Experiments were carried out on dogs, cats and rabbits. Under anaesthesia fine polythene cannulie were inserted so that injections of acetylcholine and catechol amines could be made into the portal venous, the systemic venous and the hepatic arterial systems. Carotid arterial pressure was recorded. Much larger amounts of acetylcholine were needed when injected into the portal vein than when injected into the hepatic artery to produce the same response in arterial pressure. With adrenaline and noradrenaline the difference between the two hepatic circulations was much less marked, except in some rabbits. In more than half the experiments in which it was carried out, cooling or section of the hepatic branch of the cceliac plexus altered the blood pressure response to drugs injected into the hepatic circulation, the arterial and portal systems being affected differently. Changes evoked by nerve cooling were reversible. Ganglionic blockade with hexamethonium bromide, and sympathetic blockade with choline 2:6 xylyl ether bromide or bretylium, also affected the intrahepatic circulation of blood, as did stimulation of the sympathetic nerve from the coeliac plexus. It was concluded that portal venous and hepatic arterial blood may, under some circumstances, flow through different pathways which are under autonomic control.SEVERAL authors, for example Kniseley, Block and Warner [1948], Wakim and Mann [1942], Seneviratne [1949] have investigated the circulation of normal livers with the technique of trans-illumination. In their papers they state that there was an intermittent flow through the sinusoids, and it can be deduced that various intrahepatic vascular pathways may exist, but they do not describe channelling through special vessels under the influence of nerves or injected substances. Daniel and Prichard [1951 a and b] describe a restricted (hilar) circulation in certain conditions, but consider that the blood passes through sinusoids in the deeper parts of the liver. Andrews, Hecker, Maegraith and Ritchie [1953] give physiological evidence for the shunting of arterial blood in perfused canine livers. Their conclusions have received some confirmation from the work of Szilagyi, Koscar and Kesztyus [1955] who left the liver in situ and measured the effect on general blood pressure of drugs injected into the liver circulation.In this study the work of Szilagyi et al. has been repeated with modifications, and also an attempt has been made to find whether the hepatic nerves affect intrahepatic vascular pathways. We present evidence that not only do various intrahepatic vascular pathways exist, but also that they are modified by the action of the hepatic sympathetic nerves. METHODSThe method consisted basically of comparing the amounts of drug needed to give the same change in peripheral arterial pressure, after injecting a pharmacologically active substance into the hepatic artery and portal vein alternately. There are certain
This study assessed anterior chamber parameters in healthy young adults using spectral-domain optical coherence tomography. This technique reveals the spatial relationships of the ocular structures, provides high-resolution images, and results in high degrees of intraobserver and interobserver repeatabilities.
Investigations were made on liver slices and on rat livers perfused with Ringer-Locke solution containing sulphobromophthalein. The work of Brauer and Pessotti [1949] on slices was confirmed: the equilibrium set up between the liver slices and the surrounding fluid was only partially due to metabolism of the dye. In perfusion experiments, during the first 20 min., the liver removed almost all the dye from the perfusion fluid: later the concentration of dye in the hepatic vein increased progressively with time. Cooling the liver slowed removal. At constant temperature the liver removed a fixed proportion of the dye presented to it, irrespective of the rate of flow and (within wide limits) of the dye concentration. An equilibrium between the concentrations of dye in the cells and in the sinusoids was demonstrated; the addition of plasma from different animals increased the concentration in the sinusoids, and a species difference in this effect was observed. The dye concentration of transudate coming from the surface of the liver was much higher than that of the outflow at 370 C., but not at 170 C. After a priming dose, sulphobromophthalein was released by the perfused liver, the concentration of dye in the outflow falling exponentially with the same decay constant as the dye within the liver. Bile salts reduced the storage of dye by the liver, but sodium cyanide and sodium fluoride were without effect. The existence of a mechanism for dye concentration in the cells is postulated.SULPHOBROMOPHTHALEIN was first used as an indicator of hepatic function, in 1928, by Rosenthal, but the factors which lead to its disappearance from plasma are only partially understood and the main use of the dye is as a sensitive screening test in the detection of minor degrees of hepatic dysfunction. The usual test consists of injecting 5 mg./kg. body weight intravenously, then estimating the amount of dye left in the circulation 30 min. later by withdrawing a blood sample and measuring the concentration in the plasma. Retention in the plasma of more than 5-10 per cent (the figure varying with different authors) is considered to be evidence of hepatic insufficiency. Because it is important to have an accurate guide to the degree of hepatic failure, much clinical research has been carried out using sulphobromophthalein.Sulphobromophthalein has, however, a much wider application than that of clinical pathology and may be used to investigate the passage of substances through the parenchymal cell membrane. It is bound to the albumin fraction of the plasma protein and is apparently stored by binding to hepatic protein [Andrews and Richards, 1960]. In 1949, Brauer and Pessotti carried out a series of experiments on liver slices and on perfused livers. Their observations, made in vitro, have remained unrelated to experiments carried out in vivo. Using similar methods we have attempted to relate their published data to the whole animal, and in this study we have investigated some of the factors which affect the uptake, storage and release back...
Purpose To compare the surgical outcomes and bleb morphology of limbal‐ based group with that of fornix‐based group undergone trabeculectomy with mitomycin C (MMC). Methods 50 eyes of 50 patients with trabeculectomy with MMC who were observed for 1 year were included in the study. A limbal‐based conjunctival flap was used for 25 eyes of 25 patients and a fornix‐based conjunctival flap for the other 25 eyes of 25 patients. We classified and compared the bleb morphology according to the Moorfield Bleb Grading Sistem after 1 year postoperatively, and evaluated intraocular pressure, success rates. Results There was no significant difference in the IOP and success rate in two groups. The central bleb vascularity of the limbal‐based group was stadistically lower than that of fornix‐based group (1,69±0,56 : 2,08 ±0,69, p=0,042). The risk of cystic bleb formation was higher in the limbal‐based group (34,2% : 14,6% , p = 0,047). Conclusion There was no difference between the groups in the IOP and cumulative succes rate, but fornix‐based group was recommendable concerning the low risk of cystic bleb formation.
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