The use of an automated microsampling system for the characterization of growth hormone pulsatility in newborn babies.
To overcome the difficulties of studying hormone pulsatility in the newborn, we have developed an automated microsampling system that permits the measurement of hormones in small prediluted samples of blood (40 microL) taken at 10-min intervals over 12 h. The system has been validated in adult volunteers, and the error attributable to the dilution was <4%. Using this method in 10 preterm babies, we have been able to describe pulsatile changes in GH and have demonstrated a clear postprandial elevation in GH levels peaking 60 min after a feed. Fourier transform analysis indicated a pulse periodicity of 180 min in babies who were appropriate for gestational age (n = 6), but faster, co-dominant pulse periodicities of 90-100 and 140 min in babies who were small for gestational age (weight and length below the 10th centile) (n = 4). There was no significant difference between mean, peak, and baseline GH levels between the two groups.
Adcock
C J
CJ
Department of Paediatrics, University of Oxford, The John Radcliffe, Headington, United Kingdom.
Ogilvy-Stuart
A L
AL
Robinson
I C
IC
Lewin
J E
JE
Holly
J M
JM
Harris
D A
DA
Watts
A P
AP
Doyle
K L
KL
Matthews
D R
DR
Wilkinson
A R
AR
Dunger
D B
DB
D000328:Adult; D001774:Blood Chemical Analysis / Q000295:instrumentation / Q000706:statistics & numerical data; D001800:Blood Specimen Collection / Q000295:instrumentation*; D005069:Evaluation Studies as Topic; D005260:Female; D005583:Fourier Analysis; D019382:Human Growth Hormone / Q000097:blood* / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn / Q000097:blood / Q000502:physiology*; D007234:Infant, Premature / Q000097:blood / Q000502:physiology; D007236:Infant, Small for Gestational Age / Q000097:blood / Q000502:physiology; D008832:Microchemistry / Q000295:instrumentation / Q000706:statistics & numerical data; D008875:Middle Aged; D010903:Pituitary Gland, Anterior / Q000378:metabolism; D015203:Reproducibility of Results
D019382:Human Growth Hormone