oxytocin and Adenoma

Hypopituitarism is defined as one or more partial or complete pituitary hormone deficiencies, which are related to the anterior and/or posterior gland and can have an onset in childhood or adulthood. The most common aetiology is a sellar or suprasellar lesion, often an adenoma, which causes hypopituitarism due to tumour mass effects, or the effects of surgery and/or radiation therapy. However, other clinical conditions, such as traumatic brain injury, and autoimmune and inflammatory diseases, can result in hypopituitarism, and there are also genetic causes of hypopituitarism. Furthermore, the use of immune checkpoint inhibitors to treat cancer is increasing the risk of hypopituitarism, with a pattern of hormone defects that is different from the classic patterns and depends on mechanisms that are specific for each drug. Moreover, autoantibody production against the pituitary and hypothalamus has been demonstrated in studies investigating the development or worsening of some cases of hypopituitarism. Finally, evidence suggests that posterior pituitary damage can affect oxytocin secretion. The aim of this Review is to summarize current knowledge on non-classic and emerging causes of hypopituitarism, so as to help clinicians improve early identification, avoid life-threatening events and improve the clinical care and quality of life of patients at risk of hypopituitarism.

Topics: Adenoma; Adrenocorticotropic Hormone; Autoimmune Hypophysitis; Brain Injuries, Traumatic; Dwarfism, Pituitary; Empty Sella Syndrome; Endocrine System Diseases; Genetic Diseases, Inborn; Humans; Hypoglycemia; Hypogonadism; Hypophysitis; Hypopituitarism; Hypothyroidism; Immune Checkpoint Inhibitors; Oxytocin; Pituitary Apoplexy; Pituitary Neoplasms; Subarachnoid Hemorrhage

Oxytocin (OXT) has been reported to act as a growth regulator in various tumor cells. However, there is a paucity of data on the influence of OXT on cell proliferation of corticotroph adenomas. This study aimed to examine whether OXT affects cell growth in pituitary tumor cell lines (AtT20 and GH3 cells) with a focus on corticotroph adenoma cells.. Reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay were conducted with AtT20 cells to confirm the effects of OXT on hormonal activity; flow cytometry was used to assess changes in the cell cycle after OXT treatment. Moreover, the impact of OXT on proliferating cell nuclear antigen (PCNA), nuclear factor κB, and mitogen-activated protein kinase signaling pathway was analyzed by Western blot.. OXT treatment of 50 nM changed the gene expression of OXT receptor and pro-opiomelanocortin within a short time. In addition, OXT significantly reduced adrenocorticotropic hormone secretion within 1 hour. S and G2/M populations of AtT20 cells treated with OXT for 24 hours were significantly decreased compared to the control. Furthermore, OXT treatment decreased the protein levels of PCNA and phosphorylated extracellular-signal-regulated kinase (P-ERK) in AtT20 cells.. Although the cytotoxic effect of OXT in AtT20 cells was not definite, OXT may blunt cell proliferation of corticotroph adenomas by altering the cell cycle or reducing PCNA and P-ERK levels. Further research is required to investigate the role of OXT as a potential therapeutic target in corticotroph adenomas.

Topics: ACTH-Secreting Pituitary Adenoma; Adenoma; Animals; Cell Line, Tumor; Cell Proliferation; Cell Survival; Gene Expression; MAP Kinase Signaling System; Mice; Oxytocin; Pro-Opiomelanocortin; Proliferating Cell Nuclear Antigen; Rats; Receptors, Oxytocin

Spontaneous pituitary adenomas are common in certain strains of the laboratory rat. Investigations of Wistar rats of two years chronic toxicity studies revealed pituitary tumors in 50% of the females and 26% of the males. The morphology of the spontaneous changes in the pituitary gland was investigated with immunohistochemical and histological methods. The peroxidase-antiperoxidase (PAP) technique was used to localize different hormones (LH, ACTH) in cells of the pars intermedia and pars distalis as well as neurophysin, oxytocin and vasopressin the terminals of the classic neurosecretory system of the pars nervosa. The results show that most of the neoplasms were endocrinologically inactive chromophobe adenomas of the pars distalis.

Topics: Adenoma; Adrenocorticotropic Hormone; Animals; Female; Immunoenzyme Techniques; Luteinizing Hormone; Male; Neurophysins; Oxytocin; Pituitary Gland; Pituitary Neoplasms; Rats; Rats, Inbred Strains; Vasopressins

Topics: Acetylcholine; Adenoma; Animals; Cortisone; Estrone; Female; Neoplasms, Experimental; Nicotine; Oxytocin; Pituitary Neoplasms; Rats; Sodium Chloride; Vasopressins; Water-Electrolyte Balance