scholarly journals Effect of stirring during fixation upon immunofluorescence. Results with distribution of albumin-producing cells in liver.

1976 ◽  
Vol 24 (8) ◽  
pp. 926-932 ◽  
Author(s):  
M Horikawa ◽  
N Chisaka ◽  
S Yokoyama ◽  
T Onoé

When the immunofluroscent study on the distribution and the incidence of albumin-producing hepatocytes in the rat liver was performed by the method of Sainte-Marie, the number of positive cells showed various values (10-60%). It was surmised that when the permeability of the fixative was delayed, albumin had flowed out from the cytoplasm of the unfixed hepatocytes. By the simple means of constant stirring of the fixative using a magnetic stirrer, we accomplished rapid fixation and achieved results in which positive cells attained 100%. On the other hand, the incidence of positive cells decreased markedly when rats were fed a protein-free diet.

1977 ◽  
Vol 164 (3) ◽  
pp. 549-556 ◽  
Author(s):  
Brian Mandell ◽  
Philip Stahl

iPr2P-F (di-isopropyl phosphorofluoridate) administration to rats produces a liver-dependent specific elevation of plasma β-glucuronidase activity. The response is unaffected by puromycin pretreatment. By using subcellular-fractionation techniques, the rise in plasma β-glucuronidase activity was correlated temporally with a fall in liver microsomal β-glucuronidase activity. After iPr2P-F treatment, liver microsomal membranes are depleted of β-glucuronidase but slowly return to normal over 1 week. On the other hand, liver lysosomal β-glucuronidase activity is high at early time points (less than 60min) after iPr2P-F administration but decreases to below control values; this lasts for a few days. The response to iPr2P-F was demonstrated in isolated hepatocytes prepared from iPr2P-F-treated rats. In such preparations, microsomal β-glucuronidase is lost rapidly, followed by a specific decrease in hepatocyte lysosomal β-glucuronidase. The results suggest that a pool of microsomal β-glucuronidase serves as precursor to plasma β-glucuronidase in iPr2P-F-treated rats, and further, that microsomal β-glucuronidase may serve as precursor to lysosomal β-glucuronidase.


1970 ◽  
Vol 117 (3) ◽  
pp. 539-542 ◽  
Author(s):  
M. Akhtar ◽  
A. D. Rahimtula ◽  
D. C. Wilton

The synthesis of [7α-3H]lanosterol is described. It is shown that in the conversion of [7α-3H,26,27-14C2]lanosterol into cholesterol by a rat liver system, it is the 7β-hydrogen atom that is predominantly removed. On the other hand, the conversion of doubly labelled lanosterol into ergosterol by whole yeast cells results in the loss of the 7α-hydrogen atom. These results therefore suggest that the C-7 hydrogen atoms with opposite stereochemistry are labilized by the rat liver and the yeast Δ8–Δ7 steroid isomerases.


1987 ◽  
Vol 65 (11) ◽  
pp. 989-996 ◽  
Author(s):  
Gerda Endemann ◽  
Patrick G. Goetz ◽  
John F. Tomera ◽  
William M. Rand ◽  
Sylvain Desrochers ◽  
...  

The interactions between acetate or ethanol metabolism, lipogenesis, and ketone body utilization have been studied in isolated livers from fed rats perfused with 15 mM glucose and 10 mM acetate or ethanol. The contribution of acetate to ketogenesis is constant; on the other hand, the contribution of ethanol to ketogenesis increases with time, presumably because of the accumulation of acetate in the perfusate. Ketogenesis is decreased in the presence of ethanol (but not acetate), while ketone body utilization is not affected by ethanol or acetate. Acetate contributes one third and ethanol contributes one half of the carbon incorporated into fatty acids and 3-β-hydroxysterols. Only a small fraction (less than 5%) of the incorporation of acetate or ethanol into fatty acids and sterols occurs via transient incorporation into ketone bodies.


1967 ◽  
Vol 56 (3) ◽  
pp. 403-412 ◽  
Author(s):  
K. Dahm ◽  
Monika Lindlau ◽  
H. Breuer

ABSTRACT The biogenesis of oestriol 3-monoglucuronide has been studied using different enzyme preparations of human intestine and placenta as well as of rat liver. After incubation of oestriol with the microsomal fraction of human intestine, oestriol 3-monoglucuronide was found in addition to oestriol 16α-monoglucuronide and oestriol 17β-monoglucuronide. No oestriol 3-monoglucuronide was found when 16α-hydroxyoestrone 3-monoglucuronide, prepared biosynthetically, was incubated with a 24-fold purified human placental 17β-hydroxysteroid:NAD-oxidoreductase. On the other hand, no oestriol 3-monoglucuronide was formed when 17β-oestradiol 3-monoglucuronide was subjected to the action of the microsomal 16α-hydroxylase of rat liver. These results may be explained by steric hindrance of the enzyme system involved. On the basis of the present findings it can be concluded that oestriol 3-monoglucuronide arises exclusively by direct glucuronidation of oestriol, and not by enzymatic reduction of 16α-hydroxyoestrone 3-monoglucuronide or by 16α-hydroxylation of 17β-oestradiol 3-monoglucuronide.


1983 ◽  
Vol 38 (7-8) ◽  
pp. 631-634 ◽  
Author(s):  
Winfried Michels ◽  
Eckhard Schlimme

(2'-5')-oligoadenylates bearing a 5'-terminal triphosphate or a 5'GTP-group inhibit the activity of a dinucleoside triphosphatase in rat liver nuclei thereby protecting mRNA against 5'-exonucleolytic degradation. (2'-5')-oligoadenylates, on the other hand, were known to enhance the activity of an endoribonuclease, RNaseF. Thus a synergistic effect may be assumed in vivo, i.e. cellular metabolism seems to be protected twice in virus-infected cells.


1993 ◽  
Vol 136 (1) ◽  
pp. 59-64 ◽  
Author(s):  
A. Lanni ◽  
M. Moreno ◽  
M. Cioffi ◽  
F. Goglia

ABSTRACT In the present study we report that 3,3′,5-tri-iodothyronine (T3) as well as two iodothyronines (3,5-diiodothyronine (3,5-T2) and 3,3′-di-iodothyronine (3,3′-T2)) significantly influence rat liver mitochondrial activity. Liver oxidative capacity (measured as cytochrome oxidase activity/g wet tissue) in hypothyroid compared with normal rats was significantly reduced (21%, P > 0·01) and the administration of T3 and both iodothyronines restored normal values. At the mitochondrial level, treatment with T3 stimulated respiratory activity (state 4 and state 3) and did not influence cytochrome oxidase activity. On the other hand, both the mitochondrial respiratory rate and specific cytochrome oxidase activity significantly increased in hypothyroid animals after treatment with 3,3′-T2 or 3,5-T2 (about 50 and 40% respectively). The actions of both iodothyronines were rapid and evident by 1 h after the injection. The hepatic mitochondrial protein content which decreased in hypothyroid rats (9·6 mg/g liver compared with 14·1 in normal controls, P < 0·05) was restored by T3 injection, while neither T2 was able to restore it. Our results suggest that T3 and both iodothyronines have different mechanisms of action. T3 acts on both mitochondrial mass and activity; the action on mitochondrial activity was not exerted at the cytochrome oxidase complex level. The action of the iodothyronines, on the other hand, is exerted directly on the cytochrome oxidase complex without any noticeable action on the mitochondrial mass. Journal of Endocrinology (1993) 136, 59–64


2018 ◽  
Vol 24 (3) ◽  
pp. 168-179
Author(s):  
Reza Heidari ◽  
Mohammad Mehdi Ommati ◽  
Sanya Alahyari ◽  
Negar Azarpira ◽  
Hossein Niknahad

Background: The liver is vulnerable to the toxicity induced by xenobiotics. On the other hand, it has been found that several endogenously-found amino acids have hepatoprotective properties. The current study was designed to evaluate the effect of taurine, glycine, and histidine on the liver function in an ex vivo model of prolonged organ perfusion. Methods: Rat liver was isolated and perfused with a hemoglobin- and albumin-free Krebs‑Henseleit buffer (KBH). Liver injury biomarkers were monitored at scheduled time intervals. Results: The perfusate level of lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and the potassium ion (K+) were gradually increased in control (Only KBH) group. The histopathological evaluation also revealed significant necrosis, sinusoidal dilation, and pyknosis in control liver. Moreover, significant increase in lipid peroxidation and depletion of hepatic glutathione stores were detected in the control group. It was found that taurine (5, 10 and 20 mM) and glycine (5, 10 and 20 mM)-containing KBH buffer significantly decreased the perfusate level of liver injury biomarkers. Furthermore, lower liver tissue pathological changes, decreased lipid peroxidation, and higher glutathione content was detected in amino acid-treated groups. Histidine administration showed no significant protective effect on liver injury in the current study. On the other hand, combination amino acid administration (glycine and taurine) showed a better hepatoprotective profile. Conclusion: The data obtained from the current study might help to provide safe hepatoprotective agents against xenobiotics-induced hepatotoxicity or preserve liver functionality outside the body.


1969 ◽  
Vol 47 (2) ◽  
pp. 226-229 ◽  
Author(s):  
Maurice Brossard ◽  
Louis Nicole

The effects of growth hormone and hydrocortisone on the synthesis of rat liver RNA have been studied. Administration of growth hormone stimulated the incorporation of 14C-orotic acid into 45 S preribosomal nucleolar RNA, and had no effect on the 6–50 S polydisperse nuclear RNA of extra-nucleolar origin. On the other hand, hydrocortisone stimulated the synthesis of all types of nuclear RNA, but mainly that of the 18 S class of 6–50 S polydisperse nuclear RNA.


1978 ◽  
Vol 54 (4) ◽  
pp. 355-360
Author(s):  
Berenice Reed ◽  
D. Weir ◽  
J. Scott

1. It has previously been shown that folate polyglutamates in the rat are catabolized almost exclusively via cleavage of the C-9—N-10 bond, resulting in the formation of pteridines and p-aminobenzoylglutamate. The latter catabolite is rapidly excreted, appearing in the urine as acetamidobenzoylglutamate and is undetectable in rat liver. 2. The pteridines catabolites on the other hand are retained to a much greater extent by the liver, forming an ever-increasing proportion of the retained radioactive tracer. 3. A possible role for these pteridines as cofactors in brain metabolism is discussed.


1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.


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