Rise In Lactic Acid Research Articles

Lactic acid response in the grunion

1. 1. Lactic acid levels in blood and muscle have been determined in a fish ( Leuresthes tenuis) which spawns out of water. 2. 2. Out of water, lactic acid builds up in the muscles but little enters the blood. 3. 3. During recovery in water there is an acute lactic acid rise in the blood and a slow drop in the muscle lactate. 4. 4. This is interpreted to mean that the muscles remain ischemic during the asphyxia and build up lactic acid which flushes out by the hyperemia in recovery. 5. 5. This mechanism of asphyxial defense is an analogue to the cirulatory changes found in diving and non-diving animals and man.

Circulatory adjustment in pearl divers.

A seemingly general feature in the adjustment to diving in various mammals, birds, and reptiles is a slow-down and redistribution of the circulation, leaving muscles, periphery, and certain visceral organs with a markedly reduced circulation. This saves oxygen and causes widespread reduction of the energy metabolism. Active as well as quiet diving develops bradycardia without drop in central blood pressure, and lactic acid forming in the muscles during the dive floods the blood when breathing starts. In 31 native skin divers in Australia, diving rarely exceeded 1 min. During the dive, blood pressure stayed normal while heart rate dropped to half; blood lactate (five divers) remained normal but showed an acute rise in the recovery. Evidently humans utilize an adjustment similar to animals. Most of our divers developed various cardiac arrhythmias during the dive, persisting sometimes into the beginning of the recovery. This asphyxial defense seems developed at birth, for fetal bradycardia is common during delivery, and an acute rise of lactic acid after delivery has recently been described. Phylogenetically the mechanism is ancient, for it is found also in fishes when taken out of water. Submitted on August 7, 1961

SODIUM, POTASSIUM, AND LACTIC ACID AFTER MUSCULAR EXERCISE IN THE RAT

Untrained young rats were exercised on a treadmill for a standard time at different speeds. A linear correlation between the intensity of the exercise and the degree of plasma [K] rise was observed. On the other hand, exercise at standard speed for varying durations was found to cause an increase in plasma [K] only during the early stages of the exercise. A fall in plasma [Na] was a constant accompaniment of exercise but no definite correlation to either intensity or duration was found. Lactic acid rose only with relatively severe exercise or with excitement. Blood sugar did not vary. Old rats responded to even mild exercise with a marked [K] shift accompanied by a well-defined rise in lactic acid.

SODIUM, POTASSIUM, AND LACTIC ACID AFTER MUSCULAR EXERCISE IN THE RAT

Untrained young rats were exercised on a treadmill for a standard time at different speeds. A linear correlation between the intensity of the exercise and the degree of plasma [K] rise was observed. On the other hand, exercise at standard speed for varying durations was found to cause an increase in plasma [K] only during the early stages of the exercise. A fall in plasma [Na] was a constant accompaniment of exercise but no definite correlation to either intensity or duration was found. Lactic acid rose only with relatively severe exercise or with excitement. Blood sugar did not vary. Old rats responded to even mild exercise with a marked [K] shift accompanied by a well-defined rise in lactic acid.

Effect of Adrenaline, Nor adrenaline, Isopropyl Nor adrenaline and Ephedrine on Tone and Lactic Acid Formation in Bovine Tracheal Muscle

Summary.The relaxing and the lactic acid forming effects on bovine tracheal muscle of adrenaline, nor adrenaline, isopropyl‐nor adrenaline and ephedrine were compared.All four drugs had both a relaxing and a lactic acid forming effect. The degree of relaxation tended to run parallel with the rise in lactic acid content.Drugs inhibiting glycol sis totally abolished the relaxing effect of all sympathomimetic amines that were studied.The concentrations of l‐adrenaline. l‐nor adrenaline, dl‐isopropyl‐nor adrenaline and 1‐ephedrine producing a maximal relaxing effect had a ratio of 1: 2: 10: 350.

Oxygen and Carbon Dioxide Dissociation Studies on Blood Drawn after Intravenous Injection of Pitressin.

In previous communications1, 2, 3 it was pointed out that certain well defined circulatory and respiratory changes are elicited by the intravenous injection of moderate doses of pituitrin or pitressin into unanesthetized human beings or dogs. For a brief period (5 to 10 minutes) immediately following the administration of the drugs, the venous blood draining the limbs becomes arterial in color and shows a high oxygen content, a rapidly rising lactic acid concentration, and a concomitantly lowered carbon dioxide content. There is at the same time a precipitous decrease in total oxygen consumption and a lowering of the cardiac output. In the immediately ensuing recovery period, which persists for 1 1/2 to 2 hours after the injection, the physiological picture is reversed. An abnormally dark venous blood is found, indicating increased oxygen utilization by the “starved” tissues; a further rise in lactic acid is followed by a gradual return to the pre-injection level; the carbon dioxide content returns slowly...

Relief of Parathyroid Tetany by Injections of Uranium Nitrate.

Recent studies from this laboratory1,2 have shown that slight changes in the acid-base equilibrium, with a shift in the reaction of the blood toward the acid side, exert a profound effect upon the tetany of parathyroid insufficiency.The writer and his collaborators have shown that asphyxiation by CO2 of dogs presenting violent tetany promptly brings about a return to normal in so far as tetany symptoms are concerned. The disappearance of symptoms was correlated with disturbance of the acid-base equilibrium, i. e., lowered CO2 capacity, CO2 content and pH, due to rise in lactic acid. Tetany again supervened following a return to a normal acid-base balance and disappearance of the lactic acid. The total serum calcium remained unchanged by the CO2 treatment, despite the fact the animals seemed normal and were free from tetany.Since the effect of the CO2 lasts but a brief period, and since it was considered desirable to study the experimental animals over longer periods, the present experiment with uranium ni...

Lactic Acid Formation in Muscle Extracts.

Embden and Haymann demonstrated that the addition of glycogen and sodium fluoride to freshly prepared muscle press-juice caused a very marked decrease in the inorganic phosphate which was present in the extract. Sugars were inactive in the reaction. The disappearance of the inorganic phosphate was interpreted as an esterification process in which hexose phosphate (lactacidogen) was formed. Meyerhof showed that there is a production of lactic acid during the course of glycogen degradation by muscle extracts, and that the phosphates appear to take an active part in the changes involved. Fluoride caused a decrease in the production of lactic acid as well as a disappearance of the inorganic phosphates. The fate of the added glycogen with reference to the amount of total hydrolysable carbohydrate present in the working mixtures at the end of the incubation seems not to have been studied. In our experiments we have endeavored to balance the carbohydrate loss against the lactic acid gain, and, at the same time, form some conception of the amount of carbohydrate that took part in the esterification with phosphoric acid. Simultaneous determinations of lactic acid, free sugar, total carbohydrate, and inorganic phosphate were made at 0, 30, 60, 120, and 240 minute intervals on aliquot portions of mixtures of muscle extract and glycogen solution. The extract was prepared from chopped rabbit muscle by mixing two parts of ice cold distilled water with one part of muscle and straining through muslin after allowing the mixture to stand onehalf hour at 0°. The animals were anesthetized with amytal, to prevent the rise of lactic acid in the muscle, by abolishing the death struggles, and killed by bleeding. The extract was used immediately after its preparation.