ABSTRACT
The electromechanical properties of excitable tissues have long been an area of intense investigation that has led to significant developments and refinements in electrophysiological techniques. As ion-selective microelectrodes developed, with tip diameters small enough to impale single cells, the pH regulatory mechanisms of excitable tissues were among the first to be investigated. 1 These and other pH-sensing technologies were extended for use in many tissue types and led to evidence for transmembrane Na+/H+ exchange in both epithelial and nonepithelial tissues. The purpose of this chapter is to provide a detailed description of some properties of the Na+/H+ exchangers found in excitable tissues such as those listed in Table 1. NA<sup>+</sup>/H<sup>+</sup> Exchange in Excitable Cells
Cardiac Muscle Cells
Animal
Ref.
Purkinje fiber
Sheep
2
Sheep
3
Sheep
4
Left atrium
Guinea pig
5
Cultured heart
Chick embryo
6
Chick embryo and newborn rat
7
Chick embryo
8
Chick embryo
9, 50
Chick embryo
10
Chick embryo
11
Chick embryo
12
Isolated ventricular cells
Guinea pig
13
Guinea pig
14
Skeletal Muscle Cells
Giant fiber
Barnacle
15 a
Barnacle
16
Sartorius
Frog
17
Frog
18
Semitendinosus
Frog
19
Frog
20
Soleus
Mouse
21
Rat
22
Diaphragm
Rat
23
Cultured thigh
Rat
24
Cultured cell line (L6H9)
Rat
25
Cultured pectoralis
Chick
26
Chick
27
Smooth Muscle Cells
Cultured aortic cell line (A7r5)
Rat
28
Cultured thoracic aorta
Rat
29
Rat
30
Nerve Cells
Neuron (right pallial ganglion)
Snail
31 a
Neuron (abdominal ganglion)
Crayfish
32
Neuron (ventral ganglion)
Leech
33
Giant axon
Squid
34 a
Cultured neuroblastoma (N1E-115)
Mouse
35, 36
Cultured glial cell line (C6; NN)
Rat
37
Other Electrically Responsive Cells
Sperm
Sea urchin
38
Sea urchin
39
Eggs
Sea urchin
40
Sea urchin
41
Ovary
Chinese hamster
42
Cultured pheochromocytoma (PC 12)
Rat
43
Islet β
Mouse
44
Cultured pituitary (GH4C1)
Rat
45
Lettre cell line
Mouse
46
Neutrophil
Human
47
Also coupled Na+ + HCO3 −/Cl− + H+ exchange.
