A simple method of obtaining multiple blood samples from the portal vein and the hepatic vein in the rat in vivo

A very simple and rapid technique for inserting a catheter in the portal vein and the hepatic vein in the anesthesized rat in vivo is described. The pointed, saline-containing PE tubing is frozen in liquid nitrogen, whereupon it is used as a 'needle' to insert the catheter into the blood vessel. Multiple blood samples can be obtained from the portal and the hepatic vein at the same time, so that in situ extraction of drugs by the liver can be measured in vivo, since hepatic blood flow is uninterrupted.     

Effet de quelques anesthésiques sur le flux sanguin de la muqueuse gastrique,chez le Rat

Summary Effects of ether, nembutal or urethane anaesthesia on gastric secretion and mucosal blood flow (MBF) are studied in the Rat; these 3 anaesthetics alter neither volume nor total acidity of juice, but free acidity and proteolytic activity are more importance after ether anaesthesia; MBF is highest in nembutal anaesthetized rats; therefore nembutal is the best anaesthetic for studies of digestive physiology or pharmacology.     

Eine Methode zur fortlaufenden Blutentnahme aus der Vena portae von Hunden

Summary A method is described for the introduction of a PVC.-Catheter into the portal vein of dogs. The catheter is introduced into one of the mesenteric veins of the ileum and pushed through the vena mesenterica communis until the portal vein is reached. The catheter, the end of which is fixed to the skin on the outside, can be removed without any injury to the animal by just drawing it out through the skin. The method can be applied for taking blood at various intervals during experiments on absorption, measurement of blood pressure in the portal vein and its branches, for the injection of substances directly into the liver, etc., on unanaesthetized animals.     

Smooth muscle in the hepatic artery, portal vein and hepatic vein within the liver of the raccoon and guinea pig

The amount and arrangement of smooth muscle in the intrahepatic vessels suggests that the guinea pig would be a good animal model for studying mechanisms controlling intrahepatic portal vein blood flow, while the raccoon would be good for studying hepatic vein mechanisms of control.     

Smooth muscle in the hepatic artery,portal vein and hepatic vein within the liver of the raccoon and guinea pig

Summary The amount and arrangement of smooth muscle in the intrahepatic vessels suggests that the guinea pig would be a good animal model for studying mechanisms controlling intrahepatic portal vein blood flow, while the raccoon would be good for studying hepatic vein mechanisms of control.     

Polyvinylchloride (PVC) particles implantation in mouse liver. A technique for experimental study of schistosome eggs-induced liver pathology.

An injection of suspended PVC particles in the caecal vein of mice induces a foreign-body portal granuloma reaction in the liver. Plastic casts of the portal system, after PVC particles implantation, show modifications in the portal bed and are compared with plastic casts obtained in mice infested by Schistosoma mansoni. This technique can be useful to study the cellular dynamics of the portal granuloma and can be a model for schistosomal eggs induced liver pathology.     

Polyvinylchloride (PVC) particles implantation in mouse liver. A technique for experimental study of schistosome eggs-induced liver pathology

Summary An injection of suspended PVC particles in the caecal vein of mice induces a foreign-body portal granuloma reaction in the liver. Plastic casts of the portal system, after PVC particles implantation, show modifications in the portal bed and are compared with plastic casts obtained in mice infested bySchistosoma mansoni. This technique can be useful to study the cellular dynamics of the portal granuloma and can be a model for schistosomal eggs induced liver pathology.This work was supported by an ATP (INSERM) 18.75.41 and a scholarship from the Société d'Hépatologie Expérimentale.     

Dämpfung des Kältezitterns durch Pentobarbital und Pethidin bei Ratten

Summary In rats, shivering was induced by cooling. Shivering started at 36.6°C in unanaesthetized rats and at 36.0°C in animals with light pentobarbital anaesthesia (5 mg/kg i.V.). Pethidine (2 mg/kg) lowered the onset of shivering in unanaesthetized rats to 35.3 °C and in anaesthetized animals to 33.0°C. The results suggest that the effect of pethidine upon shivering is potentiated by pentobarbital.     

Modifications of ovarian follicle reactivity to LH in rats treated with FSH at the beginning of the estrous cycle]

LH perfusion was performed on proestrus under pentobarbital anaesthesia in 4-days cyclic female Rats treated or not treated with FSH at the onset of estrous cycle. The number of follicles capable of undergoing luteinization was shown to be dependent upon the amount of LH available.     

A simple method of cannulating the portal vein and obtaining multiple blood samples in the rat

Summary A simple and rapid technique for cannulating the portal vein in the rat is described. Multiple blood samples can be obtained or alternatively substrate may be infused through the cannula.Supported by the Clayton Foundation for Research, Houston, Texas. Common resource support was also provided by the Research Service of the Veterans Administration. To whom reprint requests should be addressed as follows.     

An analysis of the effects of urethane on cardiovascular responsiveness to catecholamines in terms of its interference with Ca++ mobilization from both intra and extracellular pools

Urethane (1 X 10(-2) - 1 X 10(-1) M) reduced, in a concentration-dependent manner, both intra and extracellular Ca++ dependent noradrenaline-induced contractions of perfused rabbit ear artery as well as the tonic contractions produced by perfusion with high K+ solution. However, a quantitative analysis of the data indicated that for urethane concentrations similar to those found in plasma during anesthesia urethane antagonism is confined to noradrenaline-induced contractions which depend upon the mobilization of Ca++ from intracellular storage sites. In KCl-contracted arteries, urethane enhanced the relaxant effects of isoprenaline. - Urethane reduced the amplitude of contractions of spontaneously beating guinea-pig right atrium at concentrations which have only a limited effect on frequency. In addition, it decreased in a concentration-dependent manner the amplitude of isoprenaline-activated electrically driven, and K+ depolarized guinea-pig right ventricular strips. Urethane had no effect on the chrono and inotropic actions of isoprenaline on cardiac preparations. In in vivo experiments the chronotropic response to low doses of isoprenaline was significantly higher in urethane-treated as compared to unanesthetized rats. The higher dose of isoprenaline tested produced a significant fall in systolic blood pressure in urethane-anesthetized rats. A significant correlation exists between the chronotropic response to isoprenaline and resting heart rate values in urethane-anesthetized rats. These results indicate that urethane, at concentrations similar to those found in plasma during anesthesia selectively interferes with mobilization of Ca++ from intracellular storage sites. In addition, the interference of urethane anesthesia with the isoprenaline chronotropic effect 'in vivo' cannot be explained by a direct interference of urethane with beta-adrenoceptors at cardiac level.     

Glycogenolytic effect of vasoactive intestinal peptide in the rat in vivo

Summary The effects of VIP (300 pmol/kg), injected via the portal vein, on the glycogen content of the liver and on glycemia, were studied in the rat in vivo. VIP enhanced glycogenolysis and caused hyperglycemia in a time-dependent manner.     

Sinuslichtreizung der rezeptiven Felder einzelner Retinaneurone

Summary The action potentials of optic nerve fibres in cats were stereotactically recorded (light pentobarbital anaesthesia, Curarin-immobilization). The activation of retinal neurons stimulated by light spots within the receptive field centre was a non-linear function of the sinusoidal intensity modulation of the stimuli.     

Cardiovascular-compensatory and decompensatory responses in rats anesthetized with pentobarbital compared to chloralose-urethane

The data presented in these studies suggests that rats anesthetized with pentobarbital are better able to compensate for acute blood loss, but are less able to sustain the compensatory effort during hemorrhagic hypotension than rats anesthetized with chloralose-urethane. However, following reinfusion of shed blood the pentobarbital rats are better able to maintain their blood pressure.     

The implantation of sepharose beads in mouse livers as an aid in the study of hepatic schistosomal fibrosis

Summary An experimental model of schistosomal portal fibrosis is described. Sepharose beads the size of schistosome eggs, loaded or not with soluble egg antigen (SEA) fromSchistosoma mansoni, are injected into the coecal vein of C3H/Sn mice and become embolized in the liver. Only SEA-coated beads evoke a granulomatous reaction; this is enhanced by simultaneous priming of the mice with spleen cells fromSchistosoma mansoni-infected syngeneic animals. The fibrosis, which ensues around the beads, is stable and is much more evident after priming. Preliminary collagen tissue immunotyping reveals the presence of collagen deposits of types I and III collagen. Type IV collagen remains unchanged in the portal tracts. The model appears to be well suited for studies of the pathogenesis of portal fibrosis.This work was supported by a contract from INSERM (Action Spéciale No 3).     

Reversal of human ophthalmic vein blood flow : selective cooling of the brain]

Direction of blood flow in angularis oculi veins was recorded in humans. In mild hypothermia, blood flow was weak and directed from brain to face. In hyperthermia, however, blood flowed rapidly in the opposite direction, angularis oculi vein collecting cool facial blood and supplying cavernous sinus. Therefore selective cooling of human brain is possible.     

Effects of exchange transfusion with perfluorochemical emulsions on hepatic oxygen supply and blood flow in the rat

Summary Exchange-transfusion to hematocrit 20 with isotonic perfluorochemical (PFC) emulsions containing 3% hydroxyethylstarch (HES) in rats breathing 100% oxygen produced significant reductions of hepatic PO₂ and blood flow in comparison to rats hemodiluted with isotonic 3% or 6% HES solution. The results indicate that PFC and/or emulsifiers were associated with adverse effects on liver blood supply.This work was supported by a grant from the Kentucky Affiliate of the American Heart Association.     

Effects of exchange transfusion with perfluorochemical emulsions on hepatic oxygen supply and blood flow in the rat

Exchange-transfusion to hematocrit 20 with isotonic perfluorochemical (PFC) emulsions containing 3% hydroxyethylstarch (HES) in rats breathing 100% oxygen produced significant reductions of hepatic PO2 and blood flow in comparison to rats hemodiluted with isotonic 3% or 6% HES solution. The results indicate that PFC and/or emulsifiers were associated with adverse effects on liver blood supply.     

Membrane potential in smooth muscle cells from hypertrophic rat portal vein

Cellular and Molecular Life Sciences - Portal hypertension was induced in rats by partial ligation of the hepatic branches of the portal vein. After 5 days the vein was removed and mounted in...     

An analysis of the effects of urethane on cardiovascular responsiveness to catecholamines in terms of its interference with Ca++ mobilization from both intra and extracellular pools

Summary Urethane (1×10^–2–1×10^–1 M) reduced, in a concentration-dependent manner, both intra and extracellular Ca⁺⁺ dependent noradrenaline-induced contractions of perfused rabbit ear artery as well as the tonic contractions produced by perfusion with high K⁺ solution. However, a quantitative analysis of the data indicated that for urethane concentrations similar to those found in plasma during anesthesia urethane antagonism is confined to noradrenaline-induced contractions which depend upon the mobilization of Ca⁺⁺ from intracellular storage sites. In KCl-contracted arteries, urethane enhanced the relaxant effects of isoprenaline.—Urethane reduced the amplitude of contractions of spontaneously beating guinea-pig right atrium at concentrations which have only a limited effect on frequency. In addition, it decreased in a concentration-dependent manner the amplitude of isoprenaline-activated electrically driven, and K⁺ depolarized guinea-pig right ventricular strips. Urethane had no effect on the chrono and inotropic actions of isoprenaline on cardiac preparations. In in vivo experiments the chronotropic response to low doses of isoprenaline was significantly higher in urethane-treated as compared to unanesthetized rats. The higher dose of isoprenaline tested produced a significant fall in systolic blood pressure in urethane-anesthetized rats. A significant correlation exists between the chronotropic response to isoprenaline and resting heart rate values in urethane-anesthetized rats. These results indicate that urethane, at concentrations similar to those found in plasma during anesthesia selectively interferes with mobilization of Ca⁺⁺ from intracellular storage sites. In addition, the interference of urethane anesthesia with the isoprenaline chronotropic effect in vivo cannot be explained by a direct interference of urethane with -adrenoceptors at cardiac level.