Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.8 (cholinesterase)
 12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pyridostigmine (PST), a cholinesterase inhibitor, induces a clear growth hormone (GH) release in man by suppression of hypothalamic somatostatin (SRIH). Somatostatin suppresses thyrotrophin (TSH) release in rats and men. Earlier studies showed that the thryotrophin-releasing hormone (TRH)-induced TSH response was not altered by 60-120 mg of PST. We studied whether a larger dose (180 mg) of PST can increase the TSH response to TRH. Six healthy young men were studied with the following six tests: (Test 1) 200 micrograms of TRH i.v.; (Test 2) 180 mg of PST po; (Test 3) three different doses of PST (60, 120, 180 mg) + TRH; (Test 4) 100 micrograms of octreotide (SMS) i.v.; (Test 5) SMS + TRH; (Test 6) PST + SMS + TRH. A large dose of PST (180 mg) significantly augmented GH, TSH and prolactin responses to TRH, while smaller doses of PST (60 and 120 mg) did not significantly increase the responses of GH and TSH. While the increased TRH-induced prolactin response by PST was not suppressed by SMS, the increased responses of GH and TSH were suppressed remarkably by SMS. Most of the subjects noticed a mild to moderate abdominal pain, nausea and muscular fasciculation after the administration of a large dose of PST administration. These data suggest that suppression of hypothalamic SRIH secretion by 180 mg of PST can augment the TSH response to TRH. However, the considerable side effects should be minimized before clinical application of the combined PST-TRH test.
 ...
PMID:Combined pyridostigmine-thyrotrophin-releasing hormone test for the evaluation of hypothalamic somatostatinergic activity in healthy normal men. 758 70

To indirectly evaluate the hypothalamic somatostatin (SS) tone in patients with acromegaly, the effects of pyridostigmine (PD), a cholinesterase inhibitor which can inhibit hypothalamic SS secretion, on TRH-induced TSH secretion and the effects of SMS 201-995 on TSH or GH secretion were studied in acromegalic patients (31-69 yr, n = 10), normal young (21-24 yr, n = 7) and normal old male subjects (62-71 yr, n = 7). After pretreatment with PD (60 mg po, -30 min), normal young subjects showed significantly enhanced TSH responses to TRH (500 micrograms i.v., 0 min) compared to single administration of TRH, whereas normal old and acromegalic patients did not show such enhancement. Plasma TSH response to a single administration of TRH in acromegalic patients was significantly lower than that of normal young and old subjects. Although normal young and old subjects showed significantly enhanced GH responses to GHRH (100 micrograms i.v. at 0 min) after the pretreatment with PD (60 mg, -30 min), no such enhancement was observed in acromegalic patients. In contrast, the decrement in plasma TSH after SMS 201-995 administration was similar between normal subjects (5 young 5 old) and 7 acromegalic patients. Further, the maximal plasma GH decrement after administration was significantly greater in acromegalic patients than in the 5 normal young and 5 old subjects p < 0.01). In conclusion, hypothalamic SS tone does not appear to be elevated in acromegalic patients compared to normal young and probably old subjects.
 ...
PMID:The evaluation of hypothalamic somatostatin tone using pyridostigmine and thyrotropin releasing hormone in patients with acromegaly. 791 36