A team of researchers led by scientists at Cold Spring Harbour laboratory have identified stem cells in the pitutary gland of the mice that helps it grow even after birth. “This gland develops in the embryo, but then has a second growth spurt. After few weeks of their birth, the pituitary undergoes massive expansion due to the presence of the adult stem cells” says Dr. Enikolopov. According to the researchers, this might be the way that, a hormone secreting gland adapt, in adolescence and in adults during time of traumatic stress or to normal life changes like pregnancy.

Anatoli Gleiberman, a researcher in the lab of pituitary expert, M. Geoff Rosenfeld at the University of California, San Diego & Dr. Enikolopov, initiated a collaboration between the two labs to look for pituitary stem cells. The researchers used Nestin - tracking mice to identify candidate cells in the anterior pituitary, the section of the organ that secretes hormones. They then used other techniques to show that these are true stem cells. According to Dr. Enikolopov “There are six main lineages in the adult pituitary and we can demonstrate that one adult stem cell can generate all six lineages, with each cell type secreting a different hormone”.

The research also indicates that adult mouse pituitary includes two types of similar but not identical hormone producing cells, some that grew in the developing embryo, while some other appear later. They speculate that having two sets of cells may let the organ respond differently to the changing body conditions.

Hormones strongly influence human neuropsychiatric phenomena, including stress and depression and, all hormones are mediated through the pituitary, so changes that happen during the later growth of the gland could have lasting effects, ” said Dr Enikolopov. According to them, adult tissues undergo continuous cell turnover in response to stress, damage or physiological demand. New differentiated cells are generated from dedicated or facilitative stem cells or from self- renewing differentiated cells.

In human beings, this gland is in the size of a pea, which is present at the base of the brain, where it secretes hormone that are regulated throughout the body by various processes. But studying them in people is controversial. The study on mice has so far been successful, and the scientists are expecting the same, positive result from the pituitary glands of the human beings
Source- Science Daily