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Exp Clin Endocrinol Diabetes 1990; 96(5): 157-167
DOI: 10.1055/s-0029-1211005
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© J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York

Circannual Oscillations of Function Compared with Morphometric Changes in the Thyroid Gland of the Wistar-Rat

F. Herrmann1 , E. Peschke2 , J. Peil2 , K. Hambsch1 , D. Sorger3 , A. Herzmann4 , H.-E. Schmidt4
  • 1Policlinical Department of the Medical-Policlinical Institute (Head: Prof. Dr. R. Rogos), University of Leipzig/GDR
  • 2Institute of Anatomy (Head: Prof. Dr. R. Schultka), University of Halle/GDR
  • 3Clinic of Radiology (Head: Prof. Dr. G. Schneider), University of Leipzig/GDR
  • 4Central Institute for Isotope and Radiation Research of the Academy of Sciences/GDR (Head: Prof. Dr. Dr. K. Wetzel)
Further Information

Publication History

1990

Publication Date:
16 July 2009 (online)

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Summary

To investigate biological rhythms of the thyroid gland circannual oscillations of thyroxine (T4), triiodothyronine (T3), and thyrotropin (TSH) were compared in serum samples of untreated young male Wistar-rats with the circannual changes of thyroid weights and with the relative proportion of colloid, epithelium, and interstitium of the thyroids. Animals were kept under standard environmental conditions, however, lighting conditions simulated the natural day-night changes. Thyroid weights, T4, T3, and TSH showed a statistically significant circannual rhythm with maxima in winter and spring and minima in summer and autumn. The same circannual patterns were observed in the proportion of epithelium and interstitium of the thyroids, while the colloid exhibited an inverse circannual pattern. These data were verified by biomathematical methods, like locally adjusted functional approximation, analysis of variance, and Spearman rank correlation. Our results represent an example for the concordance between functional and morphometrical changes in the course of circannual oscillations. Furthermore, these data confirm our earlier results describing higher T4-levels in the winter time (short-day) and lower serum titers in the summer time (long-day).

Key words

Circannual patterns - T4 - T3 - TSH - Weights - Colloid - Epithelium - Interstitium of thyroids