Fig. 4. Representative examples of the cytosolic calcium
[Ca2+]i response of rectal gland artery (RGA) in
calcium-free buffer to the addition of external calcium, following treatment
with ryanodine (A) or with thapsigargin (TG) (B), compared to the response to
external calcium alone (C). Inhibition of sarcoplasmic reticulum
Ca2+-ATPase with TG or stimulation of the ryanodine receptor with
ryanodine raised [Ca2+]i; subsequent addition of
external Ca2+ resulted in a smaller increase in
[Ca2+]i compared to that observed in the absence of
TG.
