Advertisement

Hypothalamic Control of the Mammalian Sexual Maturation

Conference paper
  • 9 Downloads
Part of the Pädiatrie und Pädologie book series (PÄD SUPPL, volume 5)

Summary

The attainment of sexual maturity is a complex process which requires maturation and interaction not only of gonads and reproductive tract but also of the pituitary and essentially of the neuroendocrine mechanisms which ultimately control gonadotropin secretion. One of the more attractive hypotheses of the sexual maturation presumes the existence of the sensitivity threshold of the regulating system to the negative feedback signal, which differentiates immaturity from maturity. As the subject matures this declines. In an attempt to examine further the maturational alterations of the male hypothalamo-pituitary-gonadal axis, investigations were carried out with regard to simultaneous changes of blood LH, FSH, testosterone and dihydrotestosterone levels during the course of 24 hr; augmentation of pituitary and blood LH and FSH concentrations under the stimulus of LH-RH as a function of time and age; synthesis and release of LH and FSH in the testosterone-blocked animals at various stages of sexual maturation; and in vitro biotransformation of testosterone to its 5α-reduced metabolites by the pituitaries as a function of age. Evidence from the experimental data could be interpreted as a decrement of the feedback set-points during sexual maturatio as reflected by the transition of the responses obtained under various experimental signals. In parallel to these observations, new evidence was presented regarding not only quantitative but qualitative changes in the pituitary gonadotropins as response to the negative and positive feedback signals. This leads to new thinking with regard to the hypothesis of differential sensitivity.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bartke, A., Steele, R. E., Musto, N., Caldwell, B. V.: Endocrinology 92, 123 (1973).CrossRefGoogle Scholar
  2. Bogdanove, E. M.: Anat. Rec. 137, 117 (1967).CrossRefGoogle Scholar
  3. Bogdanove, E. M., Noun, J. M., Campbell, G. T.: Recent Progr. Hormone Res. 31, 567 (1975).PubMedGoogle Scholar
  4. Gupta, D.: In: Recent Progress in Reproductive Endocrinology. (Eds. P. G. Crosignani and V. H. T. James.) London: Academic Press 1974.Google Scholar
  5. Gupta, D., Rager, K., Zarzycki, J., Eichner, M.: J. Endocrinol. 66, 183 (1975).PubMedCrossRefGoogle Scholar
  6. Kalra, P. S., Fawcett, C. P., Krulich, L., Mccann, S. M.: Endocrinology 92, 1256 (1973).PubMedCrossRefGoogle Scholar
  7. Katongole, C. B., Naftolin, F., Short, R. V.: J. Endocrinol. 50, 457 (1971).PubMedCrossRefGoogle Scholar
  8. Katongole, C. B., Naftolin, F., Short, R. V.: J. Endocrinol. 60, 101 (1974).PubMedCrossRefGoogle Scholar
  9. Naftolin, F., Brown-Grant, K., Corker, C. S.: J. Endocrinol. 53, 17 (1972).PubMedCrossRefGoogle Scholar
  10. Ramirez, V. D., Mccann, S. M.: Endocrinology 72, 452 (1963).PubMedCrossRefGoogle Scholar
  11. Ramirez, V. D., Mccann, S. M.: Endocrinology 76, 412 (1965).PubMedCrossRefGoogle Scholar
  12. Steinberger, E., Duckett, G. E.: Endocrinology 79, 912 (1966).PubMedCrossRefGoogle Scholar
  13. Watanabe, S., Mccann, S. M.: Proc. Soc. Expt. Biol. Med. 132, 195 (1969).Google Scholar

Copyright information

© Springer-Verlag/Wien 1977

Authors and Affiliations

  1. 1.Department of Diagnostic EndocrinologyUniversity of TübingenTübingenFederal Republic of Western Germany

Personalised recommendations