HORMONES AND PROTEIN BIOSYNTHESIS IN ISOLATED RAT DIAPHRAGM

1959 ◽  
Vol 18 (4) ◽  
pp. 381-394 ◽  
Author(s):  
K. L. MANCHESTER ◽  
F. G. YOUNG
Keyword(s):  
Amino Acids ◽  
Glucose Uptake ◽  
Protein Biosynthesis ◽  
Metabolic Inhibitors ◽  
Minimal Amount ◽  
Rat Diaphragm ◽  
Rat Serum ◽  
Significant Stimulation ◽  
Normal Rat

SUMMARY 1. With rat diaphragm in vitro, addition of insulin to the medium so as to give a concentration as low as 0·05 mu./ml. of the hormone, stimulated the incorporation of [14C]glycine into protein of tissue. Simultaneous addition of glucose to the medium did not affect either the minimal amount of insulin required to produce a significant stimulation of incorporation of glycine, or the magnitude of the effect of the small concentration of insulin used. 2. Addition of a mixture of oxidized A and B chains of the insulin molecule did not affect incorporation of a mixture of labelled amino acids into the protein of isolated diaphragm, but a degraded insulin (DHA-insulin), which has about 15% of the activity of insulin in stimulating glucose uptake by diaphragm, was found to stimulate incorporation of [14C]glycine to an extent comparable with its effect in stimulating glucose-uptake. 3. Addition of rat serum, or the dipping of diaphragm in a medium containing insulin, stimulated incorporation of [14C]glycine into protein of diaphragm. Both these effects and the stimulation produced by insulin in vitro were abolished when the medium contained an antiserum to insulin. 4. Addition in vitro of growth hormone (GH) stimulated incorporation of [14C]glycine into protein of diaphragm from the hypophysectomized rat but had no effect on diaphragm from the normal rat, whether or not a small dose of insulin was also added in vitro. The action of GH in promoting incorporation of [14C]glycine into protein of diaphragm from the hypophysectomized rat was not neutralized by insulin antiserum. 5. Corticotrophin, cortisol, thyroxine, vitamin B12, vitamin D2 and linoleic acid all had no observable effect on incorporation of labelled amino acids into diaphragm. Glucagon stimulated incorporation, but the stimulation was abolished by the in vitro addition of antiserum to insulin and was probably attributable to the presence of a trace of insulin in the glucagon. 6. Anaerobiosis, and the addition of various metabolic inhibitors, were found to suppress incorporation of [14C]glycine into diaphragm protein almost entirely.

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.

Corticosteroids and incorporation of C14-phenylalanine into protein of isolated rat diaphragm

1960 ◽  
Vol 198 (5) ◽  
pp. 1111-1114 ◽  
Author(s):  
Ira G. Wool ◽  
Edward I. Weinshelbaum
Keyword(s):  
Potassium Concentration ◽  
Protein Biosynthesis ◽  
Fold Change ◽  
Prior Treatment ◽  
Rat Diaphragm ◽  
Phenylalanine Concentration ◽  
Intracellular Potassium ◽  
Intracellular Potassium Concentration ◽  
Isolated Rat

Prior treatment of rats with cortisone (2 mg/day) decreased l-phenylalanine-U-C14 incorporation into protein of isolated diaphragm. This action was not affected by a 100-fold change in the phenylalanine concentration, indicating that the steroid depresses protein biosynthesis in muscle. Hydrocortisone (50 µg/ml) added in vitro did not alter C14-phenylalanine incorporation. Large changes in intracellular potassium concentration were without influence on phenylalanine incorporation into protein of diaphragms from normal, adrenalectomized or cortisone-treated rats.

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

scholarly journals Effects of Cobalt on the Renal Erythropoietic Factor and Kidney Hydrolase Activity in the Rat

Blood ◽  
1973 ◽  
Vol 42 (6) ◽  
pp. 893-905 ◽  
Author(s):  
Robert J. Smith ◽  
James W. Fisher
Keyword(s):  
Enzyme Inhibitors ◽  
Mitochondrial Fraction ◽  
Hydrolase Activity ◽  
Marker Enzyme ◽  
Factor Activity ◽  
Rat Serum ◽  
Mitochondrial Fractions ◽  
Normal Rat ◽  
Mitochondrial Extract

Abstract In an experiment to determine the effects of cobalt on the renal erythropoietic factor and kidney hydrolase activity in the rat we obtained the following results: Cobalt produced significant increases in renal erythropoietic factor activity and plasma levels of erythropoietin which reached peak activity 12 hr after treatment. It also produced an increase in the activity of renal hydrolases, cathepsins A and B, which paralleled the increase in renal erythropoietic factor activity. Enzyme inhibitors which are specific for proteases, esterases, and metalloenzymes inhibited the activity of the renal erythropoietic factor in vitro. Polycythemic mice exposed to 7- and 8-day posthypoxic intervals still retained their ability to respond to in vitro generated erythropoietin when compared to mice treated on the fourth posthypoxic day. The erythropoietic activity generated by the light mitochondrial extract—normal rat serum (LME-NRS) reaction mixture was blocked by the antibody to erythropoietin. The relative concentrations of smooth and rough endoplasmic reticulum (microsomes) and vesicles (lysosomes) were approximately the same in the light mitochondrial fractions of kidneys from normal and cobalt-treated rats. Marker enzyme studies revealed primarily alkaline phosphatase activity in the light mitochondrial fraction. These studies correlate with electron micrographs of the LME which indicate a fraction composed mainly of microsomes. In addition, these data suggest a possible relationship between renal lysosomal hydrolase activity and the renal erythropoietic factor (Erythrogenin).

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.

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