Transcript Office of Nursing Research

Lessons Learned/Challenges
Corticotropin Releasing Hormone
(CRH)
Why Measure CRH?
• 41 amino acid
neuropeptide, plays a
major role in the
physiological response to
stress
• The principal
hypothalamic regulator of
the pituitary-adrenal axis
• Higher levels of CRH
associated with adverse
pregnancy outcomes
What Medium and Collection Method
to Use?
• Medium
– Plasma
• Collection Method
– Collection tube
• EDTA
• Protease inhibitor
– Time
• Timing of sample collection – no circadian rhythm
• Effects on plasma samples-process within 12 hrs
• Timing during pregnancy
– Temperature
• Continuously chilled at 4°C
Considerations when Processing
• Sample Processing
– Refrigerated Centrifugation
• 3,000-4,500 rpm for 15 minutes
• Aliquots siphoned and analyzed or stored
– Storage
• -80°C for < 2 years
– Plasma extraction
• Removes CRH from plasma
• Methanol vs C18 Sep-Column
• Immediately prior to assay
Factors in Selection of Assay
• Factors to consider
– Cost
– Ease
– Reliability/sensitivity of tests
• ELISA vs RIA
– Elisa (easier, rapid turnover time)
– RIA (well documented in literature, greater
sensitivity)
Lessons Learned
Challenges
• Designing research study
– Timing of collection in relation to EGA
– Stratifying for ethnicity/race
• Identify published protocol, consult with
author/experts
• Consider role of lab manager
• Evaluate each plate result with consultantassess standardized curve
• Which method of assay?
References
• Glynn, L.M., Dunekl Schetter, C., Chicz-DeMet, A., Hobel, C.J.,
& Sandman, C.A. (2006). Ethnic differences in
adrenocorticotroic hormone, cortisol and corticotropinreleasing hormone during pregnancy. Peptides, 28, 11551161.
• Latendress, G. & Ruiz, J. (2008). Bioassay research
methodology: measuring CRH in pregnancy. Biological
Research for Nursing, 10, 54-62.
• Strong, E.F., Kleinman, K.P., Gillman, M.W. et al. (2006).
Measuring corticotropin-releasting hormone in pregnant
women-comparing blood collection protocols for
epidemiological studies. Paediatric and Perinatal
Epidemiology, 20, 67-71.