Joseph Massa

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The effects of cyclic AMP treatment on total cAMP-dependent protein kinase activity in GH3 pituitary tumor cells have been studied. Incubation of cells for 24 h with 1 microM forskolin resulted in a 50% decrease in total cAMP-dependent protein kinase activity which was reversible upon removal of forskolin from culture media. A similar response was observed(More)
The effects of melatonin (Mel) and/or underfeeding (30% food restriction) on 7,12-dimethylbenzanthracene (DMBA)-induced mammary tumorigenesis were examined in female Sprague-Dawley rats fed a semipurified diet. During the promotional phase of tumorigenesis, the animals began receiving either daily afternoon Mel (250μg) or saline vehicle injections s.c. for(More)
A rat complementary DNA (cDNA) for the RI beta isoform of type I cyclic adenosine monophosphate (cAMP)-dependent protein kinase regulatory subunit was cloned and sequenced and was found to contain the entire protein coding and 3'-untranslated regions, with a single (ATTAAA) poly-adenylation site. The largest open reading frame was preceded by a short(More)
Light deprivation by blinding or exposure to short photoperiod results in depressed prolactin (PRL) cell activity and gonadal regression in the male Syrian hamster after at least 42-56 days of treatment, and both of these events can be prevented if pineal removal accompanies light deprivation. In the present study, we investigated changes in PRL cell(More)
Pituitary prolactin (PRL) cell activity (i.e. PRL messenger ribonucleic acid [mRNA] levels, PRL synthesis, and radioimmunoassayable [RIA]-PRL), and serum RIA-PRL were measured in female golden Syrian hamsters that were (1) light-deprived and then ovariectomized before loss of estrous cyclicity, (2) light-deprived but not yet acyclic, and (3) light-deprived(More)
All known actions of cAMP in the brain require cAMP-dependent protein kinase (cAMPdPK), which consists of regulatory (R) and catalytic (C) subunits (R2C2). Using homologous rat cDNAs for all known cAMPdPK subunit isoforms found in the brain (RI alpha, RI beta, RII alpha, RII beta, C alpha, C beta) we observe that, in the fetal rat brain from 12 days of(More)
Pinealectomy in the female golden Syrian hamster is not always completely effective in preventing the suppressive effects of long-term light deprivation due to blinding on pituitary prolactin (PRL) cell activity. We examined this curious phenomenon by measuring pituitary PRL mRNA levels, PRL synthesis, and radioimmunoassayable PRL, and correlating these(More)
The purpose of this study was to observe the molecular dynamics of pituitary prolactin (PRL) gene expression during the estrous cycle of the Golden Syrian hamster. PRL messenger ribonucleic acid (mRNA) levels, PRL synthesis (3H-PRL in the incubation media or incubated pituitary after a 3 hr incubation with 3H-leucine), and radioimmunoassayable (RIA) PRL (in(More)
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