Utjecaj oktreotida na lučenje hormona rasta u bolesnika s akromegalijom

A majority of growth hormone secreting pituitary adenomas respond well to somatostatin and somatostatin analogues. The acute action of octreotide, a synthetic somatostatin analogue, on growth hormone secretion was assessed in 42 patients with clinically and laboratory verified acromegaly. Octreotide was administered subcutaneously in a dose of 50 mg. Blood sampling was performed at 1-hour intervals during 6 hours of testing. The mean basal values of growth hormone (c±SE) was 26.3±4.5 ng/ml (range 6.1-66.6 ng/ml), and of IGF-I 2940±171.7 IU/l (range 2350-4856 IU/l). Reduction in growth hormone values below 5 ng/ml was recorded in 31 (73.8%), suppression by more than 50% in 5 (11.9%) and by more than 45% in 3 (7.1%) patients. Maximal suppression was noticed in the first two hours of testing. In 3 (7.1%) patients, resistance to octreotide with no change in growth hormone values was observed. In conclusion, octreotide reduces growth hormone values in most acromegalic patients. A small proportion of acromegalic patients do not respond well to octreotide, probably due to the lack of somatostatin receptors on tumor cells. We consider the acute octreotide test as a very useful tool in triage of acromegalic patients eligible for medicamentous treatment.Većina adenoma hipofize koji luče hormon rasta zadrže osjetljivost na somatostatin i njegove analoge. Ispitivano je akutno djelovanje oktreotida, sintetskog oktapeptidnog analoga somatostatina, na razinu hormona rasta u 42 bolesnika s klinički i laboratorijski potvrđenom akromegalijom. Oktreotid je primijenjen supkutano u dozi od 50 mg. Uzorci krvi za određivanje hormona rasta uzimani su svakog sata u razdoblju od šest sati. Prosječna bazalna vrijednost hormona rasta bila je 26,3±4,5 c±SE) ng/ml (raspon 6,1-66,6 ng/ml), a IGF-I 2940,2±171,7 IJ/l (raspon 2350-4856 IJ/l). Nakon primjene oktreotida razina hormona rasta u serumu snizila se na normalne vrijednosti (