. Author manuscript; available in PMC: 2014 May 1.

Published in final edited form as: Microcirculation. 2013 May;20(4):290–298. doi: 10.1111/micc.12021

Table 1.

General properties of L-type Ca²⁺ channel sparklets in arterial smooth muscle

Parameters	L-type Ca²⁺ channel Ca²⁺ sparklet
spatial spread (µm²)	0.8^a
quantal level (nM)	38^a
amplitude range (nM)	20–500^a
voltage dependency	Yes^a,^b
inhibition by nifedipine (10 µM)	Yes^a
activation by Bay-K8644 (500 nM)	Yes^a
activity (nPs)	low nP_s = 0.07
	high nP_s = 1.25^a
Ca²⁺ flux (fC)	low nP_s = 122
	high nP_s = 270^c
duration (ms)	low nP_s τ = 23
	high nP_s τ_fast = 42
	high nP_s τ_slow = 104^c

Data were obtained from L-type Ca²⁺ channel sparklets recorded in rat arterial smooth muscle.

Navedo et al (32); quantal level was determined with 20 mM Ca²⁺ at −70 mV,

Navedo et al (33),

Amberg et al (2). The signal mass and duration of L-type Ca²⁺ channel sparklets were recorded at the physiological membrane potential of −40 mV and using 2 mM extracellular Ca²⁺.