uu.seUppsala universitets publikasjoner
Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Oscillatory Ca2+ signaling in glucose-stimulated murine pancreatic β-cells: Modulation by amino acids, glucagon, caffeine and ryanodine
Uppsala universitet, Medicinska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
2001 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Oscillations in cytoplasmic Ca2+ concentration ([Ca2+]i) is the key signal in glucose-stimulated β-cells governing pulsatile insulin release. The glucose response of mouse β-cells is often manifested as slow oscillations and rapid transients of [Ca2+] i. In the present study, microfluorometric technique was used to evaluate the role of amino acids, glucagon, ryanodine and caffeine on the generation and maintenance of [Ca2+] i oscillations and transients in individual murine β-cells and isolated mouse pancreatic islets. The amino acids glycine, alanine and arginine, at around their physiological concentrations, transformed the glucose-induced slow oscillations of [Ca2+] i in isolated mouse β-cells into sustained elevation. Increased Ca2+ entry promoted the reappearance of the slow [Ca2+] i oscillations. The [Ca2+] i oscillations were more resistant to amino acid transformation in intact islets, supporting the idea that cellular interactions are important for maintaining the oscillatory activity. Individual rat β-cells responded to glucose stimulation with slow [Ca2+] i oscillations due to periodic entry of Ca2+ as well as with transients evoked by mobilization of intracellular stores. The [Ca2+] i oscillations in rat β-cells had a slightly lower frequency than those in mouse β-cells and were more easily transformed into sustained elevation in the presence of glucagon or caffeine. The transients of [Ca2+] i were more common in rat than in mouse β-cells and often appeared in synchrony also in cells lacking physical contact. Depolarization enhanced the generation of [Ca2+] i transients. In accordance with the idea that β-cells have functionally active ryanodine receptors, it was found that ryanodine sometimes restored oscillatory activity abolished by caffeine. However, the IP3 receptors are the major Ca2+ release channels both in β-cells from rats and mice. Single β-cells from ob/ob mice did not differ from those of lean controls with regard to frequency, amplitudes and half-widths of the slow [Ca2+] i oscillations. Nevertheless, there was an excessive firing of [Ca2+] i transients in the β-cells from the ob/ob mice, which was suppressed by leptin at close to physiological concentrations. The enhanced firing of [Ca2+] i transients in ob/ob mouse β-cells may be due to the absence of leptin and mediated by activation of the phospholipase C signaling pathway.

sted, utgiver, år, opplag, sider
Uppsala: Acta Universitatis Upsaliensis , 2001. , s. 40
Serie
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 0282-7476 ; 1064
Emneord [en]
Cell biology, pancreatic β-cells, islets of Langerhans, glucose, Ca2+ oscillations, Ca2+ transients, potassium, ryanodine, caffeine, glucagon, cAMP, inositol 1, 4, 5-trisphosphate, fura-2, glycine, alanine, arginine, Ca2+ channels, rats, lean mice, ob/ob mice, leptin
Emneord [sv]
Cellbiologi
HSV kategori
Forskningsprogram
medicinsk cellbiologi
Identifikatorer
URN: urn:nbn:se:uu:diva-1408ISBN: 91-554-5084-9 (tryckt)OAI: oai:DiVA.org:uu-1408DiVA, id: diva2:160918
Disputas
2001-09-26, lecture room C8:301, Biomedical Center (BMC), Uppsala, 09:15
Opponent
Tilgjengelig fra: 2001-10-04 Laget: 2001-10-04 Sist oppdatert: 2018-01-13bibliografisk kontrollert

Open Access i DiVA

fulltekst(1124 kB)1254 nedlastinger
Filinformasjon
Fil FULLTEXT01.pdfFilstørrelse 1124 kBChecksum MD5
f4af7cde4cdc9cc3142ef77d220e5aad322a8dc17b7c188f882b9a64702152cd9ee42587
Type fulltextMimetype application/pdf
Kjøp publikasjonen >>

Av organisasjonen

Søk utenfor DiVA

GoogleGoogle Scholar
Totalt: 1254 nedlastinger
Antall nedlastinger er summen av alle nedlastinger av alle fulltekster. Det kan for eksempel være tidligere versjoner som er ikke lenger tilgjengelige

isbn
urn-nbn

Altmetric

isbn
urn-nbn
Totalt: 1510 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf