Carbohydrates digestion and metabolism in the spiny lobster (Panulirus argus): biochemical indication for limited carbohydrate utilization

Abstract

As other spiny lobsters, Panulirus argus is supposed to use preferentially proteins and lipids in energy metabolism, while carbohydrates are well digested but poorly utilized. The aim of this study was to evaluate the effect of dietary carbohydrate level on digestion and metabolism in the spiny lobster P. argus. We used complementary methodologies such as post-feeding flux of nutrients and metabolites, as well as measurements of α-amylase expression and activity in the digestive tract. Lobsters readily digested and absorbed carbohydrates with a time-course that is dependent on their content in diet. Lobster showed higher levels of free glucose and stored glycogen in different tissues as the inclusion of wheat flour increased. Modifications in intermediary metabolism revealed a decrease in amino acids catabolism coupled with a higher use of free glucose as carbohydrates rise up to 20%. However, this effect seems to be limited by the metabolic capacity of lobsters to use more than 20% of carbohydrates in diets. Lobsters were not able to tightly regulate α-amylase expression according to dietary carbohydrate level but exhibited a marked difference in secretion of this enzyme into the gut. Results are discussed to highlight the limitations to increasing carbohydrate utilization by lobsters. Further growout trials are needed to link the presented metabolic profiles with phenotypic outcomes.

Evaluation of anticoagulants and hemocyte-maintaining solutions for the study of hemolymph components in the spiny lobster Panulirus argus (Latreille, 1804) (Decapoda: Achelata: Palinuridae)

“…Lobsters were kept in captivity in tanks with circulating seawater that flowthrough a biological filter, with constant aeration and photoperiod of 12 h light: 12 h darkness. Water quality was monitored twice a week: ∼26 °C, pH∼8.0, salinity 36 psu, oxygen ∼6.0 mg -l , and ammonia-N∼0.07 mg -l (Rodríguez-Viera et al, 2017). Only intermolt individuals were used (see Lyle & MacDonald, 1983).…”

A Review of Overcome the Side Effect of Digestion Process on the Drugs

“…The capsules have been manufactured for many reasons, including: some drugs are sensitive to light or air, and others have un acceptable a taste or odor, Therefore, the container is not transparent and is not permeable to air but what are the effects of stomach acids or enzymes on the functional groups of these drugs, The stomach have acidic fluid [3]. It may lead to decreased the activities of these function group and that may cause losses of drugs action [4], [5]. Let take amoxicillin as example.…”

Toward a More Comprehensive View of α-Amylase across Decapods Crustaceans: New Insights from Carnivorous

“…Moreover, α-amylase activity has been regularly reported in carnivorous crustaceans [18,26,34,55]. The relatively high α-amylase activity in spiny lobsters seems to contradict their limited metabolic use of carbohydrates [23,25,133], evidenced by the reduced activity of enzymes involved in both glycolysis and glycogen synthesis [23,25], although a recent study revealed that carbohydrate was the predominant energy substrate in 3-day fasted lobsters if previously fed a low (i.e. 40 %) protein diet [134].…”

“…Thus, lobsters were not able to fine-regulate α-amylase gene expression in spite of large changes in carbohydrate composition in diet (e.g. 6 % to 35 %) [25]. Therefore, it can be postulated that transcriptional regulatory mechanisms for α-amylase are not well developed in carnivorous lobsters, while retaining some ability to adapt α-amylase activity to very low carbohydrate diets.…”

“…Even when dietary carbohydrate cannot be efficiently used by aquatic animals [31], carbohydrates are essential and thus included in artificial feeds at 20 % to 30 % [32,33], although higher carbohydrate intake can lead to slow growth, low immunity, and high mortality rates [31,32]. Among carbohydrases, α-amylase is responsible for the hydrolysis of starch and glycogen, but remained poorly studied in carnivorous decapods until recently [18,19,[23][24][25]34]. The new information provided by these recent studies now allows drawing a more comprehensive view of the role of αamylases across decapods crustaceans.…”