Advertisement

Journal of Endocrinological Investigation

, Volume 11, Issue 7, pp 477–481 | Cite as

Decreased growth hormone (GH) response to oral Clonidine in endemic cretinism: effect of L-T3 therapy

  • M. C. N. Martins
  • M. Knobel
  • G. Medeiros-Neto
Article

Abstract

As GH secretion is dependent upon thyroid hormone availability, the GH responses to Clonidine (150 µg/m2) and the TSH and PRL response to TRH were studied in eight endemic (EC) cretins (3 hypothyroid, 5 with a low thyroid reserve) before and after 4 days of 100 µg of L-T3. Five normal controls (N) were also treated in similar conditions. Both groups presented a marked increase in serum T3 after therapy (N = 515 ± 89 ng/dl; EC = 647 ± 149 ng/dl) followed by a decrease in basal and peak TSH response to TRH. However, in the EC patients an increase in serum T4 levels and in basal PRL and peak PRL response to TRH after L-T3 therapy was observed. One hypothyroid EC had a markedly elevated PRL peak response to TRH (330 ng/dl). There were no significant changes in basal or peak GH values to treatment with L-T3 in normal subjects. In the EC group the mean basal plasma GH (2.3 ± 1.9 ng/ml) significantly rose to 8.8 ± 3.2 ng/ml and the mean peak response to Clonidine (12.7 ± 7.7 ng/ml) increased to 36.9 ± 3.1 ng/ml after L-T3. Plasma SM-C levels significantly increased in N from 1.79 ± 0.50 U/ml to 2.42 ± 0.40 U/ml after L-T3 (p < 0.01) and this latter value was significantly higher (p< 0.05) than mean Sm-C levels attained after L-T3 in the EC group (respectively: 1.14 ± 0.59 and 1.78 ± 0.68 U/ml). These data indicate that in EC the impaired GH response to a central nervous system mediated stimulus, the relatively low plasma Sm-C concentrations, and the presence of clinical or subclinical hypothyroidism may contribute to the severity of growth retardation present in this syndrome.

Key-words

Growth hormone endemic cretinism somatomedin-C hypothyroidism thyroid hormone 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Iwatsubo H., Omori K., Okada Y., Fukuchi M., Miyai K., Abe H., Kumahara Y. Human growth hormone secretion in primary hypothyroidism before and after treatment. J. Clin. Endocrinol. Metab. 27: 1751, 1967.PubMedCrossRefGoogle Scholar
  2. 2.
    Brauman H., Corviillain J. Growth hormone response to hypoglycemia in myxedema. J. Clin. Endocrinol. Metab. 28: 301, 1968.PubMedCrossRefGoogle Scholar
  3. 3.
    MacGillivray M.H., Aceto T., Frohman L.A. Plasma hormone response and growth retardation of hypothyroidism. Am. J. Dis. Child. 115: 273, 1968.PubMedGoogle Scholar
  4. 4.
    Eisenberg R.M., Sorrentino S., Knigge K.M. Plasma growth hormone and corticosterone levels in hypothyroid and euthyroid rat. Neuroendocrinology 10: 58, 1972.PubMedCrossRefGoogle Scholar
  5. 5.
    Wilkenson R, Anderson M., Smart G.A. Growth hormone deficiency in iatrogenic hypothyroidism. Br. Med. J. 1: 805, 1972.Google Scholar
  6. 6.
    Peak G.T., Birge C.A., Daughaday W.H. Alterations of radioimmunoassayable growth hormone and prolactin during hypothyroidism. Endocrinology 92: 487, 1973.CrossRefGoogle Scholar
  7. 7.
    Andreani D., Falluca F., Tamburrano G., Lavacioli M., Menzinger G. Insulin, glucagon and growth hormone in primary adult myxoedema. Diabetologia 10: 7, 1974.PubMedCrossRefGoogle Scholar
  8. 8.
    Hervas F., Morreale de Escobar G., Escobar del Rey F. Rapid effects of single small doses of L-thyroxine and triiodothyronine on growth hormone, as studied in the rat by radioimmunoassay. Endocrinology 97: 91, 1975.PubMedCrossRefGoogle Scholar
  9. 9.
    Coiro V., Braverman L.E., Christianson D., Fang S.T., Goodman H.M. Effect of hypothyroidism and thyroxine replacement on growth hormone in the rat. Endocrinology 105: 641, 1979.PubMedCrossRefGoogle Scholar
  10. 10.
    Takeuchi A., Suzuki M., Tsuchiya S. Effect of thyroidectomy on the secretory profiles of growth hormone, thyrotropin and corticosterone in the rat. Endocrinol. Jpn. 25: 381, 1978.PubMedCrossRefGoogle Scholar
  11. 11.
    Williams T., Maxon H., Thorner M.O., Frohman L.A. Blunted growth hormone (GH) response to GH-releasing hormone in hypothyroidism resolves in the euthyroid state. J. Clin. Endocrinol. Metab. 61: 454, 1985.PubMedCrossRefGoogle Scholar
  12. 12.
    Medeiros-Neto G.A., Kourides I., Almeida F., Gomes E., Cavaliere H., Ingbar S.H. Enlargement of the sella turcica in some patients with long standing untreated endemic cretinism: serum TSH-alpha, TSH-beta and prolactin response to TRH. J. Endocrinol. Invest. 4: 303, 1981.PubMedGoogle Scholar
  13. 13.
    Harrison M.R., Fierro-Benitez R., Ramirez I., Refetoff S., Stanbury J.B. Immunoreactive growth hormone in endemic cretins in Ecuador. Lancet 1: 936, 1968.CrossRefGoogle Scholar
  14. 14.
    Gil-Ad I., Topper E., Laron Z. Oral Clonidine as a growth hormone stimulation test. Lancet 2: 278, 1979.PubMedCrossRefGoogle Scholar
  15. 15.
    Fraser N.C., Seth H., Brocon N.S. Clonidine is a better test for TH deficiency than insulin hypoglycemia. Arch. Dis. Child. 58: 355, 1983.PubMedCentralPubMedCrossRefGoogle Scholar
  16. 16.
    Holder A.T., Wallis M., Biggs P., Preece M.A. Effects of growth hormone, prolactin and thyroxine on body weight, somatomedin-like activity and in vivo sulphation of cartilage in hypopituitary dwarf mice. J. Endocrinol. 85: 35, 1980.PubMedCrossRefGoogle Scholar
  17. 17.
    Cavaliere H., Knobel M., Medeiros-Neto G.A. Effect of thyroid hormone on plasma insulin-like growth factor I level in normal subjects, hypothyroid patients and endemic cretins. Horm. Res. 25: 132, 1987.PubMedCrossRefGoogle Scholar
  18. 18.
    Chernausek S.D., Underwood L.E., Utiger R.D., Van Wyk J.J. Growth hormone secretion and plasma somatomedin-C in primary hypothyroidism. Clin. Endocrinol. (Oxf.) 19: 337, 1983.CrossRefGoogle Scholar
  19. 19.
    Katakami N., Downs T.R., Frohman L.A. Decreased hypothalamic growth hormone-releasing hormone content and pituitary responsiveness in hypothyroidism. J. Clin. Invest. 77: 1704, 1986.PubMedCentralPubMedCrossRefGoogle Scholar
  20. 20.
    Contreras P., Generini G., Michelsen H., Pumarino H., Campino C. Hyperprolactinemia and galactorrhea: spontaneous versus iatrogenic hypothyroidism. J. Clin. Endocrinol. Metab. 53: 1036, 1981.PubMedCrossRefGoogle Scholar
  21. 21.
    Burch W.M., Van Wyk J.J. Triiodothyronine stimulates cartilage growth and maturation by different mechanisms. Am. J. Physiol. 252: E176, 1987.PubMedGoogle Scholar

Copyright information

© Italian Society of Endocrinology (SIE) 1988

Authors and Affiliations

  • M. C. N. Martins
    • 1
  • M. Knobel
    • 1
  • G. Medeiros-Neto
    • 1
  1. 1.Thyroid Laboratory, Division of Endocrinology, Department of Medicine, Hospital das ClinicasUniversity of Sao Paulo Medical SchoolSao PauloBrazil

Personalised recommendations