Abstract
Holla, N., O. V. Sirek, A. Sirek: Studies on the Interaction between Growth Hormone
and Dihydroergotamine in Adipose Cells. I. The lipolytic effect of dihydroergotamine.
Horrn.Metab.Res. 3: 161-166 (1971). Growth hormone (GH) alone or in combination with dexamethasone produced a barely
measurable lipolysis in the isolated rat fat cell preparation of Rodbell. In combination
with dihydroergotamine (DHE), GH was not lipolytic either, although the alkaloid by
itself caused a moderate release of glycerol and free fatty acids (FFA). The addition
of all three agents to the incubation medium produced massive lipolysis that was by
far greater than the sum of effects of individual components. DHE could not be replaced
by phentolamine. The augmented lipolytic effect was suppressive with puromycin. When
similar experiments were carried out with biologically related protein hormones such
as prolactin or placental lactogen instead of GH, DHE had no effect. These results
suggest that DHE interacted specifically with GH in a synergistic manner on metabolic
pathways not shared by other lipolytic hormones; points closely related to the synthesis
and/or action of the functional protein(s) thought to be involved in GH-stimulated
lipolysis were considered as hypothetical targets.
Key words
Lipolysis - Isolated Fat Cell - Dihydroergotamine - Growth Hormone - Prolactin - Placental
Lactogen - Phentolamine
1 Supported by the Atkinson Charitable Foundation, and the J.P. Bickell Foundation
of Toronto.
2 Holder of a fellowship from the Medical Research Council of Canada. Permanent address:
Third Department of Medicine, University of Nagoya, Nagoya, Japan.
