Both pituitary and placental growth hormone transcripts are expressed in human peripheral blood mononuclear cells (PBMC)
The hGH‐V gene codes for a variant of human pituitary growth hormone (hGH‐N) named placental growth hormone (hPGH). hPGH shares 93% amino acid identity with hGH‐N. Until now the hGH‐V gene was considered to be exclusively expressed in human placenta, where it replaces maternal circulating hGH‐N at the end of pregnancy. In this study we investigated by reverse transcriptase‐polymerase chain reaction (RT‐PCR) analysis hGH‐N, and hGH‐V, gene expression in PBMC in men, women and pregnant women. We have demonstrated that hGH‐N and hGH‐V transcripts are simultaneously produced by PBMC in both men and women as well as pregnant women. The PBMC of a PIT‐.1‐negative woman expressed only the hGH‐V transcript, but not the hGH‐N one as expected. In conclusion, hGH‐V mRNA is expressed by cells other than the syncytiotrophoblast, is not regulated by PIT‐1, and may be involved in immune regulation, as is pituitary GH.