Role of histidine-related compounds to intracellular buffering in fish skeletal muscle

Abstract

Histidine-related compounds (HRC) were analyzed in fish skeletal muscle as a means of identifying their precise role in intracellular buffering. Fish muscle was used because it contains two functionally and spatially distinct fiber types, red and white. Two fish species, rainbow trout (Salmo gairdneri) and the Pacific blue marlin (Makaira nigricans), were studied because these species demonstrate widely different activity patterns. Marlin red and white muscle buffer capacity was two times higher than trout with white muscle, buffering being two times greater than red in both species. Buffer capacity was highest in the 6.5-7.5 pH range for all tissues, which corresponded to their high anserine levels. The titrated HRC buffering was greater than the observed HRC buffering, which suggested that not all HRC were available to absorb protons. The HRC contribution to total cellular buffering varied from a high of 62% for marlin white to a low of 7% for trout red. The other principal buffers were found to be phosphate and protein with taurine contributing within red muscle in the 7.0-8.0 pH range. HRC were found to be dominant in skeletal muscle buffering by principally accounting for the buffering capacity differences found between the species and fiber types.

The relationship of pork longissimus muscle pH to mitochondrial respiratory activities, meat quality and muscle structure

“…The contrary results are difficult to explain. The extent of pH reduction is a complex process and is influenced by lactate production during anaerobic glycolysis related to factors like glycolytic potential or glycolytic enzyme activities (Monin and Sellier, 1985;Werner et al, 2010b;Scheffler et al, 2013), or by factors like residual aerobic energy production shortly after slaughter or the H + buffering capacity of the muscle fibres (Abe, 2000;Werner et al, 2010a).…”

Muscle Carnosine Metabolism and β-Alanine Supplementation in Relation to Exercise and Training

“…Carnosine is absent from plants (and therefore from vegetarian food) and invertebrates, whereas in the animal kingdom it appears in high but varying quantities in muscles from different vertebrates [6]. In humans, the muscle concentration of carnosine is 5-8 mM in wet weight (or 20-30 mmol/kg dry weight), which is comparable to the concentrations of ATP, carnitine or taurine and lower than (phospho)creatine.…”

“…Some endurance exercise type animals like pigeons and migrating birds have lower concentrations (< 5 mM), while other animals that are involved in more burst-like and sprint exercise (chicken, grey-hound dogs, thoroughbred horse) have markedly higher concentrations (20-50 mM) [7]. Some of the highest HCD concentrations, higher than the concentrations of ATP and CrP combined, have been observed in whale, whose exercise profile is characterized by extremely prolonged hypoxic dives and anaerobic energy delivery [6]. The specific evolutionary drive of high HCD content in muscles of animals involved in anaerobic work, may be of particular importance when trying to understand in what exercise conditions carnosine plays a pivotal role.…”

Hepatoprotective Effect of a Hot-Water Extract from the Edible Thorny OysterSpondylus variuson Carbon Tetrachloride-Induced Liver Injury in Mice

“…Supplements derived from marine foods have been shown to have various functions in animal and clinical experiments. For example, unsaturated fatty acids, 1,2) carotenoids, 3) and functional peptides 4,5) are being increasingly used to treat and prevent a wide variety of lifestyle-related diseases and to improve the quality of life. In this study, we focused on the hepatoprotective effect of the thorny oyster, Spondylus varius.…”