Related Experiment Videos
AVP V1 receptor-mediated decrease in Cl- efflux and increase in dark cell number in choroid plexus epithelium
C E Johanson1, J E Preston, A Chodobski
1Program in Neurosurgery, Department of Clinical Neurosciences, Brown University/Rhode Island Hospital, Providence, Rhode Island 02903, USA.
The American Journal of Physiology
|January 14, 1999
Summary
Arginine vasopressin (AVP) affects chloride transport and cell structure in adult rat choroid plexus via V1 receptors, but not in infant rats. This impacts cerebrospinal fluid (CSF) secretion and intracranial pressure regulation.
Area of Science:
- Neuroscience
- Physiology
- Cell Biology
Background:
- The choroid plexus (CP) generates cerebrospinal fluid (CSF) and possesses arginine vasopressin (AVP) V1 binding sites.
- AVP is known to reduce CSF formation and choroidal blood flow.
- The precise mechanisms by which AVP influences ion transport across the blood-CSF barrier remain largely unelucidated.
Purpose of the Study:
- To investigate the effects of AVP on chloride ion (Cl-) transport across the blood-CSF barrier in adult rat choroid plexus.
- To examine structural changes in choroid plexus epithelial cells induced by AVP.
- To compare the responsiveness of adult and infant rat choroid plexus to AVP.
Main Methods:
- Adult rat lateral ventricle choroid plexus was loaded with 36Cl- and exposed to varying concentrations of AVP.
- Chloride efflux rate coefficients were measured after AVP exposure.
- The frequency of dark, potentially dehydrated, choroid epithelial cells was quantified.
- Experiments were repeated using a V1 receptor antagonist and in infant rats.
Main Results:
- AVP significantly inhibited Cl- extrusion in adult CP, an effect blocked by a V1 receptor antagonist.
- AVP more than doubled the number of dark, possibly dehydrated, choroid epithelial cells in adult CP.
- These AVP-induced changes in Cl- efflux and dark cell frequency were not observed in infant rats.
Conclusions:
- AVP modulates ion transport and induces structural changes in the adult choroid plexus epithelium through V1 receptors.
- The observed effects are age-dependent, with infant CP showing no response.
- These findings have implications for understanding CSF secretion, intracranial pressure, and hydrocephalus development.