Effect of the intracerebroventricular administration of GR 113808, a selective 5-HT4 antagonist, on water intake during hyperosmolarity and hypovolemia

Brazilian Journal of Medical and Biological Research

L. Castro²  B. Varjão²  I. Silva²  B. Duque²  A. Batista²  R. Santana²  P. Luz²  M.a. Rocha Junior²  J.b. Fregoneze¹  E. De Castro-e-silva² 

[1] ,Universidade Federal da Bahia Instituto de Ciências da Saúde Departamento de Fisiologia

关键词: 5-HT4 receptors;    water intake;    hyperosmolarity;    hypovolemia;   

DOI  :  10.1590/S0100-879X2001000600015

来源: SciELO

【 摘 要 】

We demonstrate here that acute third ventricle injections of GR 113808, a highly selective 5-HT4 antagonist, decrease water intake induced by a previous salt load while potentiating drinking elicited by hypovolemia induced by previous subcutaneous administration of polyethylene glycol in male Wistar rats (200 ± 20 g). At the dose of 160 nmol/rat, third ventricle injections of GR 113808 induced a significant reduction of water intake in salt-loaded animals after 120 min as compared to salt-loaded animals receiving third ventricle injections of saline (salt load + GR = 3.44 ± 0.41 ml, N = 12; salt load + saline = 5.74 ± 0.40 ml, N = 9). At the dose of 80 nmol/rat, GR 113808 significantly enhanced water intake in hypovolemic animals after 120 min as compared to hypovolemic animals receiving third ventricle injections of saline (hypovol + GR = 4.01 ± 0.27 ml, N = 8; hypovol + saline = 2.41 ± 0.23 ml, N = 12). We suggest that central 5-HT4 receptors may exert a positive drive on water intake due to hyperosmolarity and a negative input on drinking provoked by hypovolemia.

【 授权许可】

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