THE CALORIGENIC ACTION OF EPINEPHRINE IN FROGS BEFORE AND AFTER HEPATECTOMY. (From the State Institute for the Study of Malignant Disease, Buflalo)

Size: px

Start display at page:

Download "THE CALORIGENIC ACTION OF EPINEPHRINE IN FROGS BEFORE AND AFTER HEPATECTOMY. (From the State Institute for the Study of Malignant Disease, Buflalo)"

Amie Chandler
5 years ago
Views:

1 THE CALORIGENIC ACTION OF EPINEPHRINE IN FROGS BEFORE AND AFTER HEPATECTOMY BY CARL F. CORI AND K. W. BUCHWALD (From the State Institute for the Study of Malignant Disease, Buflalo) (Received for publication, May 8, 1931) Meyerhof (1) has shown that increased lactic acid formation in muscle is accompanied by an increase in respiration. This is due to the fact that part of the lactic acid formed is reconverted to glycogen under expenditure of oxidative energy. As Meyerhof found, for each oxygen equivalent of 1 mol of lactic acid used above the basal oxygen consumption, 2 to 5 mols of lactic acid may be reconverted to glycogen. Since epinephrine causes an increased lactic acid formation in muscle and an increase in oxygen consumption, it was natural to think of a connection between the two and to ascribe the calorigenic action of epinephrine to the extra expenditure of energy required for the reconversion process. The present paper and others which are to follow, may be regarded as an examination of this hypothesis. Calculation of Extra Oxygen ConsumptionIf the above hypothesis is correct, epinephrine injections in frogs should cause less lactic acid to appear under aerobic than anaerobic conditions, because part of the lactic acid formed aerobically would be reconverted to glycogen. In Table II of the preceding paper (2) the excess lactic acid formed as the result of epinephrine injection amounted to 306 mg. per kilo of frog under anaerobic and to 169 mg. under aerobic conditions, a difference of 137 mg. The extra oxygen consumption required for the removal of 137 mg. of lactic acid may be calculated as follows: Assuming a ratio (lactic acid disappeared: lactic acid oxidized) of 4: 1, or of 137:34.2, one finds that 25.3 cc. of O2 are required to oxidize 34.2 mg. of lactic acid. In other words, in the experiments in Table II of the preceding paper the frogs should have consumed an extra amount of 25.3 cc. of 02 per Zcilo. The figure just arrived at offers a tieans of putting the above hypothesis to an experiment,al test. 367

2 Calorigenic Action of Epinephrine Measurement of the Oxygen Consumption of FrogsAn apparatus similar to that described by Meyerhof and Meier (3) was used. A cylindrical flask of about 500 cc. capacity, provided with indentations for the support of a wire net, was connected by means of a ground joint with a BarcroftWarburg manometer. 25 cc. of 10 per cent KOH were placed in the bottom of the flask for the absorption of COz. The flasks were submerged in a large water bath provided with two stirrers and kept at a temperature of 15. The calculation of the vessel constant was carried out as described by Warburg (4) and corrections for changes in temperature and barometric pressure were made by means of a thermobarometer. All values are expressed in cc. of 02 per kilo of frog, reduced to standard conditions of temperature and pressure. Immobilization of FrogsIn the present experiments it was necessary to measure the oxygen consumption for several consecutive hours, first under basal conditions and then after the epinephrine injection. Many fruitless attempts were made with normal and decerebrated frogs. The former remained under basal conditions for only short periods of time; the latter were sufficiently quiet when undisturbed, but the handling incidental to the injection caused them to move a good deal during the first half hour after the injection. It should be noted that the movements have a much stronger influence on the oxygen consumption of cold blooded than of warm blooded animals. Paralysis of the frogs by injection of drugs, such as curare, novocaine, or urethane, was undesirable for various reasons, and besides, it would have precluded the use of the same animals for experiments on several consecutive days. The following procedure was finally adopted. The brain was divided by means of a Goltz puncture between the hemispheres and the talami optici. With a fine needle introduced into the spinal canal the cord was destroyed from the medulla downward. Such animals, when properly operated upon, are able to breathe spontaneously, but otherwise they are completely immobilized. They survive for several days and such operations as hepatectomy can be performed on them without the use of an anesthetic. Plan of ExperimentsThe animals were immobilized on the day previous to the experiments. They were placed overnight in shallow water, care being taken to keep the nostrils free. It was found

3 C. F. Cori and K. W. Buchwald 369 advantageous to cover those parts of the body which remained outside of the water with wet gauze. In a number of experiments the liver was excised after all vascular connections were tied. On the following morning the animals were weighed, placed in the containers, and kept for several hours at 15, so as to allow for adjustments of the metabolism to that temperature. Oxygen consumption was then measured for 2 consecutive hours. After 2 hours the frogs were removed from the containers, injected with 0.1 cc. of salt solution, and immediately replaced. This was done in order to test the effect of an injection on oxygen consumption. 10 minutes were allowed for the establishment of temperature equilibrium before the measurement of the oxygen consumption was resumed. After 1 hour the animals were again removed from their containers but this time they received an injection of 0.05 to 0.1 mg. of epinephrine into the throat lymph sack, otherwise the procedure was the same as after the injection of salt solution. The experiment was terminated 2 to 3 hours after the administration of epinephrine. Eflect of Epinephrine on Oxygen Consumptio?tIn spite of the precautions taken, the oxygen consumption of frogs was not found to be as regular as that of mammals. This may be due to the fact that the frog as an aquatic animal is accustomed to periods of anaerobiosis and has therefore a metabolism less nicely regulated than that of mammals. The irregularities in O2 consumption would undoubtedly disappear in observation periods of several hours duration, but unfortunately long metabolism periods were not practicable in the present work. In the last two columns of Table I the increase in O2 consumption after the epinephrine injection was calculated. In the majority of the cases epinephrine caused a rise in the O2 consumption of the control as well as the hepatectomized animals and with few exceptions this rise was larger in the 1st than in the 2nd hour after the injection. During the 3rd hour after the injection the O2 consumption had in all cases returned to the basal level. The following discussion will be based mainly on the average values recorded in Table II. It may be seen that the O2 consumption during the first and second basal periods of the control animals did not differ by more than 3.3 per cent; in the case of the hepatectomized animals the difference was even smaller. This indicates

4 370 Calorigenic Action of Epinephrine TABLE I Injuence oj Epinephrine on 02 Consumption of Immobilized Frogs Controls, 1st day Controls, 2nd day Hepatectomized, 1st day Hepatectomized, 2nd day consumed per kilo of frog per hr. at 15 Basal % aolutiol 1st injechr. iid. tion ~ cc. cc. cc ' st hr. Ed. 2 cc. cc. cc , , c l.f < , ! After epinephrine injection let hr. 2nd hr. P er cent percenl D Hepatectomized, 3rd day Hepatectomized, th day * This animal was able to make slight movements that the number of experiment,s was large enough to eliminate the irregularities in the O2 consumption which were encountered in individual experiments.

5 C. F. Cori and K. W. Buchwald The handling of the animals incidental to the injection of salt solution (or of water) produced a slight rise in the 02 consumption, amounting to 8.8 per cent in the control and to 8.7 and 5.0 per cent in hepatectomized animals. The average basal 02 consumption (inclusive of the metabolism period after the injection of salt solution) amounted to 33.2 cc. per kilo of frog per hour for the control animals. Deducting this from the O2 consumption in the 1st and 2nd hours after the epinephrine injection one finds = 17.0 and = 11.0, a total of,%?.o cc. of extra O2 consumption as the result of the epinephrine injection. This agrees TABLE Influence of Epinephrine on 02 Consumption of Immobilized Frogs (Average Values of Table I) Type of experiment II 01 consumed per kilo of frog per hr. at 15 8 Ingeg3rin No. of...e&e basal 23 Basal 2 epi$$lrine consumption injection s.4 dr ;.z 1st 2nd z,g 1st hr. hr. < hr. h:. 1st hr. K: cc. cc. cc. cc. cc. Per cent Pfl cent Controls (liver intact) st day after hepatectomy.., nd.., &d I th I ::::; very well with the value of 25.3 cc. which was arrived at by calculation in a preceding section (p. 367) and lends support to the conception that the calorigenic action of epinephrine is due to reconversion of lactic acid. On the 1st day after removal of the liver the extra oxygen consumption after the epinephrine injection amounted to 18.1 cc. as compared to 28.0 cc. for frogs with intact liver, showing that the calorigenic action of epinephrine is diminished after hepatectomy. It may be assumed that part of the caiorigenic action takes place in the liver, since a reconversion of lactic acid to glycogen has been demonstrated in that organ following epinephrine injection

6 372 Calorigenic Action of Epinephrine (5). Apart from the removal of the liver, the response to epinephrine depends on the condition of the animals. On the 2nd and 3rd days after hepatectomy (plus destruction of most of the cen TABLE Efect of Epinephtine Injections on Sugar and Lactic Acid Content of Immobilized Frogs The temperature was 15. The animals were analyzed 2 hours after the injection and all values were calculated in mg. r 100 gm. of body weight. III Epinephriaeinjected Liver intact Hepatectomized I attic acid Ez method BemediC~ method zk4.7 f8.0 zt7.8 f9.2 f * 21.7, 41.4* f9.5 h9.3 f7.8 zt7.6 A7.3 l 3 days after hepatectomy; not included in average. t &tic said zk f8.3 tral nervous system) as the condition of the animals declined, the calorigenic action of epinephrine became progressively weaker and in some individual experiments (Frog 9 on the 3rd day and Frog 18

7 C. F. Cori and K. W. Buchwald 373 on the 4th day, Table I) it disappeared entirely. Since weak calorigenic actions were also observed in pithed frogs with intact liver when the animals were in poor condition, there is reason to believe that the lack of response to epinephrine some time after hepatectomy is due to the approaching death of the animal. Sugar and Lactic Acid Formation in Immobilized aizd Hepatectomized FrogsThe average lactic acid content of the immobilized frogs in Table III was practically the same as that of normal frogs (52.2 as compared to 47.2 mg. per 100 gm.). The former animals (like those used for the metabolism experiments in Table I) were immobilized 24 hours prior to the experiment. Since the lactic acid content did not rise appreciably during that time, the 02 consumption after immobilization must have remained large enough to prevent an accumulation of lactic acid. An increase in the sugar and lactic acid content was observed when epinephrine waa injected into immobilized frogs with intact liver (Table III). In contrast to this epinephrine failed to cause a rise in t he sugar content of immobilized and hepatectomized frogs. As in the case of the mammal (imann (6), Soskin (7)), sugar production in frogs is a function of the liver and in the absence of this organ there is apparently no other carbohydrate reserve present which can yield glucose. Though the muscles of these hepatectomized frogs contained considerable amounts of glycogen, the latter was not changed to glucose when epinephrine was injected. There was, however, a rise in lactic acid following the injection of epinephrine into hepatectomized frogs. DISCUSSION The calorigenic action of epinephrine which is ascribed to the reconversion of lactic acid in liver and muscle is in some respects similar to the specific dynamic action of amino acids. According to our present knowledge the increased oxygen consumption following the administration of amino acids represents the energy required for the conversion of amino acids to carbohydrate and in the case of alanine t.he intermediary product,s on the pat,h of this transformation would. actually be either lactic or pyruvic acid. Since the catabolism of amino acids depends on their deaminat,ion in the liver (Bollman, Mann, and Magath (8)), it seems probable that this organ is the principal site of extra heat production after

8 Calorigenic Action of Epinephrine amino acid ingestion. Similarly, in mammals the lactic acid which escapes from muscle during epinephrine action is reconverted to glycogen in the liver under expenditure of oxidative energy. The calorigenic action of epinephrine, though somewhat diminished in intensity, persists after removal of the liver in the frog. The question as to whether epinephrine acts calorigenically in mammals after removal of the liver has not been decided with certainty. Soskin s (9) experiments cannot be accepted as final, because they were performed on animals with a rapidly declining oxygen consumption. His conclusion that epinephrine injections did not arrest this rapid decline should not be interpreted to mean that epinephrine might not raise the oxygen consumption under more favorable experimental conditions. The observation made in experiments on frogs, that the calorigenic action often disappeared a few hours before death, lends support to this interpretation. There is reason to believe that the O2 consumption of normal resting muscle (as that of active muscle) is connected with the glycogen s lactic acid cycle described by hleyerhof. Some glycogen is constantly converted to lactic acid and the latter is removed at the expense of osidative energy. Epinephrine by accelerating the breakdown of glycogen to lactic acid in muscle would thus raise the heat production by an intensification of normal muscle metabolism. Justification for this conception isseen in the fact that the efficiency of the reconversion process during epinephrine action, as measured by the ratio (total lactic acid disappeared: lactic acid oxidized),was found to be of the same order of magnitude as in normal muscle, i.e. 4 to 1. Meyerhof and Neier (3), using intact frogs, found a value for the above ratio of 5 to 1 during rest and of 4.5 to 1 during recovery from muscular activity. A further discussion of the calorigenic action of epinephrine requires a consideration of the results obtained on mammals and will be presented later. SUMMART Following the injection of epinephrine into immobilized frogs, the O2 consumption rose on an average 51 per cent in the 1st and 33 per cent in t,he 2nd hour with a return to the basal level in the 3rd hour. The total extra Oz used during this period was 28 cc. per kilo of frog, while the extra O2 calculated from the difference in

9 C. F. Cori and K. W. Buchwald 375 aerobic and anaerobic lactic acid formation on the basis of a 4 to 1 reconversion ratio amounted to 25.3 cc. In immobilized and hepatectomised frogs the extra O2 consumption after epinephrine injection was 18 cc. per kilo or 35 per cent less than in immobilized frogs with intact liver. On the 2nd and 3rd days after removal of the liver, as the condition of the animals declined, the calorigenic action of epinephrine became progressively weaker. The sugar content of hepatectomized frogs did not rise when epinephrine was injected; there was, however, an increase in the lactic acid content. It is assumed that the calorigenic action of epinephrine in frogs is due to an accelerated lactic acid formation with subsequent reconversion of this lactic acid in muscle and liver, a process which is known to be accompanied by expenditure of oxidative energy. BIBLIOGRAPHY 1. Meyerhot, O., Arch. ges. Phytiol., 188,114 (1921). 2. Buchwald, K. W., and Cori, C. F., J. Biol. Chem., 9!2,3!56 (1931). 3. Meyerhot, O., and Meier, R., Arch. ges. Physiol., 204,488 (1924). 4. Warburg, O., Biochem. Z., 142,317 (1923). 5. Cori, C. F., and Cori, G. T., J. Biol. Chem., 79, 309 (1928). 6. Mann, F. C., Medicine, 6,419 (1927). 7. Soskin, S., Am. J. Physiol., 81,332 (1927). 8. Bollman, J. L., Mann, F. C., andmagath, T. B., Am. J. Physiol., 78,258 (19243). 9. Soskin. S., Am. J. Physiol., 83,162 (1927).

10 THE CALORIGENIC ACTION OF EPINEPHRINE IN FROGS BEFORE AND AFTER HEPATECTOMY Carl F. Cori and K. W. Buchwald J. Biol. Chem. 1931, 92: Access the most updated version of this article at Alerts: When this article is cited When a correction for this article is posted Click here to choose from all of JBC's alerts This article cites 0 references, 0 of which can be accessed free at ml#reflist1

THE CARBOHYDRATE METABOLISM OF TUMORS.

THE CARBOHYDRATE METABOLISM OF TUMORS. II. CHANGES IN THE SUGAR, LACTIC ACID, AND CO COMBINING POWER OF BLOOD PASSING THROUGH A TUMOR. BY CARL F. CORI AND GERTY T. CORI. (From the State Institute for ihe