Endocrine profile of catch-up growth in the cynomolgus monkey.
We studied catch-up growth following withdrawal of glucocorticoid administration in seven intact prepubertal cynomolgus monkeys. To reduce stress during blood sampling, a vascular access port was implanted subcutaneously in each animal for the duration of the study. After a baseline observation period of 50 weeks, the monkeys received injections of dexamethasone at a dose of 100 micrograms.kg-1.day-1 for 15 weeks. Growth velocity was monitored every 3 weeks by measuring lower leg length and body weight. Spontaneous serum growth hormone (GH) concentrations and GH levels after insulin and L-dopa stimulation, as well as serum insulin-like growth factor I (IGF-I) and plasma thyrotropin, triiodothyronine and thyroxine, were measured during the study. Differences between animals were analyzed by repeated measures analysis of variance and Student's paired t-test. Mean +/- SEM growth velocity (mm/3 weeks) decreased from 0.90 +/- 0.08 during the baseline period to 0.29 +/- 0.07 (p < 0.001) during the period of growth retardation, and increased to 1.23 +/- 0.2 (p < 0.001) during the period of catch-up growth. Spontaneous GH and peak GH levels following insulin did not show any significant variation during the study. Peak GH during the L-dopa test decreased from 15.4 +/- 3.2 micrograms/l during the baseline period to 6.2 +/- 2.4 micrograms/l during the period of growth retardation (p < 0.05), and increased to 23.0 +/- 5.9 micrograms/l during the period of catch-up growth (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Marin
G
G
Developmental Endocrinology Branch, National Institute of Child Health and Human Development, Bethesda, MD.
Malozowski
S N
SN
Barnes
K
K
Southers
J
J
Cristiano
A
A
Cassorla
F
F
D000818:Animals; D003907:Dexamethasone; D004702:Endocrine Glands / Q000378:metabolism*; D006130:Growth Disorders / Q000097:blood / Q000139:chemically induced / Q000503:physiopathology; D013006:Growth Hormone / Q000097:blood; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007866:Leg / Q000254:growth & development; D007980:Levodopa / Q000494:pharmacology; D008252:Macaca fascicularis; D008297:Male; D009994:Osmolar Concentration; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000503:physiopathology; D014284:Triiodothyronine / Q000097:blood
D007328:Insulin; D014284:Triiodothyronine; D007980:Levodopa; D007334:Insulin-Like Growth Factor I; D003907:Dexamethasone; D013006:Growth Hormone