Utilization of substrates for testosterone and estradiol-17 beta production by small follicles of the chicken ovary.
A study was conducted to characterize steroidogenesis in small ovarian follicles (1-10 mm in diameter) of the hen.


OBJECTIVE
1) to determine basal estradiol-17 beta (E2) production by different sizes of small follicles; 2) to determine the ability of intact small follicles to utilize exogenous substrates for testosterone (T) and E2 production; and 3) to investigate the preferred steroidogenic pathway in small follicles. Small follicles which had not entered the hierarchy were isolated from ovaries obtained 2 hr after oviposition and divided into three groups: small white follicles (SWF; 1-2 mm in diameter), large white follicles (LWF; 2-4 mm in diameter), and small yellow follicles (SYF; 5-10 mm in diameter). Yolk and granulosa cells were removed from LWFs and SYFs and the remaining theca layer was called a follicle shell. Intact follicles or follicle shells (4/4 ml/tube) were incubated in avian Ringer's buffer supplemented with 10 mM HEPES and 0.1% BSA at 37 degrees C for 3 hr with various treatments. Testosterone and E2 were measured in the medium. The SYFs and their corresponding follicle shells produced the greatest amount of E2 when E2 production was expressed per follicle. Addition of 2 mM 8-Br-cAMP to the incubation medium stimulated E2 production by all sizes of follicles and follicle shells. However, follicle shells produced lower basal- and 8-Br-cAMP-stimulated E2 secretion compared to corresponding intact follicles.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Physiology, University of Illinois at Urbana-Champaign 61801.
K A
KA
Lee
J M
JM
Bahr
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D002645:Chickens / Q000378:metabolism*; D000242:Cyclic AMP / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D003687:Dehydroepiandrosterone / Q000378:metabolism; D004958:Estradiol / Q000096:biosynthesis*; D005260:Female; D006888:Hydroxycholesterols / Q000494:pharmacology; D006080:Ovarian Follicle / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D010053:Ovary / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism; D015290:Second Messenger Systems; D013739:Testosterone / Q000096:biosynthesis*
D006888:Hydroxycholesterols; D015124:8-Bromo Cyclic Adenosine Monophosphate; D013739:Testosterone; D003687:Dehydroepiandrosterone; D011374:Progesterone; D004958:Estradiol; C007997:25-hydroxycholesterol; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases