Journal of Clinical Endocrinology & Metabolism, Vol 79, 495-501, Copyright © 1994 by Endocrine Society

ARTICLES

Somatostatin analog treatment slows growth and the tempo of reproductive maturation in female rhesus monkeys

ME Wilson and JM Tanner
Yerkes Primate Research Center, Emory University, Atlanta, Georgia 30322.

The present study tested the hypothesis that a reduction in serum GH during adolescence would result in slower growth and delayed puberty. Skeletal growth and maturation as well as indices of reproductive development were studied in juvenile female rhesus monkeys receiving a constant sc infusion of a somatostatin analog, Sandostatin, at a dose of approximately 4.50 micrograms/kg BW.day (Ssa; n = 6) and in untreated females (Con; n = 6) from 18 months of age through the luteal phase of the second ovulation. Although age at menarche was similar in Con and Ssa females, first ovulation was delayed significantly in Ssa females, such that the interval between menarche and first ovulation was significantly longer in Ssa females. Serum concentrations of GH, insulin-like growth factor-I (IGF-I), and IGF-binding protein-3 were reduced in Ssa females, particularly after menarche. Although changes in body weight were similar between Ssa and Con females, growth in height was significantly greater in Con females. Furthermore, peak growth velocity in height occurred at a significantly later age in SSa females, but at a similar degree of skeletal maturity. Serum insulin and glucose levels in response to iv glucose were similar in the two groups; however, fasting levels of serum glucose decreased significantly in both groups with advancing age, but the decrease was greater in Con. During the luteal phase of the first 2 ovulatory cycles, there were diminished serum progesterone in 16.7% (2 of 12) of the Con and 41.7% (5 of 12) of the Ssa females. Serum estradiol was significantly lower throughout the first 2 ovulatory cycles in Ssa females, whereas serum LH and IGF-I were similar to those in Con females. Multiple regression analyses revealed that age at menarche was best predicted from the amount of growth in height before menarche, whereas those females who had higher serum IGF-binding protein-3 levels before menarche had an earlier growth spurt, and those who grew faster had a shorter interval between menarche and first ovulation. These data indicate that treatment with a long-acting somatostatin analog, which produces a relative deficiency in the GH axis, slows growth and delays the tempo of puberty. The data suggest that this delay may be due to a reduction in gonadal sensitivity to LH.

This article has been cited by other articles:

				M. E. Wilson and B. Kinkead Gene-Environment Interactions, Not Neonatal Growth Hormone Deficiency, Time Puberty in Female Rhesus Monkeys Biol Reprod, April 1, 2008; 78(4): 736 - 743. [Abstract] [Full Text] [PDF]

				M.E. Wilson, K. Chikazawa, J. Fisher, D. Mook, and K.G. Gould Reduced Growth Hormone Secretion Prolongs Puberty But Does Not Delay the Developmental Increase in Luteinizing Hormone in the Absence of Gonadal Negative Feedback Biol Reprod, August 1, 2004; 71(2): 588 - 597. [Abstract] [Full Text] [PDF]

				K. J. Suter, C. R. Pohl, and M. E. Wilson Circulating Concentrations of Nocturnal Leptin, Growth Hormone, and Insulin-Like Growth Factor-I Increase before the Onset of Puberty in Agonadal Male Monkeys: Potential Signals for the Initiation of Puberty J. Clin. Endocrinol. Metab., February 1, 2000; 85(2): 808 - 814. [Abstract] [Full Text]

				D. R. Mann, M. A. Akinbami, K. G. Gould, and V. D. Castracane A Longitudinal Study of Leptin During Development in the Male Rhesus Monkey: The Effect of Body Composition and Season on Circulating Leptin Levels Biol Reprod, February 1, 2000; 62(2): 285 - 291. [Abstract] [Full Text]

				K. L. Keen, A. J. Burich, D. Mitsushima, E. Kasuya, and E. Terasawa Effects of Pulsatile Infusion of the GABAA Receptor Blocker Bicuculline on the Onset of Puberty in Female Rhesus Monkeys Endocrinology, November 1, 1999; 140(11): 5257 - 5266. [Abstract] [Full Text]