Cyclic AMP increases cytoplasmic free calcium in renin-secreting cells from rat kidney

Rok, strany: 2009, 404 - 413

The renin-secreting juxtaglomerular cells (JGC) in the media of the afferent arteriole at the vessel pole are the major source of circulating renin. The control of renin secretion is complex with increases in cAMP being the major stimulus and increases in intracellular free Ca²⁺ concentration ([Ca²⁺]i) being inhibitory. We measured [Ca²⁺]i in the afferent arteriole from mostly JGC. Manoeuvres that increase cAMP (e.g. isoproterenol) or dibutyryl-cAMP elicited an increase in [Ca²⁺]i which was ∼40% of that induced by angiotensin II (3 nmol/l). The Ca²⁺ response occurred in 50–90% of the cases, and increasing the stimulus increased responder frequency but not response size. The response was (almost) abolished by removal of extracellular Ca²⁺, prevented by inhibitors of store-operated Ca²⁺ channels (Gd³⁺ and 2-aminoethoxydiphenyl-borate), but was unaffected by isradipine or protein kinase A inhibitors. It was not produced by an activator of EPACs (exchange protein activated by cAMP) and was not accompanied by changes in membrane potential. The data suggest that in rat JGC, cAMP, perhaps directly, activates store-operated Ca²⁺ channels to increase [Ca²⁺]i. One could speculate that this increase in [Ca²⁺]i serves to finely adjust the stimulating effect cAMP-increasing signals on the renin-angiotensin system.

ISO 690:

Laske-Ernst, J., Chmielnicki, M., Quast, U., Russ, U. 2009. Cyclic AMP increases cytoplasmic free calcium in renin-secreting cells from rat kidney. In General Physiology and Biophysics, vol. 28, no.4, pp. 404-413. 0231-5882.

APA:

Laske-Ernst, J., Chmielnicki, M., Quast, U., Russ, U. (2009). Cyclic AMP increases cytoplasmic free calcium in renin-secreting cells from rat kidney. General Physiology and Biophysics, 28(4), 404-413. 0231-5882.