Abnormalities in glucose-stimulated insulin release, /sup 45/Ca uptake, and /sup 86/Rb efflux in diabetic Chinese hamster islets

Journal Article · Fri May 01 00:00:00 EDT 1987 · Diabetes; (United States)

OSTI ID:6472551

Frankel, B J; Sehlin, J

We loaded islets from normal and diabetic Chinese hamsters with /sup 86/Rb (an analogue for K+) and measured /sup 86/Rb efflux during stimulation with 20 mM D-glucose. Genetically diabetic Chinese hamsters were selected from a subline (L) known for subnormal pancreatic insulin release and excessive pancreatic glucagon release in vitro. /sup 86/Rb accumulation in 1 mM glucose was normal in the diabetic islets. Similar to the pattern of /sup 86/Rb efflux previously seen from normal rat and mouse islets, 20 mM glucose suppressed /sup 86/Rb efflux within 1-2 min, and efflux remained suppressed until return to 1 mM glucose in both normal and diabetic hamster islets. After the first 2 min of 20 mM glucose, suppression of /sup 86/Rb efflux was somewhat greater in the diabetic hamster islets than in the normals. In addition, glucose-stimulated insulin release and /sup 45/Ca uptake were significantly reduced in the diabetic islets. Therefore, in the diabetic hamster islets, there is at least no impairment in the initial suppression of /sup 86/Rb efflux by glucose. This suggests that the diabetic beta-cells recognize glucose and carry out the initial steps in the stimulus-secretion coupling sequence normally. The later, excessive suppression of /sup 86/Rb efflux may be due to impaired Ca/sup 2 +/-induced changes in /sup 86/Rb efflux, suggesting that defective regulation of intracellular Ca/sup 2 +/ activity, rather than defective regulation of K+ permeability, may lead to the impaired insulin secretion.

• Research Organization: Univ. of Umea, Sweden
• OSTI ID: 6472551
• Journal Information: Diabetes; (United States), Vol. 5
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
DIABETES MELLITUS
PATHOLOGY
INSULIN
BIOCHEMICAL REACTION KINETICS
CALCIUM 45
GLUCOSE
HAMSTERS
RADIOISOTOPES
RUBIDIUM 86
TISSUE DISTRIBUTION
ALDEHYDES
ALKALI METAL ISOTOPES
ALKALINE EARTH ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CALCIUM ISOTOPES
CARBOHYDRATES
DAYS LIVING RADIOISOTOPES
DISEASES
DISTRIBUTION
ENDOCRINE DISEASES
EVEN-ODD NUCLEI
HEXOSES
HORMONES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KINETICS
MAMMALS
METABOLIC DISEASES
MINUTES LIVING RADIOISOTOPES
MONOSACCHARIDES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
REACTION KINETICS
RODENTS
RUBIDIUM ISOTOPES
SACCHARIDES
VERTEBRATES
550901* - Pathology- Tracer Techniques