Figure 1. Inhibition of protein tyrosine kinase reduces taurine release.

Taurine release from isolated SON perfused with control (300 mosmol l⁻¹) and hyposmotic (280 mosmol l⁻¹, grey bar) solutions. Release is expressed as percentage of control baseline. A, application of the PTK inhibitor genistein (50 μM), for the duration indicated by the open bar, decreases taurine release in both osmotic conditions (n= 5). B, the genistein inactive analogue daidzein has no effect (n= 3). C, the other PTK inhibitor tyrphostin B44 (50 μM) similarly reduces the osmodependent release of taurine (n= 4). D, tyrphostin A1, the tyrphostin inactive analogue, does not affect release (n= 4).