Adrenal TGFbeta1 mRNA levels fall during late gestation and are not regulated by cortisol in the sheep fetus. 2003

Catherine L Coulter, and Mark D Salkeld, and I Caroline McMillen
Department of Physiology, Medical School Building, The University of Adelaide, Adelaide, SA 5005, Australia. catherine.coulter@adelaide.edu.au

During mammalian development there are periods when the fetal adrenal is either relatively refractory or increasingly sensitive to trophic stimulation. This pattern of regulation of adrenal growth and function ensures that the fetal lungs, liver, brain and kidney are exposed in a programmed temporal sequence to the genomic actions of circulating glucocorticoids. The factors which act to maintain periods of adrenal quiescence are not known. In the present study we have measured the level of messenger RNA (mRNA) expression of a putative inhibitor of adrenal steroidogenesis, transforming growth factor beta 1 (TGFbeta1), and a key steroidogenic enzyme, cytochrome P450 17alpha hydroxylase (CYP17), during periods of adrenal quiescence and activation in the sheep fetus. We have also investigated the relative roles of the fetal hypothalamic-pituitary axis and cortisol in the regulation of expression of adrenal TGFbeta1 and CYP17 mRNA during late gestation. Adrenal expression of TGFbeta1 was greatest at around 100 days gestation, at a time when the fetal sheep adrenal is relatively refractory to trophic stimulation and there was an inverse relationship between the expression of TGFbeta1 and CYP17 mRNA in the adrenal gland during the peripartum period. Whilst disconnection of the fetal hypothalamic-pituitary disconnection (HPD) axis resulted in a decrease in adrenal CYP 17 mRNA expression, there was no effect of fetal HPD, with or without cortisol replacement, on adrenal TGFbeta1 mRNA expression in late gestation. Thus TGFbeta1 may play a role in inhibiting adrenal steroidogenesis and ensuring that the adrenal remains relatively refractory to trophic stimulation during mid gestation. The maintenance of low adrenal TGFbeta1 expression during late gestation is not dependent, however, on stimulation by the fetal hypothalamic-pituitary axis.

UI MeSH Term Description Entries
D007031 Hypothalamus Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE. Lamina Terminalis,Preoptico-Hypothalamic Area,Area, Preoptico-Hypothalamic,Areas, Preoptico-Hypothalamic,Preoptico Hypothalamic Area,Preoptico-Hypothalamic Areas
D009929 Organ Size The measurement of an organ in volume, mass, or heaviness. Organ Volume,Organ Weight,Size, Organ,Weight, Organ
D010902 Pituitary Gland A small, unpaired gland situated in the SELLA TURCICA. It is connected to the HYPOTHALAMUS by a short stalk which is called the INFUNDIBULUM. Hypophysis,Hypothalamus, Infundibular,Infundibular Stalk,Infundibular Stem,Infundibulum (Hypophysis),Infundibulum, Hypophyseal,Pituitary Stalk,Hypophyseal Infundibulum,Hypophyseal Stalk,Hypophysis Cerebri,Infundibulum,Cerebri, Hypophysis,Cerebrus, Hypophysis,Gland, Pituitary,Glands, Pituitary,Hypophyseal Stalks,Hypophyses,Hypophysis Cerebrus,Infundibular Hypothalamus,Infundibular Stalks,Infundibulums,Pituitary Glands,Pituitary Stalks,Stalk, Hypophyseal,Stalk, Infundibular,Stalks, Hypophyseal,Stalks, Infundibular
D005333 Fetus The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN. Fetal Structures,Fetal Tissue,Fetuses,Mummified Fetus,Retained Fetus,Fetal Structure,Fetal Tissues,Fetus, Mummified,Fetus, Retained,Structure, Fetal,Structures, Fetal,Tissue, Fetal,Tissues, Fetal
D005865 Gestational Age The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated from the onset of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization. It is also estimated to begin from fertilization, estrus, coitus, or artificial insemination. Embryologic Age,Fetal Maturity, Chronologic,Chronologic Fetal Maturity,Fetal Age,Maturity, Chronologic Fetal,Age, Embryologic,Age, Fetal,Age, Gestational,Ages, Embryologic,Ages, Fetal,Ages, Gestational,Embryologic Ages,Fetal Ages,Gestational Ages
D006854 Hydrocortisone The main glucocorticoid secreted by the ADRENAL CORTEX. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions. Cortef,Cortisol,Pregn-4-ene-3,20-dione, 11,17,21-trihydroxy-, (11beta)-,11-Epicortisol,Cortifair,Cortril,Epicortisol,Hydrocortisone, (11 alpha)-Isomer,Hydrocortisone, (9 beta,10 alpha,11 alpha)-Isomer,11 Epicortisol
D000302 Adrenal Cortex The outer layer of the adrenal gland. It is derived from MESODERM and comprised of three zones (outer ZONA GLOMERULOSA, middle ZONA FASCICULATA, and inner ZONA RETICULARIS) with each producing various steroids preferentially, such as ALDOSTERONE; HYDROCORTISONE; DEHYDROEPIANDROSTERONE; and ANDROSTENEDIONE. Adrenal cortex function is regulated by pituitary ADRENOCORTICOTROPIN. Cortex, Adrenal
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D012333 RNA, Messenger RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. Messenger RNA,Messenger RNA, Polyadenylated,Poly(A) Tail,Poly(A)+ RNA,Poly(A)+ mRNA,RNA, Messenger, Polyadenylated,RNA, Polyadenylated,mRNA,mRNA, Non-Polyadenylated,mRNA, Polyadenylated,Non-Polyadenylated mRNA,Poly(A) RNA,Polyadenylated mRNA,Non Polyadenylated mRNA,Polyadenylated Messenger RNA,Polyadenylated RNA,RNA, Polyadenylated Messenger,mRNA, Non Polyadenylated
D012756 Sheep Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS. Ovis,Sheep, Dall,Dall Sheep,Ovis dalli

Related Publications

Catherine L Coulter, and Mark D Salkeld, and I Caroline McMillen
October 1996, The Journal of endocrinology,
Catherine L Coulter, and Mark D Salkeld, and I Caroline McMillen
March 1993, Neuroendocrinology,
Catherine L Coulter, and Mark D Salkeld, and I Caroline McMillen
May 1993, The Journal of endocrinology,
Catherine L Coulter, and Mark D Salkeld, and I Caroline McMillen
November 2007, Endocrinology,
Catherine L Coulter, and Mark D Salkeld, and I Caroline McMillen
May 1998, The Journal of physiology,
Catherine L Coulter, and Mark D Salkeld, and I Caroline McMillen
January 1980, Reproduction, nutrition, developpement,
Catherine L Coulter, and Mark D Salkeld, and I Caroline McMillen
January 1986, Endocrinology,
Catherine L Coulter, and Mark D Salkeld, and I Caroline McMillen
December 1996, Pediatric research,
Catherine L Coulter, and Mark D Salkeld, and I Caroline McMillen
May 1994, The Journal of physiology,
Copied contents to your clipboard!