Renal Portal Research Articles

A NOTE ON THE HEAD KIDNEY AND KIDNEY OF THE PERCH PERCA FLUVIATILIS (LINNAEUS), WITH SPECIAL REFERENCE TO THE BLOOD VASCULAR SYSTEM

A brief account is given of the morphology, internal structure and blood vascular system of the head kidney and kidney of the perch. The cardinal anterior and posterior veins pursue an odd course through the head kidney, and the interrenal tissue occurs within the head kidney particularly around the junction of these veins. The bulk of the head kidney, as in most teleosts, is a mass of lymphoid tissue. The blood vessels associated with the kidneys have an essentially segmental arrangement, as have the kidneys themselves. However, some arteries given off from the aorta traverse the kidneys without further branching on the way to the body wall. Others supply the kidneys themselves with blood and are true renal arteries. At least three‐quarters of the blood from the kidneys, body wall, cardinal vein, etc., is carried by the right posterior cardinal vein, due to the degenerate condition of the left posterior cardinal. There appears to be a renal portal system with veins from the body wall joining with those in the kidney via venous plexuses.

Hepatic and Renal Effects on Potency of Estrogenic Stilbene Derivatives in Chickens

A statistical method for the assay of estrogen activity in chicks was developed and used to characterize 3 phenolic estrogens related to stilbene and 2 ester and 1 ether derivative of each. The most potent of each class of compound was hexestrol and its derivatives; the most potent classes of compounds were the esters. Using 3 alternative injection sites, the first 2 of which ensure absorption via the hepatic or renal portal systems, and the third of which leads directly to the general circulation, permitted an estimation of the effects of the liver and kidney during a single passage. The liver destroyed or excreted up to 99.9%, and the kidney over 50%, of the phenols. Esterification reduced inactivation in the liver and almost abolished it in the kidney. The ethers were likewise little affected by kidney passage, and their potency was augmented in the liver.

The Excretion of Urea Following its Infusion Through the Renal Portal System of the Fowl

SUMMARY The infusion of urea unilaterally through the renal portal system of the fowl results in a greater excretion of urea on the infused side. This is due mainly to a diuresis caused by the diffusion of urea. A similar unilateral response is shown by uric acid, but this is accounted for by differences in concentration rather than in volume. The value of renal portal infusion as a test of tubular secretion is discussed.

Renal tubular effects of ammonium salts on electrolyte transport.

It has been established that ammonia salts exert a direct renal tubular effect in the chicken. The injection of ammonium chloride into the renal portal circulation produces a predominantly unilateral effect, characterized by inhibition of both the reabsorption of sodium, chloride, bicarbonate, and water and the secretion of potassium and hydrogen ions. An increase in total ammonia excretion was also observed. The inhibition of electrolyte and water transport is independent of the anion infused. Natriuresis and diuresis are produced by the ammonium salts of chloride, sulfate, nitrate, and acetate. The effect is not dependent upon the development of metabolic acidosis. Furthermore, an increase in endogenous ammonia production and excretion provided by the infusion of precursor amino acids does not interfere with electrolyte transport. Thus, the inhibitory effect of ammonium salts is probably a consequence of an increase in the concentration of ammonium ion in the peritubular circulation. The results are consistent with the thesis that ammonium ion may substitute for potassium on the linked sodium-potassium exchange pump on the contraluminal surface of the renal tubule cell.

The Blood Supply of the Liver of the Turkey and the Anatomy of the Biliary Tract with Reference to Infection with Histomonas meleagridis

SUMMARY A description is given of the blood supply to the liver of the turkey, and the anatomy of the bile ducts. The arterial supply consists of right and left hepatic arteries which are derived from different branches of the coeliac artery. The hepatic portal system consists of a large right portal vein from the intestines and spleen and small left portal veins from the gizzard and proventriculus. The right portal vein connects with the renal portal system by the coccygeo-mesenteric and hypogastric veins. The two bile ducts are joined within the substance of the liver. These results are discussed with particular reference to the pathogenesis of histomoniasis.

The Excretion of Inulin, Creatinine and Ferrocyanide by the Fowl

SUMMARY The renal clearances of various substances have been determined in the anaesthetized hen and the following conclusions drawn. The renal portal vessels supply only the tubules and not the glomeruli since the inulin clearance of both kidneys remains the same when inulin is perfused through the portal system on one side. Exogenous creatinine, exogenous and endogenous creatine, ferrocyanide and probably thiosulphate have clearances greater than inulin and are therefore secreted. Endogenous creatinine has a clearance less than inulin. Infusion through the renal portal system as a test of tubular secretion is not as reliable as the method of comparing clearances with the glomerular filtration rate.

The Renal Clearance of Uric Acid and P-Amino-Hippurate in the Fowl

The renal clearances of endogenous uric acid, p-atnitw-hippurate and diodone were determined in anaesthetized hens. The mean values and the Standard Deviation were respectively: 68·5 ± 10·35 ml./min., 67·6 ± 17·82 ml./min. and 50·2 ± 15·25 ml./min. The value of these clearances as estimates of the minimum renal plasma flow is discussed in relation to the renal portal system.

Excretion of L-malic acid in the chicken.

The mechanism of excretion of malic acid has been studied during infusion of sodium salts of l-malic acid, succinic acid and malonic acid in the chicken. Infusion of preformed l-malate results in its filtration and reabsorption in the nephron; no renal tubular secretion is seen under these circumstances. However, when succinate is infused in the renal portal circulation, malate is excreted in larger amounts on the ipsilateral side than on the other. Malonate, a succinoxidase inhibitor, not only fails to abolish this excretion but actually enhances it. Infusion of malonate alone does not produce any excretion of malic acid. It is concluded that the renal tubular secretion of l-malate is limited to that which is synthesized in the tubular cells and does not occur even when large amounts of infused l-malate are present in the peritubular circulation. The enhancement of malate excretion by malonate during succinate infusion may occur from either malonate decarboxylation or malonate suppression of a malate reabsorptive limb in the nephron.

Renal action of parathyroid extract in the chicken.

The renal action of parathyroid extract has been studied in the chicken, in which a renal portal system facilitates separation of renal tubular from systemic and glomerular effects. It was found that net secretion of phosphate occurs in the chicken kidney both at endogenous plasma phosphate levels and during the infusion of phosphate. The rate of secretion seems to be independent of the plasma phosphate concentration. Infusion of parathyroid extract into one renal portal system results in a unilateral increase in phosphate excretion. In some experiments unilateral net secretion of phosphate occurred. No consistent changes in glomerular filtration rate or plasma phosphate concentration occur when parathyroid extract is administered. These results indicate that parathyroid extract has a direct action on the renal tubule in the chicken.

Excretion of Na22 and K42 by the perfused bullfrog kidney and the effect of some poisons.

Perfusion of the bullfrog (Rana catesbiana) kidney with Na22 and K42 via the renal portal system results in a urine with a high content of both isotopes. These isotopes must enter the urine by passing though the wall of the renal tubule or the collecting ducts since glomerular filtration of the portal fluid was negligible. The descending order of equilibration of these radioisotopes and of D2O is in general from D2O to K42 to Na22. Calculation of the unidirectional-reabsorptive and excretory movements across the tubules suggest that the depression in net reabsorption of sodium and potassium by azide, cyanide, and dinitrophenol is due more to a decrease in the unidirectional reabsorptive movement than to an increase in the excretory movement. The unidirectional excretory movements of sodium and of potassium show no consistent trend during the control periods and continue in the same fashion during the perfusion of the poisons. It is inferred that the excretory movements of sodium and potassium are of a passive nature, or that they depend upon a type of energetic process different from that involved in the reabsorptive movement.

Tubular excretion of histamine in the hen.

Summary.The renal tubular excretion of injected histamine has been investigated according to a method which takes advantage of the renal portal circulation in the bird. It was found that in the hen histamine is effectively excreted by the tubules to an extent comparable with the secretion of phenol red.

Pharmacology of smooth muscle valve in renal portal circulation of birds.

The avian renal portal system, first described by Jacobson in 1822(1) was not proved functional until 1948 by Sperber(2). In the bird the external iliac vein (EIV) communicates with the internal iliac vein which drains into the renal parenchyma. The EIV also connects directly to the renal vein (RV) by a large venous shunt. Interposed at the point of communication from EIV to RV is a valve-like structure described by Spanner (3) which is of variable shape in various species of birds but which is composed of smooth muscle, and usually has a conical shape with single or multiple apical openings. When contracted, the valve would tend to divert iliac vein blood through the kidney and when relaxed, blood would pass directly into the renal vein. Sperber described the position and appearance of the valve (Fig. 1) and presumed that it regulated blood flow to the renal tubules. Sperber clearly illustrated the functional significance of the renal portal system in the chicken by demonstrating that phenol red injected...

CIRCULATORY CYCLES IN THE VERTEBRATES*

CIRCULATORY CYCLES IN THE VERTEBRATES*

A New Method for the Study of Renal Tubular Excretion in Birds

THE existence of a renal portal circulation in birds has hitherto lacked experimental confirmation. In order to investigate this question, the following method has been adopted.

CONSTRICTION OF RENAL VESSELS IN THE FROG (RANA ESCULENTA) AND ITS EFFECTS ON THE SYSTEMIC BLOOD‐PRESSURE

A method is described which permits daily readings of the frog's systemic blood‐pressure to be made in light ancesthesia.Constriction of one or of both renal portal veins was performed in frogs (Rana esculenta) in which the abdominal vein had been ligated. The constriction had no effect on the systemic blood‐pressure.Obstruction of the aorta just above the origin of the renal arteries in Rana esculenta did not alter the frogs' blood‐pressure, neither did this operation do so in combination with constriction of the renal portal veins.Some of these experiments were done in the Molteno Institute for Parasitology. It is a pleasure to thank Professor Keilin for the facilities he gave me.

Effect of Epinephrine on Potassium Balance in the Perfused Hind Limbs of the Frog

Intravenous injection of epinephrine produces an immediate transitory rise in the level of plasma potassium.1, 2, 3 The duration and magnitude of this effect differs in different animal species and a subsequent fall in [K]s to below normal is equally marked and less transitory, especially in man.4 The initial rise in [K] s seems to originate in the liver2 but it appeared possible that the skeletal muscle might be involved in the slower and more sustained decline.Perfusion preparations of the isolated hind limbs of the doublepithed frog were made. The perfusion fluid was a 3% gum acacia solution with the salt content and pH adjusted to correspond with normal frog Ringer's solution except for K which was somewhat high (5.18 to 6.03 m.eq./l). A perfusion pump supplied pulsating pressure to the inflow cannula entering the terminal aorta. The out-flow was collected from cannulae in the renal portal veins, all other egress being prevented by ligatures. [K] was determined5 in arterial and venous samples collecte...

Structure and Function of the Peritoneal Funnels of the Frog, Rana pipiens

Heidenhain found no trace of peritoneal funnels in the frog's kidney. Spengel first saw these funnels in such forms as R. ternporaria, B. cinereus, D. pictus, and Bombinator. He claimed that in the Coecilia and Urodela there was a connection between these funnels and the malpighian bodies but that in B. cinereus he found a connection with the fourth section of the uriniferous tubule. Simultaneously but independently Meyer, using the silver nitrate method, counted 195 openings on the adult frog's kidney. Nuss-baum reported that in larval anura the connections were between the peritoneal tubes and the neck of the malpighian body while this connection was shifted, in the adult anura, to the renal veins. He showed this renal vein connection more conclusively in R. fusca, R. esculenta, B. calamita, and A. obstetricans. In the same year Hoffman stated that these tubules in the adult anura end blindly. Ecker claimed that the funnels were very difficult to find; that they did not connect any part of the uriniferous tubule with the body cavity; and that their superficial terminations had no cilia. Marshall and Bles described the embryonic formation of these funnels and tubes and showed that in R. temporatia they lose their early connections with the malpighian bodies and uriniferous tubules and finally empty into renal veins. Farrington injected carmine into the renal portal veins and found it emerging from the peritoneal funnels but he did not indicate why blood corpuscles were not likewise liberated into the body cavity of untreated frogs. He did state that in the Urodela these tubes opened into the uriniferous tubules but in both R. catesbiana and R. virescens they opened into branches of the renal portal veins.

The development of the posterior cardinal veins in relation to the swim bladder in Lepidosteus

AbstractThe origin and development of the posterior cardinals and associated veins in relation to the swim bladder, as well as their morphology, have been studied in Lepidosteus. The posterior cardinals develop, beginning in the 4‐mm. stage, as sinuses in the mesenchyme dorsal to the gut and near the mesonephori. A pneumatic vein appears first in the 13‐mm. stage. It collects from the posterior portion of the swim bladder and empties into the right posterior cardinal. In the younger stages the caudal vein empties directly into the posterior cardinals as is the case in the adult cyclostome, but by the 58‐mm. stage it has joined veins dorsal to the mesonephori forming a renal portal system. An anal vein appears in the region of the anus and joins the caudal. Later, with the development of the renal portal system, the anal separates from the caudal to become the single posterior extension of the posterior cardinals. The posterior portion of the right cardinal contributes largely to the development of an abdominal portal vein extending from the posterior root of the right posterior cardinal to the liver. These relationships of the posterior cardinals differ from those found in other fishes, due perhaps to the function of the right cardinal and its pneumatic branch in collecting blood from the swim bladder.

Evidence of Excretion of Iron Salts by Proximal Convolution of the Nephron of the Frog's Kidney

It is becoming increasingly evident that the glomerulus and tubule constitute functionally different sites for the elimination of the various urinary constituents. Several investigators have demonstrated that the proximal convolution of the vertebrate kidney is secretory in function. The studies of Holton and Bensley on the mammalian kidney when it is excreting dyes and iron salts under conditions of very low blood pressure indicate a secretory process in the elimination of these substances. Verne, however, studying the aglomerular fish kidney, shows that this type of kidney does not excrete iron salts in appreciable amounts. These studies suggested that the Nussbaum experiment, with modifications, might prove valuable in determining the possible function of the proximal convolution in the excretion of iron salts. Male frogs (Rana pipiens) were used in the experiments, the account of which follows. The animals were anesthetized by injecting from 1.0 to 1.4 cc. of a 10% solution of urethane into the submaxillary lymph sac. Operation to expose the kidney was made by using a thermocautery. Pelvic lymph hearts were removed in order to eliminate possible lymphatic circulation, the coeliacomesenteric artery ligated, and the intestine removed. The peritoneum extending from the right kidney to the right body wall was cut through and the lateral branches of the renal portal were cauterized, permitting deflection of the kidney and exposure of the dorsal aorta and the urogenital arteries. The latter were pulled out to the right with a small hook, doubly ligated, and severed, care being taken to treat in like manner all branches of the aorta between the juncture of the coeliaco-mesenteric artery and the bifurcation of the aorta to form the iliac arteries.

Experiments concerning the question of secretion of phenolsulphone-phthalein by the renal tubule

Among the most important methods of study which have been applied to the question of secretion by the renal tubule are those which involve the use of dyes. Heidenhain revived the Bowman theory of secretion, largely because of his observations relating to the elimination of indigo carmin—observations which form the beginning of a voluminous and confusing literature. The importance of complete information concerning the mode of excretion of certain dyes can scarcely be denied: they resemble most of the normal urinary con­stituents in that the concentration in which, after injection, they appear in the urine is higher than that in the blood. As has frequently been argued, if the mechanisms which take part in the excretion of these substances can be identi­fied, light will be thrown upon the processes of normal urine formation. The experimental advantage which derives from their colour is obvious. Phenolsulphonephthalein (phenol red) was introduced as a clinical test of renal function by Rowntree and Geraghty(1) in 1912. Among their experi­ments was one which convinced them that the tubule was actively concerned in its elimination. After section of the renal arteries in the frog, a phenol-red solution was perfused through the renal portal vessels at a pressure of 35 cm. water. The resulting appearance of the dye in the ureteral fluid convinced them that it had been “secreted” by the tubule. It was soon shown by Bainbridge, Collins and Menzies(2), however, that such high pressure in the renal portal vessels may drive fluid through the efferent vessels into the glome­ruli; thus their “proof” that the glomeruli had not been involved in the observed excretion was invalidated.