Page 63 - 《水产学报》2025年第10期

于莺曼，等 水产学报, 2025, 49(10): 109604

Effects of dietary oxaloacetic acid on growth performance, glucose and
lipid metabolism, and muscle fiber development in
largemouth bass(Micropterus salmoides)

YU Yingman , LIANG Yuyang , LIU Mengting , LUO Yuan , QIAO Fang ,
ZHANG Meiling , DU Zhenyu *
Laboratory of Aquatic Animal Nutrition and Environmental Health (LANEH),
School of Life Sciences, East China Normal University, Shanghai 200241, China

Abstract: Under intensive aquaculture systems, largemouth bass (Micropterus salmoides) is highly susceptible to nutritional
metabolic disorders, which severely compromise growth performance and muscle quality. Oxaloacetic acid (OAA), a critical
intermediate in the tricarboxylic acid (TCA) cycle, plays a pivotal regulatory role in regulating energy metabolism homeostasis
and holds potential as a functional feed additive. However, its regulatory effects on aquaculture species remain unclear. This
study investigated the effects of dietary oxaloacetic acid (OAA) supplementation on growth performance, glucose-lipid meta-
bolism, and muscle fiber development in largemouth bass. Juvenile largemouth bass [initial weight: (8.79 ± 0.04) g] were fed
four isonitrogenous and isolipidic diets: control (C), 0.5% OAA (LA), 1% OAA (MA), and 2% OAA (HA), with three replic-
ates per group, for 8 weeks. Compared to the control group, OAA supplementation significantly decreased weight gain rate and
whole-body total lipid content, while increasing feeding rate. No significant differences were observed in feed conversion ratio,
carcass ratio, or whole-body total protein content. Serum glucose, pyruvate, lactate, insulin, and muscle glycogen levels showed
no significant differences among groups, while hepatic glycogen in the LA group significantly increased compared to the con-
trol group. Hepatic citrate content decreased progressively with increasing OAA inclusion level, whereas succinate dehydro-
+
genase (SDH) activity increased significantly. The HA group exhibited a significant decrease in the NADH/NAD ratio in
+
muscle tissue, accompanied by a significant increase in liver NADH content and muscle NAD content. Hepatic total lipid con-
tent and results of Oil Red O staining revealed reduced lipid droplet accumulation in the HA group, accompanied by decreased
total lipid and triglyceride (TG) levels in muscle. Furthermore, OAA supplementation downregulated lipid synthesis genes (fas,
pparγ, srebp2, lipin1) and upregulated lipid catabolism genes (atgl, lpla, pparα, cpt1a) in liver and muscle. Interestingly, OAA
significantly increased the proportion of small-diameter muscle fibers (20–50 μm) while reducing that of large-diameter fibers
(110–140 μm). The expression of myogenic regulatory factors (myog, myod) was significantly upregulated by OAA. Dietary
OAA supplementation reduced lipid deposition, enhanced TCA cycle activity and promoted muscle fiber proliferation and dif-
ferentiation in largemouth bass. This study revealed the important role of OAA in regulating glucose and lipid metabolism and
myofiber growth and development in fish, and also provided a new choice of feed additive for the aquaculture industry.
Key words: Micropterus salmoides; oxaloacetic acid; TCA cycle; lipolysis; muscle fiber
Corresponding author: DU Zhenyu. E-mail: zydu@bio.ecnu.edu.cn
Funding projects: National Key Research and Development Program (2023YFD2400603)

中国水产学会主办 sponsored by China Society of Fisheries https://www.china-fishery.cn
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