Effects of pulsatile delivery of basal growth hormone on lipolysis
in humans .
Cersosimo, Eugenio, Fotini Danou, Mai Persson, and John M Miles.
Endocrine Research Unit, Mayo Clinic and Foundation, Rochester, MN
55904
APStracts 3:0043E, 1996.
Growth hormone (GH) excess stimulates lipolysis but its role in the
hierarchy of lipolysis regulation is not clear. We studied whether
pulsatile GH delivery is required for its lipolytic effect. Using the
"pancreatic clamp", 8 subjects were randomized to 3
protocols: A) GH deficiency; B) constant GH infusion; C) pulsatile GH
delivery (same total GH as B). Pulsatile GH was given in 4
consecutive "bursts" with symmetric peak width (60 min),
amplitude of 10.7 (men) and 15 ng/kg.min (women), and peak width at
half-height of 15 min. Palmitate flux (PF) was measured at baseline
and in the last hour of each study with 3H-palmitate. GH (ng/ml)
decreased from 3.5 to 2.0 in A (p<0.05); it remained between
3.2-4.0 in B (p<0.05), whereas in C it fluctuated between 2.7
-5.0 (p<0.05). Palmitate concentration ([mu]mol/L) was 150 at
baseline; it did not change in A & B (137+/-17 & 136+/-12,
respectively), but increased to 198+/-16 (p<0.05) in C. PF
([mu]mol/kg.min) was 2.7 at baseline and did not change in B (2.4+/
-0.2); it decreased to 2.2+/-0.1 in A (p<0.05); it increased to
3.1+/-0.3 (p<0.05) in C. These experiments provide evidence that
pulsatile secretion of GH is required for its lipolytic effect.
Received 27 November 1995; accepted in final form 20 February
1996.
APS Manuscript Number E553-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 March 96