Cortisol-induced changes in plasma glucose, protein, and thyroid hormone levels, and liver glycogen content of coho salmon (Oncorhynchus kisutch Walbaum)

1989 ◽  
Vol 67 (11) ◽  
pp. 2746-2750 ◽  
Author(s):  
M. M. Vijayan ◽  
J. F. Leatherland

Coho salmon given intraperitoneal implants of hydrogenated coconut oil alone or coconut oil containing cortisol at 1, 5, or 10 mg/fish exhibited dose-related increases in plasma cortisol levels at day 15. After 30 days, plasma cortisol levels were significantly higher in the cortisol-implanted groups but there was no dose-related response. Plasma T3 levels were lowered in cortisol-treated fish, but plasma T4 levels were not consistently affected. Plasma glucose levels were significantly higher in the group treated with cortisol at 10 mg/fish than in the controls on both sampling days, whereas liver glycogen content and hepatosomatic index were significantly lower in the cortisol-treated groups at day 30 but not at day 15. Plasma protein levels were not significantly different between treatments at either sampling time. The splenosomatic indices were not significantly different in the three treatment groups at day 15, but at day 30 the values in the 5 and 10 mg/fish cortisol-treated groups were significantly higher than in the controls.

Author(s):  
Shana O Warner ◽  
Abby M Wadian ◽  
Marta S. Smith ◽  
Ben Farmer ◽  
Yufei Dai ◽  
...  

Iatrogenic hypoglycemia is a prominent barrier to achieving optimal glycemic control in patients with diabetes, in part due to dampened counterregulatory hormone responses. It has been demonstrated that elevated liver glycogen content can enhance these hormonal responses through signaling to the brain via afferent nerves, but the role that hypoglycemia in the brain plays in this liver glycogen effect remains unclear. During the first 4hrs of each study, the liver glycogen content of dogs was increased by using an intraportal infusion of fructose to stimulate hepatic glucose uptake (HG; n=13), or glycogen was maintained near fasting levels with a saline infusion (NG; n=6). After a 2hr control period, during which the fructose/saline infusion was discontinued, insulin was infused intravenously for an additional 2hrs to bring about systemic hypoglycemia in all animals, whereas brain euglycemia was maintained in a subset of the HG group by infusing glucose bilaterally into the carotid and vertebral arteries (HG-HeadEu; n=7). Liver glycogen content was markedly elevated in the two HG groups (43±4, 73±3 and 75±7 mg/g in NG, HG and HG-HeadEu, respectively). During the hypoglycemic period, arterial plasma glucose levels were indistinguishable between groups (53±2, 52±1 and 51±1 mg/dL, respectively), but jugular vein glucose levels were kept euglycemic (88±5 mg/dL) only in the HG-HeadEu group. Glucagon and epinephrine responses to hypoglycemia were higher in HG compared to NG, whereas despite the increase in liver glycogen, neither increased above basal in HG-HeadEu. These data demonstrate that the enhanced counterregulatory hormone secretion that accompanies increased liver glycogen content requires hypoglycemia in the brain.


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.


1960 ◽  
Vol 199 (6) ◽  
pp. 1051-1055 ◽  
Author(s):  
Florent Depocas ◽  
Roberto Masironi

Various parameters of glucose metabolism were measured with C14-glucose in unanesthetized warm- and cold-acclimated rats at 30° and 6°C. Exposure of warm-acclimated rats to cold was associated with a decrease in turnover time of plasma glucose, no change in glucose pool size and space, an increase in rates of turnover and oxidation of body glucose, an increase in the ratio of the oxidation rate to the turnover rate, no change in percentage of respiratory CO2 derived from glucose oxidation, and a decrease in liver glycogen content. Approximately reversed changes were observed in cold-acclimated rats transferred from a cold to a warm environment except in the values of turnover time of plasma glucose and terminal liver glycogen content which underwent smaller changes. It is concluded that cold-induced thermogenesis in white rats, whether acclimated to warm or cold environments, is associated with an increase in carbohydrate catabolism proportionate to the increase in energy metabolism.


1975 ◽  
Vol 32 (6) ◽  
pp. 753-760 ◽  
Author(s):  
D. J. McLeay ◽  
D. A. Brown

In the static study (no exercise), liver glycogen stores were unchanged during 12-h exposure to 0.8 of the 96-h LC50; longer exposures caused a progressive decrease to levels one fifth those of controls at 72 h. Plasma glucose levels in fish held in 0.8 LC50 effluent for 3–96 h were elevated; at 96 h, glucose had increased threefold. Mean values for plasma lactate were elevated significantly at 3, 6, 24, 72, and 96 h.In the exercise (swimming one body length per second)–rest study, muscle glycogen levels decreased 53–78% during exercise in water or effluent (0.7 LC50) for 4–12 h, and did not recover during 12-h rest in water. Muscle glycogen for fish exercised for 12 h in effluent and then rested for 4 or 12 h in effluent was lower compared to values for fish exercised in effluent and then rested in water. There was no difference in liver glycogen levels offish exercised in effluent or water for 4–12 h. Values of liver glycogen for fish exercised in effluent for 12 h and then rested for 4, 8, or 12 h in effluent decreased 60–70% compared to fish exercised in water for 12 h and then rested in water and by 55–65% from fish exercised in effluent for 12 h and rested in water for 4–12 h. Plasma glucose levels were elevated one- to fourfold during exercise in water or effluent. Fish resting in water for 4, 8, or 12 h following exercise in water had relatively stable glucose levels; whereas for fish exercised and then rested in effluent the glucose levels increased twofold during resting. Plasma lactate levels were elevated five- to sixfold during exercise in water or effluent for 4–12 h, declining to values 1–2 times those of stock fish within 4-h rest. Plasma lactate levels for fish exercised in effluent and then rested in effluent or water were continually higher than those for fish exercised and rested in water.It was concluded that measurement of carbohydrate metabolites, particularly blood sugar levels, in unexercised fish could prove useful as a rapid method for measuring toxicity of pulpmill effluents and other pollutants.


Planta Medica ◽  
2019 ◽  
Vol 85 (06) ◽  
pp. 465-472 ◽  
Author(s):  
Ivica Jeremic ◽  
Sasa Petricevic ◽  
Vanja Tadic ◽  
Dragana Petrovic ◽  
Jelena Tosic ◽  
...  

AbstractMenopause is characterized by deep metabolic disturbances, including decreased insulin sensitivity, adiposity, and changes in lipid profiles. Estrogen replacement therapy can partially reverse these changes, and while it is safe in most healthy postmenopausal women, there are still existing concerns regarding an increased risk for breast and endometrial cancer as well as a risk for cardiovascular and thromboembolic disease. Therefore, certain natural compounds with positive metabolic effects may be considered as a possible alternative or adjunctive treatment in patients not willing to take estrogens or patients with contraindications for estrogens. The aim of this study was to investigate the influence of Sideritis scardica (mountain tea) extract on metabolic disturbances induced by ovariectomy in rats. The study included 24 rats divided into three groups: ovariectomized rats treated with 200 mg/kg S. scardica extract for 24 weeks (n = 8), ovariectomized non-treated (n = 8), and Sham-operated (n = 8) rats. Food intake, weight gain, body composition, fasting glucose levels, response to oral glucose challenge, liver glycogen content, catalase activity, thiol groups, and malondialdehyde concentrations as well as AMP-activated protein kinase activity in liver cells were studied. Ovariectomized rats treated with S. scardica extract had lower blood triglycerides, reduced fasting glucose levels, as well lower glucose peaks after oral glucose challenge, increased liver glycogen content, and significantly higher catalase activity and thiol group concentration than non-treated ovariectomized rats. The ability of S. scardica extract to attenuate metabolic disturbances associated with ovariectomy was associated with the activation of AMP-activated protein kinase in liver cells.


2008 ◽  
Vol 20 (1) ◽  
pp. 96 ◽  
Author(s):  
M. P. Green ◽  
M. C. Berg ◽  
R. S. F. Lee

Somatic cell nuclear transfer (NT) is associated with an increased incidence of abnormal placental and fetal development. Postnatal survival of NT offspring to weaning and even into adult life is lower when compared to contemporary offspring produced by artificial insemination (AI). Neonatal NT calves are hypoglycemic and lethargic initially but show increased frequency of feeding later on. These and other symptoms suggest that NT animals have impaired homeostatic mechanisms. Despite this, NTs that survive beyond weaning appear normal, but underlying health problems can become apparent when NTs are subjected to physiological stressors. The health and physiology of predominantly (75%) Jersey NT bull calves (n = 9), derived from a fetal myogenic cell line, and control Jersey AI bull calves (n = 5) were investigated. At 6 months of age, animals were subjected to a series of physiological intravenous hormonal challenges to test the responses of individual organs. Pancreatic insulin secretion response was assessed via a glucose tolerance test (GTT) and direct adrenal resistance via ACTH administration. The response of the hypothalamic-pituitary-adrenal (HPA) axis was assessed via a glucagon challenge. Except for glucagon, the doses given were adjusted for body weight at the time of challenge and all animals were fasted overnight. Plasma glucose, insulin, glucagon, and cortisol concentrations were measured using commercial assays. All animals were euthanized at approximately 7 months of age and a full postmortem (PM) was undertaken. Calf and organ weights were recorded. Liver glycogen content was also determined. Parameters and challenge data were analyzed by one-way or as repeated measures ANOVA. NT and AI calves appeared healthy at the time of the physiological challenges, and at PM, no major gross or histological organ abnormalities were recorded. There were no differences in the relative mean liver and adrenal weights between NT and AI. Basal plasma glucose concentrations were similar between NT and AI controls but the post-fasting decrease in glucose concentration was greater (P < 0.05) in controls than in NTs. There was no difference in response between the groups to the GTT. The NTs showed a slower response to ACTH than did AI controls. Glucose and insulin secretion were significantly higher (P < 0.05) whereas initial cortisol release was significantly lower (P < 0.05) after glucagon administration. Plasma glucagon levels and liver glycogen content did not differ between NT and controls. The current study indicates that surviving NT calves appear healthy, but when physiologically challenged, demonstrate reduced adrenal sensitivity and altered HPA axis response. These response deviations are indicative of underlying physiological differences and could explain the increased susceptibility of NT animals to physiological stressors. Ultimately, the cloning procedures may affect the long-term health of cloned offspring.


2018 ◽  
Vol 108 (0) ◽  
Author(s):  
Leandro Fabrício Fiori ◽  
Bruno R. S. Figueiredo ◽  
Audrei Pavanello ◽  
Vander Silva Alves ◽  
Paulo Cezar de Freitas Mathias ◽  
...  

ABSTRACT Considering that the anti-predation behaviour of prey fishes may vary with predator hunting strategy, we experimentally investigated the physiological responses of Astyanax bimaculatus (Linnaeus, 1758) shoals to the presence of two piscivorous fish species with different hunting modes: sit-and-wait and active pursuit. In addition, we evaluated the influence of underwater visibility conditions on the interaction between predator and prey. We tested the hypotheses that: (i) prey plasma cortisol and glucose levels vary according to piscivore hunting strategy, and (ii) no reduction in plasma glucose and cortisol levels takes place in turbid environments due to the inability of prey to accurately recognise predators by non-visual signals. The results revealed that the presence of piscivorous fish increased plasma cortisol levels in prey, with no significant difference recorded between the two hunting strategy treatments. We also observed no significant change in plasma glucose levels in different water transparency conditions. Thus, we conclude that physiological changes in the selected prey fish do not vary with predator hunting mode, and it is therefore necessary to consider the ability of the prey to recognise and evaluate danger, regardless of piscivore hunting strategy.


1997 ◽  
Vol 273 (2) ◽  
pp. E262-E267 ◽  
Author(s):  
S. Metzger ◽  
N. Goldschmidt ◽  
V. Barash ◽  
T. Peretz ◽  
O. Drize ◽  
...  

Mice bearing interleukin-6 (IL-6)-secreting tumor were used to study the chronic effect of IL-6 on carbohydrate metabolism. Mice were injected with allogeneic tumor cells transduced with the murine IL-6 gene. Serum IL-6 levels were correlated exponentially with tumor weight. Secretion of IL-6 from the developed tumors was associated with decreased food consumption, reduced body weight, and reduced blood glucose levels. Insulin levels did not change, and 2-deoxyglucose uptake was not affected in most tissues examined. A significant increase of 2-deoxyglucose uptake was measured in the liver. Glycogen content in the liver determined 0, 6, 12, and 18 days after tumor inoculation was 42, 23, 12, and 3 mg/g, respectively. The activity of phosphoenolpyruvate carboxykinase was not affected. The activity of glucose-6-phosphatase (G-6-Phase) determined 6, 12, and 18 days after tumor injection was 84, 70, and 50% of G-6-Pase activity in pair-fed mice bearing nonsecreting tumors, respectively. G-6-Pase mRNA levels were markedly reduced due to inhibition of G-6-Pase gene transcriptional rate.


1981 ◽  
Vol 241 (5) ◽  
pp. R330-R335 ◽  
Author(s):  
N. Geary ◽  
W. Langhans ◽  
E. Scharrer

The suppression of food intake elicited in rats by injection of pancreatic glucagon and the accompanying changes in energy metabolite flux were investigated. Glucagon injections, 120-360 micrograms ip, were made as rats began the first meal of the dark phase after food deprivation during the light phase. Glucagon-injected rats terminated their meals sooner and ate smaller meals than vehicle-injected rats. For metabolic assays, rats were identically treated and killed just at meal onset or 15 min later. Portal vein blood glucose increased similarly in all rats allowed to feed, whereas plasma nonesterified fatty acid and D-(-)-3-hydroxybutyrate levels decreased during feeding. In contrast, hepatic vein and aorta blood glucose levels increased more after glucagon than after vehicle injections. Liver glycogen content decreased after glucagon injections. The highest glucagon dose only had slight lipolytic and ketogenic effects. It was concluded the glycogenolytic and hyperglycemic action of glucagon may generate a satiety signal sufficient to cause premature termination of meals. Changes in ketone and lipid fluxes do not appear necessary for this behavioral effect.


1976 ◽  
Vol 70 (2) ◽  
pp. 207-214 ◽  
Author(s):  
M. DALLE ◽  
P. DELOST

SUMMARY Concentrations of cortisol, corticosterone and cortisone in the plasma and adrenal glands, liver glycogen and plasma glucose of foetal, newborn and mother guinea-pigs were estimated during the last 6 days of pregnancy and throughout the first 24 h post partum. At the same time progesterone was measured in the plasma of the mother. During the prepartum rise in foetal plasma cortisol levels and liver glycogen, no significant change in the foetal adrenal cortisol content was observed. The plasma and adrenal cortisol concentrations of the mother were much higher than those observed in the foetus and increased significantly before parturition. In the mother as in the foetus, cortisone and corticosterone represent only a small percentage of corticosteroids compared with cortisol. These results indicate that the autonomous capacity of foetal adrenals, inhibited by maternal secretions before term, appears suddenly at birth.


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