1969
We first tested whether chronic hyperprolactinemia inhibited two neuroendocrine parameters necessary for female fertility : pulsatile LH secretion and the estrogen - induced LH surge .
 hyperprolactinemia, estrogen
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 hyperprolactinemia, estrogen