Increasing fetal adrenal formation of cortisol from pregnenolone during baboon (Papio papio) gestation.
Increasing fetal adrenal formation of cortisol from pregnenolone during baboon (Papio papio) gestation.
复制标题
在狒狒 (Papio papio) 妊娠期间,通过孕烯醇酮增加胎儿肾上腺皮质醇的形成。
DOI:
10.1095/biolreprod17.5.701
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发表时间:
1977
影响因子:
3.6
通讯作者:
J. D. Townsley
中科院分区:
文献类型:
--
作者:
G. Pepe;J. A. Titus;J. D. Townsley
To determine the maturational changes leading to adrenocortical self-sufficiency in baboon neonates, fetal adrenal growth and cortisol (F) production, in vitro, from pregnenolone (P5), progesterone (P4) and 11-deoxycortisol (S) were examined at various times during gestation. Adrenal weight of animals delivered prematurely (100-179 days gestation, term = 184) by cesarean section (N = 17) or spontaneously (N = 13) at term (181 ± 4 days, X ± SE), tripled during the second half of gestation (r = 0.82; P<0.0O1; Y = 403e0.0I7X) and resulted primarily from growth of cortical fetal zone tissue. F production from [3H1P5, [3H1P4 or I3HIS(1512Ci, lOlhg) by 50 mg homogenized tissue from selected glands incubated with NADPH was determined following extraction, and purification of [3 HI F. Resultswere combined from animals deliveredby cesarean section 84 to 54 days (N = 4), or 24 to 17 days prior to term (N = 3)and from neonates iday old (N = 3) or Sand 12 days old (N = 2). F production from S (68.2 percent ± 13.1 percent, X ± SE) and P4 (42.4 percent ± 2.9 percent) either remained constant or decreased during the study period, while that from P5 (6.9 percent ± 1.9 percent) increased (P<0.001) from 3 ± I pmole/mg at midgestation to 14 ± 5 pmole/mg shorly before term, reaching 51 ± 13 pmole/mg 1 day after spontaneous delivery. When corrected for adrenal weight, F production from S (88-118 nmole/2 adrenals) and P4 (46-77 nmole/2 adrenals) remained constant whereas that from P5 increased (P<0.001) from 0.3 ± 0.1 nmole/2 adrenals at midgestation to 17 ± 5 nmole/2 adrenalsI day after spontaneous delivery. This capacity was maintained in the first 12 days of life. Thus fetal adrenal 313-hydroxysteroid dehydrogenase-isomerase activity is increased, while 11(3-,17n- and 21-hydroxylase activities are relatively greater but unchanged during gestation. It is concluded that increased 3j3-hydroxysteroid dehydrogenase-isomerase combined with adrenal growth permits increased utilization of P5 for F synthesis towards term. These changes may be important in ensuring adrenocortical self-sufficiency when, after delivery, placental P4 is no longer available for F production.