In JoVE (1)
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Articles by Hilary J. Broderick in JoVE
Local Application of Drugs to Study Nicotinic Acetylcholine Receptor Function in Mouse Brain Slices Staci E. Engle1, Hilary J. Broderick1, Ryan M. Drenan1 1Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University In this paper, we describe a useful method to study ligand-gated ion channel function in neurons of acutely isolated brain slices. This method involves the use of a drug-filled micropipette for local application of drugs to neurons recorded using standard patch clamp techniques.
Other articles by Hilary J. Broderick on PubMed
Potentiation of Sulfonylurea Action by an EPAC-selective CAMP Analog in INS-1 Cells: Comparison of Tolbutamide and Gliclazide, and a Potential Role for EPAC Activation of a 2-APB-sensitive Ca2+ Influx Molecular Pharmacology. Oct, 2012 | Pubmed ID: 23071106 Tolbutamide and gliclazide block the KATP channel Kir6.2/Sur1, causing membrane depolarization and stimulating insulin secretion in pancreatic beta cells. We examined the ability of the EPAC-selective cAMP analog 8-pCPT-2'-O-Me-cAMP-AM to potentiate the action of these drugs, and the mechanism that might account for it. Insulin secretion stimulated by both 200 Î¼M tolbutamide and 20 Î¼M gliclazide, concentrations that had equivalent effects on membrane potential, was inhibited by thapsigargin (1 Î¼M) or the L-type Ca2+ channel blocker nicardipine (2 Î¼M), and was potentiated by 8-pCPT-2'-O-Me-cAMP-AM at concentrations > 2 Î¼M in INS-1 cells. Ca(2+) transients stimulated by either tolbutamide or gliclazide were inhibited by thapsigargin or nicardipine and were significantly potentiated by 8-pCPT-2'-O-Me-cAMP-AM at 5 Î¼M but not 1Î¼M. Both tolbutamide and gliclazide stimulated phospholipase C activity; however, only gliclazide did so independently of its activity at KATP channels, and this activity was partially inhibited by pertussis toxin. 8-pCPT-2'-O-Me-cAMP-AM alone (5 Î¼M) did not stimulate insulin secretion, but did increase intracellular Ca(2+) concentration significantly, and this activity was inhibited by 25 Î¼M 2-aminoethoxydiphenylborate (2-APB) or the removal of extracellular Ca(2+). 8-pCPT-2'-O-Me-cAMP-AM potentiation of insulin secretion stimulated by tolbutamide was markedly inhibited by 2-APB (25 Î¼M), and enhanced by the PKC inhibitor Bisindolylmaleimide I (1 Î¼M). Our data demonstrate that the actions of both tolbutamide and gliclazide are strongly potentiated by 8-pCPT-2'-O-Me-cAMP-AM, that gliclazide can stimulate phospholipase C activity via a partially pertussis toxin-sensitive mechanism, and that 8-pCPT-2'-O-Me-cAMP-AM potentiation of tolbutamide action may involve activation of a 2-APB-sensitive Ca(2+) influx.