Chinese Journal of Physiology

Chinese Journal of Physiology, 1929, Vol, [II, No, 1, pp. 57—68.

FURTHER STUDIES ON THYROID AND HAIR GROWTH*

HSI-CHUN CHANG anp TEH-PEI FENG

(From the Department of Physiology, Peking Union Medical College, Peping)

Received for publication October 4, 1928

That the thyroid gland has a specific influence upon hair growth has been proposed on the basis of the following observations (2). Feeding of thyroid extract to the albino rat accelerates hair growth in a number of individuals. Thyroidectomy besides decreasing body weight, retards hair growth. Partial starvation results not only in decrease of body weight but in retardation of hair growth and atrophy or regression of the thyroid (1). If, however, an adequate amount of thyroid extract is given to the starved animal, an acceleration of hair growth may be demonstrated in spite of insufficient anabolism from starvation and excessive catabolism secondary to thyroid feeding.

In the present study we have endeavoured to determine more precisely the nature of the thyroid effect and as to whether the hair response is a pure thyroid reaction, or one reproducible by some one of its chemical constituents. Incidently the factors of age and sex were

further studied. EXPERIMENTAL

Albino rats of the same age and sex (litter mates) were used for each experiment. A small square area was shaved on the right side of the back in the Chicago series, and on each side of the back in the Peping series. The number of days required for the completion of hair growth in the shaved areas was recorded. A reading of the normal rate of hair growth was obtained as,a control in each experimental animal, shaving being done over the same area, for the successive readings.

*This work was started in the Hull Physiological Laboratory, Chicago, and con-

tinued in Peping. 57