Expression and localization of growth hormone-releasing hormone messenger ribonucleic acid in rat placenta: in vitro secretion and regulation of its peptide product. 1990

A N Margioris, and G Brockmann, and H C Bohler, and M Grino, and N Vamvakopoulos, and G P Chrousos
Developmental Endocrinology Branch, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.

The placenta is the source of many hypothalamic peptides. We now report that GH-releasing hormone (GHRH) mRNA was detectable in rat placenta. On Northern blot hybridization analysis, the size of the placental GHRH transcript was the same with the putative GHRH precursor mRNA. On in situ hybridization, the cells expressing the GHRH mRNA had the morphological characteristics of cytotrophoblasts. In addition, immunoreactive (IR) postranslational products of GHRH were present in rat placental extracts and in the effluent of in vitro perifused placentae. On gel filtration chromatography, the bulk of IR-GHRH present in placental extracts and perifusion effluent had the same size as the authentic hypothalamic GHRH (5.2K). A higher mol wt form of IR-GHRH of about 10K was also present and may represent the pro-GHRH predicted from the sequence of the GHRH cDNA. The mean basal release of IR-GHRH in the perifusion effluent from full thickness rat placental fragments was 337.3 +/- 38.5 (+/- SE; n = 48) pg/10 min fraction.g tissue. Depolarization by 56 mM KCl increased the concentration of the secreted immunoreactive peptide to 632.2 +/- 50.5. A 10-min exposure to 8-bromo-cAMP caused an immediate, monophasic, and dose-dependent increase in IR-GHRH secretion, which lasted between 20-30 min. The ensuing response to a KCl pulse was similar in size and pattern to that in the control channels. In contrast, a 10-min pulse of phorbol 12-myristate 13-acetate (a protein kinase-C-irreversible activator) induced a gradual, prolonged, and dose-dependent increase in basal GHRH secretion which lasted for at least 4 h. Additionally, phorbol 12-myristate 13-acetate enhanced KCl-induced GHRH secretion. In conclusion, our data suggest that the GHRH gene is expressed in the rat placenta. The placental GHRH transcript and its peptide products appear to have the same size as their hypothalamic counterparts, while the site of its placental GHRH synthesis is the cytotrophoblast. Finally, the secretion of placental GHRH seems to be regulated by both the adenyl cyclase and the protein kinase-C pathways.

UI MeSH Term Description Entries
D009693 Nucleic Acid Hybridization Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503) Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D010477 Perfusion Treatment process involving the injection of fluid into an organ or tissue. Perfusions
D010920 Placenta A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES). Placentoma, Normal,Placentome,Placentas,Placentomes
D011247 Pregnancy The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH. Gestation,Pregnancies
D002850 Chromatography, Gel Chromatography on non-ionic gels without regard to the mechanism of solute discrimination. Chromatography, Exclusion,Chromatography, Gel Permeation,Chromatography, Molecular Sieve,Gel Filtration,Gel Filtration Chromatography,Chromatography, Size Exclusion,Exclusion Chromatography,Gel Chromatography,Gel Permeation Chromatography,Molecular Sieve Chromatography,Chromatography, Gel Filtration,Exclusion Chromatography, Size,Filtration Chromatography, Gel,Filtration, Gel,Sieve Chromatography, Molecular,Size Exclusion Chromatography
D005260 Female Females
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
D013007 Growth Hormone-Releasing Hormone A peptide of 44 amino acids in most species that stimulates the release and synthesis of GROWTH HORMONE. GHRF (or GRF) is synthesized by neurons in the ARCUATE NUCLEUS of the HYPOTHALAMUS. After being released into the pituitary portal circulation, GHRF stimulates GH release by the SOMATOTROPHS in the PITUITARY GLAND. Growth Hormone-Releasing Factor,Somatocrinin,Somatotropin-Releasing Factor 44,Somatotropin-Releasing Hormone,GHRH 1-44,GRF 1-44,Growth Hormone-Releasing Factor 44,Human Pancreatic Growth Hormone-Releasing Factor,Somatoliberin,hpGRF 44,Growth Hormone Releasing Factor,Growth Hormone Releasing Factor 44,Growth Hormone Releasing Hormone,Somatotropin Releasing Factor 44,Somatotropin Releasing Hormone
D014018 Tissue Distribution Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios. Distribution, Tissue,Distributions, Tissue,Tissue Distributions

Related Publications

A N Margioris, and G Brockmann, and H C Bohler, and M Grino, and N Vamvakopoulos, and G P Chrousos
January 1996, Reproduction, fertility, and development,
A N Margioris, and G Brockmann, and H C Bohler, and M Grino, and N Vamvakopoulos, and G P Chrousos
July 1992, The Journal of clinical endocrinology and metabolism,
A N Margioris, and G Brockmann, and H C Bohler, and M Grino, and N Vamvakopoulos, and G P Chrousos
January 1995, Endocrinology,
A N Margioris, and G Brockmann, and H C Bohler, and M Grino, and N Vamvakopoulos, and G P Chrousos
June 1997, Endocrinology,
A N Margioris, and G Brockmann, and H C Bohler, and M Grino, and N Vamvakopoulos, and G P Chrousos
March 1997, Endocrinology,
A N Margioris, and G Brockmann, and H C Bohler, and M Grino, and N Vamvakopoulos, and G P Chrousos
September 1990, Endocrinology,
A N Margioris, and G Brockmann, and H C Bohler, and M Grino, and N Vamvakopoulos, and G P Chrousos
October 1989, The Journal of clinical endocrinology and metabolism,
A N Margioris, and G Brockmann, and H C Bohler, and M Grino, and N Vamvakopoulos, and G P Chrousos
March 1994, Endocrinology,
A N Margioris, and G Brockmann, and H C Bohler, and M Grino, and N Vamvakopoulos, and G P Chrousos
March 1993, Endocrinology,
A N Margioris, and G Brockmann, and H C Bohler, and M Grino, and N Vamvakopoulos, and G P Chrousos
December 1996, Endocrinology,
Copied contents to your clipboard!