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

An invasive TSH-secreting adenoma inducing mild hyperthyroidism was diagnosed in a 16-year-old male. Initial surgical treatment led to a temporary clinical and biological improvement. Recurrence of the thyrotoxicosis was treated with the somatostatin analogue, SMS 201-995 (octreotide) with normalization of the serum thyroid hormone levels with a dose of 200 micrograms per day. With immunoelectron microscopy, the tumour cells appeared poorly granulated with small secretory granules located at the periphery of the cells; only part of those were immunoreactive with an anti-TSH beta monoclonal antibody. No specific TRH binding site was found in a tumour membrane preparation. By quantitative autoradiography, somatostatin specific binding sites were as numerous in the TSH-secreting tumour as in control GH-secreting tumours. Binding kinetics and guanosine triphosphate dependency of the binding were equivalent in the TSH and GH tumours tested. Although all of the tumour cells displayed the same ultrastructural features, some were non-immunoreactive, suggesting that they could secrete an altered form of TSH. The absence of TRH receptors in the tumour cells is in accordance with previous reports on this type of tumour. We confirm the efficiency of octreotide treatment in this case of neoplastic TSH inappropriate secretion. The therapeutic effect of octreotide goes along with the presence of a high density of guanine nucleotide-dependent somatostatin binding sites in the tumour cells.
 ...
PMID:A human TSH-secreting adenoma: endocrine, biochemical and morphological studies. Evidence of somatostatin receptors by using quantitative autoradiography. Clinical and biological improvement by SMS 201-995 treatment. 185 93

Thyrotrophin secreting pituitary adenomas are a rare cause of recurrent thyrotoxicosis. We report on a 47 year old woman with an 8-year history of this condition. In this case the somatostatin analogue, octreotide, normalized thyroid hormone levels. It was associated with marked tumour shrinkage, with striking reduction of the suprasellar extension and improved appearances in the region of the left cavernous sinus shown by high resolution computerized tomography. Following surgery she developed a biochemical relapse which responded to the reinstitution of octreotide. On long term treatment she developed stomach cramps and gallstones. Octreotide was discontinued. We review previous reports of this condition and discuss the role of octreotide in its management.
 ...
PMID:Shrinkage of thyrotrophin secreting pituitary adenoma treated with octreotide. 185 68

Inappropriate hypersecretion of TSH was investigated in a 25 year old man whose hyperthyroidism had relapsed 4 years after subtotal thyroidectomy. Serum TSH levels were further increased by both TRH and metoclopramide and were partially suppressed by triiodothyronine (120 micrograms/day). The serum alpha-subunit: TSH molar ratio was less than 1.0, and computerised axial tomography showed no evidence of a pituitary tumour. These features are characteristic of inappropriate TSH secretion due to thyrotroph resistance to thyroid hormones. A long-acting somatostatin analogue (SMS 201-995), 50 micrograms injected sc twice-daily for three days, suppressed TSH levels and nearly normalised thyroid hormone levels. Somatostatin analogues may be therapeutically useful in thyrotoxicosis due to non-tumoural inappropriate TSH hypersecretion.
 ...
PMID:Hyperthyroidism due to non-tumoural inappropriate TSH secretion. Effect of a long-acting somatostatin analogue (SMS 201-995). 287 71

The responses in plasma glucose, insulin, C-peptide, glucagon and somatostatin to an oral glucose load were studied in 10 thyrotoxic patients and 10 matched euthyroid controls. The thyrotoxic patients had higher mean fasting plasma glucose (P less than 0.05) and responded to oral glucose with an earlier peak at 30 min which was higher than the corresponding glucose level in the controls (P less than 0.05). Impaired glucose tolerance was found in 3 patients. Fasting insulin and C-peptide levels were normal in the thyrotoxic patients when corrected for the higher glucose levels. Following glucose ingestion, there was no significant difference between the areas under the insulin or C-peptide curves in patients and controls, but Seltzer's insulinogenic index was reduced in the patients (P less than 0.01) suggesting an impaired pancreatic B-cell response to oral glucose. Mean basal glucagon was normal in the thyrotoxic patients. However, while in the controls plasma glucagon became suppressed following glucose ingestion (P less than 0.0001), no significant suppression was found in the patients. In the thyrotoxic patients, mean basal somatostatin was normal, but the area under the somatostatin curve following glucose ingestion was significantly increased (P less than 0.02). Our findings suggest that decreased glucagon suppression and impaired insulin response after glucose ingestion are involved in glucose intolerance in thyrotoxicosis. Enhanced somatostatin responses to oral glucose in thyrotoxicosis may have contributed to the observed impairment in pancreatic B-cell responsiveness.
 ...
PMID:Glucose intolerance in thyrotoxicosis roles of insulin, glucagon and somatostatin. 288 18

Known since 1967 and usually familial, the syndrome of tissue resistance to thyroid hormones may take one of two different forms, depending on the receptors involved. When resistance affects both peripheral and pituitary receptors, plasma thyroid hormone levels are high despite the lack of thyrotoxicosis, thyroxine and triiodothyronine are ineffective, even in high dosage, and plasma TSH increases to explode under TRH. When resistance only affects pituitary receptors, there is moderate thyrotoxicosis with paradoxical and inappropriate TSH increase. Contrary to expectations, nuclear receptors to triiodothyronine are perturbed in only a few cases. Reduction of thyrotropic hyperfunction, which is the primary purpose of treatment, can be achieved with D-forms of thyroid hormones or with somatostatin and its derivatives.
 ...
PMID:[The syndrome of tissue resistance to thyroid hormones]. 288 29

Long-acting somatostatin analogues such as SMS 201-995 (Sandoz) are being evaluated in a wide range of clinical indications, including gut neuroendocrine tumours and acrogemaly. Long-term continuous SMS 201-995 treatment has achieved useful symptomatic improvement in diarrhoea in 4 patients with metastatic VIPomas who had relapsed following previous treatment. Clinical improvement has outlasted suppression of VIP secretion (suggesting an additional direct antisecretory action of SMS 201-995) and has occurred despite expansion of hepatic metastases. In 6 patients with tumours secreting gastrin and/or glucagon, secretion of these peptides was acutely inhibited by SMS 201-995. However, endocrine and clinical responses to chronic treatment have been less consistent. SMS 201-995 is active orally at doses of 4-8 mg and when given thrice-daily to 6 patients with active acromegaly, suppressed mean 24-h growth hormone levels by 51-88%. Despite significantly reduced plasma insulin concentrations, glucose tolerance did not deteriorate. SMS 201-995 was also effective in suppressing thyroid-stimulating hormone (TSH) and thyroid hormone secretion in a patient with mild thyrotoxicosis due to non-tumoural inappropriate TSH hypersecretion. In all cases SMS 201-995 treatment has been well tolerated and has few side-effects.
 ...
PMID:Clinical evaluation of SMS 201-995. Long-term treatment in gut neuroendocrine tumours, efficacy of oral administration, and possible use in non-tumoural inappropriate TSH hypersecretion. 289 35

Thyrotropic pituitary adenoma is a rare disease fortunately diagnosed with increasing frequency. Its originality lies in the fact that it occurs in two very different pathological contexts. The first form raises few problems: the occurrence of a pituitary tumoral syndrome in a patient with hypothyroidism, even of relatively short duration, should suggest the diagnosis. In such cases of reactive thyrotropic adenoma, simple correction of the hypothyroidism by replacement therapy seems to be capable not only of curing the thyroid disorder and lowering TSH values, but also of promoting regression of the pituitary tumour. Primary autonomous adenoma responsible for TSH hypersecretion followed by thyrotoxicosis belongs to the realm of inappropriate TSH secretion, and it should be diagnosed whenever high, or even normal (at least non-suppressed). TSH levels coexist with peripheral hyperthyroidism. As a rule, the presence of a pituitary tumour differentiates this adenoma from non-tumoral inappropriate TSH secretion due to resistance to thyroid hormones. Primary thyrotropic pituitary adenoma is treated by surgery. In case of failure or relapse, radiotherapy or medical treatment with a dopaminergic agonist or a long-acting somatostatin analogue may be considered.
 ...
PMID:[Thyrotropic pituitary adenoma. Clinical aspects, course and treatment]. 295 27

A 20-year-old female presented with thyrotoxicosis associated with amenorrhoea and galactorrhoea after oral contraceptive withdrawal. Serum TSH was persistently elevated (mean: 28 +/- 3.1 microU/ml during 24-h sampling and did not vary significantly after TRH, bromocriptine or somatostatin. Prolactin levels remained constantly at the upper limit of normal (mean: 20.6 +/- 2.1 ng/ml, with a minimal increase after TRH, a slight decrease after somatostatin (54%) and a marked decrease after bromocriptine (88.5%). Surgical exploration revealed an unusually firm tumour adherant to the wall of the sella turcia; electron microscopic study showed that it was composed almost exclusively of thyrotrophs. After a transient period of euthyroidism post-operatively, T3 toxicosis occurred with an increased TSH level (15.5 microU/ml) and a rise in TSH and alpha subunit in response to TRH. An increase in T4 followed while prolactin remained low.
 ...
PMID:Hyperthyroidism due to a pituitary TSH secreting tumour with amenorrhoea-galactorrhoea. 718 98

A unique thyrotrophin (TSH)-secreting pituitary tumour is described in a patient with a history of recurrent thyrotoxicosis. Unlike other previously reported TSHomas, the tumour is insensitive to octreotide, a somatostatin analogue. It does not accumulate [111In]octreotide but expresses functional dopamine receptors and responds to the D-isomer of thyroxine, two characteristics beneficial in the management of the patient.
 ...
PMID:Large somatostatin-insensitive thyrotrophin-secreting pituitary tumour responsive to D-thyroxine and dopamine agonists. 790 58

Altered GH responses to several pharmacological stimuli, including GHRH, have been found in hyperthyroidism. The mechanisms underlying these disturbances have not been fully elucidated. GH-releasing peptide-6 (GHRP-6) is a synthetic hexapeptide that specifically stimulates GH release both in vitro and in vivo. The mechanism of action of GHRP-6 is unknown, but it probably acts by inhibiting the effects of somatostatin on GH release. The aim of this study was to evaluate the effects of GHRP-6 on GH secretion in patients with hyperthyroidism (n = 9) and in control subjects (n = 9). Each subject received GHRP-6 (1 microg/kg, iv), GHRH (100 microg, iv), and GHRP-6 plus GHRH on 3 separate days. GH peak values (mean +/- SE; micrograms per L) were significantly lower in hyperthyroid patients compared to those in control subjects after GHRH alone (9.0 +/- 1.3 vs. 27.0 +/- 5.2) and GHRP-6 plus GHRH (22.5 +/- 3.5 vs. 83.7 +/- 15.2); a lack of the normal synergistic effect of the association of both peptides was observed in thyrotoxicosis. However, a similar GH response was seen in both groups after isolated GHRP-6 injection (31.9 +/- 5.7 vs. 23.2 +/- 3.9). In summary, we have shown that hyperthyroid patients have a normal GH response to GHRP-6 together with a blunted GH responsiveness to GHRH. Our data suggest that thyroid hormones modulate GH release induced by these two peptides in a differential way.
 ...
PMID:Different growth hormone (GH) response to GH-releasing peptide and GH-releasing hormone in hyperthyroidism. 863 30


1 2 Next >>