ABSTRACT
Mice testis in organ culture (31 degrees C) produce a steroid free substance which inhibits FSH secretion by rat pituitary cells. Histologically, Sterloti cells alone remain normal after a few days in culture. A hypothalamic action of inhibin is demonstrated in vitro. The intraglandular content in LHRH is inversely related to the amount of inhibin present in the culture medium. In the testis, DNA synthesis is depended of inhibin. This is demonstrated by studies of the incorporation of tritiated thymidine in testicular DNA in vivo and in vitro. In conclusion, inhibin is produced by Sertoli cells and acts not only at this pituitary level but also on the hypothalamus and the testis.
Subject(s)
Proteins/physiology , Testicular Hormones/physiology , Animals , Culture Techniques , Hypothalamus/metabolism , Inhibins , Male , Mice , Proteins/metabolism , Rabbits , Sertoli Cells/metabolism , Testicular Hormones/metabolism , Testis/cytology , Testis/metabolismABSTRACT
tritiated thymidine is incorporated into DNA of spermatogonia type B as proved by autohistoradiography when injected in vivo three hours before the sacrifice. Maximum binding and specific activity (labelled thymidine expressed in DPM per mg DNA) are obtained in pubertal rats aged 42 days and weighting 150 g. Inhibin preparation extracted from rete testis fluid (RTF3) specifically inhibits tritiated thymidine into testicular DNA. Thus, no modification of incorporation into hepatic DNA is observed and the preparation loses its inhibitory effect when denatured by heating and trypsin digestion. Tritiated thymidine incorporation into testicular DNA is poor in normal adult rats and in pubertal hypophysectomized animals, RTF3 does not modify the thymidine incorporation in both conditions. The reasons for this lack of effect are discussed. An experimental condition of spermatogonial regeneration is obtained by testicular irradiation. Inhibin preparation inhibits the regenerative DNA synthesis.
Subject(s)
DNA/biosynthesis , Proteins/pharmacology , Testicular Hormones/pharmacology , Testis/metabolism , Aging , Animals , Autoradiography , Hypophysectomy , Male , Rats , Testis/drug effects , Testis/radiation effects , Thymidine/metabolism , Time FactorsABSTRACT
We have studied the effects of ultrasound on the female rat fertility. When utilized at similar power than for human beings, the echography reduces significantly the number of foetus counted at the 15th day of the gestation. A direct action of the ultrasounds on the mechanisms of the ovulation is to be considered.