Role of hormones in glucose-6-phosphate dehydrogenase adaptation of rat liver

1962 ◽  
Vol 202 (3) ◽  
pp. 401-406 ◽  
Author(s):  
Helen M. Tepperman ◽  
Jay Tepperman
Keyword(s):  
Food Intake ◽  
Hormone Treatment ◽  
Additional Increase ◽  
Phosphogluconate Dehydrogenase ◽  
Hypophysectomized Rats ◽  
Ad Libitum ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Determining Factor ◽  
Rule Out

The hepatic enzymes glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase increase markedly in activity on refeeding after a 48-hr fast in the intact rat, but fail to do so in the hypophysectomized animal. Treatment with somatotrophin, cortisone, and thyroid hormone individually and in pairs failed to restore this adaptation to refeeding, but a combination of the three repaired the defect. Similar observations were made on increases in these enzymes in response to fructose feeding in ad libitum-fed hypophysectomized rats. Triple hormone-treated animals in which the enzyme increase in response to fructose feeding was restored were the only ones which gained weight. To rule out possible effects of variations in food intake as a determining factor in the response, hypophysectomized rats fed measured amounts of a starch-fructose diet by stomach tube were compared with suitable controls. A striking increase in enzyme activity occurred in these animals even when no hormone treatment was given, and no additional increase could be induced by treating with the three hormones. It is concluded that the liver cell of the hypophysectomized rat has an autonomous capacity to modify its enzyme profile selectively without the direction or support of hormones of pituitary origin. These hormones may exert their effects in ad libitum-fed animals by influencing food intake and intestinal hexose absorption rates.

scholarly journals Oxytocinergic cells of the posterior hypothalamic paraventricular nucleus participate in the food entrained clock

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mario Caba ◽  
Enrique Meza ◽  
Carolina Escobar ◽  
Angeles Jiménez ◽  
Mario Daniel Caba-Flores ◽  
...  
Keyword(s):  
Food Intake ◽  
Hypothalamic Nucleus ◽  
Restricted Feeding ◽  
Adult Rats ◽  
Peripheral Oscillators ◽  
Food Anticipatory Activity ◽  
Ad Libitum ◽  
Anticipatory Activity ◽  
Oxytocinergic Cells

AbstractThe mechanisms underlying food anticipatory activity are still poorly understood. Here we explored the role of oxytocin (OT) and the protein c-Fos in the supraoptic nucleus (SON), medial (PVNm) and posterior (PVNp) regions of the paraventricular hypothalamic nucleus. Adult rats were assigned to one of four groups: scheduled restricted feeding (RF), ad libitum (AL), fasting after restricted feeding (RF-F), to explore the possible persistence of oscillations, or ad libitum fasted (AL-F). In the SON and in the PVNm, OT cells were c-Fos positive after food intake; in contrast, OT cells in the PVNp showed c-Fos activation in anticipation to food access, which persisted in RF-F subjects. We conclude that OT and non-OT cells of the SON and PVNm may play a role as recipients of the entraining signal provided by food intake, whereas those of the PVNp which contain motor preautonomic cells that project to peripheral organs, may be involved in the hormonal and metabolic anticipatory changes in preparation for food presentation and thus, may be part of a link between central and peripheral oscillators. In addition, due to their persistent activation they may participate in the neuronal network for the clock mechanism that leads to food entrainment.

scholarly journals Oxytocinergic Cells of the Posterior Hypothalamic Paraventricular Nucleus Participate in the Food Entrained Clock

2021 ◽  
Author(s):  
Mario Caba ◽  
Enrique Meza ◽  
Carolina Escobar ◽  
Angeles Jiménez ◽  
Mario Daniel Caba-Flores ◽  
...  
Keyword(s):  
Food Intake ◽  
Hypothalamic Nucleus ◽  
Restricted Feeding ◽  
Adult Rats ◽  
Peripheral Oscillators ◽  
Food Anticipatory Activity ◽  
Ad Libitum ◽  
Anticipatory Activity ◽  
Oxytocinergic Cells

Abstract The mechanisms underlying food anticipatory activity is still not well understood. Here we explored the role of oxytocin (OT) and the protein c-Fos in the supraoptic nucleus (SON) and in the medial (PVNm) and posterior (PVNp) regions of the paraventricular hypothalamic nucleus. Adult rats were assigned to one of four groups: scheduled restricted feeding (RF), Ad libitum (AL), fasting after restricted feeding (RF-F), to explore the possible persistence of oscillations, or Ad libitum fasted (AL-F). In the SON and in the PVNm, OT cells were c-Fos positive after food intake; contrasting, OT cells in the PVNp showed c-Fos activation in anticipation to food access, which persisted in RF-F subjects. We conclude that OT cells of the SON and PVNm may play a role as recipients of the entraining signal provided by food intake, whereas those of the PVNp which contain motor preautonomic cells that project to peripheral organs, may be involved in the hormonal and metabolic anticipatory changes in preparation for food presentation and thus, may be part of a link between central and peripheral oscillators. In addition, due to their persistent activation they may participate in the neuronal network for the clock mechanism that leads to food entrainment.

Migratory fat deposition in European quail: a role for prolactin?

1995 ◽  
Vol 146 (1) ◽  
pp. 71-79 ◽  
Author(s):  
T Boswell ◽  
P J Sharp ◽  
M R Hall ◽  
A R Goldsmith
Keyword(s):  
Food Intake ◽  
Body Mass ◽  
Strong Association ◽  
Fat Deposition ◽  
Daily Rhythm ◽  
Plasma Prolactin ◽  
Coturnix Coturnix ◽  
Ad Libitum ◽  
Ovine Prolactin

Abstract The present study addresses the role of prolactin as a regulator of migratory fattening in European quail (Coturnix coturnix). Plasma prolactin levels in captive birds undergoing migratory fattening in an outdoor aviary and in the laboratory were measured by radioimmunoassay with an antibody raised against recombinant-derived chicken prolactin. No strong association between prolactin and migratory fattening was apparent, and prolactin levels were more closely related to daylength, with the highest concentrations being reached on long days. Plasma prolactin profiles were similar in intact and castrated male quail. Prolactin was secreted in a daily rhythm, with the highest concentrations occurring early in the photophase. However, when birds were food-restricted for 50 days during a migratory phase, there was no difference in fat deposition between birds food-deprived for the first half of the daily photophase compared with those deprived for the second half. Fattening was reduced in the food-restricted birds relative to ad libitum-fed controls, but there was no difference in plasma prolactin levels between the groups. Injections of ovine prolactin (4 mg/kg) significantly increased food intake and body mass of birds maintained on long days, but there were no differences in fattening between birds injected in the morning compared with those injected in the afternoon. Collectively, these results do not support a major role for prolactin in the regulation of migratory fat deposition in European quail. Journal of Endocrinology (1995) 146, 71–79

scholarly journals Activities of Catalase and Pentose Phosphate Pathway Dehydrogenases during Dormancy Release in Nectarine Seed

1990 ◽  
Vol 115 (6) ◽  
pp. 987-990 ◽  
Author(s):  
Hening Hu ◽  
Gary A. Couvillon
Keyword(s):  
Pentose Phosphate Pathway ◽  
Catalase Activity ◽  
Prunus Persica ◽  
Enzymic Activity ◽  
Pentose Phosphate ◽  
Significant Activity ◽  
Phosphogluconate Dehydrogenase ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Thiourea Treatment

The activities of catalase and of glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH), the two key enzymes in the pentose phosphate pathway (ppp), were measured in the seeds of Prunus persica (L.) Batsch var. nectarina Maxim `Nectarine 7'. The seeds were subjected to three imbibition treatments: 1) continuous 24C; 2) continuous 4C; and 3) application of thiourea (TU)/gibberellic acid (GA) at various concentrations to seed held at 24C then subsequently chilled at 4C. Treatments of continuous 24 or 4C indicated that catalase, G6PDH, and 6PGDH exhibited significant activity increases only when the seeds obtained germination potential, which occurred in the seeds chilled for 7 weeks at 4C. Seeds held at 24C did not germinate and showed little change with time in G6PDH and 6PGDH activity. There was only a slight increase in catalase activity beginning 3 weeks following treatment initiation and a decrease in activity following 13 weeks of treatment. Thiourea treatment resulted in an inhibition of catalase activity and a stimulation of G6PDH, but had no effect on 6PGDH activity. However, no correlation between enzymic activity and seed germination was found. The results strongly questioned the role of the ppp and catalase activity in dormancy control as previously hypothesized.

The possible role of some enzymes in sclerotia formation in Aspergillus ochraceus

1983 ◽  
Vol 29 (6) ◽  
pp. 718-723 ◽  
Author(s):  
Nachman Paster ◽  
Ilan Chet
Keyword(s):  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Pentose Phosphate ◽  
Aspergillus Ochraceus ◽  
Phosphogluconate Dehydrogenase ◽  
Cycle Plays ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
The Glyoxylate Cycle

The role of some enzymes in sclerotia production by Aspergillus ochraceus was studied using a sclerotia-producing strain grown under conditions in which sclerotia production was either favoured or inhibited. In addition, a mutant strain incapable of producing sclerotia was used. No significant differences in patterns of soluble proteins, polyphenol oxidase, and esterases could be detected electrophoretically by gel electrophoresis, while the peroxidase pattern of both the sclerotia-producing strain and the mutant showed three bands as compared with two bands that appeared when sclerotia formation was inhibited. The activities of the tricarboxylic acid cycle enzymes, malate dehydrogenase and succinate dehydrogenase, and those of the pentose-phosphate pathway, glucose-6 phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, were almost identical in sclerotia- and nonsclerotia-producing mycelia. The activities of isocitrate lyase and malate synthetase, key enzymes of the glyoxylate cycle, and that of glyoxylate dehydrogenase which is related to this cycle were significantly reduced when sclerotia formation was inhibited either by methionine or by high levels of CO2. It is suggested that the glyoxylate cycle plays an important role in sclerotia formation in the fungus.

scholarly journals Altered acylated ghrelin response to food intake in congenital generalized lipodystrophy

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244667
Author(s):  
Camilla O. D. Araújo ◽  
Renan M. Montenegro ◽  
Amanda P. Pedroso ◽  
Virgínia O. Fernandes ◽  
Ana Paula D. R. Montenegro ◽  
...  
Keyword(s):  
Food Intake ◽  
Analogue Scale ◽  
Caloric Intake ◽  
Acylated Ghrelin ◽  
Congenital Generalized Lipodystrophy ◽  
Meal Intake ◽  
Obese Subjects ◽  
Ad Libitum ◽  
Low Levels

Background Patients with congenital generalized lipodystrophy (CGL) have very low levels of leptin and are described as having a voracious appetite. However, a direct comparison between CGL and eutrophic individuals is lacking, regarding both appetite parameters and acylated ghrelin, the hormone form that is active in acute food intake stimulation. The objective of the present study was to address whether and in what extent the subjective appetite parameters and acylated ghrelin response to a meal are affected in CGL individuals, in comparison to eutrophic individuals. Additionally, an obese group was included in the study, to allow the comparison between a leptin-resistant and a leptin-deficient condition on these aspects. Methods Eutrophic controls (EUT, n = 10), obese subjects (OB, n = 10) and CGL (n = 11) were fasted overnight and then received an ad libitum meal. Blood was collected and the visual analogue scale was applied before and 90 minutes after the meal. An additional blood sample was collected at 60 minutes for ghrelin determination. Results The CGL patients showed low fasting levels of leptin and adiponectin, dyslipidemia, and insulin resistance. The caloric intake was similar among the 3 groups. However, both CGL (p = 0.02) and OB (p = 0.04) had shorter satiation times than EUT. The CGL patients also had lower satiety time (p = 0.01) and their sensation of hunger was less attenuated by the meal (p = 0.03). Fasting acylated ghrelin levels were lower in CGL than in EUT (p = 0.003). After the meal, the levels tended to decrease in EUT but not in CGL and OB individuals. Conclusion The data indicate that, although not hyperphagic, the CGL patients present appetite disturbances in relation to eutrophic individuals. Their low fasting levels of acylated ghrelin and the absence of the physiological drop after meal intake suggest a role of these disturbances in hunger attenuation and satiety but not in acute satiation.

scholarly journals Effect of opioid receptors agonists on feeding behaviour using different diets in ad libitum fed neonatal chicken

2017 ◽  
Vol 62 (No. 3) ◽  
pp. 98-109
Author(s):  
S. Arva ◽  
M. Zendehdel ◽  
Y. EbrahimNezhad ◽  
J. Ghiasi Ghalehkandi ◽  
S. Hassanpour ◽  
...  
Keyword(s):  
Food Intake ◽  
Opioid Receptor ◽  
Feeding Behaviour ◽  
Receptor Agonist ◽  
Energy Ratio ◽  
Standard Diet ◽  
Opioid Receptor Agonist ◽  
Group A ◽  
Ad Libitum

Despite progress in studying the role of opioids in reward, the effect of opioid receptors on feeding behaviour in ad libitum fed meat-type chicken offered different diet types is still unclear. So in this study, 12 experiments (each included 4 groups) were designed to determine the role of μ, δ, and κ receptors with different diets on feeding responses in ad libitum fed neonatal chicken. In Experiment 1, group A chicken were intracerebroventricularly (ICV) injected with saline, groups B–D chicken were ICV injected with DAMGO (µ-opioid receptor agonist; 125, 250, and 500 pmol), then standard diet without fat was offered. In Experiment 2, group A chicken were ICV injected with saline, groups B–D chicken were ICV injected with DAMGO (125, 250, and 500 pmol) and diet with nutrient energy ratio 20% below standard was provided to the birds. Experiments 3–4 were similar to Experiment 1, except after injection, diets containing nutrient energy ratio 20% above standard and standard diet with fat were provided to the birds, respectively. In Experiment 5, chicken were ICV injected with saline, DPDPE (δ-opioid receptor agonist) at doses of 20, 40, and 80 nmol, and then received standard diet without fat. Experiments 6–8 were similar to Experiment 5 in which diet containing nutrient energy ratio by 20% lower than standard, diet containing nutrient energy ratio by 20% higher than standard, and diet containing fat were provided instead of standard diet without fat to the birds, respectively. In Experiment 9, birds received ICV injection of saline and U-50488H (κ-opioid receptor agonist; 10, 20, and 40 nmol) and were provided standard diet without fat. Experiments 10–12 were similar to Experiment 9 but after ICV injection, birds were fed diet containing by 20% lower nutrient energy ratio, diet containing by 20% higher nutrient energy ratio, and standard diet containing fat, respectively. Then the cumulative food intake was measured until 180 min post injection. According to the results, DAMGO decreased while DPDPE and U-50488H increased the food intake (P < 0.05). These findings suggest endogenous governing food preferences via δ- and κ-opioid receptor in ad libitum fed neonatal chicken.

Interactions between growth hormone and nutrition in hypophysectomized rats: body composition and production of insulin-like growth factor-I

1993 ◽  
Vol 139 (1) ◽  
pp. 117-126 ◽  
Author(s):  
P. C. Bates ◽  
P. T. Loughna ◽  
J. M. Pell ◽  
D. Schulster ◽  
D. J. Millward
Keyword(s):  
Body Composition ◽  
Growth Factor ◽  
Food Intake ◽  
Food Consumption ◽  
Gastrocnemius Muscle ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Hypophysectomized Rats ◽  
Ad Libitum

ABSTRACT Hypophysectomy of adult rats results in a loss of body growth which can be reversed by treatment with GH. The increased growth caused by administration of GH is accompanied by an increase in food consumption. The effects of GH and interactions with nutrition were investigated by treating hypophysectomized rats with GH and either providing unrestricted food or preventing the increased food consumption by pair-feeding with the same intake as that of the hypophysectomized animals. Over the 7-day experimental period, the GH-treated animals grew significantly when food was available ad libitum but did not gain body weight when an increase in food intake was prevented. However, there was a significant interaction between GH and nutrition on body composition; GH significantly decreased body fat and increased the protein: fat ratio only in the animals with the restricted intake. Gastrocnemius muscle weight was increased by GH regardless of food intake, but heart weight did not increase and liver weight was actually decreased by GH teatment when food intake was restricted. Serum concentrations of insulin and insulin-like growth factor-I (IGF-I) were increased by GH in the rats with food available ad libitum but not in the pair-fed rats. However, the liver concentration of IGF-I and its mRNA were increased by GH although the increase in IGF-I mRNA was modulated by the restricted food intake. The decreased weight of the liver in the pair-fed GH-treated rats, despite the increase in IGF-I mRNA, suggests that IGF-I does not influence liver growth. In the gastrocnemius muscle, however, GH increased IGF-I mRNA concentration similarly in both rats with food available ad libitum and in pair-fed rats. Decreased nutrition therefore modulated the action of GH but emphasized its nutrient partitioning effect, thus increasing the anabolic drive towards skeletal muscle growth; this appeared to be mediated by the local production of IGF-I within the muscle. Journal of Endocrinology (1993) 139, 117–126

Expression of Glucose-6-phosphate Dehydrogenase and 6-Phosphogluconate Dehydrogenase Isoform Genes in Suspension-Cultured Arabidopsis thaliana Cells

2008 ◽  
Vol 63 (9-10) ◽  
pp. 713-720 ◽  
Author(s):  
Yuling Yin ◽  
Hiroshi Ashihar
Keyword(s):  
Arabidopsis Thaliana ◽  
Stationary Phase ◽  
Transcript Accumulation ◽  
Transcript Levels ◽  
Phosphogluconate Dehydrogenase ◽  
Pi Starvation ◽  
Murashige Skoog ◽  
Almost All ◽  
Glucose 6 Phosphate Dehydrogenase

The activities of glucose-6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (6PGDH, EC 1.1.1.44) were found to increase in suspensioncultured Arabidopsis thaliana cells after 10-day-old stationary phase cells were transferred to fresh Murashige-Skoog medium. The activities of these enzymes peaked early in the exponential growth stage of the culture (day 4) and then decreased gradually. The transcript levels of six isoform genes of G6PDH (AtG6PD1 to AtG6PD6) and three of 6PGDH (At6PGD1 to At6PGD3) were monitored during the culture. Two distinct transcript accumulation patterns were observed. In type A, the level of transcripts increased rapidly one day after the cells were inoculated into the fresh medium, and then remained almost constant until the culture reached its stationary phase (day 7). In type B, the transcripts were accumulated transiently at the first day after cell inoculation, then promptly decreased. We also investigated the effect of phosphate (Pi)-starvation and recovery on the expression of these genes. For this, the early stationary phase cultures (day 7) were transferred to fresh Pi-free culture medium. During 7 days of phosphate starvation, no growth of cultures was observed, and the transcript levels of all G6PDH and 6PGDH isoform genes were reduced, apart from one G6PDH isoform gene, AtG6PD5, which was continuously expressed throughout Pi-starvation. Compared to the reduction of almost all isoform genes of G6PDH in Pi-starved cultures, the reduction of 6PGDH genes was less severe. We discuss the localization and possible role of individual isoform genes of G6PDH and 6PGDH in connection with published databases.

Sign in / Sign up

Export Citation Format

Share Document