title: Surfactant protein C: hormonal control of SP-C mRNA levels in vitro.
abstract: We have studied hormonal regulation of the surfactant protein C (SP-C) in fetal 18-dah rat lung explants. SP-C mRNA was detected in Northern blots with a specific rat SP-C cDNA probe and quantified by densitometry. Treatment of the explants with dexamethasone resulted in a dose-dependent increase of the SP-C mRNA level. Transcriptional assays have shown that the regulation of SP-C mRNA by dexamethasone involves a transcriptional step. Administration of the cAMP analogues, 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP) or dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP), produced a dose-dependent increase of SP-C mRNA levels, with maximum stimulation observed at 200 microM. The thyroid hormone T3 had no effect on SP-C mRNA levels, whether administered alone or in combination with dexamethasone. Variation in the effects of the above hormones on three surfactant protein mRNAs, SP-A, SP-B and SP-C, indicates that the hormonal regulation of the surfactant proteins is a complex process and that each gene is, in part, differentially regulated.
authors.affiliation: Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115.
authors.forename: S V
authors.initials: SV
authors.lastname: Veletza
authors.forename: K V
authors.initials: KV
authors.lastname: Nichols
authors.forename: I
authors.initials: I
authors.lastname: Gross
authors.forename: H
authors.initials: H
authors.lastname: Lu
authors.forename: D W
authors.initials: DW
authors.lastname: Dynia
authors.forename: J
authors.initials: J
authors.lastname: Floros
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D003994:Bucladesine / Q000494:pharmacology*; D002467:Cell Nucleus / Q000187:drug effects / Q000502:physiology*; D003001:Cloning, Molecular; D003907:Dexamethasone / Q000494:pharmacology*; D005333:Fetus; D015723:Gene Library; D006801:Humans; D007700:Kinetics; D008168:Lung / Q000187:drug effects / Q000502:physiology*; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D009924:Organ Culture Techniques; D011510:Proteolipids / Q000235:genetics* / Q000378:metabolism; D011663:Pulmonary Surfactants / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D015345:Oligonucleotide Probes; D011510:Proteolipids; D011663:Pulmonary Surfactants; D012333:RNA, Messenger; D015124:8-Bromo Cyclic Adenosine Monophosphate; D003994:Bucladesine; D003907:Dexamethasone