Periodic changes in the liver volume and changes in the portal venous pressure.

Abstract

1) We have made clear the periodic contractions in the volume of such organs, as the spleen, intestine, kidney, etc., and the periodic changes in the venous and arterial blood pressures, resulting from above phenomena (8, 9, 10). However, now we were able to observe the volume changes of periods ranging from 15 to 38seconds in the liver, brought about by intravenous injections of Ringer's solution, sodium citrate, etc. (fig. 1 and 2).2) The connection between the change in liver volume and respiration is, during expiration, the liver volume decreases, while during inspiration it increases, but as can be seen in fig. 2, during rhythm occurrence in the liver, no changes could be seen in this amplitude of the respiration on the curve of liver volume. Also no changes in amplitude were observed on the respiratory curve, transmitted from the thoracic wall (fig. 1). Furthermore, directly after an intravenous injection of a solution of sodium citrate, a change occurred in the respiratory movement but this was different from the periodic change in the liver volume.3) Bainbridge and Dale (2) have shown that periodic contractions occur in a gall-bladder, and the periods were approximately 3 times per minute. This is quite similar to what we have seen in the liver, but periodic contractions can also be seen in a liver from which the gall-bladder has been completely removed (fig. 1), so it is quite correct to assume that in our cases this was not caused by the contraction of the gall-bladder.4) The fact that the splanchnic nerves control the liver is beyond doubt (6), but by their severance or even by the severance of the vagus nerves of both sides, the occurrence of a periodic volume change in the liver could not be disappeared. This phenomenon was also seen after the hepatic artery had been ligated. Thus, from the above facts we can see that the periodic changes seen on the volume curve of the liver have connections with the liver tissue proper and with the hepatic vessels.5) However, two types of periodic volume change in the liver can be differentiated. The first, as shown in fig. 1 and 2, is when the direction of change in the liver and the changes in the arterial and venous blood pressure are the opposite, namely when the contraction of the liver caused a rise in portal and arterial pressure. The other as shown in fig. 3 is when the 3 changes are in the same direction, namely the rise in portal and arterial pressure are observed simultaneously to the increase in the liver volume.6) In the cases shown in fig. 1 and 2, since the change in portal pressure and the change in liver volume showed opposite directions, the change in liver volume is thought an active one and based on contractions of the liver. This causes an increase in resistance of the portal blood flow, thus it can be considered as producing an increase in portal pressure. Regarding the active contraction of the liver, it contracts in response to stimulation of the splanchnic nerves (6), and also contracts markedly to adrenaline (7). Also regarding the existence of smooth muscle in the liver, there are reports that it has been found not only in the hepatic veins but also in the cental and sublobular veins (1).On comparing the periods of contraction confirmed in the spleen, intestine and kidney, with that of the liver, they are both approximately 25seconds, and stimulations which cause periodic contractions in the spleen etc., also cause rhythmical volume changes in the liver. This gives us grounds to suppose that the periodic contractions of these organs are but the rhythms of their smooth muscles.7) The case cited in example 1 of table 1, shows that the volume change of the liver was 0.65 to 1.0cc. and that the change in portal venous pressure was 6-16mm. saline. This change of pressure corresponds to 11.9% of its portal pressure.