ß-Cell–Mediated Signaling Predominates Over Direct a-Cell Signaling in the Regulation of Glucagon Secretion in Humans  

Oleh:

Cooperberg, Benjamin A. ; Cryer, Philip E.

Jenis: Article from Journal - ilmiah internasional
Dalam koleksi: Diabetes Care vol. 32 no. 12 (Dec. 2009), page 2275-2280.

Ketersediaan

Perpustakaan FK Nomor Panggil: D05.K.2009.03 Non-tandon: 1 (dapat dipinjam: 0) Tandon: tidak ada

Lihat Detail Induk

Isi artikel

OBJECTIVE Given evidence of both indirect and direct signaling, we tested the hypothesis that increased ß-cell–mediated signaling of a-cells negates direct a-cell signaling in the regulation of glucagon secretion in humans. RESEARCH DESIGN AND METHODS We measured plasma glucagon concentrations before and after ingestion of a formula mixed meal and, on a separate occasion, ingestion of the sulfonylurea glimepiride in 24 basal insulin-infused, demonstrably ß-cell–deficient patients with type 1 diabetes and 20 nondiabetic, demonstrably ß-cell–sufficient individuals; the latter were infused with glucose to prevent hypoglycemia after glimepiride. RESULTS After the mixed meal, plasma glucagon concentrations increased from 22 ± 1 pmol/l (78 ± 4 pg/ml) to 30 ± 2 pmol/l (103 ± 7 pg/ml) in the patients with type 1 diabetes but were unchanged from 27 ± 1 pmol/l (93 ± 3 pg/ml) to 26 ± 1 pmol/l (89 ± 3 pg/ml) in the nondiabetic individuals (P < 0.0001). After glimepiride, plasma glucagon concentrations increased from 24 ± 1 pmol/l (83 ± 4 pg/ml) to 26 ± 1 pmol/l (91 ± 4 pg/ml) in the patients with type 1 diabetes and decreased from 28 ± 1 pmol/l (97 ± 5 pg/ml) to 24 ± 1 pmol/l (82 ± 4 pg/ml) in the nondiabetic individuals (P < 0.0001). Thus, in the presence of both ß-cell and a-cell secretory stimuli (increased amino acid and glucose levels, a sulfonylurea) glucagon secretion was prevented when ß-cell secretion was sufficient but not when ß-cell secretion was deficient. CONCLUSIONS These data indicate that, among the array of signals, indirect reciprocal ß-cell–mediated signaling predominates over direct a-cell signaling in the regulation of glucagon secretion in humans.

Opini Anda

Klik untuk menuliskan opini Anda tentang koleksi ini!

Kembali