抗生物質이 動物成長에 미치는 影響에 關한 實驗的硏究

Abstract

[한글]

[영문]

The growth-promoting action of antibioties is apparently confirmed by experiments, but little is known regarding the actual mechanism involved in the growth stimulation. It would appear that the following possibilities exist: 1) Changes in the bacterial population in the intestine by antibiotics. 2) Catalytic action of antibiotics on the endocrine glands, as in the case of vitamins. The population of inestinal microflora has been previously determined in quantitative way by others, in an attempt to correlate these changes with antibiotics. However,

only a few studies are available in reference to the catalytic action of antibiotics on the endocrine glands. The purpose of the present study is to explore the aspect, that is, the possible participation of antibiotics in endocrine functions.

In a 5 week period of the experiments, tetracycline, oxytetracycline, chlortetracycline and penicillin are found to promote the growth of tadpole when 10 ppm of each antibiotics are added to the surrounding medium. among them, the growth-promoting actions of the oxytetracycline and tetracycline are most pronounced.

In the chickens, the oxytetracycline significantly promotes the growth and increases the consumption of noted that a statistically significant decrease in the weights of both the gizzard (with its contents) and the washed intestine.

Nevertheless, the slight increment is shown in other visceral organs of the oxytetracycline treated group.

The administration of 1 gm. of thiopental, a potent antithyroid substance, per kg. of diet has produced a marked reduction in growth rate as well as in visceral weights. However, the weight loss with thipental is not only prevented by concomitantly feeding with oxytetracycline at a level of 500mg. per kg. of diets, but also, at the end of 5 week's feeding the growth is significantly promoted as in the control.

It is thus suggested that antibiotics may somehow influence the endocrine system, possibly through the thyroid gland.