Fetal rat brains contain luteinizing hormone/human chorionic gonadotropin receptors

The reverse transcription-polymerase chain reaction/Southern, Northern and Western blottings demonstrated that 19-day-old fetal rat brains contained the luteinizing hormone (LH)/human chorionic gonadotropin (hCG) receptor transcripts and receptor protein. Further investigation with Western blotting demonstrated that diencephalon, mesencephalon, rhombencephalon and telencephalon and several areas in each of these regions contained the LH/hCG receptor protein. The receptor protein levels in different regions were somewhat variable but they were not different from each other or from the whole brain. The 15-day-old fetal rat brains contained lower receptor protein levels which increased by 3-fold in 17-day-old and by 12-fold in 19-day-old fetal rat brains with no further significant increase in 21-day-old fetal, neonatal or adult rat brains. In summary, fetal rat brains contained LH/hCG receptors and these receptors were developmentally regulated. These findings suggest that the gonadotropins LH and hCG may regulate growth, development and differentiation in fetal brain.