Understanding plasma treatment effect on human acyl-ghrelin concentrations

S.L. Deschaine, L. Leggio

Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Basic Research and National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Bethesda, MD, USA. lorenzo.leggio@nih.gov

---

• Pharmacology

OBJECTIVE: We evaluated the effect of different concentrations of the esterase inhibitor, AEBSF, and acid treatment on acyl-ghrelin stability in human plasma samples subjected to a freeze/thaw cycle.

MATERIALS AND METHODS: Four plasma samples were collected from each donor and treated with the following concentrations of AEBSF: 2 mg/ml, 1 mg/ml, 0.6 mg/ml, and 0 mg/ml. For each plasma tube collected, half of the aliquots were treated with HCl and stored at -80°C before measuring acyl-ghrelin concentration using enzyme-linked immunosorbent assay (ELISA).

RESULTS: Treatment with 1 mg/ml AEBSF + HCl resulted in significantly higher acyl-ghrelin levels compared to all other treatments except 2 mg/ml AEBSF + HCl or 0.6 mg/ml AEBSF + HCl. While all HCl-treated samples had higher acyl-ghrelin levels than their AEBSF-matched un-acidified samples, only samples treated with 1 mg/ml AEBSF significantly differed in acyl-ghrelin levels as a result of HCl treatment.

CONCLUSIONS: Our results suggest the use of 1 mg/ml AEBSF with HCl for optimal acyl-ghrelin stability in human plasma samples subjected to a freeze/thaw cycle before assay. Given that 2 mg/ml and 0.6 mg/ml AEBSF + HCl did not significantly differ from 1 mg/ml AEBSF + HCl, our data suggest that the use of AEBSF with HCl more potently prevents de-acylation of ghrelin than either treatment alone.

Free PDF Download