Inhibition by Salbutamol of GHRH-Induced GH Release in Type 1 Diabetes Mellitus

Summary

Patients with type 1 diabetes mellitus (IDDM) show augmented GH secretion, which is implicated in the pathogenesis of microvascular complications. On the other hand, it is well known that β-adrenergic receptors have inibitory influence on GH secretion, likely via stimulation of hypothalamic somatostatin. Since the possibility of pharmacological suppression of GH secretion would be of value in IDDM, we investigated the effect of salbutamol (SAL, 4 mg orally at -60 min) on the GH response to GHRH (1 μg/kg iv at 0 min) in 6 well-controlled (mean HbA_1c±SEM: 7.3±0.5%) patients with IDDM. Salbutamol was able to inhibit basal GH levels (p < 0.05) as well as to abolish the GHRH-induced GH rise. After SAL administration, a significant (p <0.05) reduction of glucagon levels was also found. Our data show that the enhancement of β₂ adrenergic activity by oral therapeutical doses of SAL inhibits basal and GHRH-stimulated GH secretion in patients with IDDM.

Key words

Growth Hormone - Growth Hormone-Releasing Hormone - Salbutamol - Insulin Dependent - Diabetes Mellitus