Inorganic polyphosphate regulates functions of thymocytes via activation of P2X purinoreceptors.

Inorganic polyphosphate (polyP) is an ancient polymer, which was proven to be a signalling molecule in the mammalian brain, mediating the communication between astrocytes via activation of P2Y purinoreceptors and modulating the activity of neurons. There is very limited information regarding the ability of polyP to transmit the information as an agonist of purinoreceptors in other cells and tissues. Here, we show that application of polyP to the suspension of primary thymocytes increases the concentration of intracellular calcium.

Effect of plant flavonoids on the volume regulation of rat thymocytes under hypoosmotic stress.

Background: Cell volume regulation and volume-regulated anion channels are critical for cell survival in non-isosmotic conditions, and dysregulation of this system is detrimental. Although genes and proteins underlying this basic cellular machinery were recently identified, the pharmacology remains poorly explored.

Methods: We examined effects of 16 flavonoids on the regulatory volume decrease (RVD) of thymocytes under hypoosmotic stress assessed by light transmittance and on the activity of volume-sensitive chloride channel by patch-clamp technique.