The pituitary gland and lymph organs, such as spleen, thymus, and peripheral blood, produce Growth hormone (GH). GH receptors are found on the surface of some lymphocytes. Previous studies have shown that GH has a function in the regulation of immunity and has been shown to have the following functions:
T and B cell growth.
Maturation of blood progenitor (stem) cells.
Modulation of the cytokine system.
Surprisingly, human pituitary GH deficiency is not followed by immune deficiency. Perhaps, the local production of GH by lymph tissues compensates for the absence of pituitary GH and prevents the loss of immune function.
CONCLUSION: GH production by the lymph system in humans may prevent immune deficiency in people who have low production of pituitary GH. GH is known to have a number of immune functions and there is evidence in the studies for a clear relationship between the endocrine and immune systems.
NOTE: This summary was based on the PubMed abstract. The complete article is not available for review. Various amino acid (including l-glutamine and l-arginine) and homeopathic supplements have been shown to stimulate GH production.