Effects of flavonoids on insulin secretion and 45Ca2+ handling in rat islets of Langerhans

in Journal of Endocrinology
Authors:
C.S.T. Hii
Search for other papers by C.S.T. Hii in
Current site
Google Scholar
PubMed
Close
and
S.L. Howell
Search for other papers by S.L. Howell in
Current site
Google Scholar
PubMed
Close
Restricted access
Rent on DeepDyve

Sign up for journal news

ABSTRACT

The effects of some flavonoids, a group of naturally occurring pigments one of which has been claimed to possess antidiabetic activities, on insulin release and 45Ca2+ handling have been studied in isolated rat islets of Langerhans. Insulin release was enhanced by approximately 44–70% when islets were exposed to either (−)epicatechin (0·8 mmol/l) or quercetin (0·01–0·1 mmol/l); others such as naringenin (0·1 mmol/l) and chrysin (0·08 mmol/l) inhibited hormone release by approximately 40–60%. These effects were observed only in the presence of 20 mmol glucose/l. Quercetin (0·01 mmol/l) and (−)epicatechin (0·8 mmol/l) both inhibited 45Ca2+ efflux in the presence and absence of extracellular Ca2+. In the presence of 20 mmol glucose/l both the short-term (5 min) and steady-state (30 min) uptake of 45Ca2+ were significantly increased by either quercetin or (−)epicatechin. These results suggest that the stimulatory compounds such as quercetin and (−)epicatechin may, at least in part, exert their effects on insulin release via changes in Ca2+ metabolism.

J. Endocr. (1985) 107, 1–8

 

  • Collapse
  • Expand