In an attempt to clarify the mechanisms by which angiotensin II (AII) and arginine vasopressin (AVP) regulate mesangial cell function, we examined the membrane potential change of mesangial cells and found that cells contracted and membrane potential depolarized in response to AII and AVP. The depolarization was associated with decreased input resistance. Ca ionophore A23187 caused similar mesangial cell contraction and depolarization. The reversal potential (Vr) of the depolarization response to AII and AVP was -29 +/- 3 and -25 +/- 7 mV (mean +/- SD), respectively. Not only the Vr of the AII-induced depolarization but also Vr of the Ca ionophore-induced response was dependent upon the extracellular Cl- concentration. Further, AII and AVP caused cell contraction and membrane depolarization in Ca++-free medium containing 0.5 mM EGTA. These data suggest the presence of Ca++ -activated Cl- channels in the mesangial cells and that AII and AVP increase Cl- permeability via an elevation of [Ca++]i released from the intracellular organellae.
T Okuda, N Yamashita, K Kurokawa
Usage data is cumulative from April 2023 through April 2024.
Usage | JCI | PMC |
---|---|---|
Text version | 76 | 0 |
51 | 14 | |
Figure | 0 | 1 |
Scanned page | 82 | 1 |
Citation downloads | 7 | 0 |
Totals | 216 | 16 |
Total Views | 232 |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.