Effect of octapeptide somatostatin analogue (SMS 201-995) on plasma 7B2 (a neuroendocrine polypeptide) levels in patients with acromegaly.
We studied the sequential changes of plasma levels of immunoreactive '7B2' (IR-7B2), a neuroendocrine polypeptide, after a subcutaneous injection of 50 micrograms of synthetic octapeptide somatostatin analogue (SMS 201-995) in seven patients with acromegaly due to GH-producing pituitary adenoma. Compared to the basal levels, mean plasma IR-7B2 and GH levels significantly decreased, until 5 and 10 h respectively after the administration of SMS 201-995. The mean (+/- SEM) nadir levels of plasma IR-7B2 and GH were 68.1 +/- 10.1 and 13.1 +/- 6.9%, respectively, compared to mean plasma levels before treatment (100%). Plasma IR-7B2 as well as GH levels did not change significantly when saline was administered subcutaneously to three acromegalic patients. In addition, plasma IR-7B2 levels did not change significantly after the administration of SMS 201-995 in normal subjects or in patients with primary hypothyroidism in whom SMS 201-995 induced a decrease of plasma TSH levels. These results strongly suggest that SMS 201-995 has an unequivocal suppressive effect on the synthesis and/or the secretion of 7B2 in human somatotroph adenoma cells.
Natori
S
S
Third Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Iguchi
H
H
Ohashi
M
M
Nakao
R
R
Bloom
S R
SR
Nawata
H
H
D000172:Acromegaly / Q000097:blood* / Q000209:etiology; D000236:Adenoma / Q000150:complications / Q000378:metabolism*; D000328:Adult; D000368:Aged; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D051859:Neuroendocrine Secretory Protein 7B2; D015282:Octreotide / Q000494:pharmacology*; D010907:Pituitary Hormones / Q000097:blood*; D010911:Pituitary Neoplasms / Q000150:complications / Q000378:metabolism*
D009419:Nerve Tissue Proteins; D051859:Neuroendocrine Secretory Protein 7B2; D010907:Pituitary Hormones; C497678:SCG5 protein, human; D013006:Growth Hormone; D015282:Octreotide