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Peripheral benzodiazepine receptors in isolated human pancreatic islets
Author(s) -
Giusti Laura,
Marchetti Piero,
Trincavelli Letizia,
Lupi Roberto,
Martini Claudia,
Lucacchini Antonio,
Guerra Silvia Del,
Tellini Cristina,
Carmellini Mario,
Navalesi Renzo
Publication year - 1997
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/(sici)1097-4644(199702)64:2<273::aid-jcb10>3.0.co;2-k
Subject(s) - receptor , endocrinology , medicine , gabaa receptor , pancreatic islets , population , chemistry , insulin , biology , islet , environmental health
Peripheral benzodiazepine receptors have been shown in some endocrine tissues, namely the testis, the adrenal gland, and the pituitary gland. In this work we evaluated whether peripheral benzodiazepine receptors can be found in the purified human pancreatic islets and whether they may have a role in insulin release. Binding of the isoquinoline compound [ 3 H]1‐(2‐chlorophenyl‐N‐methyl‐1‐methyl‐propyl)‐3‐isoquinolinecarboxamide ([ 3 H]PK‐11195), a specific ligand of peripheral benzodiazepine receptors, to cellular membranes was saturable, and Scatchard's analysis of the saturation curve demonstrated the presence of a single population of binding sites, with an affinity constant value of 9.20 ± 0.80 nM and a maximum number of binding sites value of 8913 ± 750 fmol/mg of proteins. PK‐11195 and 7‐chloro‐1,3‐dihydro‐1‐methyl‐5‐(p‐chlorophenyl)‐2H‐1,4‐benzodiazepin‐2‐on (Ro 5‐4864) significantly potentiated insulin secretion from freshly isolated human islets at 3.3 mM glucose. These results show the presence of peripheral benzodiazepine receptors in purified human pancreatic islets and suggest their role in the mechanisms of insulin release. J. Cell. Biochem. 64:273–277. © 1997 Wiley‐Liss, Inc.