Effects of Parity and Serum Prolactin Levels on the Incidence and Regression of DMBA-Induced Tumors in OFA hr/hr Rats

<table>Serum prolactin (PRL) levels in DMBA-treated rats at the end of the experiment. (a) Nulliparous rats (Null) and rats after a cycle of pregnancy and lactation (PL) had significantly lower serum PRL than rats implanted with 17-<i>β</i> estradiol in the arcuate nucleus (I) (<svg height="11.375" id="M9" style="vertical-align:-0.30096pt" version="1.1" viewbox="0 0 75.025002 11.375" width="75.025002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
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</svg>). This group is referred to as hyperprolactinemic rats. (b) When classified depending the development (T), absence (NT), or regression (PL RegT) of mammary tumors, the implanted rats developing tumors showed significantly higher levels of serum PRL than the rest of the animals (<svg height="11.375" id="M10" style="vertical-align:-0.30096pt" version="1.1" viewbox="0 0 75.025002 11.375" width="75.025002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
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</svg>) including implanted rats without tumors.</table>

BioMed Research International

fig1

Figure 1

Figure 1: Effects of Parity and Serum Prolactin Levels on the Incidence and Regression of DMBA-Induced Tumors in OFA hr/hr Rats 