Growth hormone abuse in the horse: preliminary assessment of a mass spectrometric procedure for IGF-1 identification and quantitation.

This research article discusses a new method to detect the use of growth hormones (GH) in horses using mass spectrometry readings of insulin-like growth factor 1 (IGF-1) levels in serum. The study sets to establish a more specific test method for GH abuse in horse racing over the previously used immunoradiometric assay.

Overview of research methodology and objective

• The study focused on detecting the abuse of growth hormones (GH) in horses. GH abuse is prevalent as it could enhance the competitive edge of horses.
• Insulin-like growth factor 1 (IGF-1), a biological marker, exhibits significant increases after GH administration. Therefore, IGF-1 was identified as a promising marker for GH abuse detection.
• Previously, an immunoradiometric assay (IRMA) was used for screening GH abuse in horses. However, for legal prosecution and authoritative enforcement, the study suggests a need for a more specific method of IGF-1 quantification.
• The objective of the research was to develop a highly specific method using HPLC electrospray mass spectrometry (LC/ESI-MS) to analyze IGF-1 level in horse serum.

Study design and procedure

• The research designed a new method using high-performance liquid chromatography (HPLC) coupled with electrospray mass spectrometry (LC/ESI-MS). This method was intended to accurately measure IGF-1 levels in serum.
• The researchers conducted element composition analysis, which involves the fragmentation pattern of molecular ions to assert the structural identity of IGF-1.
• The study also employed endoproteinase Asp-N digestion followed by LC/MS and LC/MS/MS characterisations to confirm the identity of IGF-1.
• Finally, the amounts of IGF-1 were quantified as the intact molecule against an internal standard.

Implication of the study

• The research suggests that the newly developed LC/ESI-MS is a strong candidate for a more definitive method of IGF-1 detection.
• This new method could potentially provide a more specific and accurate assessment of GH abuse in horses, which might be beneficial for regulatory bodies such as horseracing authorities.