RELEASE OF INSULIN FROM ISOLATED RAT PANCREAS IN VITRO

1960 ◽  
Vol XXXV (IV) ◽  
pp. 560-567 ◽  
Author(s):  
P. R. Bouman
Keyword(s):  
Glucose Uptake ◽  
Ringer Solution ◽  
Pancreatic Tissue ◽  
Diabetic Rats ◽  
Pancreatic Ducts ◽  
Muscular Tissue ◽  
Rat Diaphragm ◽  
Rat Pancreas ◽  
Isolated Rat

ABSTRACT Krebs-Ringer solution in which pancreatic tissue of normal rats had been previously incubated, did not stimulate the glucose uptake of the isolated rat diaphragm. An increased glucose uptake was observed, however, after adding incubate of pancreatic tissue from rats in which the pancreatic ducts had been ligated 6 weeks prior to the experiment. Glucose uptake in the isolated diaphragm was also increased by joint incubation with pancreatic tissue of normal rats. Diaphragmatic glucose uptake was not stimulated by joint incubation with pancreatic tissue of alloxan-diabetic rats. It was concluded that insulin is released from pancreatic tissue under in vitro conditions. Unless muscular tissue is present, this insulin is completely inactivated, presumably by proteolytic pancreatic enzymes.

In vitro Effect of Growth Hormone on the Glucose Uptake of Isolated Rat Diaphragm

Nature ◽  
1957 ◽  
Vol 179 (4557) ◽  
pp. 472-473 ◽  
Author(s):  
P. J. RANDLE ◽  
J. E. WHITNEY
Keyword(s):  
Growth Hormone ◽  
Glucose Uptake ◽  
Rat Diaphragm ◽  
Vitro Effect ◽  
Isolated Rat

THE EFFECT OF GROWTH HORMONE AND OF CORTISOL ON THE RESPONSE OF ISOLATED RAT DIAPHRAGM TO THE STIMULATING EFFECT OF INSULIN ON GLUCOSE UPTAKE AND ON INCORPORATION OF AMINO ACIDS INTO PROTEIN

1959 ◽  
Vol 18 (4) ◽  
pp. 395-408 ◽  
Author(s):  
K. L. MANCHESTER ◽  
P. J. RANDLE ◽  
F. G. YOUNG
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Glucose Uptake ◽  
Carbohydrate Metabolism ◽  
Rat Diaphragm ◽  
Pituitary Growth Hormone ◽  
Isolated Rat ◽  
Stimulation Of

SUMMARY 1. The effect of hypophysectomy, or of adrenalectomy, and injection of pituitary growth hormone (GH) or of cortisol, on the uptake of glucose and the incorporation of glycine into protein by isolated rat diaphragm, and the effect of the addition of insulin in vitro on these processes, has been studied. 2. Both hypophysectomy and adrenalectomy raised the uptake of glucose by isolated diaphragm, while treatment of the intact or of the hypophysectomized rat with GH, or of the intact or of the adrenalectomized rat with cortisol, depressed it. Although hypophysectomy and adrenalectomy did not influence the additional glucose uptake induced by 200 mu./ml. of insulin in vitro, both these operations enhanced the effect of 0·1–1·0 mu./ml. of insulin on glucose uptake by diaphragm in vitro. Treatment of the rat with GH or cortisol diminished the rise in glucose uptake of diaphragm induced by 0·1–1·0 mu./ml. insulin. 3. Hypophysectomy depressed, and administration of GH to the intact or hypophysectomized rat raised, the incorporation of glycine into protein of the isolated diaphragm, but neither of these operations altered the magnitude of the stimulation of incorporation induced by 1·0 mu./ml. insulin. 4. Adrenalectomy raised, and administration of cortisol to the intact or adrenalectomized rat depressed, the incorporation of glycine into protein of the isolated diaphragm; adrenalectomy enhanced, the injection of cortisol diminished, the effect of 1·0 mu./ml. insulin on these processes. 5. The possibility that GH directs insulin towards the stimulation of protein synthesis, in part by restraining the action of insulin on carbohydrate metabolism, is discussed.

THE ADRENAL CORTEX AND EFFECTS OF ADRENALINE ON CARBOHYDRATE METABOLISM IN THE ISOLATED RAT DIAPHRAGM

1963 ◽  
Vol 44 (1) ◽  
pp. 90-100
Author(s):  
P. R. Bouman ◽  
W. Dermer
Keyword(s):  
Glucose Uptake ◽  
Carbohydrate Metabolism ◽  
Glycogen Content ◽  
Qualitative Change ◽  
Glycogen Metabolism ◽  
Synergistic Action ◽  
Rat Diaphragm ◽  
Glycogen Deposition ◽  
Isolated Rat

ABSTRACT The in vitro effects of adrenaline on glycogen metabolism and glucose uptake were studied in diaphragms of intact, adrenalectomized and adrenodemedullated rats decapitated under »Nembutal« anaesthesia. Adrenalectomy and pretreatment of adrenalectomized rats with cortisol caused an increase in the net loss of glycogen induced by adrenaline. When glycogen deposition in the absence of adrenaline was also taken into account, the overall magnitude of the glycogenolytic response appeared to be unchanged. The apparent qualitative change in response induced by these procedures was attributed to increased initial glycogen values. In diaphragms of adrenalectomized and adrenodemedullated rats the response to adrenaline was identical, the initial glycogen content being the same in these preparations. None of the experimental procedures affected the variable inhibition of glucose uptake by adrenaline. These results do not favour the existence of a »permissive« or synergistic action of adrenocortical steroids with regard to the effects of adrenaline on peripheral carbohydrate metabolism.

EFFECTS OF ADRENALINE ON CARBOHYDRATE METABOLISM IN THE ISOLATED DIAPHRAGM OF INTACT AND ADRENALECTOMIZED RATS AS INFLUENCED BY »NEMBUTAL« ANAESTHESIA

1960 ◽  
Vol XXXV (IV) ◽  
pp. 541-550 ◽  
Author(s):  
P. R. Bouman ◽  
W. Dermer
Keyword(s):  
Glucose Uptake ◽  
Carbohydrate Metabolism ◽  
Glycogen Content ◽  
Glycogen Metabolism ◽  
Rat Diaphragm ◽  
Simultaneous Inhibition ◽  
Glycogen Deposition ◽  
Isolated Rat ◽  
Adrenalectomized Rats

ABSTRACT Hemidiaphragms of intact and adrenalectomized rats which had been killed by decapitation, were incubated for 1 hour at 37° C under aerobic conditions. Glucose uptake and glycogen deposition were determined. Addition of adrenaline in vitro (1 μg/ml) caused a substantial decrease in glucose uptake in both types of diaphragms, this decrease being equivalent to a simultaneous inhibition of glycogen deposition. »Nembutal« anaesthesia prior to decapitation was found to alter the response to adrenaline. This change was most clearly observed in diaphragms of adrenalectomized rats. Here, adrenaline mainly affected glycogen metabolism by way of glycogen degradation, whereas the overall magnitude of the response was not materially changed. However, glucose uptake appeared to be only slightly decreased by adrenaline under these conditions. The change in response to adrenaline was attributed to the higher initial glycogen content observed in diaphragms of nembutalized rats. It was suggested that prevention of an acute release of endogenous adrenergic substances, occurring after decapitation of unanaesthetized donor rats, may be the actual cause of this phenomenon. Attention was drawn to the significance of the initial glycogen content as an important factor in carbohydrate metabolism of the isolated rat diaphragm.

THE ASSAY OF INSULIN IN VITRO BY MEANS OF THE GLUCOSE UPTAKE OF THE ISOLATED RAT DIAPHRAGM

1956 ◽  
Vol 14 (1) ◽  
pp. 82-86 ◽  
Author(s):  
P. J. RANDLE
Keyword(s):  
Glucose Uptake ◽  
Dose Response ◽  
Response Curve ◽  
Dose Response Curve ◽  
Rat Diaphragm ◽  
Minimum Concentration ◽  
Isolated Rat

SUMMARY An in vitro method of insulin assay based upon the glucose uptake of the isolated rat diaphragm is described and a statistical appraisal of the method given. The minimum concentration of insulin which was detected by this method was of the order of 10−4 i.u. of insulin/ml. The index of precision (λ) varied in eighteen studies of regression from 0·18 to 0·74. The slope of the log dose-response curve was found to vary significantly from experiment to experiment. The results are briefly compared with those obtained with other in vitro methods of insulin assay.

SENSITIVITY OF THE RAT DIAPHRAGM TO GROWTH HORMONE.

1967 ◽  
Vol 54 (4) ◽  
pp. 645-662 ◽  
Author(s):  
Å. Hjalmarson ◽  
K. Ahrén
Keyword(s):  
Growth Hormone ◽  
Inhibitory Effect ◽  
Rat Diaphragm ◽  
Intracellular Accumulation ◽  
Slight Effect ◽  
Kidney Capsule ◽  
Muscle Tissues ◽  
Hypophysectomized Rats ◽  
Isolated Rat

ABSTRACT The effect of growth hormone (GH) in vitro on the rate of intracellular accumulation of the non-utilizable amino acid α-aminoisobutyric acid (AIB) was studied in the intact rat diaphragm preparation. Bovine or ovine GH (25 μg/ml incubation medium) markedly stimulated the accumulation of AIB-14C by diaphragms from hypophysectomized rats, while there was no or only a very slight effect on diaphragms from normal rats. In diaphragms from rats with the pituitary gland autotransplanted to the kidney capsule GH in vitro stimulated the accumulation of AIB-14C significantly more than in diaphragms from normal rats but significantly less than in diaphragms from hypophysectomized rats. Injections of GH intramuscularly for 4 days to hypophysectomized rats made the diaphragms from these rats less sensitive or completely insensitive to GH in vitro. These results indicate strongly that the relative insensitivity to GH in vitro of diaphragms from normal rats is due to the fact that the muscle tissues from these rats has been exposed to the endogenously secreted GH. The results show that GH can influence the accumulation of AIB-14C in the isolated rat diaphragm in two different ways giving an acute or »stimulatory« effect and a late or »inhibitory« effect, and that it seems to be a time-relationship between these two effects of the hormone.

scholarly journals THE EFFECT OF GROWTH HORMONE ON GLUCOSE UPTAKE BY THE ISOLATED RAT DIAPHRAGM

1952 ◽  
Vol 197 (1) ◽  
pp. 151-166 ◽  
Author(s):  
C.R. Park ◽  
David H. Brown ◽  
Marvin. Cornblath ◽  
William H. Daughaday ◽  
M.E. Krahl
Keyword(s):  
Growth Hormone ◽  
Glucose Uptake ◽  
Rat Diaphragm ◽  
Isolated Rat

THE INFLUENCE OF POTASSIUM ION UPON GLUCOSE UPTAKE AND GLYCOGEN SYNTHESIS IN THE ISOLATED RAT DIAPHRAGM

1955 ◽  
Vol 33 (1) ◽  
pp. 687-694 ◽  
Author(s):  
D. W. Clarke
Keyword(s):  
Glucose Uptake ◽  
Glycogen Synthesis ◽  
Potassium Ion ◽  
Ion Concentration ◽  
Rat Diaphragm ◽  
High Potassium ◽  
High Concentrations ◽  
Glycogen Breakdown ◽  
Isolated Rat

The amounts of glucose taken from a medium, and the amounts of glycogen synthesized, by rat hemidiaphragms were studied under various conditions. High concentrations of potassium ion inhibited the glucose uptake and there was also a reduced net glycogen synthesis. Glycogen breakdown was probably not increased by high potassium ion concentration. The effect of potassium was most marked when conditions were such that one would ordinarily expect a considerable glucose uptake or glycogen synthesis. The action of insulin was not peculiarly susceptible to potassium ion inhibition.

Lowering of plasma glucose in diabetic rats by antilipolytic agents

1988 ◽  
Vol 254 (1) ◽  
pp. E23-E30 ◽  
Author(s):  
G. M. Reaven ◽  
H. Chang ◽  
H. Ho ◽  
C. Y. Jeng ◽  
B. B. Hoffman
Keyword(s):  
Glucose Uptake ◽  
Plasma Glucose ◽  
Plasma Free Fatty Acid ◽  
Diabetic Rats ◽  
Plasma Insulin Concentration ◽  
Glucose Response ◽  
Adenosine Receptor Agonist ◽  
Lower Plasma Glucose

Both nicotinic acid (NA) and the adenosine receptor agonist phenylisopropyladenosine (PIA) are potent antilipolytic agents. We have evaluated the ability of these compounds to lower plasma glucose concentration in 450-g male diabetic rats. Diabetes was induced by intravenous streptozotocin, and the rats were studied 7-10 days later. Mean (+/- SE) fasting glucose decreased 4 h after subcutaneous injections of PIA at 0 and 2 h. A similar change in plasma glucose level was also seen in rats injected with NA. The decrease in the concentration of plasma glucose in both instances was preceded by marked sustained reductions in plasma free fatty acid (FFA) concentrations; FFA decreased in PIA-injected rats and in response to NA. With injection of normal saline, neither plasma glucose nor FFA concentrations decreased in diabetic rats. There was no change in the plasma insulin concentration of rats that had hypoglycemic responses to PIA or NA. In vitro glucose uptake was determined in isolated adipocytes, and both PIA and NA were shown to increase basal and maximal insulin-stimulated glucose uptake. The stimulating effect of the two compounds was similar, and the magnitude of the effect was comparable in adipocytes from either normal or diabetic rats. As a result, neither NA nor PIA could restore the defects in glucose transport to normal in adipocytes from diabetic rats. Insulin-stimulated glucose uptake was assessed in vivo by determining the steady-state glucose response of diabetic rats to a continuous infusion of insulin and glucose and was found to be significantly enhanced in response to NA compared with NaCl.(ABSTRACT TRUNCATED AT 250 WORDS)

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