Fatty acids and insulin secretion

V Grill, E Qvigstad - British Journal of Nutrition, 2000 - cambridge.org
V Grill, E Qvigstad
British Journal of Nutrition, 2000cambridge.org
It has long been recognized that acute elevation of non-esterified fatty acids (NEFA)
stimulates insulin secretion to a moderate extent both in vitro and in vivo. The effects of
longer-term exposure to elevated fatty acids have, however, been investigated only recently.
Our own studies in the rat have documented the time dependence of NEFA effects, with
inhibition of glucose-induced insulin secretion being apparent after 6–24 h in vivo exposure
to Intralipid or in vitro exposure to palmitate, oleate and octanoate. Evidence indicates that …
It has long been recognized that acute elevation of non-esterified fatty acids (NEFA) stimulates insulin secretion to a moderate extent both in vitro and in vivo. The effects of longer-term exposure to elevated fatty acids have, however, been investigated only recently. Our own studies in the rat have documented the time dependence of NEFA effects, with inhibition of glucose-induced insulin secretion being apparent after 6–24 h in vivo exposure to Intralipid or in vitro exposure to palmitate, oleate and octanoate. Evidence indicates that the inhibitory effects are coupled to fatty acid oxidation in B-cells, with ensuing reduction in glucose oxidation, in parallel with diminished activity of the pyruvate dehydrogenase enzyme. These findings were essentially confirmed in human pancreatic islets. In the db/db mouse, a model of type 2 diabetes with obesity, evidence was obtained for elevated NEFA playing a significant role in decreased glucose-induced insulin secretion. Evidence also indicates that elevated NEFA inhibit insulin biosynthesis and increase the proinsulin : insulin ratio of secretion. Results on experimentally induced elevations of NEFA in non-diabetic and diabetic humans are thus far inconclusive. Further studies are needed to ascertain the impact of elevated NEFA on insulin secretion in clinical settings.
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