Atrial natriuretic peptide participates in the regulation of vestibular blood flow

The effects of flunarizine and pentoxifylline on vestibular blood flow in the guinea pig

“…Recent studies in the guinea pig model used in our current study have shown that increases in VBF can be induced with the exogenous application of atrial natriuretic peptide [22] and betahistine [7,17]. Related studies using the Mongolian gerbil observed systemically driven increases in VBF in response to angiotensin III infusions [20] and increases in VBF in response to local applications of nitrous oxide [3].…”

Modification of Atrial Natriuretic Peptide Receptor Expression in the Rat Inner Ear

“…Subsequently, these and other receptor have been confirmed in the inner ear of the rat and human (18,(25)(26)(27). Their up-regulation in response to the local administration of ANP to the rat inner ear has been demonstrated (26), and Rachel et al (28) were able to illustrate a direct influence on the regulation of vestibular blood flow in response to this administration. Qvotrup et al (29) reported a factor endogenous to ELS tissue, tentatively named saccin, which exerts a potent natriuresis upon systemic administration.…”

Natriuretic Peptide Receptors in the Human Endolymphatic Sac

“…It is likewise possible that the ANP system could be involved in fluid production by the stria vascularis. 28 The natriuretic properties of ANPs in the kidney are well-known, and their association with excretory organs such as the gallbladder and choroid plexus supports this notion. Although ANP receptors have been demonstrated in the inner ear, their association with fluid transport in the endolymphatic system is, at this point, only conjecture.…”

“…Results of additional studies 5,27 have also confirmed the presence of peptide receptors in the inner ear. Results of a study by Rachel et al 28 showed that infusion of ANP directly into the inner ear of guinea pigs contributes to the regulation of vestibular blood flow. Results of a more recent study 29 suggest that epithelial cells of the ELS contain an endogenous hormone, tentatively named "saccin," that exerts a strong natriuresis.…”

“…The exact mechanism of action has not been elucidated but intuitively would involve either regulation of fluid production by the stria vascularis or absorption by the ELS. 28 It has been suggested that the ELS affects fluid homeostasis in the endolymphatic system through modulation of the osmotic milieu of this space, with the secretion of osmotically active substances into its lumen; however, the mechanism of action is unknown. 16 It is conceivable that ANPs could be involved in this mechanism.…”