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.     

The effect of urethane and pentobarbital anaesthesia and hepatic portal vein catheterization on liver blood flow in the rat

Summary The effect of urethane and pentobarbital anaesthesia and hepatic portal vein catheterization on liver blood flow was investigated in the rat. Liver blood flow with pentobarbital anaesthesia was 40% greater than with urethane. Hepatic portal vein catheterization had no effect under pentobarbital anaesthesia whereas it produced an 18% fall in liver blood flow with urethane.Acknowledgments. This work was supported by grants from ICI Pharmaceuticals and Mersey Regional Health Authority (Research Scheme No. 338). We wish to thank Mr P.J. Roberts for much skilled assistance and Evans Medical Ltd for the kind gift of drugs.     

ATPase activity of guinea pig heart muscle

Riassunto L'Autore ha studiato l'influenza della concentrazione degli ioni Ca⁺⁺ e Mg⁺⁺ sull'ATPasi degli atri e dei ventricoli di cuore di cavia. Tale attività è maggiore a pH 9,2 che a pH 6,8. Mentre il Ca⁺⁺ influisce differenziando decisamente le attività degli atri da quelle dei ventricoli, il Mg⁺⁺ accentua piuttosto una differenza tra la parte destra e la sinistra. Il calore distrugge quasi completamente l'attività enzimatica dopo una permanenza a 60° per 20 min.     

Adenosine triphosphate concentration in guinea pig muscle after denervation

Riassunto L'enervazione produce una notevole diminuzione dell'ATP nei muscoli gastrocnemi di cavia. In cavie trattate con tossina tetanica ed enervate immediatamente prima in uno dei due arti posteriori, l'ATP diminuisce più nell'arto enervato che in quello opposto, in preda a contrazione tetanica. I rapporti P/O del muscolo enervato diminuiscono rapidamente ed un notevole grado di disaccoppiamento delle ossidazioni dalle fosforilazioni è già in atto 12 h dopo l'enervazione.L'ATPasi dei sarcosomi dell'arto enervato aumenta notevolmente già dopo le prime ore, poi diminuisce. L'ATPasi delle miofibrille tende invece a diminuire progressivamente. Si conclude che un basso contenuto di ATP nel muscolo non basta da solo a spiegare lo stato di contrattura dei muscoli tetanizzati.     

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.     

Effect of taurine administration on liver lipids in guinea pig

The oral administration of 0.4% taurine in drinking water for 14 consecutive days showed the following hepatic effects in male guinea pig. The percentage of tauro-conjugated biliary bile acids was increased from 17.2-54.2%; the ratio liver weight/body weight was increased, and fatty change was induced. Liver triglyceride concentration was accordingly increased; diglyceride and phosphatidylcholine concentrations were reduced by the treatment, while phosphatidylethanolamine level was not affected. These changes suggest an adverse effect of taurine administration on phosphatidylcholine hepatic synthesis.     

Effect of taurine administration on liver lipids in guinea pig

Summary The oral administration of 0.4% taurine in drinking water for 14 consecutive days showed the following hepatic effects in male guinea pig. The percentage of tauro-conjugated biliary bile acids was increased from 17.2–54.2%; the ratio liver weight/body weight was increased, and fatty change was induced. Liver triglyceride concentration was accordingly increased; diglyceride and phosphatidylcholine concentrations were reduced by the treatment, while phosphatidylethanolamine level was not affected. These changes suggest an adverse effect of taurine administration on phosphatidylcholine hepatic synthesis.     

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...     

Glutaminase I activity in guinea pig and rabbit liver and kidney tissues

Zusammenfassung Aktive Glutaminase I wurde in Meerschweinchen- und Kaninchenleber, in Nierengewebsextrakten und in Mitochondrienpräparaten der erwähnten Organe bei pH 7,2 nachgewiesen.dl-Glutaminsäure bewirkte eine ausgesprochene Hemmung des Enzyms nach Zusatz von Phosphat. In hypertonischer Sukrosenährlösung lässt sich eine Aktivierung durch Phosphatzusatz gewöhnlich nicht nachweisen, selbst nicht beim pH-Optimum 7,2, es sei denn bei sehr hohen Phosphatkonzentrationen.     

Granuloma formation in rat liver after hepatic vein ligation

Summary After occlusion of the hepatic vein draining 1 lobe of the rat liver, macrophage granulomas develop which are reproducible and apparently related to a heat-labile macrophage mobilising factor.     

Cholinergic nerves in the rat portal vein

Summary The innervation of the rat portal vein was studied using the cholinesterase histochemical method 2 plexuses of cholinergic nerve fibers were found; an external plexus localized at the level of the outer adventitial layers and an inner plexus at the level of the adventitial-medial transitional zone and in the outer layers of the media.Acknowledgments. We thank Dr C. Cavallotti for his kind help and criticism. The kind help of Dr W. Collier and of the staff of the laboratory of Neurobiology as well as the bibliographic assistance of Istituto Superiore di Sanità (Serv. Documentazione, Dr Magliola) are gratefully acknowledged.     

Calyculin a increases voltage-dependent inward current in,smooth muscle cells isolated from guinea pig taenia coli

The effects of a potent phosphatase inhibitor, calyculin A (CL-A), on inward currents in guinea pig taenia coli smooth muscle cells were examined. CL-A increased the inward current, and this effect of CL-A was inhibited by a protein kinase C inhibitor, H-7, and by nifedipine. Phorbol 12,13-dibutyrate, an activator of protein kinase C, also increased the inward current and this effect was antagonized by H-7. These results suggest that in guinea pig taenia coli smooth muscle cells CL-A may facilitate the opening of thel-type Ca²⁺ channels through the protein kinase C-dependent phosphorylation system.