Fig. 5.

Effect of ANG-II hypertension on the afferent arteriolar diameter and calcium signalling responses to ATP. Panel a presents the changes in afferent arteriolar diameter in kidneys from normotensive rats (black symbols) and from Ang-II hypertensive rats (grey symbols). Data are expressed as a percentage of the control diameter. ATP was administered in concentrations of 0.1–100 μM. Values represent average diameters measured over the last 2 min of each treatment period and plotted as means ± SE. *P < 0.05, significant difference from control diameter; ^#P < 0.05 significant difference from normotensive controls. b Presents the change in intracellular calcium concentration (detected by fura 2) induced by 10 µM ATP in single preglomerular smooth muscle cells taken from normotensive (black trace) and ANG II hypertensive rats (grey trace). The period of ATP administration is depicted by the black bar. Data are modified from an earlier report [11]