Hepatic arterial perfusion regulates portal venous flow between hepatic sinusoids and intrahepatic shunts in the normal rat liver in vitro

2001 ◽  
Vol 443 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Barry Alexander ◽  
Howard Cottam ◽  
Richard Naftalin
Keyword(s):  
Rat Liver ◽  
Portal Venous Flow ◽  
Venous Flow ◽  
Arterial Perfusion ◽  
Normal Rat ◽  
Intrahepatic Shunts

THE ROLE OF THE ADRENAL GLAND IN THE CONTROL OF AMINO ACID INCORPORATION INTO PROTEIN OF ISOLATED RAT LIVER MICROSOMES

1960 ◽  
Vol 21 (2) ◽  
pp. 177-189 ◽  
Author(s):  
A. KORNER
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Female Rats ◽  
Male Rats ◽  
Rat Liver Microsomes ◽  
Hypophysectomized Rats ◽  
Normal Rat ◽  
Secondary Result

SUMMARY 1. Microsomes, isolated from rat liver a day after adrenalectomy, incorporate more radioactive amino acid into their protein in vitro than microsomes from normal rat liver. This enhanced rate of incorporation progressively declines with time after adrenalectomy until it reaches a plateau level which is below the normal rate of incorporation. 2. Following adrenalectomy microsomes isolated from liver of male rats show a greater rise in incorporating ability than those from liver of female rats, and maintain it longer. 3. Most of the increased incorporation observed in the in vitro system soon after adrenalectomy of the rat, and most of the decreased incorporation observed in rats adrenalectomized for some time, results from alterations in the microsomes which change their ability to incorporate activated amino acids into proteins. 4. Treatment of rats with cortisol acetate results in an increase in the ability of liver microsomes to incorporate amino acid into protein. This heightened incorporating ability is probably a secondary result of the breakdown of extrahepatic tissue protein which is stimulated by cortisol. 5. Somewhat similar responses to acute adrenalectomy and to treatment with cortisol were found in hypophysectomized rats. 6. The protein anabolic response of adrenalectomized rats to treatment with insulin, and of adrenalectomized-hypophysectomized rats to treatment with insulin or growth hormone, is greater than that shown by rats which possess adrenal glands.

Changes induced by cadmium administration on thyroxine deiodination and sulfhydryl groups in rat liver

1993 ◽  
Vol 138 (2) ◽  
pp. 219-224 ◽  
Author(s):  
B. Paier ◽  
K. Hagmüller ◽  
M. I. Noli ◽  
M. Gonzalez Pondal ◽  
C. Stiegler ◽  
...  
Keyword(s):  
Body Weight ◽  
Rat Liver ◽  
Colorimetric Method ◽  
Amyl Alcohol ◽  
Sulfhydryl Groups ◽  
Serum Hormone ◽  
Protein Sulfhydryl ◽  
Normal Rat ◽  
Protein Sulfhydryl Groups

ABSTRACT The effects of cadmium on 5′-deiodination of thyroxine (T4) by rat liver and on the hepatic concentration of non-protein sulfhydryl groups (NPSH) were studied in Wistar rats of 200–250 g body weight. A group of ten rats was injected with cadmium chloride (300 μg/100 g body weight i.p.) daily for 4 days. Another group of six rats received, in addition, dithiothreitol (DTT; 1 mg/100 g body weight i.p.) daily for the same period. A group of eight normal untreated rats served as control. T4 deiodination was also determined in aliquots of liver from untreated rats, with cadmium (2 or 5 mmol/l) and with or without DTT (0, 2·5, 5 or 10 mmol/l) plus 1 μCi 125I-labelled T4. Hepatic NPSH were measured by a colorimetric method employing dithioldinitrobenzoic acid. Homogenates were incubated for 90 min at 37 °C and chromatographed in a tertiary amyl alcohol: hexane: ammonia (2 mol/l) (10: 1: 12) system. Cadmium-injected rats showed a significant (P <0·01) decrease in T4 deiodination and in the generation of 125I (P <0·01) and tri-iodothyronine (T3) (P <0·02). NPSH were also decreased (P <0·02). Administration of DTT restored T4 deiodination and NPSH to normal. In-vitro addition of cadmium or DTT to normal rat liver homogenates induced similar effects on the degradation of T4. Serum concentrations of T4 (P <0·01) and T3 (P <0·01) declined significantly in cadmium-injected rats, whereas DTT administration failed to normalize serum hormone levels. The data suggest that cadmium may have decreased 5′-deiodinating activity through binding to sulfhydryl groups of 5′-deiodinase as it does in other enzymes. The effects on serum T4 concentrations may be unrelated to those on 5′-deiodinase. Journal of Endocrinology (1993) 138, 219–224

scholarly journals Degradation of Stearoyl-Coenzyme A Desaturase: Endoproteolytic Cleavage by an Integral Membrane Protease

1998 ◽  
Vol 9 (12) ◽  
pp. 3445-3453 ◽  
Author(s):  
F. Scott Heinemann ◽  
Juris Ozols
Keyword(s):  
Rat Liver ◽  
Coenzyme A ◽  
Liver Microsomes ◽  
Integral Membrane Protein ◽  
Rat Liver Microsomes ◽  
Selective Degradation ◽  
Endoproteolytic Cleavage ◽  
Microsomal Membranes ◽  
Normal Rat

Stearoyl-coenzyme A desaturase (SCD) is a key regulator of membrane fluidity, turns over rapidly, and represents a prototype for selective degradation of resident proteins of the endoplasmic reticulum. Using detergent-solubilized, desaturase-induced rat liver microsomes we have characterized a protease that degrades SCD. Degradation of SCD in vitro is highly selective, has a half-life of 3–4 h, and generates a 20-kDa C-terminal fragment of SCD. The N terminus of the 20-kDa fragment was identified as Phe177. The cleavage site occurs in a conserved 12-residue hydrophobic segment of SCD flanked by clusters of basic residues. The SCD protease remains associated with microsomal membranes after peripheral and lumenal proteins have been selectively removed. SCD protease is present in normal rat liver microsomes and cleaves purified SCD. We conclude that rapid turnover of SCD involves a constitutive microsomal protease with properties of an integral membrane protein.

scholarly journals In vitro investigation of the impact of pulsatile blood flow on the vascular architecture of decellularized porcine kidneys

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Peter R. Corridon
Keyword(s):  
Blood Flow ◽  
Blood Perfusion ◽  
Pulsatile Blood Flow ◽  
Venous Outflow ◽  
Venous Flow ◽  
Vascular Architecture ◽  
Arterial Perfusion ◽  
In Vitro Investigation ◽  
The Impact

AbstractA method was established using a scaffold-bioreactor system to examine the impact pulsatile blood flow has on the decellularized porcine kidney vascular architecture and functionality. These scaffolds were subjected to continuous arterial perfusion of whole blood at normal physiological (650 ml/min and 500 ml/min) and pathophysiological (200 ml/min) rates to examine dynamic changes in venous outflow and micro-/macrovascular structure and patency. Scaffolds subjected to normal arterial perfusion rates observed drops in venous outflow over 24 h. These reductions rose from roughly 40% after 12 h to 60% after 24 h. There were no apparent signs of clotting at the renal artery, renal vein, and ureter. In comparison, venous flow rates decreased by 80% to 100% across the 24 h in acellular scaffolds hypoperfused at a rate of 200 ml/min. These kidneys also appeared intact on the surface after perfusion. However, they presented several arterial, venous, and ureteral clots. Fluoroscopic angiography confirmed substantial alterations to normal arterial branching patterns and patency, as well as parenchymal damage. Scanning electron microscopy revealed that pulsatile blood perfusion significantly disrupted glomerular microarchitecture. This study provides new insight into circumstances that limit scaffold viability and a simplified model to analyze conditions needed to prepare more durable scaffolds for long-term transplantation.

scholarly journals Fibrin Modulates Shear-Induced NETosis in Sterile Occlusive Thrombi Formed under Haemodynamic Flow

2019 ◽  
Vol 119 (04) ◽  
pp. 586-593 ◽  
Author(s):  
Xinren Yu ◽  
Scott Diamond
Keyword(s):  
Venous Pressure ◽  
Aminocaproic Acid ◽  
Tissue Type ◽  
Net Generation ◽  
Neutrophil Accumulation ◽  
Venous Flow ◽  
Pressure Drops ◽  
Arterial Perfusion ◽  
Sytox Green

AbstractNeutrophils can release extracellular traps (NETs) in infectious, inflammatory and thrombotic diseases. NETs have been detected in deep vein thrombosis, atherothrombosis, stroke, disseminated intravascular coagulation and trauma. We have previously shown that haemodynamic forces trigger rapid NETosis within sterile occlusive thrombi in vitro. Here, we tested the effects of thrombin, fibrin and fibrinolysis on shear-induced NETosis by imaging NETs with Sytox Green during microfluidic perfusion of factor XIIa-inhibited or thrombin-inhibited human whole blood over fibrillar collagen (±tissue factor). For perfusions under venous pressure drops (19 mm Hg/mm-clot), thrombin generation did not alter the near-zero level of NET generation. In contrast, production of thrombin/fibrin led to a twofold reduction in neutrophil accumulation and a sixfold reduction in NET generation after 30 minutes of arterial perfusion (163 mm Hg/mm-clot). Exogenously added tissue type plasminogen activator (tPA) drove robust fibrinolysis; however, tPA did not trigger NETosis under venous flow. In contrast, tPA did enhance NET generation in clots subjected to arterial pressure drops. After 45 minutes of arterial perfusion, clots treated with 30 nM tPA had a threefold increase in total NET production and a twofold increase in normalized NET generation (measured as deoxyribonucleic acid:neutrophil) compared with fibrin-rich clots. Blocking fibrin polymerization resulted in similar level of NET release seen in tPA-treated clots, whereas ε-aminocaproic acid abolished the NET-enhancing effect of tPA. Therefore, fibrin suppresses NET generation and the absence of fibrin promotes NETs. We demonstrated that shear-induced NETosis was strongly inversely correlated with fibrin in sterile occlusive clots.

Agents affecting lipid metabolism. XXXVI. Effect of N-cyclohexyl linoleamide on hepatic cholesterogenesis in vitro

1968 ◽  
Vol 46 (11) ◽  
pp. 1430-1432 ◽  
Author(s):  
D. Dvornik
Keyword(s):  
Lipid Metabolism ◽  
Rat Liver ◽  
Final Concentration ◽  
Normal Rat ◽  
Liver Homogenates ◽  
Hepatic Cholesterogenesis

N-Cyclohexyl linoleamide, reported to be antihypercholesterolemic in rabbits, was examined for its effect on hepatic cholesterogenesis in vitro. At a final concentration of 1 × 10−3 M the compound had no effect on the incorporation into cholesterol of 3H-acetate and 2-14C-mevalonate incubated simultaneously with normal rat liver homogenates.

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