Short-term stimulation of net glycogen production by insulin in rat hepatocytes

1981 ◽  
Vol 675 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Fritz Nyfeler ◽  
Paul Fasel ◽  
Paul Walter
1987 ◽  
Vol 247 (1) ◽  
pp. 233-235 ◽  
Author(s):  
S K Moule ◽  
J D McGivan

Epidermal growth factor causes a transient stimulation of alanine transport in hepatocytes. The stimulation is maximal after 30 min, and the rate returns to the control value after 90 min. These characteristics are very similar to the short-term stimulation of alanine transport by glucagon, which has been attributed to cell membrane hyperpolarization.


1985 ◽  
Vol 128 (2) ◽  
pp. 525-530 ◽  
Author(s):  
G.V. Gnoni ◽  
M.J.H. Geelen ◽  
C. Bijleveld ◽  
E. Quagliariello ◽  
S.G. van den Bergh

Endocrinology ◽  
2005 ◽  
Vol 146 (9) ◽  
pp. 3959-3966 ◽  
Author(s):  
Anna M. Giudetti ◽  
Monica Leo ◽  
Math J. H. Geelen ◽  
Gabriele V. Gnoni

Abstract Short-term effects of 3,5-l-diiodothyronine (T2) on lipid biosynthesis were studied in cultured hepatocytes from hypothyroid rats. A comparison with the effects of T3 was routinely carried out. After T2 addition to cell cultures, a distinct stimulation of fatty acid and cholesterol syntheses, measured as incorporation of [1-14C]acetate into these lipid fractions, was observed. The T2 dose-dependent effect on both metabolic pathways, already detectable at 10−8-10−9m, reached a 2-fold stimulation at 10−5m T2. At this concentration, the stimulatory effect was evident within 1 h of T2 addition to the hepatocytes and increased with time up to the length of the experimental period of 4 h. T2 stimulation of lipogenesis was also confirmed by incubating hepatocytes with [3H]H2O, used as an independent index of lipogenic activity. The effects of T2 are rather specific as 3,3′,5,5′-tetraiodo-d-thyronine and 3,5-diiodo-l-tyrosine were practically ineffective on both fatty acid and cholesterol synthesis. Analysis of various lipid fractions showed that T2 addition to the cells produced a significant stimulation of the incorporation of newly synthesized fatty acids into both neutral and polar lipids. By comparing the effects induced by T2 with those seen in the presence of T3, it appeared that T2 was able to mimic T3 effects. Experiments conducted in the presence of cycloheximide, a protein synthesis inhibitor, indicated that the T2 stimulatory effect on fatty acid and cholesterol synthesis was essentially independent of protein synthesis.


1988 ◽  
Vol 256 (1) ◽  
pp. 197-204 ◽  
Author(s):  
D Tosh ◽  
G M M Alberti ◽  
L Agius

Hepatocytes isolated from the periportal or perivenous zones of livers of fed rats were used to study the long-term (14 h) and short-term (2 h) effects of glucagon on gluconeogenesis and ketogenesis. Long-term culture with glucagon (100 nM) resulted in a greater increase (P less than 0.01) in gluconeogenesis in periportal than in perivenous cells (93 +/- 16 versus 30 +/- 14 nmol/h per mg of protein; 72% versus 30% increase), but short-term incubation (2 h) with glucagon resulted in similar stimulation in the two cell populations. Rates of ketogenesis (acetoacetate and D-3-hydroxybutyrate production) were not significantly higher in periportal cells cultured without glucagon, compared with perivenous cells. However, after long-term culture with glucagon, the periportal cells had a significantly higher rate of ketogenesis (from either palmitate or octanoate as substrate), but a lower 3-hydroxybutyrate/acetoacetate production ratio, suggesting a more oxidized mitochondrial NADH/NAD+ redox state despite the higher rate of beta-oxidation. Periportal hepatocytes had a higher activity of carnitine palmitoyltransferase but a lower activity of citrate synthase than did perivenous cells. These findings suggest that: (i) glucagon elicits greater long-term stimulation of gluconeogenesis in periportal than in perivenous hepatocytes maintained in culture; (ii) after culture with glucagon, the rates of ketogenesis and the mitochondrial redox state differ in periportal and perivenous hepatocytes.


2020 ◽  
pp. 121-134
Author(s):  
S. A. Andryushin

In 2019, a textbook “Macroeconomics” was published in London, on the pages of which the authors presented a new monetary doctrine — Modern Monetary Theory, MMT, — an unorthodox concept based on the postulates of Post-Keynesianism, New Institutionalism, and the theory of Marxism. The attitude to this scientific concept in the scientific community is ambiguous. A smaller part of scientists actively support this doctrine, which is directly related to state monetary and fiscal stimulation of full employment, public debt servicing and economic growth. Others, the majority of economists, on the contrary, strongly criticize MMT, arguing that the new theory hides simple left-wing populism, designed for a temporary and short-term effect. This article considers the origins and the main provisions of MMT, its discussions with the mainstream, criticism of the basic tenets of MMT, and also assesses possible prospects for the development of MMT in the medium term.


1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.


2021 ◽  
pp. 1-10
Author(s):  
Michihiro Osumi ◽  
Daisuke Shimizu ◽  
Yuki Nishi ◽  
Shu Morioka

Background: Patients with brachial plexus avulsion (BPA) usually experience phantom sensations and phantom limb pain (PLP) in the deafferented limb. It has been suggested that evoking the sensation of touch in the deafferented limb by stimulating referred sensation areas (RSAs) on the cheek or shoulder might alleviate PLP. However, feasible rehabilitation techniques using this approach have not been reported. Objective: The present study sought to examine the analgesic effects of simple electrical stimulation of RSAs in BPA patients with PLP. Methods: Study 1: Electrical stimulation of RSAs for 60 minutes was conducted for six BPA patients suffering from PLP to examine short-term analgesic effects. Study 2: A single case design experiment was conducted with two BPA patients to investigate whether electrical stimulation of RSAs was more effective for alleviating PLP than control electrical stimulation (electrical stimulation of sites on side opposite to the RSAs), and to elucidate the long-term effects of electrical stimulation of RSAs. Results: Study 1: Electrical stimulation of RSAs evoked phantom touch sensations in the deafferented limb, and significantly alleviated PLP (p <  0.05). Study 2: PLP was alleviated more after electrical stimulation on RSAs compared with control electrical stimulation (p <  0.05). However, the analgesic effects of electrical stimulation on RSAs were observed only in the short term, not in the long term (p >  0.05). Conclusions: Electrical stimulation of RSAs not only evoked phantom touch sensation but also alleviated PLP in the short term. The results indicate that electrical stimulation of RSAs may provide a useful practical rehabilitation technique for PLP. Future studies will be required to clarify the mechanisms underlying immediate PLP alleviation via electrical stimulation of RSAs.


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