Absence of development of late steroidogenic lesions in rat testis during the end of fetal life.
In the rat during the last 4 days of fetal life, the production of testosterone by the testis does not increase, whereas the plasma level of biological LH-like activity rises sharply. The present study was designed to test whether this phenomenon is attributed to the development of defects in the activity of the enzyme 17 alpha-hydroxylase and C17,20-lyase (called late steroidogenic lesions) during the end of fetal life. As this occurrence would lead to an age-related decrease in the ratio testosterone/progesterone, the testicular productions of these two steroids were evaluated on 18.5, 20.5, and 21.5 days postconception. Three different measurements were performed: (a) the in vivo testicular contents; (b) the in vitro secretions during a 120-min incubation in the presence or in the absence of 100 ng/ml ovine LH; (c) the testicular contents after these incubations. These measurements never revealed a decrease in the ratio testosterone/progesterone as a function of fetal age. It would appear that late steroidogenic lesions do not develop during the end of fetal life in the rat.
Habert
R
R
Laboratoire de Physiologie du Développement et U.A. C.N.R.S. no. 307, Universite Paris, France.
Veniard
B
B
Brignaschi
P
P
Gangnerau
M N
MN
Picon
R
R
D000818:Animals; D005314:Embryonic and Fetal Development; D005260:Female; D066298:In Vitro Techniques; D007985:Leydig Cells / Q000378:metabolism; D008297:Male; D011247:Pregnancy; D011374:Progesterone / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D013737:Testis / Q000196:embryology* / Q000378:metabolism; D013739:Testosterone / Q000096:biosynthesis*
D013739:Testosterone; D011374:Progesterone