EFFECTS OF PROGESTERONE, OESTRADIOL AND/OR CLOMIPHENE ON LIVER GLYCOGEN AND BLOOD GLUCOSE IN INTACT AND ADRENALECTOMISED RATS DURING DELAYED IMPLANTATION

1974 ◽  
Vol 76 (4) ◽  
pp. 678-688
Author(s):  
M. S. Sankaran ◽  
M. R. N. Prasad

ABSTRACT Prolonged administration of progesterone alone caused significant changes in liver glycogen. Oestradiol-17β increased the liver glycogen 18 hours after the treatment. A single administration of clomiphene citrate on day 9 post-coitum (pc) inhibited the oestradiol or progesterone induced increase in hepatic glycogen. Bilateral adrenalectomy on day 3 pc abolished the changes in liver glycogen induced by progesterone, oestradiol and/or clomiphene. Administration of progesterone, oestradiol or clomiphene caused a decrease in blood glucose levels in rats during delayed implantation. Although the effects of progesterone and oestradiol on blood glucose levels were abolished by adrenalectomy, clomiphene induced changes persisted in the adrenalectomised rats. It is concluded that progesterone, oestradiol and/or clomiphene induced changes in liver glycogen are mediated through the adrenal glands. Changes in the blood glucose levels are discussed in relation to increased insulin level in the blood and also in relation to the increased glucocorticoid secretion following various treatments.

2017 ◽  
Vol 37 (14) ◽  
Author(s):  
Hyunbae Kim ◽  
Ze Zheng ◽  
Paul D. Walker ◽  
Gregory Kapatos ◽  
Kezhong Zhang

ABSTRACT Cyclic AMP-responsive element binding protein, hepatocyte specific (CREBH), is a liver-enriched, endoplasmic reticulum-tethered transcription factor known to regulate the hepatic acute-phase response and lipid homeostasis. In this study, we demonstrate that CREBH functions as a circadian transcriptional regulator that plays major roles in maintaining glucose homeostasis. The proteolytic cleavage and posttranslational acetylation modification of CREBH are regulated by the circadian clock. Functionally, CREBH is required in order to maintain circadian homeostasis of hepatic glycogen storage and blood glucose levels. CREBH regulates the rhythmic expression of the genes encoding the rate-limiting enzymes for glycogenolysis and gluconeogenesis, including liver glycogen phosphorylase (PYGL), phosphoenolpyruvate carboxykinase 1 (PCK1), and the glucose-6-phosphatase catalytic subunit (G6PC). CREBH interacts with peroxisome proliferator-activated receptor α (PPARα) to synergize its transcriptional activities in hepatic gluconeogenesis. The acetylation of CREBH at lysine residue 294 controls CREBH-PPARα interaction and synergy in regulating hepatic glucose metabolism in mice. CREBH deficiency leads to reduced blood glucose levels but increases hepatic glycogen levels during the daytime or upon fasting. In summary, our studies revealed that CREBH functions as a key metabolic regulator that controls glucose homeostasis across the circadian cycle or under metabolic stress.


1969 ◽  
Vol 45 (3) ◽  
pp. 367-374 ◽  
Author(s):  
D. J. S. HUNTER

SUMMARY Maternal blood glucose, foetal blood glucose and liver carbohydrate levels were estimated after foetuses were injected with glucagon through the uterine wall on days 19½, 20½ and 21½ of gestation in the rat. Glucagon had a hyperglycaemic effect in the foetus on all the days studied but the response was greater and more rapid on day 21½ of gestation. Glucagon was shown to decrease liver glycogen on day 20½ and 21½ but again the response was more rapid and more pronounced on day 21½. The normal levels of foetal liver glycogen were similar to those previously found but the normal foetal blood glucose values are lower than previous results. Decrease in liver glycogen observed in the control group of foetuses on day 21½ of gestation together with a loss in foeto-maternal blood glucose relationship on that day of gestation suggest that on day 21½ the foetal rat develops the ability to mobilize hepatic glycogen and thereby to alter its blood glucose level independently from the mother. The significance of the low blood glucose levels found in the foetus is discussed.


Author(s):  
J. E. Michaels ◽  
J. T. Hung ◽  
R. R. Cardell

In normal animals glycogen levels in the liver are closely related to blood sugar levels. High levels of glucose in the blood stimulate uptake of glucose by liver hepatocytes and synthesis of glycogen whereas low blood glucose levels result in breakdown of glycogen and release of glucose into the blood. After adrenalectomy and overnight fasting, liver glycogen levels in the rat are reduced to about 0.03%. The adrenalectomized rat is easily stimulated to form new glycogen by injection of a glucocorticoid hormone such as dexamethasone (DEX).


1964 ◽  
Vol 207 (2) ◽  
pp. 411-414 ◽  
Author(s):  
Jiro Oyama ◽  
William T. Platt

Unrestrained mice were centrifuged for varying periods ranging from 0.5 to 10 hr at 2.5, 5, and 10 x gravity. Liver glycogen and blood glucose levels increased significantly depending on the g load and exposure time. Adrenalectomy completely abolished the glycogen deposition response. The glycogen response was a critical function of the age of mice; unweaned mice did not respond. Blood corticosterone increased significantly prior to the deposition of glycogen. Centrifuged fed mice deposited three times the amount of glycogen of fasted mice. There was no significant difference in the amount of glycogen deposited in centrifuged mice previously starved for 1, 2, or 3 days. It is concluded that the increased glycogen deposited following centrifugation is effected by an increased elaboration of adrenal corticosterone.


2017 ◽  
Vol 36 (4) ◽  
pp. 433
Author(s):  
Nurhidajah Nurhidajah ◽  
Nurrahman Nurrahman

The process of germination of grains such as rice, could increase some nutritional values of  amino acids and dietary fiber. Red rice and its sprouts are believed to be able to decrease blood glucose in patients with diabetes mellitus (DM). The aim of this study was to evaluate the hypoglycemic effect of red rice sprouts in STZ-NA induced diabetic rats on blood glucose level, insulin level, and HOMA-IR and HOMA-β index. This experimental study was conducted based on randomized post test only control group design using 24 male Wistar rats aged 2.5 months. Rats were divided into 4 groups, one group without induction of STZ-NA fed with a standard diet (control) and three groups of STZ- NA induced with a standard diet, red rice and red rice germ. Experiments were conducted for 6 weeks. The results showed that sprouted red rice lowered blood glucose levels by 61.88 % and the value of HOMA-IR (insulin resistance parameters) by 56.82%. Insulin level increased by 16.35 % and HOMA-β by 763.6 %. This study showed that red rice germ was able to decrease blood glucose levels and increase insulin resistance of DM rats and the strength of the pancreatic beta cells. ABSTRAKProses perkecambahan biji-bijian seperti beras, dapat meningkatkan beberapa nilai gizi seperti asam amino dan serat pangan. Beras merah dan kecambahnya diyakini mampu menurunkan glukosa darah pada penderita diabetes melitus (DM). Tujuan penelitian ini adalah mengevaluasi efek hipoglikemik kecambah beras merah pada tikus diabetes yang diinduksi STZ-NA terhadap kadar glukosa darah, insulin, serta indeks HOMA-IR dan HOMA β. Penelitian ini bersifat eksperimental in vivo pada hewan coba tikus Wistar jantan usia 2,5 bulan sebanyak 24 ekor dengan desain penelitian randomized post test only control group. Tikus dibagi menjadi 4 kelompok, masing-masing 1 kelompok tanpa induksi STZ-NA dengan diet standar dan 3 kelompok diinduksi STZ-NA dengan diet standar, beras merah dan kecambah beras merah. Percobaan dilakukan selama 6 minggu. Hasil penelitian menunjukkan kecambah beras merah mampu menurunkan kadar glukosa darah sebesar 61,88 % dan nilai HOMA-IR (parameter resistensi insulin) 56,82 %. Kadar insulin meningkat 16,35 % dan HOMA β 763,6 %. Disimpulkan, kecambah beras merah mampu menurunkan kadar glukosa darah dan memperbaiki kondisi resistensi insulin tikus DM, dan kekuatan sel beta pankreas.


PEDIATRICS ◽  
1963 ◽  
Vol 32 (6) ◽  
pp. 1002-1006
Author(s):  
Donnell D. Etzwiler

Glucagon or a placebo preparation was administered to 65 juvenile diabetics on 74 separate occasions. When the initial blood glucose of these children showed them to be in reasonably good control, glucagon produced a hyperglycemic effect. However, when the blood glucose levels were markedly elevated, the effect of glucagon was less predictable. The depletion of liver glycogen stores and the possible effect of contaminating insulin in glucagon preparations are discussed.


1982 ◽  
Vol 243 (1) ◽  
pp. R179-R184 ◽  
Author(s):  
W. W. Winder ◽  
M. A. Beattie ◽  
R. T. Holman

Endurance exercise training produces major adaptations in hormonal and metabolic responses to exercise. This study was designed to determine whether the differences in hormone response persist in the fasted condition when liver glycogen is depleted. Rats were run on a motor-driven rodent treadmill 5 days/wk for periods up to 2 h/day for 10 wk. Trained and nontrained rats were then fasted 24 h and were run for periods ranging from 0- to 60 min. At the end of 60 min of exercise muscle glycogen was higher in trained rats (2.9 +/- 0.3 vs. 1.1 +/- 0.1 mg/g). Blood glucose was maintained at higher levels in trained rats throughout the course of the exercise (3.2 +/- 0.1 vs. 2.3 +/- 0.1 mM after 60 min). Plasma concentrations of glucagon and epinephrine increased in both groups during the exercise but were significantly lower in trained animals. Differences between trained and nontrained animals in stress hormone responses to exercise persist in the fasted state and appear to be a consequence of the capacity of trained animals to maintain higher blood glucose levels.


1982 ◽  
Vol 243 (3) ◽  
pp. R450-R453
Author(s):  
W. Langhans ◽  
N. Geary ◽  
E. Scharrer

The effects of feeding on liver glycogen content and blood glucose in the hepatic and hepatic portal veins were investigated in rats. Liver glycogen content decreased about 25% during meals both in rats refed after 12 h food deprivation (23 +/- 1 to 17 +/- 1 mg glycogen/g liver) and in ad libitum-fed rats taking fully spontaneous meals (44 +/- 2 to 32 +/- 2 mg/g). Liver glycogen began to increase within 30 min after meals in ad libitum-fed rats. Hepatic vein blood glucose levels at meal onset (118 +/- 4 mg/dl in the food-deprived rats, 127 +/- 4 in ad libitum-fed rats) and at meal end (155 +/- 3 and 166 +/- 5 mg/dl, respectively) were similar in the two groups. Portal vein blood glucose increased during meals in the previously food-deprived rats (83 +/- 4 to 116 +/- 6 mg/dl) but not in the ad libitum-fed rats (127 +/- 5 to 132 +/- 3 mg/dl). Mechanisms that may elicit prandial glycogenolysis and the possible role of this effect in the production of meal ending satiety are discussed.


1986 ◽  
Vol 251 (1) ◽  
pp. R137-R142 ◽  
Author(s):  
H. B. John-Alder ◽  
R. M. McAllister ◽  
R. L. Terjung

The functional significance of gluconeogenesis in prolonging endurance during submaximal activity was assessed in untrained and endurance-trained rats. Gluconeogenesis was inhibited at the phosphoenolpyruvate carboxykinase reaction by 3-mercaptopicolinic acid (3-MPA). Endurance was significantly reduced by 3-MPA in untrained (-32%; P less than 0.005) and in trained rats (-26%; P less than 0.001). Metabolic correlates of fatigue were examined in trained rats. At exhaustion, 3-MPA-treated rats had only 3% of resting hepatic glycogen, 46% of resting white quadriceps glycogen, and 37% of resting blood glucose. All of these substrates were at higher levels in sham-injected controls after the same duration of running (130 min). Glycogen levels in red quadriceps, blood lactate levels, and blood glycerol levels were not different between groups. Plasma free fatty acid levels were elevated to the same extent in both groups after 90 min of activity, remained high at 130 min in controls, but had returned to resting levels in the severely hypoglycemic 3-MPA-treated rats at exhaustion. The results indicate that gluconeogenesis is important for maintaining blood glucose levels and for prolonging endurance time during submaximal activity.


1988 ◽  
Vol 60 (3) ◽  
pp. 499-507 ◽  
Author(s):  
Susan Southon ◽  
Z. Kechrid ◽  
A. J. A. Wright ◽  
Susan J. Fairweather-Tait

1. Male, 4–5-week-old, genetically diabetic mice (C57BL/KsJ db/db) and non-diabetic heterozygote litter-mates (C57BL/KsJ db/+)were fed on a diet containing 1 mg zinc/kg (low-Zn groups) or 54 mg Zn/kg (control groups) for 27 d. Food intakes and body-weight gain were recorded regularly. On day 28, after an overnight fast, animals were killed and blood glucose and insulin concentrations, liver glycogen, and femur and pancreatic Zn concentrations were determined.2. The consumption of the low-Zn diet had only a minimal effect on the Zn status of the mice as indicated by growth rate, food intake and femur and pancreatic Zn concentrations. In fact, diabetic mice fed on the low-Zn diet had a higher total food intake than those fed on the control diet. The low-Zn diabetic mice had higher fasting blood glucose and liver glycogen levels than their control counterparts. Fasting blood insulin concentration was unaffected by dietary regimen.3. A second experiment was performed in which the rate of loss of 65Zn, injected subcutaneously, was measured by whole-body counting in the two mouse genotypes over a 28 d period, from 4 to 5 weeks of age. The influence of feeding low-Zn or control diets was also examined. At the end of the study femur and pancreatic Zn and non-fasting blood glucose levels were determined.4. All mice fed on the low-Zn diet showed a marked reduction in whole-body 65Zn loss compared with those animals fed on the control diet. In the low-Zn groups, the loss of 65Zn from the diabetic mice was significantly greater than that from heterozygote mice. This difference was not observed in the control groups. Blood glucose levels were elevated in the low-Zn groups. Possible reasons for these observations are discussed.5. The present study demonstrates an adverse effect of reduced dietary Zn intake on glucose utilization in the genetically diabetic mouse, which occurred before any significant tissue Zn depletion became apparent.


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