| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 6269616 | Journal of Neuroscience Methods | 2011 | 5 Pages |
Methods currently employed to study the release of hormones such as arginine vasopressin (AVP), while sensitive, suffer from a low temporal resolution such that the monitoring of AVP release on a moment-to-moment basis is not possible. Here, we describe a new approach to indirectly monitor the temporal profile of AVP release from the neurohypophysis of transgenic rats expressing an AVP-eGFP fusion gene. Using fibre-optic probes (termed 'optrodes') we were able to indirectly monitor AVP release via a reporter moiety in real-time. This method is a major advance over current methods used to monitor AVP release. Intravenous administration of hypertonic saline (3Â M NaCl) induced a rapid (latency of 2-3Â s) increase in fluorescence detected in the neurohypophysis that lasted on average for 60Â s - a response that was highly reproducible. Infusion of sodium nitroprusside induced a rapid fall in blood pressure accompanied by a rapid, stimulus-locked increase in fluorescent signal that returned to baseline with the recovery of blood pressure to pre-stimulus levels - again this response was highly reproducible. Withdrawal of blood (to simulate haemorrhage) also resulted in a stimulus-locked increase in fluorescence that return to baseline after the withdrawn blood was returned to the animal. In conclusion, we developed a highly sensitive approach that allows the indirect measurement of AVP release via the monitoring of a reporter gene in real-time. This technology can be adapted to permit the study of a whole array of neurohormones/chemicals in transgenic animals expressing a fluorescent reporter construct.
⺠Methods used to monitor vasopressin release suffer from a low temporal resolution. ⺠We describe a novel approach to monitor neurohypophysial vasopressin release in transgenic rats expressing an AVP-eGFP fusion gene. ⺠Using fibre-optic probes ('optrodes') we were able to indirectly monitor vasopressin release via a reporter moiety in real-time. ⺠This method is a major advance over current methods used to monitor vasopressin release.
