The Arris and Gale lectures on the physiological factors involved in the causation of dropsy : delivered before the Royal College of Surgeons of England on February 17th, 19th, and 21st, 1896 / by Ernest H. Starling.

  • Starling, Ernest Henry, 1866-1927.
Date:
1896
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Licence: Public Domain Mark

Credit: The Arris and Gale lectures on the physiological factors involved in the causation of dropsy : delivered before the Royal College of Surgeons of England on February 17th, 19th, and 21st, 1896 / by Ernest H. Starling. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    while in the hepatic capillaries the pressure is very little altered or may even be somewhat increased. Hence the only region of the body below the point of obstruction where the capillary pressure is not much diminished is the liver. Now we find that the liver is also the sole source of the lymph ob- tained under these circumstances. If the hepatic lymphatics be ligatured and the thoracic aorta be then obstructed, the flow of lymph from the thoracic duct is absolutely stopped. In these three cases, therefore, the lymph production in the organs of the abdomen is found to be absolutely proportional to the changes of the capillary pressures in these organs. In another set of experiments we find that a marked increase in the lymph-flow is produced by a general rise of capillary pressure in all the organs of the abdomen. Such a general rise of capillary pressure may be produced by the injection of large quantities of normal saline fluid into the circulation, giving rise to a condition of hydremic plethora. Under such circumstances the lymph may be increased from 50 to 100 times in amount, and may in some cases run from the cannula in the duct in a steady stream. Now, in hydrsemic plethora there are two changes in the circulation which might possibly be responsible for the increased production of lymph: firstly, the change in the composition of the blood, and, secondly, the increased pressure in the capillaries of the abdominal viscera. We can decide which of these two factors is responsible for the increased lymph-flow by a very simple experiment. Previously to injecting 300 c.c. of normal saline we bleed the dog to 300 c.c., so that after the injection the total amount of circulating fluid is the same as at the beginning of the experiment. In this way we entirely avoid any rise of capillary pressure, while we have diluted the blood to an even greater extent than in the experiments in which hydrsemic plethora was produced. The effect of such a simple hydrsemia is to increase the lymph-flow from 3 c.c. in 10 minutes to 4 or 6 c.c. in 10 minutes, whereas if hydraemic plethora were produced the lymph would be in- creased from 3 c.c. to 30, 50, or 100 c.c. in 10 minutes. It is evident, therefore, that in the production of this increased lymph-flow the all important factor is the rise of capillary pressure. Exactly the same interpretation holds good for the action of a certain class of bodies which were grouped together by Heidenhain in the second class of lymphagogues. These include bodies such as salt, sugar, potassium, iodide, kc. The injection of a strong solution of dextrose (30 grms. in 30 c.c. water) into the veins of an animal causes a considerable increase in the lymph-flow from the thoracic duct. The lymph at the same time becomes more watery than at the commencement of the experiment. Heidenhain ascribes this effect to a specific excitation of the secretory activities of the endothelial cells. The effect, however, can be explained in a much more simple fashion. All these solutions have an osmotic pressure which is considerably higher than that of normal blood plasma. A solution of dextrose that should be