511889 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Twin Study)

Chemical References

• 2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine
• SLC6A4 protein, human
• Serotonin Plasma Membrane Transport Proteins
• Serotonin
• Cinanserin

Topics

• Adult
• Bulimia (genetics, metabolism)
• Cinanserin (analogs & derivatives)
• Female
• Humans
• Longitudinal Studies
• Phenotype
• Serotonin (physiology)
• Serotonin Plasma Membrane Transport Proteins (metabolism)