Sermorelin · research summary

Qualitative identification of growth hormone-releasing hormones in human plasma by means of immunoaffinity purification and LC-HRMS/MS.

Analytical and bioanalytical chemistry · 2016. Summary drawn from the study's full text. Each statement is followed by the exact sentence it comes from. This is a research summary, not medical advice.

Study type

Analytical method development and validation study involving in vitro, rat in vivo, and human in vivo administration experiments.
“The aim of the present study was to develop a method for the simultaneous detection of four different GHRHs and respective metabolites from human plasma by means of immunoaffinity purification and subsequent nano-ultrahigh performance liquid chromatography-high resolution/high accuracy (tandem) mass spectrometry.”

Subjects

Rats (Rattus norvegicus) and one healthy male human volunteer.
“EDTA blood samples were collected from rats 2, 4, and 8 h after intravenous administration of GHRH (one compound per test animal).”

Sample size

Three rats per compound for the animal study and one human volunteer for the human study.
“0.1 mg of each GHRH was administered intravenously to three rats (Rattus norvegicus, Wistar, 200–300 g bodyweight at dosing).”

Duration

Sampling occurred up to 8 hours post-administration in rats and up to 270 minutes (4.5 hours) post-administration in the human subject.
“Blood was sampled at 2, 4, and 8 h after injection and specimens were centrifuged at 13,000×g for 20 min to produce serum or EDTA plasma, which was stored at −20 °C until analysis.”

Reported findings

The developed immunoaffinity-mass spectrometry method was validated and found to be fit for purpose with a lower limit of detection below 50 pg/mL.
“The method was fully validated and found to be fit for purpose considering the parameters specificity, linearity, recovery (19–37 %), lower limit of detection (<50 pg/mL), imprecision (<20 %), and ion suppression/enhancement effects.”
Intact GHRH compounds were detected in rat plasma for at least 4 hours, but anticipated metabolites were not confirmed in the rodent samples.
“All intact substances were detected for at least 4 h but no anticipated metabolite was confirmed in laboratory rodents’ samples”
A specific metabolite of Sermorelin (GHRH3-29) was detected in human plasma 30 minutes after subcutaneous injection, while the intact drug was not detected.
“conversely, a Geref metabolite (GHRH3-29) was found in a human plasma sample collected after subcutaneous injection of the drug to a healthy male volunteer.”

Limitations stated by the authors

Further studies are required to account for potential species-related differences in metabolism and elimination, and the detection window for Sermorelin in humans was limited.
“Further studies are however required and warranted to account for potential species-related differences in metabolism and elimination of the target analytes”

Source: PubMed 26879649 · DOI 10.1007/s00216-016-9377-3 · all study summaries

Study type

Analytical method development and validation study involving in vitro, rat in vivo, and human in vivo administration experiments.

“The aim of the present study was to develop a method for the simultaneous detection of four different GHRHs and respective metabolites from human plasma by means of immunoaffinity purification and subsequent nano-ultrahigh performance liquid chromatography-high resolution/high accuracy (tandem) mass spectrometry.”

Duration

Sampling occurred up to 8 hours post-administration in rats and up to 270 minutes (4.5 hours) post-administration in the human subject.

“Blood was sampled at 2, 4, and 8 h after injection and specimens were centrifuged at 13,000×g for 20 min to produce serum or EDTA plasma, which was stored at −20 °C until analysis.”

Reported findings

The developed immunoaffinity-mass spectrometry method was validated and found to be fit for purpose with a lower limit of detection below 50 pg/mL.

“The method was fully validated and found to be fit for purpose considering the parameters specificity, linearity, recovery (19–37 %), lower limit of detection (<50 pg/mL), imprecision (<20 %), and ion suppression/enhancement effects.”

Intact GHRH compounds were detected in rat plasma for at least 4 hours, but anticipated metabolites were not confirmed in the rodent samples.

“All intact substances were detected for at least 4 h but no anticipated metabolite was confirmed in laboratory rodents’ samples”

A specific metabolite of Sermorelin (GHRH3-29) was detected in human plasma 30 minutes after subcutaneous injection, while the intact drug was not detected.

“conversely, a Geref metabolite (GHRH3-29) was found in a human plasma sample collected after subcutaneous injection of the drug to a healthy male volunteer.”

Limitations stated by the authors

Further studies are required to account for potential species-related differences in metabolism and elimination, and the detection window for Sermorelin in humans was limited.

“Further studies are however required and warranted to account for potential species-related differences in metabolism and elimination of the target analytes”