Seasonality of glycogen phosphorylase activity in crucian carp (Carassius carassius L.)

Among vertebrates able to tolerate periods of oxygen deprivation, the painted and red-eared slider turtles ( Chrysemys picta and Trachemys scripta) and the crucian carp ( Carassius carassius) are the most extreme and can survive even months of total lack of oxygen during winter. The key to hypoxia survival resides in concerted physiological responses, including strong metabolic depression, protection against oxidative damage and–in air-breathing animals–redistribution of blood flow. Each of these responses is known to be tightly regulated by nitric oxide (NO) and during hypoxia by its metabolite nitrite. The aim of this review is to highlight recent work illustrating the widespread roles of NO and nitrite in the tolerance to extreme oxygen deprivation, in particular in the red-eared slider turtle and crucian carp, but also in diving marine mammals. The emerging picture underscores the importance of NO and nitrite signaling in the adaptive response to hypoxia in vertebrate animals.

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Socializing makes thick-skinned individuals: on the density of epidermal alarm substance cells in cyprinid fish, the crucian carp (Carassius carassius)

Journal of Comparative Physiology A ◽

10.1007/s00359-010-0550-4 ◽

2010 ◽

Vol 196 (9) ◽

pp. 639-647 ◽

Cited By ~ 5

Author(s):

Ole B. Stabell ◽

Anne Vegusdal

Keyword(s):

Crucian Carp ◽

Cyprinid Fish ◽

Alarm Substance ◽

Carassius Carassius ◽

Alarm Substance Cells ◽

Crucian Carp Carassius Carassius

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Regulation of muscle glycogen phosphorylase activity following short-term endurance training

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1996.270.2.e328 ◽

1996 ◽

Vol 270 (2) ◽

pp. E328-E335 ◽

Cited By ~ 32

Author(s):

A. Chesley ◽

G. J. Heigenhauser ◽

L. L. Spriet

Keyword(s):

Endurance Training ◽

Muscle Glycogen ◽

Glycogen Phosphorylase ◽

Citrate Synthase ◽

Phosphorylase Activity ◽

Short Term ◽

Mitochondrial Potential ◽

Before And After ◽

Glycogen Phosphorylase Activity ◽

Muscle Biopsies

The purpose of this study was to examine the regulation (hormonal, substrate, and allosteric) of muscle glycogen phosphorylase (Phos) activity and glycogenolysis after short-term endurance training. Eight untrained males completed 6 days of cycle exercise (2 h/day) at 65% of maximal O2 uptake (Vo2max). Before and after training subjects cycled for 15 min at 80% of Vo2max, and muscle biopsies and blood samples were obtained at 0 and 30 s, 7.5 and 15 min, and 0, 5, 10, and 15 min of exercise. Vo2max was unchanged with training but citrate synthase (CS) activity increased by 20%. Muscle glycogenolysis was reduced by 42% during the 15-min exercise challenge following training (198.8 +/- 36.9 vs. 115.4 +/- 25.1 mmol/kg dry muscle), and plasma epinephrine was blunted at 15 min of exercise. The Phos a mole fraction was unaffected by training. Muscle phosphocreatine utilization and free Pi and AMP accumulations were reduced with training at 7.5 and 15 min of exercise. It is concluded that posttransformational control of Phos, exerted by reductions in substrate (free Pi) and allosteric modulator (free AMP) contents, is responsible for a blunted muscle glycogenolysis after 6 days of endurance training. The increase in CS activity suggests that the reduction of muscle glycogenolysis was due in part to an enhanced mitochondrial potential.

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Lernaea cyprinacea (Copepoda, Lernaeidae) on crucian carp (Carassius carassius) from Lake Dlinnoe in the Basin of the Middle Reaches of the Vychegda River

Russian Journal of Ecology ◽

10.1134/s1067413606020111 ◽

2006 ◽

Vol 37 (2) ◽

pp. 135-140

Author(s):

G. N. Dorovskikh ◽

L. R. Makarova

Keyword(s):

Crucian Carp ◽

Carassius Carassius ◽

Lernaea Cyprinacea ◽

Crucian Carp Carassius Carassius

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Regulation of glycolytic enzymes during anoxia in the turtle Pseudemys scripta

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1989.257.2.r278 ◽

1989 ◽

Vol 257 (2) ◽

pp. R278-R283 ◽

Cited By ~ 6

Author(s):

S. P. Brooks ◽

K. B. Storey

Keyword(s):

Heart Muscle ◽

Glycogen Phosphorylase ◽

White Muscle ◽

Fold Increase ◽

Glycolytic Enzymes ◽

Phosphorylase Activity ◽

Enzyme Form ◽

Red Muscle ◽

Km Value ◽

Glycogen Phosphorylase Activity

The glycolytic enzymes glycogen phosphorylase, phosphofructokinase (PFK), and pyruvate kinase (PK) were assessed in liver, heart, red muscle, and white muscle of aerobic and 5-h anoxic turtles (Pseudemys scripta) for changes in total activity and kinetic parameters. Anoxia induced statistically significant changes in these glycolytic enzymes in each of the four organs assayed. Compared with normoxic controls, anoxic liver showed a 3.3-fold increase in glycogen phosphorylase activity, a 1.5-fold increase in the PFK I50 value for citrate (concentration that inhibits initial activity by 50%), a 1.5-fold increase in the PFK Michaelis constant (Km) value for fructose 6-phosphate (P), and an increased maximal activity of PK. Anoxic heart muscle showed a 2.6-fold decrease in glycogen phosphorylase activity and, for PFK, a 1.7-fold decrease in the Km value for ATP and a twofold increase in the I50 value for citrate. In anoxic white muscle, PFK showed a fivefold lower Km value for fructose-6-P and a threefold lower activator concentration producing half-maximal activation (A50) for potassium phosphate than the aerobic enzyme form. Changes in anoxic white muscle PK included a twofold increase in the Km value for ADP and a 1.7-fold decrease in the I50 value for alanine. In red muscle, anoxia affected only the Km value for ATP, which was 50% higher than the value for the aerobic enzyme form. Fructose 2,6-diphosphate (P2) levels also decreased in heart muscle and increased in red and white muscle during anoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

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