Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 28-year-old man with a thyroid stimulating hormone/prolactin (TSH/PRL)-secreting pituitary macroadenoma is discussed in relation to dopamine D2 and somatostatin receptor single-photon emission tomography (SPET). The patient presented with decreased vision in the left eye as a result of a temporal visual field defect and with mild hyperthyroidism. Medical therapy was tried. A test dose of both octreotide and bromocriptine resulted in an acute reduction in serum levels of TSH, alpha-subunits and PRL, whereas there was no response to TRIAC. Somatostatin and dopamine D2 receptors were present on the tumour as visualised by SPET with the ligands indium-111 diethylene triamine penta-acetic acid (DTPA)-octreotide (111In-SMS) and iodine-123 iodobenzamide (123I-IBZM), respectively. Therefore, treatment with octreotide 150 micrograms t.i.d. subcutaneously and bromocriptine 10 mg b.i.d. orally was given for > 12 and > 6 weeks, respectively. Following this treatment the visual defects disappeared, although tumour size, as measured by CT scanning, and serum TSH levels did not decrease. SPET with 111In-SMS and 123I-IBZM after therapy revealed no change or a possible increase in somatostatin receptor binding potential and a possible decrease in dopamine D2 receptor binding potential. The lack of long-term effects of the medical treatment is discussed. It is concluded that a high somatostatin and dopamine D2 receptor binding potential in vivo in a TSH/PRL-producing adenoma does not necessarily predict a successful outcome of medical treatment.
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PMID:Imaging of dopamine D2 and somatostatin receptors in vivo using single-photon emission tomography in a patient with a TSH/PRL-producing pituitary macroadenoma. 833 37

Non-functioning pituitary tumors are relatively common. A large number of these tumors are incidentally found pituitary microadenomas (<1 cm) and are usually of no clinical importance. Those tumors that require treatment are generally macroadenomas and come to medical attention because of mass effect and/or hypopituitarism. Visual field defects are present in roughly 70% of patients with non-functioning macroadenoma at the time of diagnosis and the majority of these patients have at least growth deficiency and hypogonadism. By immunocytochemistry, the large majority of these tumors are glycoprotein producing and less commonly they are non-functioning somatotroph, lactotroph or corticotoph adenomas. In contrast to the immunocytochemistry results, only a minority of these tumors actively secrete intact gonadotrophs or glycoprotein subunits. Therapy is directed at eliminating mass effect and correcting hypopituitarism. There are anecdotal reports of tumor shrinkage during therapy with either dopamine agonists or somatostatin agonists; however tumor response to medical treatment is not reliable. For most patients, transphenoidal resection of the tumor is the preferable primary treatment. Surgery improves visual defects in the majority of patients and a lesser number will recover pituitary function. In the past, pituitary radiation was commonly administered following pituitary surgery; however the need for routine radiation has recently been reevaluated. Although tumor recurrence at 10 years post surgery may be as high as 50%, few patients with recurrence will have clinical symptoms. Close follow-up with surveillance pituitary scans should be performed after surgery and radiation therapy reserved for patients having significant tumor recurrence.
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PMID:Clinically non-functioning pituitary adenoma. 1708 98

Clinically non-functioning pituitary adenomas and gonadotroph-cell adenomas are relatively common: microadenomas (< 1cm) are usually pituitary incidentalomas while most macroadenomas are revealed by mass effect and/or hypopituitarism. They are rarely associated with high gonadotropin (Luteinizing hormone, LH; Follicle-stimulating hormone FSH) levels while increased alpha-subunit levels are more frequent. Immunocytochemistry of pituitary tumor confirms the diagnosis of clinically non-functioning or gonadotroph-cell adenoma. Pituitary MRI follow-up seems to be indicated for microadenoma. Treatment of macroadenoma with visual field defect or hypopituitarism is transphenoidal surgery, but cure is rarely obtained and tumor recurrence is significant during follow-up. Therefore postoperative treatment (pituitary radiotherapy or medical treatment with dopamine agonists or somatostatin analogs) should be discussed against close follow-up with repeated MRI scans.
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PMID:[Clinically non functioning pituitary adenomas and gonadotroph-cell adenomas]. 1899 May 42