Untersuchungen zum antilipolytischen Effekt des Insulins am menschlichen Fettgewebe in vitro

Cell size and the antilipolytic effect of insulin in human subcutaneous adipose tissue

“…In agreement with previous investigation [9,13,15,26], the present results show that the lipolysis of human subcutaneous adipose tissue is closely related to the size of the fat cells. Although the antilipolytic effect of insulin (100 gU/ml) seems to be cell sizedependent, this relationship may be more apparent than real.…”

“…From a number of earlier experiments it was ascertained that the two lipolytic agents would be used in a concentration (2 • 10-5M) which induced nearly maximal lipolysis. The concentration of insulin (100 gU/ml) was chosen firstly because it was within the normal physiological range; secondly be-cause we observed that a further rise in insulin concentration was not concomitant with substantial increase in the antilipolytic effect (Gries et al [8]).…”

Fatty acids and insulin secretion

“…Insulin inhibits fatty acid release through lipolysis. It is often overlooked that there is a hierarchy of insulin's actions[21] and that while promotion of glucose uptake into cells requires a significant increase in insulin from basal, inhibition of lipolysis is exquisitely sensitive to insulin[22–23].…”

“…Various other mechanisms of effect of chronic elevation of NEFA upon β‐cells have been suggested including; changes in membrane fluidity[5–53], toxic effects upon ion transportation through the cell membrane[33], effects on the transporter GLUT 2, and a possible association with nitric oxide, or increased free radical concentrations[53].…”

Metabolische Aspekte der Fettsucht

“…Das Produkt der Reaktion, das zyklische 3',5'-Adenosinmonophosphat, ist ein intermediäres Produkt bei der Aktivierung der Phosphorylase und hormonstimulierbaren Lipase(35,44,56, 65). Insulin wirkt antilipolytisch; dieser Effekt konnte sowohl am Rattenfettgewebe als auch am menschlichen Fettgewebe nachgewiesen werden(27,32,39).Damitist die Lipolyse des Fettgewebes das Ergebnis eines Zusammenspiels lipolytischer und antilipolytischer Hormone und abhängig außerdem von der Intaktheit der sympathischen Innervation. Es enthält selbst Enzyme zum Abbau und zur Synthese der Katecholamine (66) und verhält sich bei der Stimulierung wie ein vom Sympathicus innerviertes Organ.…”