Table 2.

Metabolites identified in bovine oviductal extracellular vesicles across the estrous cycle, ordered by chemical classes ¹.

Metabolite	Chemical Taxonomy Subclass Description	Identified (I)/Quantified (Q)	Function
Valine	Amino acids, peptides, and analogues (Proteinogenic) Essential amino acids	I/Q	Involved in stress, energy and muscle metabolism
Threonine	Amino acids, peptides, and analogues (Proteinogenic) Essential amino acids	I	Involved in biosynthesis of proteins
Methionine	Amino acids, peptides, and analogues (Proteinogenic) Essential amino acids	I/Q	Required for normal growth and development
Leucine	Amino acids, peptides, and analogues (Proteinogenic) Essential amino acids	I	Involved in biosynthesis of proteins, stress, energy, and muscle metabolism. Stimulates insulin release
Isoleucine	Amino acids, peptides, and analogues (Proteinogenic) Essential amino acids	I/Q	Involved in stress, energy and muscle metabolism.
Proline	Amino acids, peptides, and analogues Conditionally essential amino acids (Proteinogenic)	I	Involved in biosynthesis of proteins
Glycine	Amino acids, peptides, and analogues Non-essential amino acids (Proteinogenic)	I/Q	Involved in the body’s production of DNA, phospholipids, and collagen, and in release of energy.
Alanine	Amino acids, peptides, and analogues Non-essential amino acids (Proteinogenic)	I/Q	One of the most important amino acids released by muscle, functioning as a major energy source. Regulator of glucose metabolism, lymphocyte reproduction and immunity.
Glutamate	Amino acids, peptides, and analogues (Non-essential alpha Amino Acids)	I	Involved in biosynthesis of proteins Role as neurotransmitter, a chemical used by nerve cells to send signals to other cells.
Creatine	Amino acids, peptides, and analogues (endogenous amino acid: synthesized from arginine, glycine, and methionine)	I/Q	Role in energy metabolism. Responsible for the production of ATP in skeletal muscle through the process of oxidative phosphorylation inside the mitochondria.
Ethanolamine	Amines	I	Widely distributed in biological tissue and is a component of lecithin.
Carnitine	Quaternary ammonium salts Non-proteinogenic amino acids	I/Q	Important in providing energy to muscles Described as a vitamin, an amino acid, or essential metabolite
Choline	Quaternary ammonium salts (Essential Vitamin)	I/Q	Considered an essential vitamin. Precursor for the neurotransmitter acetylcholine, which is involved in many functions including memory and muscle control.
Lactate	Alpha hydroxy acids and derivatives (Energy Substrate)	I/Q	Plays a role in several biochemical processes and is produced in the muscles during intense activity
Myoinositol	Alcohols and polyols	I/Q	Involved in the Inositol phosphate metabolism and the Phosphatidylinositol signaling system.
Glucose-1-phosphate	Carbohydrates and carbohydrate conjugates (Energy Substrate)	I/Q	Glycogenolysis produces glucose-1-phosphate and no energy.
Maltose	Carbohydrates and carbohydrate conjugates (Energy Substrate)	I/Q	Maltose can be broken down into two glucose molecules
Glucose	Carbohydrates and carbohydrate conjugates (Energy Substrate)	I	Primary source of energy
Succinate	Dicarboxylic acids and derivatives	I/Q	Component of the citric acid or TCA cycle and is capable of donating electrons to the electron transfer chain.
Formate	Carboxylic acids	I	Essential intermediary metabolite in folate-mediated one-carbon metabolism Responsible for both metabolic acidosis and disrupting mitochondrial electron transport and energy production.
Acetate	Carboxylic acid derivates	I/Q	Acetate in the form of acetyl CoA is used in metabolism to yield chemical energy.
Acetone	Carbonyl compounds	I/Q	One of the ketone bodies produced during ketoacidosis. Since ketosis develops under serious metabolic circumstances, all the mechanisms that balance or moderate the effects of ketosis enhance the chance for survival.

¹ Information detailed on the table was obtained from “The human metabolome database” (http://www.hmdb.ca/).