title: Circulating immunoreactive growth hormone releasing hormone concentrations and growth hormone response to growth hormone releasing hormone in short children.
abstract: To study the role of peripheral immunoreactive growth hormone releasing hormone (ir-GHRH) concentrations and the GHRH test in the evaluation of growth hormone (GH) secretion in short stature, 46 children with a mean age of 9.4 years (range 1.6-16.3 years) and a mean relative height score of -3.2 SD (range -5.0-2.1 SD) were investigated. The children were divided into prepubertal (n = 35) and pubertal (n = 11) and the prepubertal children further into three groups based on their maximal GH responses to insulin-induced hypoglycaemia (IIH) and clonidine: (1) GH deficient subjects (maximal GH < 10 micrograms/l in both tests); (2) discordant responders (maximal GH < 10 micrograms/l in one test and > or = 10 micrograms/l in the other); and (3) normal responders (maximal GH > or = 10 micrograms/l in both tests). Peripheral ir-GHRH concentrations were measured during the IIH test by radioimmunoassay after purification of plasma samples on Sep-pak cartridges. Among the prepubertal children 10 fell into group 1, 16 into group 2 and 9 into group 3. Children in group 1 were older than those in group 3. There were no significant differences in relative heights and weights or absolute and relative growth velocities between the groups. Subjects in groups 1 and 2 had lower maximal GH responses to GHRH than those in group 3. There were no significant differences in the basal plasma ir-GHRH concentrations between the groups. Nine children (19.6%) had somatotrophs with a poor response to a single dose of exogenous GHRH (maximal GH < 10 micrograms/l).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Paediatrics, University of Oulu, Finland.
authors.forename: P J
authors.initials: PJ
authors.lastname: Tapanainen
mesh_terms: D000293:Adolescent; D001824:Body Constitution; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D003000:Clonidine; D005260:Female; D006130:Growth Disorders / Q000097:blood / Q000503:physiopathology*; D013006:Growth Hormone / Q000172:deficiency / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000097:blood / Q000502:physiology; D006801:Humans; D007223:Infant; D008297:Male; D011627:Puberty
chemical_list: D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D003000:Clonidine