RESUMO
Clinical use of olanzapine frequently causes severe hyperglycemia as an adverse effect. In this study, we elucidated mechanisms by which olanzapine reduced insulin secretion using the hamster pancreatic ß-cell line HIT-T15. Reverse transcriptional-PCR analysis revealed expression of dopamine (D2, D3 and D4), serotonin (5-HT2A, 5-HT2B, 5-HT2C, and 5-HT6), and histamine (H1 and H2) receptors in HIT-T15 cells. Olanzapine decreased insulin secretion from HIT-T15 cells at clinically relevant concentrations (64-160 nM). A dopamine D2 agonist, D3 antagonist, and D4 antagonist suppressed insulin secretion, whereas a D2 antagonist and D3 agonist increased it. A serotonin 5-HT2B agonist slightly increased insulin secretion, while a 5-HT2C antagonist slightly decreased it. Other agonists and antagonists for serotonin receptors did not affect insulin secretion. A histamine H1 agonist increased insulin secretion, whereas an H1 antagonist and H2 agonist suppressed it. Our results suggest that dopamine (D2, D3 and D4), serotonin (5-HT2B and 5-HT2C), and histamine (H1 and H2) receptors, which are expressed on pancreatic ß-cells, directly modulate insulin secretion from pancreatic ß-cells. Thus, olanzapine may induce hyperglycemia in clinical settings by suppressing insulin secretion from pancreatic ß-cells through inhibition of dopamine D3, serotonin 5-HT2B and 5-HT2C, and histamine H1 receptors.
Assuntos
Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Receptores de Amina Biogênica/antagonistas & inibidores , Receptores de Amina Biogênica/metabolismo , RNA Mensageiro/genética , Receptores de Amina Biogênica/genética , Receptores Dopaminérgicos/genética , Receptores Dopaminérgicos/metabolismo , Receptores Histamínicos/genética , Receptores Histamínicos/metabolismo , Receptores de Serotonina/genética , Receptores de Serotonina/metabolismoRESUMO
The effects of carbonation treatment (1 to 5 MPa, 30 min) plus heat treatment (30 to 80°C, 30 min) in the presence of various fatty acid esters (FAEs; 0.05 and 0.1%, wt/vol) on counts of viable Bacillus subtilis spores were investigated. FAEs or carbonation alone had no inactivation or growth inhibition effects on B. subtilis spores. However, carbonation plus heat (CH; 80°C, 5 MPa, 30 min) in the presence of mono- and diglycerol fatty acid esters markedly decreased counts of viable spores, and the spore counts did not change during storage for 30 days. The greatest decrease in viable spore counts occurred in the presence of monoglycerol fatty acid esters. Under CH conditions, inactivation and/or growth inhibition occurred at only 80°C and increased with increasing pressure. The greatest decrease in spore counts (more than 4 log units) occurred with CH (80°C, 5 MPa, 30 min) in the presence of monoglycerol fatty acid esters. However, this treatment was less effective against Bacillus coagulans and Geobacillus stearothermophilus spores.