244
JOHN C. DITTMER
been determined. The only fully characterized individual phospholipid
is dipalmitoylglycerophosphorylcholine, which was isolated by Thannhauser et al. (25, 46). The fatty acids of the sphingomyelin of brain
have been reported by Rennkamp (26) as 46% stearic, 34% nervonic plus
lignoceric, 6% behenic, 2% each of palmitic and arachidic, and 10% of an
unidentified hexacosenoic acid. Folch (29) reported that the brain
phosphatidylserine contains equal quantities of stearic and oleic acids.
Klenk and Böhm (11) have found a somewhat more complex fatty acid
composition for serine- and ethanolamine-rich fractions of brain. Their
data, with the data of Klenk and associates (27) for the lecithin fraction of brain, are given in Table IV. The fatty aldehydes from the
whole phospholipid fraction of brain have been reported by Thannhauser et al. (47) to be entirely saturated, with palmitaldehyde predominating. In contrast to this, Klenk (48) and Leupold (49) report the
presence of appreciable quantities of unsaturated Ci 8 aldehyde.
B. MUSCLE
It has been shown that the phospholipid content is different in the
three types of muscle, voluntary, cardiac, and involuntary or smooth.
The work of Bloor (50) shows that while the total concentration of
phospholipid in a given muscle of a wide variety of species varies, the
relative amount of phospholipid in the three different types of muscle
does not vary considerably. In general, cardiac muscle has a much
higher phospholipid content than does skeletal or smooth muscle; and
with the exception of some individual smooth muscles, skeletal muscle
phospholipid concentration is higher than that of smooth muscle. A
summary of data available is given in Table V.
Various phospholipids have been isolated from muscle and characterized. Almost all this work has been limited to mammalian heart
muscle, notably beef heart, and the flesh of fish. Evidence for the presence of phosphatidylcholine and phosphatidylethanolamine in heart
has been obtained by a number of workers, but a large part of the
choline and ethanolamine occurs as plasmalogen (51-55). There is some
evidence for phosphatidylserine (54, 56), but it has never been isolated
on its own. Phosphatidylinositol has been isolated and well characterized (54, 57). Another well-characterized phospholipid of heart
muscle is the polyglycerolphosphatide cardiolipin, which was first isolated
by Pangborn (58, 59). Its structure, as shown in Fig. 5, is now well
substantiated (54, 60).
The characterization of the phospholipids of the flesh of fish has
been carried out on haddock by Olley and Lovern (61) and on cod by
Garcia et al. (62). This work has been reviewed by Lovern (63). The
JOHN C. DITTMER
been determined. The only fully characterized individual phospholipid
is dipalmitoylglycerophosphorylcholine, which was isolated by Thannhauser et al. (25, 46). The fatty acids of the sphingomyelin of brain
have been reported by Rennkamp (26) as 46% stearic, 34% nervonic plus
lignoceric, 6% behenic, 2% each of palmitic and arachidic, and 10% of an
unidentified hexacosenoic acid. Folch (29) reported that the brain
phosphatidylserine contains equal quantities of stearic and oleic acids.
Klenk and Böhm (11) have found a somewhat more complex fatty acid
composition for serine- and ethanolamine-rich fractions of brain. Their
data, with the data of Klenk and associates (27) for the lecithin fraction of brain, are given in Table IV. The fatty aldehydes from the
whole phospholipid fraction of brain have been reported by Thannhauser et al. (47) to be entirely saturated, with palmitaldehyde predominating. In contrast to this, Klenk (48) and Leupold (49) report the
presence of appreciable quantities of unsaturated Ci 8 aldehyde.
B. MUSCLE
It has been shown that the phospholipid content is different in the
three types of muscle, voluntary, cardiac, and involuntary or smooth.
The work of Bloor (50) shows that while the total concentration of
phospholipid in a given muscle of a wide variety of species varies, the
relative amount of phospholipid in the three different types of muscle
does not vary considerably. In general, cardiac muscle has a much
higher phospholipid content than does skeletal or smooth muscle; and
with the exception of some individual smooth muscles, skeletal muscle
phospholipid concentration is higher than that of smooth muscle. A
summary of data available is given in Table V.
Various phospholipids have been isolated from muscle and characterized. Almost all this work has been limited to mammalian heart
muscle, notably beef heart, and the flesh of fish. Evidence for the presence of phosphatidylcholine and phosphatidylethanolamine in heart
has been obtained by a number of workers, but a large part of the
choline and ethanolamine occurs as plasmalogen (51-55). There is some
evidence for phosphatidylserine (54, 56), but it has never been isolated
on its own. Phosphatidylinositol has been isolated and well characterized (54, 57). Another well-characterized phospholipid of heart
muscle is the polyglycerolphosphatide cardiolipin, which was first isolated
by Pangborn (58, 59). Its structure, as shown in Fig. 5, is now well
substantiated (54, 60).
The characterization of the phospholipids of the flesh of fish has
been carried out on haddock by Olley and Lovern (61) and on cod by
Garcia et al. (62). This work has been reviewed by Lovern (63). The