Cholecystokinin actions in the parabrachial nucleus: effects on thirst and salt appetite
Menani, J.V.; Johnson, A.K.; Johnson, A.K.
American Journal of Physiology 275(5 Pt 2): R1431-R1437
1998
ISSN/ISBN: 0002-9513 PMID: 9791058 Document Number: 493676
The present study investigated the effects of bilateral injections of the nonselective CCK receptor antagonist proglumide or CCK-8 into the lateral parabrachial nuclei (LPBN) on the ingestion of 0.3 M NaCl and water induced by intracerebroventricular injection of ANG II or by a combined treatment with subcutaneous furosemide (Furo) + captopril (Cap). Compared with the injection of saline (vehicle), bilateral LPBN injections of proglumide (50 mg 200 nl-1 site-1) increased the intake of 0.3 M NaCl induced by intracerebroventricular ANG II (50 ng/1 ml). Bilateral injections of proglumide into the LPBN also increased ANG II-induced water intake when NaCl was simultaneously available, but not when only water was present. Similarly, the ingestion of 0.3 M NaCl and water induced by the treatment with Furo (10 mg/kg) + Cap (5 mg/kg) was increased by bilateral LPBN proglumide pretreatment. Bilateral CCK-8 (0.5 mg 200 nl-1 site-1) injections into the LPBN did not change Furo + Cap-induced 0.3 M NaCl intake but reduced water consumption. When only water was available after intracerebroventricular ANG II, bilateral LPBN injections of proglumide or CCK-8 had no effect or significantly reduced water intake compared with LPBN vehicle-treated rats. Taken together, these results suggest that CCK actions in the LPBN play a modulatory role on the control of NaCl and water intake induced by experimental treatments that induce hypovolemia and/or hypotension or that mimic those states. Reprinted by permission of the publisher.