T. Lauder (Thomas Lauder) Brunton.

On disorders of digestion, their consequences and treatment online

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of urine. This does occur, though not invariably, when the
splanchnics are divided; but section of the spinal cord, by
paralysing the intestinal and other vessels, lowers the blood
pressure so much that the supply of blood to the kidney is not
only much below the normal, but is so small that the secretion of
urine is generally almost completely arrested.

The nerves of the kidney consist of a number of small branches
running along the renal artery and containing a number of ganglia.
When these nerves are cut the -vessels of the kidney dilate ; when
they are stimulated the vessels contract. A number of these fibres
pass to the kidney from the spinal cord through the splanchnics, so
that when the sjolanchnics are cut the vessels of the kidney usually
dilate, and when they are irritated, they contract.

The whole of the nerves, however, do not pass through the
splanchnics, for stimulation of a sensory nerve, of the medulla
oblongata, or of the spinal cord in the neck, will cause contraction
of the renal vessels after both splanchnics have been cut, and
section of the splanchnics does not always cause the renal vessels
to dilate.

The nervous centre for the renal arteries is probably, like
the chief vaso-motor centre for the body generally, in the
medulla oblongata ; but in all probability there are also sub-
sidiaiy centres in the spinal cord and in the solar and mesenteric
plexuses.

The reason for supposing these latter centres to exist is, that
stimulation of the periiDheral end of the splanchnic, divided
at its passage through the diajahragm, causes contraction of both
kidneys, and the vessels of the kidney of the side opposite to
the stimulated nerve commence to contract later than that on
the same side. A delay like this in the action of the stimulus
means that it has not acted directly, but through the medium
of ganglia.

When the splanchnics are divided, the vessels of the kidney
sometimes dilate and the kidney increases in size; a profuse
secretion of urine may take place, which quickly increases to a
maximum and remains for a considerable time. This, however.



362 ON THE ACTION AND USE OF DIURETICS.

is not a constant effect, and not unfrequently the vessels do not
dilate, and the kidney, instead of increasing, diminishes in size-
This is what to a certain extent might be expected, inasmuch as a
section of the splanchnics causes dilatation of the intestinal vessels
and lowers the blood pressure, and thus diminishes the supply of
blood to the kidney.

When a puncture is made in the medulla oblongata in the
floor of the fourth ventricle, profuse secretion also occurs, but
this differs from that caused by section of the splanchnics, in
being preceded by slight diminution, in rising rapidly to a
maximum, and then rapidly falling. These characters seem to
show that it is due to irritation of some vaso-dilating mechanism^
rather than to any paralysis.

Stimulation of the vaso-motor centre in the medulla oblongata
by venous blood, or by drugs such as strychnine or digitalis, has a
twofold action on the kidney, for it tends to cause contraction not
only in the vessels of the kidney, but in those of other parts of the
body. The effect on the kidney is thus a complicated one, for the
contraction of the intestinal and other vessels by raising the blood
pressure tends to drive blood into the kidneys at the same
time that the contraction of the renal arteries tends to keep it out.
When the renal nerves are cut, the renal vessels no longer oppose
the entrance of blood, and therefore the renal vessels dilate very
greatly when the vaso-motor centre is stimulated ; but when the
renal nerves are intact the result is a varying one, for sometimes
contraction of the renal vessels may be so great as to prevent the
entrance of blood into the kidney, however high the general blood
pressure may rise ; at other times the general high blood pressure
may be able to dilate the renal arteries in spite of any resistance
they may offer. These different conditions may occur subse-
quently to one another ; and this stimulation of the vaso-motor
centre may cause contraction of the renal vessels succeeded by
dilatation, or vice versa. Thus Mr. Power and I found that on
injecting digitalis into the circulation of a dog the blood pressure
rose, but the secretion of urine was either greatly diminished or
ceased altogether. Here it is evident that the renal vessels had
contracted so nmch as to prevent the circulation through the
kidney, notwithstanding the rise which had taken place in the
blood pressure. After a while the blood pressure began to fall,
and then the secretion of urine rose much above its normal,
• Heidenhain, Hermanns Handbuch d. Physiologic, vol. v. Th. 1, p. 366.



BLOOD PRESSURE AND URINARY SECRETION. 363

showing that the general blood pressure was then able again to
drive the blood into the kidneys.^

Similar observations were made by Mr. Pye and myself with
regard to erythrophloeum, and the accompanying curves show well
the result of the mutual action of rise in blood pressure and con-
traction of the renal arteries upon the secretion of urine. It will
be noticed that at first the blood pressure rises more quickly than
the secretion of urine, the circulation through the kidney appear-
ing to be opposed by the renal arteries. This opposition is then



as

C 3










Fig. 50. — CuiTes stowing the effect of erythropWoenm upon the blood pressure and
secretion of urine. 'S torn. Phil. Trails. , -vol. 167.

overcome, and the secretion of the urine rises more quickly than
the general blood pressure. The renal vessels again appear to
contract, so that the urine diminishes while the blood pressure
rises still further. We have next oscillations due first to one
factor and then to the other being predominant ; and then, when
the blood pressure rises to its maximum, we find that the urine
is at its minimum, the secretion of urine again rising as the
blood pressure falls.

A good deal of discussion has arisen regarding the mode of
action of digitalis^ and it has been stated by many to act as a
diuretic only in cases of heart disease, and to have no diuretic
action in health. In my own experiments, however, I found that
it acted as a very marked diuretic even in health, and the explan-
ation of this discrepancy may possibly be that, in my own case, the
1 Royal Society's Proceedings, No. 153, 1871



334 ON THE ACTION AND USE OF DIURETICS.

normal blood pressure was low, whereas in tlie others it was
probably much higher; but I am uncertain regarding the true
explanation, though I am certain of the fact.

By causing increased secretion of water through the kidneys
diuretics may increase the concentration of the blood and thus
produce thirst, or cause absorption of water from the intercellular
tissue or serous cavities in dropsies. In my own experiments on
digitalis I weighed all my food and measured all my drink for
nearly six months, taking exactly the same quantity every day.
After producing profuse diuresis by a large dose of digitaline (sixty
milligrammes in two days), such thirst ensued that I was forced to
take a quantity of water to allay it.^

Mode of Action of Diuretics. — From what has already been said,
it is evident that diuretics may act in several ways. They may
act:

(A) On the circulation in the kidney, raising the pressure in the
glomeruli.

(1) Locally (a) by contracting the efferent vessels, or the arterial
twigs which pass directly to the capillary plexus ; (b) by causing
dilatation of the renal arteries, and thus increasing the supply of
blood to the kidney. Tiiis they may do also in more ways than
one, for they may either paralyse the vaso-motor nerves of the
kidney, or act on vaso-dilating mechanisms.

(2) They may raise the blood pressure generally by causing the
contraction of vessels in other parts of the body.

(B) Other diuretics may act on the secreting cells of the tubules,
and may increase both the amount of water and the amount of
solids excreted by them.

Diuretics have been by some classified as stimulating and
sedative; and the sedative class agrees very closely with the one
which we have just indicated as acting on the kidneys through the
circulation.

From what has been said of the action of diuretics it is evident
that we may hoiie to do much more by combining them, than by
using them singly. Thus we see that digitalis, instead of acting as
a diuretic, may completely arrest the renal circulation, and stop the
secretion altogether. If, however, we can combine it with some-
thing which will produce dilatation of the renal vessels, while the
general blood pressure remains high, we shall greatly increase the

' The experiments were made in 1865 and published in part in my thesis on
Digitalis, with some Observations 071 Urine. London: Chui'chill, 1868.



ACTION OF NITRITES. 3G3

circulation through the kidney, and obtain the desired result.
Experiments in regard to this were made by Grutzner with nitrite
of sodium. He found that this substance increased the secretion
of urine when the blood pressure was reduced to a minimum by
curara ; and he found that it also had this effect when the blood
pressure was raised by imperfect respiration. When the vaso-
motor centre was excessively stimulated however-, by allowing the
blood to become very venous, the nitrite of sodium no longer
produced any increase of secretion.

All nitrites have an action on the blood-vessels more or less
alike. All of them cause the arterioles to dilate either by an
action on their muscular walls or ou the peripheral terminations of
vaso-motor nerves. One of the commonest diuretics is spiritus
stheris nitrosi, which contains nitrite of ethyl. Sometimes this is
combined with acetate of ammonia as a diaphoretic, sometimes
with digitalis, broom, or spirit of juniper, as a diuretic. We have
already seen that the action of the skin and of the kidneys are
complementary, so that if we increase the secretion from the one
we tend to diminish that of the other. At first sight then it might
appear curious that we should use the same drug to increase the
secretion of both. Yet there can be little doubt from clinical
experience that nitrous ether is useful for both purposes, and the
reason of its utility at once becomes evident when we remember
that it is strictly neither diaplioretic nor diuretic, but its action is
simply that of dilating the vessels, and consequently allowing the
blood to flow freely in whatever direction it may be determined by
other conditions. If by combining it with digitalis we can dilate the
renal arteries while those of the other parts of the body remain
contracted, it is evident that we shall obtain a much freer flow of
urine than we could by the administration of digitalis alone.

If instead of a diuretic like digitalis, which acts chiefly through
the blood-vessels, we combine spirits of nitrous ether with salts of
potassium, which act on the secreting structure, it is evident that
we are likely to obtain from the increased circulation in the kid-
neys caused by the nitrites a much more plentiful secretion than
the potassium salts alone would have produced.

The mode of action of diuretics may perhaps be rendered clearer
by the following table. At present the data we possess are insuf-
ficient to allow us to classify diuretics with absolute certainty
according to their mode of action, yet I think the accompanying
table may be fairly said to represent our present knowledge of the



3G6 ON THE ACTION AND USE OF DIURETICS.

subject, its imperfections being indicated by tbe nunaber of notes
of interrogation which the table contains.



TABLE SHOWING THE PKOBABLE MODE OF ACTION OF DIURETICS.



Raise arte-
rial pres-
sure



Generally I ^"^^^^^^^^ action of the heart by alcohol.

■^ ( Contraction of vessels in intestine and throughout the body.



Locally in
kidney.,.



r Digitalis.
j Erythrophloeura.
j Strophanthus.
< Squill.
I Convallaria.

Strychnia.
LCold to surface.

rSy action on vaso-motor ( ? The same as in

Contract efferent vcs'^cls or centres, ( preceding list,
arteria recta so as to raise [

pressure in glomerulus and <, C? Broom,

lessen absorption la tu- j By local action on vessels or | ? Turpentine.



bules, or both.



Dilate afferent veasela



nervous structures in the
L kidney itself.



< ? Junipei-.
I ? Copaiba,
t? Cantharidea.



(Paralyse vaso-motor nerves or ( Nitrites,
involuntary muscular fibre. •< AlcohoL
^ Stimulate vaso-dilating nerves (? Urea.*



Act on the se-
ereting nerves, C
or secreting )
cells of the )
kidney itself.



Increase water excreted.



Incrcdse soUds excreted.



f Urea.
\ Caffeine.

f Liquor potassae.

( Potassium acetate, &c.



* "Wlien a cun-ent of blood is passed artificially through an excised kidney, the stream is much
accelerated by the addition of urea. Abeles, Siiz-D:r. d. at. k. Wltiia- Akad. Bd. 87, Abt, 3, April,
1833.

It not infrequently happens that one is able to understand a
hypothesis more clearly when it is put in a diagrammatic form,
and that one can thus perceive more readily the particular points
in which it may be erroneous, even if true in the main. I there-
fore subjoin a diagram of the circulation and secreting apparatus
of the kidne}'' to show the parts which are probably affected by
different diuretics : —



Afferent vessels. (?) Dilated by nitrous
ether, potassium nitrite



Efferent vessels. (?) Contracted by digi- (
talis, strychnme, erythiophloeum, squill. '



Tubules. (?) Stimulated by urea and potao- ,

slum nitrite, acetate, <fcc. Caffeine, tur- J y

pontine, cantharidine (?) Paralysed by|
curare (?)




Fig. 51. — Diagram to show the parts of the secreting apparatus of the kidney which
are probably atfected by dififerent diui'etics.

Uses. — Diuretics may be employed either for the purpose of
removing water or solids from the body. They are used :



USES OF DIURETICS. 3G7

1st, to remove the excess of fluid met with in the tissues and
serous cavities in cases of dropsy.

2nd, to hasten the removal of injurious Avaste products and
poisonous substances from the blood.

3rd, to dilute the urine.

In cases ■where the accumulation of fluid depends on venous
congestion, as for example in cardiac dropsy, those diuretics which
act on the general vascular system, like digitalis, strophanthus,
squill, or erythrophloeum, are most efficient because they tend to
remove the cause of the dropsy, as well as to assist the absorption
and excretion of the fluid already effused.

When the dropsy depends on the disease of the kidneys or liver,
other diuretics should either be given instead of, or along with,
digitalis or squill, even in cases of cardiac disease. Where digitalis
or squill are not proving efScacious, the addition of a little blue
pill greatly assists their action, though it would be hard to say in
what way it does so.

In dropsy depending on kidney disease, decoction of broom, and
oil of juniper, and nitrous ether, are amongst the most reliable
diuretics, and copaiba in hepatic dropsy.

Diuretics are used to increase the secretion of solids in febrile
conditions, and in cases of kidney disease where the excretion of
waste products is deficient, and their retention threatens to prove
injurious. In sacTi cases, nitrate and bi-tartrate of potassium,
turpentine, and juniper, and caffeine are useful.

Diuretics are also used to increase the proportion of water in the
urine, and thus to prevent the solids being deposited from it and
forming calculi in the kidney or bladder ; or even to dissolve again
concretions which have been already formed.

Water is perhaps the most powerful diuretic we possess, although
fewer experiments have been made with it upon animals than with
the others. The diuretic action of water drunk by a healthy man
is very marked, and it appears impossible to explain its elimination
by a mere increase in blood-pressure, whether general or local. It
has, as we have remarked, the power of increasing tissue change,
and thus multiplying the products of tissue waste which result
from it, but it removes those waste products as fast as they are
formed, and thus, by giving rise to increased appetite, provides
fresh nutriment for the tissues, and thus acts as a true tonic. In
persons who are accustomed to take too little water, the products
of tissue waste may be formed faster than they are removed, and



368 ON THE ACTION AND USE OF DIURETICS.

thus accumulating may give rise to disease. If water be freely
drunk by sucli persons, the products of waste will be removed, and
health maintained or restored. Thus many gouty persons are
accustomed to take little or no water except in the form of a small
cup of tea or coffee daily, besides what they get in the form of wine
or beer. In such people a large tumbler of water drunk every
morning, and especially with the addition of some nitrate or
carbonate of potassium, will prevent a gouty paroxysm. Still
more numerous, possibly, is the class of people who rise in the
morning feeling weak and languid, more tired, indeed, than when
they went to bed. Now fatigue may be regarded as the imjDerfect
response of muscles and nerves to stimuli, and such an imperfection
in their action may be due either to their imperfect nutrition or to
the imperfect removal of the products of their waste. Many such
people are well fed, they sleep soundly, and it seems almost impos-
sible to believe that the fatigue which they feel in the morning
can result from imperfect nutrition, more especially as one finds
that after moving about, the languor appears in a great measure
to pass off. It seems to me that this languor must depend upon
imperfect removal of the waste products from the body, as we
know that the secretion of urine in healthy persons is generally
much less during the night than during the day. I am therefore
in the habit of advising such people to drink a tumbler of water
before going to bed in order to aid the secretion of urine and
elimination of the waste products during the night. In some
cases, though not in all, the result has been satisfactory, and
possibly might have been still more so had I added to the water
the bi-carbonate and nitrate of potassium which, as I have already
mentioned, is so useful in cases of gout.

Lately a plan of treating gout by draughts of water at intervals
during the day has been a good deal employed and is in many
cases successful. As an example of this I subjoin the diet used
along with this treatment by a medical friend of mine who has
been a martyr to gout, but who feels himself perfectly well as long
as he adheres strictly to this course of diet : —

7.30 A.M. Ten fluid ounces very hot water.

8 A.M. Breakfast: Equal parts of weak tea and milk, a small

quantity of white sugar, a slice of fat bacon without a strip

of lean, bread and fresh buttei".
1 P.M. Milk pudding, rice, sago, tapioca, macaroni, or blanc mange,

and small biscuits with butter, ten fluid ounces hot water.



EOT WATER IN GOUT AND GRAVEL. 369

4 to 5 P.M. Ten fluid ounces hot water.

C P.M. Dinner: White fish or fowl (usually boiled), greens, bread,

no potatoes, claret seven fluid ounces.
8 to 9 P.M. Ten fluid ounces hot water.
11 P.M. Ten fluid ounces hot water.

If he indulges either in meat or game, or drinks copiously of
claret, or omits one or two glasses of hot water, he feels gouty and
gravelly next day. It is obvious that by this plan of treatment, in
which the ingestion of nitrogenous food is most strictly limited, at
the same time that every facility is given for the elimination of
the products of nitrogenous waste by the large quantities of hot
water drunk in the course of the day, the accumulation of waste in
the tissues ought to be most effectually prevented.

Adjuvants to Diuretics. — As the amount of urine secreted
depends upon the difference in pressure between the blood in the
glomeruli and the urine in the tubules, it is evident that any
pressure on the tubules, whether caused by obstruction of the
ureter by a calculus, by the mechanical pressure of dropsical
accumulations in the abdomen, or by distension of the venous
plexus in the kidney itself, will tend to lessen the secretion of
urine. Consequently we sometimes find that in such cases
diuretics fail to act until the pressure has been relieved by
paracentesis in cases of dropsy, or the venous congestion lessened
by the use of a brisk purgative, or by cupping over the loins.

If the venous congestion be very great, as in cases of mitral
disease or of chronic bronchitis with emphysema and dilated heart,
bleeding from the arm may be advantageous or even imperatively
necessary. In dilated heart and in mitral incompetence the action
of digitalis on the heart itself, strengthening its action and
enabling it more effectually to pump the blood out of the venous
into the arterial system and thus to reduce venous congestion, will
aid its action upon the kidneys.



INDEX.



Abdominal circulation in cliolerin, 2G9

Abdominal muscles in vomiting, action
of, 166

Abernethian Society, papers read be-

' fore, 113 note, 307 note

Absorption, ia intestines,! 6; in urinary
tubules, 354 ; of alcohol, 160 ; of
digestive ferments, 227 ; of fat, 9 ;
part of digestion, 6 ; through skin, 5

Acacia, emulsion with cod-liver oil,
134

Acetic acid in stomach, 241

Acid-albumin, 314, 316

Acid from food, 33 ; fruits, 63 ; in-
creased in gastric juice, 33 note

Acidity, 28, 32, 64 ; and cough, 40 ;
of gastric juice in fever, 180

Acids, effect of, on heart and veEsels,
343, 350; in headache, 109, 198

Action of Infused Beverages on Teptic
Digestion., J. W. Fraser, referred
to, 64 note

Activity of man maintained by com-
bustion, 3

Adam's diet table, 62

Adipose tissue. See Fat.

Adviser, quoted, 66

JEsop's Fables, quoted, 266

Afferent nerves, which excite vomit-
ing, 171

African West Coast, oedema on, 347

Agaricus muscarius, 265, 278 ; other
varieties, 259

Air swallowed, as a cause of flatulence,
29, 30 ; before vomiting, 167

Albertoni, Professor, on the action of
peptones, 247

Albini, obser%'ations on bile, 201

Albrecht, on convulsions and dental
caries, 94

Albumin, action of pancreatic juice



on, 14 ; detection of, in urine, 31 3 ;
hydration of, 8 ; precipitated by
alcohol, 142 ; by ipecacuanha, 178
note; by tartar emetic, 178 ; varie-
ties, 37

Albuminoids in stomach, 12

Albuminous tissues, action of mercury
on, 232

Albuminuria, 35, 246, 356 ; arsenic
in, 328 ; case of, 326 ; cause of
ansemia, 313 ; causes of, 324 ; effect
of meat, fat, and time of day, 327 ;
elaterium in, 208 ; from imperfect
digestion, 329 ; summary, 329 ;
symptoms of, 315 ; temporary, 36,
66 note, 243, 317 ; time and place,
322 ; treatment of, 320

Albuminuric dropsy, 346 ; headache,
111

Alcohol, 41, 69, 121, 366 ; absorption
of, 150 ; and cold, 159 ; as a cause
of gastric catarrh, 153 ; as a food,

153 ; as a poison, 161 ; as a stimu-
lant, 157 ; action on heart, 149 ;
skin, 141; stomach, 143 ; coagulates
albumin, 142; coma from, 148 ; effect
on amceboid movements, 150 ; on
circulation, 147 ; on diarrhoea, 143 ;
on motor ganglia of heart, 163 ; in
mental processes, 154 ; on muscles,

154 ; on the pulse, 158 ; on red
corpuscles, 160 j on temperature,
158; food or poison, 140; in Arctic
regions, 169 ; in fever, 151 ; oxida-
tion of, 152 ; physiological action
of, 162 ; reasons for drinking, 140;
reflex action of, 147 ; summary of
effects of, 163

Alkali-albumin, 314
Alkalies, effect on heart and vessels,
343 ■ in headache, 109, 198

B B 2



372



INDEX.



Alkaloids, from maize, 279 ; from
putrefaction, 281 ; in the blood,
290 ; in cholera stools, 290 ; in
fseces, 290; in urine, 290 ; relation
to albumin, 13. See also Ptomaines.
Aloes, 72, 186, 188, 191, 208
Alteratives, action on ferments, 228 ;
meaning of term, 223 ; mode of
action of, 225 ; resemblance to
nutritives, 226 ; summary, 232
Althann, 251
Alum in vomiting, 176
Amanita muscaria, 2(J5, 283
American cure for drunkenness, 57
Ammonia salts in urine, 76
Ammonium bromide in dyspepsia, 67;

chloride ia liver disease, 73
Amoeboid movements, effect of alcohol

on, 150
Arnyl nitrite, 232 ; in cholera, 268
^na^mia, causes of, 311 ; from albu-
minuria, 313 ; headache of, 109 ; in
migraine, 85 ; of brain in intoxi-
cation, 161 ; symptoms of, 307
Anaesthesia from destruction of hip-

pooampal convolutions, 98
Anfesthetics in dental cases, 96
Animals, over-eating in, 68 ; fat in,

129
Anrep, V., 2F'6



Online LibraryT. Lauder (Thomas Lauder) BruntonOn disorders of digestion, their consequences and treatment → online text (page 37 of 40)