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[Reprinted from SCIENCE, N. S., Vol. XLI., No. 1062, Pages 689-691, May 7, 1915]
Me?S, E dward By-ow tº "2.
THE OSMOTIC PROPERTIES OF DIFFERENT KINDS OF MUSCLE
IN two recent articles! I have pointed out
that the osmotic properties” of the smooth and
striated muscle of the frog and of the clam’s
adductor muscle were strikingly different.
Loeb suggests” that the differences observed by
me might be due to the fact that “the smooth
muscle of the stomach . . . can not be ob-
tained in as natural a condition as . . . striped
muscle . . . .” Still more recently, in an
article published from Loeb's laboratory, v.
Körösy* has enlarged upon Loeb's suggestion
and has described some experiments purport-
ing to uphold it.
The reasons for thinking that the differences
in the osmotic behavior of the three types of
muscle mentioned above can not be due to
any difference in the manner of their prepara-
tion seem to me very cogent; they have already
been largely given in my articles dealing with
the subject. But it has not previously been
possible to give them completely or to bring
them together into one place, and, in view of
the suggestions of Loeb and v. Körösy, it
seems worth while to do this now.
The first difficulty which one meets in com-
paring the reactions of smooth and striated
muscle is that cutting across the fibers or re-
moving the “natural surface” does not have
the same effect on the two tissues. Striated
muscle goes almost immediately into rigor in
the neighborhood of a cut across its fibers.
1 Meigs, The Journal of Ezperimental Zoology,
Vol. 13, p. 497, 1913; The Journal of Biological
Chemistry, Vol. 17, p. 81, 1914.
2. By ‘‘osmotic properties” I mean those prop-
erties of the tissues which determine the character-
istic changes of weight undergone by them when
immersed in various solutions.
8 Loeb, SCIENCE, N. S., Vol. 37, p. 430, 1913.
4 V. Körösy, Zeitschrift für physiologische
Chemie, Vol. 93, pp. 171 et seq., 1914.
This condition is accompanied by acid forma-
tion,” by swelling, and by the loss of irritabil-
ity and of the characteristic osmotic properties
of the tissue; it spreads gradually from the
point of injury to other parts. Cutting across
the fibers of smooth muscle causes a contrac-
tion which is soon followed by relaxation;
there is no tendency toward acid formation,
swelling or loss of irritability either in the
neighborhood of the cut or in any other por-
tion of the tissue. These facts, which are
ignored by Loeb and v. Körösy, are very signif-
icant; they suggest at the outset, what is con-
firmed by all my subsequent work, that the
fibers of striated muscle are surrounded by
characteristie semi-permeable surfaces, injury
to which produces profound changes in the
tissue; and that no such surfaces exist in the
case of smooth muscle. They are incompatible
with the view that the osmotic properties of
the tissues are alike. Finally, they show that
my preparations of smooth muscle, in spite of
the fact that their fibers have been cut, are
more nearly comparable to uninjured than to
injured preparations of striated muscle.
But one need not stop here. The rigor, etc.,
produced in the neighborhood of a cut across
the fibers of striated muscle spreads only
gradually from the injured to the uninjured
regions; hence, if the injured area be propor-
tionally small, the preparation will react
osmotically for the first hour or so very nearly
like an uninjured muscle. If a frog's sartorius
be cut across its middle, either half of the
muscle will have about the same proportions
of “natural surface” and “unnatural sur-
face” as the preparations of frog’s stomach
muscle used in my experiments. Such a cut
5 Fletcher and Hopkins, The Journal of Physiol-
ogy, Vol. 35, pp. 261 et seq., 1907.
2 SCIENCE)
sartorius reacts for the first hour in all re-
spects very much like an uninjured sartorius.
The strikingly different osmotic reactions char-
acteristic of smooth muscle showed themselves
in my preparations long before the end of the
first hour.
Further, the effects of cutting across the
fibers or of exposing an “unnatural surface ’’
in smooth muscle may be studied experi-
mentally by comparing the reactions of prep-
arations which have been cut in many places
with those of others which have been cut as
little as possible. Such experiments show that
cutting has no perceptible effect after the first
few minutes; for the first few minutes it pro-
duces a very slight tendency for the prepara-
tion to lose fluid. Examination of the differ-
ences in the osmotic reactions of smooth and
striated muscle under different circumstances
shows that these differences can not be ex-
plained as the result either of this or of any
ºther conceivable effect of injury. Smooth
muscle, for instance, swells more rapidly than
striated muscle in Ringer's solution, but less
rapidly in half-strength Ringer; it would be
a very extraordinary hypothesis that these
opposite differences were both the effects of
injury. Still less can the swelling of smooth
muscle in solutions of non-electrolytes and the
peculiar changes of weight undergone by it in
double-strength and half-strength Ringer solu-
tion be explained as the result of injury by
any one who will take the trouble to make a
careful study of these phenomena.
In order to obtain a preparation of striated
muscle comparable to my preparations of
smooth muscle v. Körösy pared off the surface
layers of a frog’s gastrocnemius with a razor
and used the core which was left. This is, to
say the least, a severe test. The gastrocnemius
is for the most part composed of short fibers
which run diagonally across it and end in the
fascia covering its surface. The procedure
adopted by v. Körösy would therefore give a
surface largely or entirely composed of the
cut ends of the muscle fibers. My prepara-
tions of stomach muscle were covered on one
side by the serosa and on the other by a part
of the connective tissue which lies between the
muscular and mucous coats of the stomach;
these two surfaces made up about nine tenths
that of the whole preparation, and were cer-
tainly as “natural” as that which is left
covering a striated muscle after it is torn
away from the skin and from the neighboring
muscles.
V. Körösy tried only one experiment which
bears on the osmotic differences between the
smooth and striated muscle of the frog. He
immersed his muscle core in 0.23 M saccharose
solution and found that it gained weight fairly
rapidly. It is to be presumed that lactic acid
was being rapidly produced over the whole
surface of v. Körösy’s preparation,” and it is
not surprising, therefore, that it should gain
weight in either 0.23 M saccharose solution or
in any other solution nearly isosmotic with
frog’s blood. But, in view of the considera-
tions given above, it can hardly be supposed
that this experiment shows that the osmotic
properties of smooth and striated muscle are
alike.
V. Körösy also immersed his gastrocnemius
cores in various hypertonic NaCl solutions, and
found that they lost weight in the early stages
of their immersion." These results are to be
compared with mine on the adductor muscle
of the clam, which had already begun to gain
weight after five minutes' immersion in a
strongly hypertonic NaCl solution.* My prep-
aration was certainly not any more injured
than v. Körösy’s in this case, yet under com-
parable experimental conditions it gained
weight and his lost. I do not understand,
therefore, why he thinks that his experiments
with the gastrocnemius core indicate that the
osmotic properties of the various kinds of
muscle under consideration are alike, nor do
I understand his remark on page 173, which I
take to mean that we need information about
the changes of weight undergone by clam’s
muscle in the early stages of its immersion in
6 Fletcher and Hopkins, The Journal of Physiol-
ogy, Vol. 35, pp. 261 et seq., 1907; Laquer, Zeit-
schrift für physiologische Chemie, Vol. 93, p. 69,
1914.
* Loc. cit., pp. 170 and 171 and Table fl.
8 Meigs, The Journal of Biological Chemistry,
Vol. 17, Experiment 17, p. 97, 1914.
SCIENCE 3
hypertonic solutions. We already have de-
tailed information on this point.”
With regard to v. Körösy’s supposition (pp.
172 and 173) that my preparations of frog's
stomach muscle were contaminated with acid,
I can only say that it is incorrect. I took
particular pains to avoid contamination of the
muscle with the stomach contents; the prep-
arations were decidedly alkaline to litmus at
the beginnings of the experiments and re-
mained so for at least twenty-four hours.
° Meigs, loc. cit., Experiments 3 and 17, pp. 95
and 97.
It seems to me that any further attempt to
show that the smooth and striated muscle of
the frog and the adductor muscle of the clam
are all equally subject to the “law of Avo-
gadro-van’t Hoff” should be based on experi-
ments on all three kinds of muscle and on
careful consideration of the data already at
hand, rather than on experiments confined to
striated muscle and backed up only by experi-
mentally unfounded suppositions.
EDWARD B. MEIGs
THE WISTAR INSTITUTE OF
ANATOMY AND BIOLOGY
UNIVERSITY OF MICHIGAN
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