Leucine – Potent Activator of Protein Synthesis in Dogs
Summary
L-leucine is a branched-chain amino acid (BCAA) that occupies a uniquely powerful position in mammalian nutrition: it is the only amino acid capable of independently activating the mTORC1 (mechanistic target of rapamycin complex 1) signalling pathway — the master regulator of protein synthesis, cell growth and metabolic coordination.¹˒² This places leucine in a category beyond simple nutrition — it functions as a nutrient signal, instructing muscle cells to initiate the translation of mRNA into new protein.
For dogs, this signalling role has particular relevance as they age. Sarcopenia — the progressive, age-related loss of skeletal muscle mass and strength — is well documented in geriatric dogs, with muscle biopsy studies confirming fibre atrophy, mitochondrial alterations and upregulated autophagy in ageing canine skeletal muscle.³ Leucine supplementation has been shown to restore muscle protein synthesis rates in ageing mammalian models and is specifically recommended as part of nutritional strategies for canine sarcopenia management in veterinary literature.⁴˒⁵
Beyond muscle, canine research from the WALTHAM Centre for Pet Nutrition demonstrated that BCAA supplementation — comprising leucine, isoleucine and valine — improved cognitive performance in senior dogs during exercise, with greater benefit observed in the older age group.⁶ Emerging evidence also connects leucine to intestinal health through its activation of mTOR signalling in enterocytes, its enhancement of intestinal secretory IgA production, and its reduction of oxidative stress in intestinal epithelial cells.⁷˒⁹˒¹²
In Bonza Boost Bioactive Bites, L-leucine at 30 mg per chewy forms part of a comprehensive amino acid support system alongside taurine, L-carnitine, DL-methionine, L-cysteine and L-tryptophan — targeting muscle maintenance, metabolic efficiency and healthy ageing.
Key Takeaways
- L-leucine is the most potent amino acid activator of the mTORC1 signalling pathway, directly stimulating muscle protein synthesis through phosphorylation of downstream translation initiation factors.¹˒²
- Sarcopenia (age-related muscle wasting) is well documented in geriatric dogs, with biopsy evidence showing fibre atrophy, mitochondrial dysfunction and dysregulated autophagy in ageing canine muscle.³
- Leucine supplementation has been shown to restore or normalise muscle protein synthesis in ageing models, and is specifically recommended in veterinary literature as part of sarcopenia management strategies.⁴˒⁵
- BCAA supplementation improved cognitive performance in senior dogs in a WALTHAM Centre study, with greater benefit to the older age group — potentially through modulation of brain neurotransmitter balance.⁶
- Leucine supports intestinal health by activating mTOR in enterocytes, enhancing secretory IgA production for mucosal immunity, and reducing reactive oxygen species in intestinal epithelial cells.⁷˒⁹˒¹²
- In Boost, L-leucine works alongside a comprehensive amino acid profile including taurine, L-carnitine and DL-methionine to support muscle maintenance, metabolic efficiency and healthy ageing.
In this guide:
- What is L-leucine?
- Bioactive mechanisms: how L-leucine works
- Health benefits for dogs
- L-leucine and gut health
- Why Bonza includes L-leucine in Boost
- Safety profile
- How to support your dog’s muscle health as they age
- Dosage guidelines
- Frequently asked questions
- Related reading
- References
- Editorial Information
What Is L-Leucine?
L-leucine (chemical formula C₆H₁₃NO₂) is one of the three branched-chain amino acids (BCAAs) — alongside isoleucine and valine — named for the branched aliphatic side chain in their molecular structure. Leucine is an essential amino acid, meaning dogs cannot synthesise it and must obtain it through diet. It is the most abundant BCAA in dietary protein, typically representing approximately 7–10% of the amino acid content of quality protein sources.
What distinguishes leucine from all other amino acids is its unique and potent signalling capacity. While all essential amino acids are necessary substrates for protein synthesis, leucine alone can independently activate the mTORC1 pathway — the central kinase complex that coordinates protein translation, ribosome biogenesis and cell growth.¹˒² This means leucine does not merely provide building material; it actively instructs cells to begin the process of assembling new protein. No other single amino acid possesses this signalling potency.
Leucine’s essentiality is absolute: without dietary leucine, muscle protein synthesis cannot proceed regardless of how abundant other amino acids may be. This makes it particularly critical for maintaining lean muscle mass in growing puppies, active working dogs and — most significantly from a health perspective — ageing senior dogs experiencing the progressive muscle decline of sarcopenia.
The three BCAAs share a unique metabolic feature in mammalian physiology: unlike most amino acids, which are primarily metabolised in the liver, BCAAs largely bypass hepatic first-pass metabolism and are preferentially metabolised in skeletal muscle. This direct route to muscle tissue is one reason BCAAs have such pronounced effects on muscle protein metabolism. In skeletal muscle, leucine can be oxidised for energy, transaminated to α-ketoisocaproate (KIC), or further metabolised to β-hydroxy-β-methylbutyrate (HMB) — a metabolite that has itself attracted research interest for anti-catabolic properties in muscle.⁵
Bioactive Mechanisms: How L-Leucine Works
mTORC1 Pathway Activation
The mechanistic target of rapamycin complex 1 (mTORC1) is an evolutionary conserved multiprotein kinase complex that functions as the central integrator of nutrient availability, energy status and growth factor signals to regulate cell growth and protein synthesis.¹˒² mTORC1 consists of the mTOR kinase itself, regulatory-associated protein of mTOR (Raptor), and mammalian lethal with SEC13 protein 8 (mLST8/GβL).
Leucine activates mTORC1 through a mechanism involving the Rag GTPase system. When intracellular leucine concentrations rise — as occurs after a protein-containing meal — leucine is sensed by the cellular leucine sensor Sestrin2, which releases its inhibition of the GATOR2 complex. This triggers a cascade that recruits mTORC1 to the lysosomal surface where it can be activated by the GTPase Rheb.¹
Once activated, mTORC1 phosphorylates two key downstream effectors that directly promote mRNA translation. The first is ribosomal protein S6 kinase 1 (S6K1), which enhances translation initiation and ribosome biogenesis. The second is eukaryotic initiation factor 4E-binding protein 1 (4E-BP1) — phosphorylation of 4E-BP1 releases eIF4E, allowing formation of the active eIF4E·eIF4G translation initiation complex.²
This has been directly demonstrated in mammalian muscle tissue. Suryawan et al. (2008) showed in neonatal pigs that leucine infusion stimulated skeletal muscle protein synthesis, and that this effect was completely blocked by rapamycin (an mTORC1 inhibitor), confirming that leucine acts specifically through mTORC1.² The same study demonstrated that leucine increased phosphorylation of mTOR, S6K1 and 4E-BP1 and promoted formation of the active eIF4E·eIF4G complex — all hallmarks of mTORC1-driven translation initiation.
Protein Degradation Inhibition
Leucine’s anabolic effects extend beyond stimulating protein synthesis. There is evidence that leucine also represses proteasomal protein degradation, effectively working both sides of the protein turnover equation to favour net protein accretion.¹ In intestinal tissue, enteral leucine infusion decreased proteasome activity in human duodenal mucosa while enhancing intestinal cell proliferation — demonstrating that leucine’s dual action on synthesis and degradation operates across multiple tissue types, not just muscle.¹⁰
Metabolic Signalling Beyond Muscle
Leucine’s signalling reach extends beyond muscle protein synthesis. Through mTORC1 and related pathways, leucine influences fatty acid oxidation, mitochondrial biogenesis and insulin secretion. In adipose tissue, leucine activates mTOR to promote lipogenesis and adipocyte differentiation. In pancreatic β-cells, leucine stimulates insulin secretion through its metabolism to produce ATP and through allosteric activation of glutamate dehydrogenase.¹
Leucine also promotes mitochondrial biogenesis through activation of the PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha) pathway, which coordinates the expression of nuclear and mitochondrial genes required for new mitochondria formation.¹ This is particularly relevant for ageing, as mitochondrial decline is a hallmark of both sarcopenia and cellular senescence.
Health Benefits for Dogs
Muscle Maintenance and Sarcopenia Prevention
Sarcopenia — the age-related progressive loss of skeletal muscle mass, strength and function — is a well-recognised clinical condition in geriatric dogs. Affected dogs typically show visible muscle wasting that is most pronounced in the hindquarters, with relatively preserved muscle mass in the forelimbs. This creates a characteristic body shape change that many owners attribute to weight loss, when it is in fact specifically muscle that is being lost.
Pagano et al. (2015) conducted the most detailed investigation of canine sarcopenia mechanisms to date, examining muscle biopsies from 25 geriatric dogs (aged 15–22 years) compared with five healthy young controls. The study documented significant fibre atrophy, sarcoplasmic vacuolisation and mitochondrial alterations in geriatric muscle. Critically, they also demonstrated upregulated expression of autophagy markers (Beclin 1, LC3 and p62), indicating that age-related muscle wasting in dogs involves dysregulated cellular recycling pathways — the same pathways that mTORC1 signalling (activated by leucine) helps coordinate.³
The Royal Canin Vet Focus review on sarcopenia management in older dogs specifically identifies leucine as an essential amino acid that stimulates and initiates muscle protein synthesis, noting that leucine supplementation has been shown to restore or normalise muscle protein synthesis in other species. The review recommends leucine as part of a multi-component nutritional strategy for canine sarcopenia alongside increased protein intake, omega-3 fatty acids and vitamin D.⁵
While direct leucine supplementation trials in sarcopenic dogs remain to be conducted, the mechanistic basis for benefit is exceptionally strong. The mTORC1 signalling pathway is highly conserved across mammalian species, and leucine’s ability to activate this pathway has been demonstrated in every mammalian model tested. Research in canine skeletal muscle has confirmed that dogs possess the same mTOR signalling architecture, with studies in athletic dogs demonstrating that phosphorylated ribosomal protein S6 (p-RpS6) — a downstream indicator of mTOR activity — responds to nutritional and exercise stimuli.¹¹
Cognitive Function
A particularly noteworthy canine-specific study was conducted by Fretwell et al. (2006) at the WALTHAM Centre for Pet Nutrition. In this controlled trial, 24 dogs — 12 young (1.5–3.5 years) and 12 senior (>8 years; range 11.1–13.1 years) — were supplemented with BCAAs (40% valine, 35% leucine, 25% isoleucine) or a control before completing agility courses requiring both physical dexterity and cognitive function.⁶
The results showed that BCAA supplementation reduced the loss of cognitive performance across successive rounds of the course, with the effect being most pronounced in senior dogs. Unsupplemented senior dogs showed a marked increase in errors as they progressed to a novel (unfamiliar) course configuration, while supplemented senior dogs maintained better cognitive performance throughout.⁶
The proposed mechanism involves BCAAs competing with tryptophan for transport across the blood-brain barrier. During exercise, plasma tryptophan rises, potentially increasing brain serotonin synthesis and contributing to central fatigue. Elevated BCAA levels reduce tryptophan brain uptake, maintaining the neurotransmitter balance needed for sustained cognitive performance.⁶ Additionally, BCAAs serve as substrates for glutamate and subsequently GABA synthesis in the brain, directly supporting excitatory and inhibitory neurotransmitter balance.
Metabolic Health
Leucine’s influence on metabolic regulation extends to insulin sensitivity and energy metabolism. Through its effects on mTORC1 signalling in muscle and adipose tissue, leucine helps coordinate the metabolic response to feeding, promoting efficient nutrient partitioning — directing amino acids toward muscle protein synthesis rather than fat storage. The stimulation of insulin secretion by leucine also supports glucose uptake into muscle cells, potentially contributing to improved glycaemic regulation.¹
For dogs prone to weight gain or those on weight management programmes, leucine’s ability to preferentially support lean mass maintenance while promoting efficient metabolism may be particularly beneficial. Maintaining lean muscle mass is one of the most effective strategies for supporting healthy metabolic rate, as muscle tissue is significantly more metabolically active than adipose tissue.
L-Leucine and Gut Health
The Gut–Metabolic Axis
The gut–metabolic axis describes the bidirectional communication between the intestinal environment and systemic metabolic regulation. The gut microbiome influences energy harvest from food, bile acid metabolism, short-chain fatty acid production and the secretion of gut hormones that regulate appetite and glucose homeostasis. Leucine intersects this axis through its direct effects on intestinal epithelial cells and its influence on intestinal immune function.
mTOR Signalling in the Intestinal Epithelium
The intestinal epithelium is one of the most rapidly renewing tissues in the body, with complete turnover occurring every 3–5 days. This extraordinary rate of cell proliferation requires robust protein synthesis capacity — and mTORC1 signalling, activated by leucine, plays a central role in coordinating this process.
Ban et al. (2004) demonstrated that leucine activates the mTOR signalling pathway in rat intestinal epithelial cells, phosphorylating both p70 S6 kinase and 4E-BP1 in a rapamycin-sensitive manner.¹² This indicates that the same leucine-sensing mechanism that drives muscle protein synthesis also operates in intestinal cells, supporting the rapid protein turnover required for epithelial renewal and barrier maintenance.
Research in weaned pigs has shown that dietary leucine supplementation alleviates rotavirus-induced diarrhoea by improving the intestinal mucosal barrier and upregulates mucin 1 and mucin 2 production in the jejunal mucosa, with increased phosphorylated mTOR levels confirming involvement of the PI3K-Akt-mTOR pathway.¹³ Leucine also increases the mRNA expression of porcine β-defensins — antimicrobial peptides that contribute to innate immune defence at the mucosal surface — through the Sirt1/ERK/90RSK signalling pathway.¹⁴ Proteomic analysis of leucine-treated porcine intestinal epithelial cells has further identified 101 differentially expressed proteins associated with cell proliferation, metabolism and phagocytosis, confirming leucine’s broad modulatory role in intestinal epithelial function.⁸
Intestinal Secretory IgA Production
Song et al. (2020) demonstrated that dietary leucine supplementation improved intestinal health in mice by enhancing intestinal secretory IgA (SIgA) production. SIgA is the most abundant immunoglobulin in mucosal secretions and serves as the first line of immunological defence on the intestinal surface, neutralising pathogens, preventing bacterial adhesion to epithelial cells and maintaining the integrity of the epithelial barrier.⁷
The mechanism involved activation of the mTOR signalling pathway and modulation of gut microbiota composition. Leucine supplementation upregulated the expression of factors involved in both T cell-dependent and T cell-independent SIgA production pathways, and altered the microbial community in ways that further supported SIgA secretion.⁷ This positions leucine as a nutrient that supports mucosal immunity through both direct cell signalling and indirect microbiome modulation.
Oxidative Stress Reduction in Intestinal Cells
Hu et al. (2017) demonstrated that leucine supplementation reduces reactive oxygen species (ROS) levels in porcine intestinal epithelial cells through an energy metabolism switch from oxidative phosphorylation toward glycolysis, mediated by the mTOR-HIF-1α pathway.⁹ This was the first evidence that leucine actively protects intestinal cells from oxidative damage — a function that complements the structural barrier-supporting roles of other amino acids like L-cysteine and glutamine.
These gut health effects connect leucine to the broader gut–metabolic axis — where intestinal integrity, mucosal immunity and microbiome health all influence systemic metabolic regulation, including the efficiency with which dietary nutrients are absorbed and directed toward muscle maintenance.
Why Bonza Includes L-Leucine in Boost
Bonza Boost Bioactive Bites deliver 30 mg of L-leucine per 4.5 g chewy as part of a comprehensive amino acid and metabolic support system designed to maintain lean muscle mass, support cognitive function and promote healthy ageing. Leucine works in concert with several other amino acids in the Boost formulation:
L-leucine (30 mg) — the primary mTORC1 activator, directly stimulating muscle protein synthesis and supporting intestinal epithelial renewal and mucosal immunity.
Taurine (300 mg) — supports cardiac muscle function, bile acid conjugation for fat absorption, and provides additional antioxidant protection. Taurine also supports neurological function, complementing leucine’s cognitive benefits.
L-carnitine (30 mg) — facilitates the transport of long-chain fatty acids into mitochondria for β-oxidation, supporting the energy metabolism that powers muscle function and complementing leucine’s role in mitochondrial biogenesis.
DL-methionine (45 mg) — an essential sulphur amino acid that supports protein synthesis and the trans-sulphuration pathway, contributing to glutathione production and structural protein integrity.
L-cysteine (30 mg) — the rate-limiting glutathione precursor that supports the antioxidant defence system protecting muscle tissue from exercise-induced and age-related oxidative damage.
L-tryptophan (15 mg) — the serotonin precursor that supports mood regulation and sleep quality, complementing the BCAA-mediated neurotransmitter balancing effects.
This amino acid architecture ensures that leucine’s powerful mTOR-activating signal is matched by adequate substrate availability — because leucine stimulates protein synthesis, but the sustained production of new protein requires the full complement of essential and non-essential amino acids. The complete protein supplied by Bonza Superfoods & Ancient Grains provides this foundational amino acid pool.
Safety Profile
L-leucine has an excellent safety profile in canine nutrition. As an essential amino acid present in all dietary proteins, it is consumed naturally in every meal. No toxicity has been reported from leucine supplementation at nutritional or moderately elevated levels in dogs or other companion animals.
The WALTHAM Centre study (Fretwell et al., 2006) administered BCAA supplements to dogs of various breeds and ages without reporting any adverse effects.⁶ The doses used were proportional to those shown to be safe and effective in human athletes.
The dose of L-leucine in Bonza Boost (30 mg per chewy, equivalent to approximately 6.67 mg/kg body weight in a 10 kg dog) is a nutritional-level dose well within established safe parameters. For context, a standard complete canine diet already provides leucine as part of the protein content — Boost supplementation adds a targeted amount to ensure the mTOR signalling threshold is consistently met, particularly in ageing dogs whose protein intake or absorption may be suboptimal.
Leucine supplementation should be used with caution in dogs with hepatic encephalopathy or severe liver disease where protein metabolism is compromised, as with any amino acid supplement. Consult your veterinarian if your dog has a diagnosed metabolic condition.
How to Support Your Dog’s Muscle Health as They Age
A step-by-step approach to maintaining lean muscle mass and mobility throughout your dog’s life.
- Feed a high-quality, complete protein diet
Muscle maintenance requires a consistent supply of all essential amino acids. Bonza Superfoods & Ancient Grains provides a complete amino acid profile from carefully combined plant proteins, ensuring the substrate availability that leucine’s anabolic signal depends on.
- Add targeted amino acid supplementation with Boost
Give one Bonza Boost chewy per 10 kg body weight daily. The combination of L-leucine (mTOR activation), taurine (cardiac and neurological support), L-carnitine (energy metabolism) and the complete amino acid profile supports muscle protein synthesis from multiple angles.
- Maintain consistent, appropriate physical activity
Regular exercise is one of the most effective stimuli for muscle maintenance, and leucine’s effects on protein synthesis are amplified when combined with physical activity. For senior dogs, low-impact activities like swimming, controlled walking and gentle play help maintain muscle mass without overstressing joints.
- Monitor muscle condition regularly
Learn to assess your dog’s muscle condition score by feeling the muscles over the hindquarters, shoulders and spine. Early detection of muscle loss allows earlier intervention. If you notice progressive thinning — particularly of the hindquarter muscles — discuss this with your veterinarian.
- Support gut health for optimal nutrient absorption
Leucine and other amino acids can only build muscle if they are properly absorbed from the diet. The probiotics (Calsporin and L. helveticus), prebiotics and postbiotics in Boost support the gut environment needed for efficient amino acid absorption.
- Consider increasing protein intake in senior dogs
Contrary to outdated advice about restricting protein in older dogs, current veterinary nutrition evidence supports maintaining or increasing protein intake in seniors to combat sarcopenia. Discuss appropriate protein levels with your veterinarian, particularly if your dog is showing signs of muscle loss.
Dosage Guidelines
| Dog weight | Boost chewies per day | L-leucine per day |
|---|---|---|
| Up to 10 kg | 1 chewy | 30 mg |
| 10–20 kg | 2 chewies | 60 mg |
| 20–30 kg | 3 chewies | 90 mg |
| 30–40 kg | 4 chewies | 120 mg |
| Over 40 kg | 5 chewies | 150 mg |
The L-leucine dosage in Bonza Boost is a nutritional-level supplement designed to provide a consistent mTOR-activating signal for muscle maintenance. These doses complement dietary leucine intake and are designed for daily use alongside a complete diet.
Frequently Asked Questions
L-leucine is one of the three branched-chain amino acids (BCAAs), alongside isoleucine and valine. While all three BCAAs are essential amino acids with important metabolic roles, leucine is uniquely potent in activating the mTORC1 signalling pathway that drives muscle protein synthesis.¹ ² The other BCAAs contribute to energy metabolism and neurotransmitter balance, but leucine provides the primary anabolic signal.
Leucine supplementation benefits dogs at any adult life stage, but becomes particularly important from around 7 years of age in larger breeds and 9–10 years in smaller breeds — when age-related changes in muscle protein synthesis begin to accelerate. Starting supplementation before visible sarcopenia develops is preferable to attempting to rebuild lost muscle.
Leucine stimulates muscle protein synthesis, ⁴ but rebuilding lost muscle also requires adequate total protein intake, appropriate exercise stimulus and management of any underlying conditions contributing to muscle wasting. Leucine is most effective as part of a comprehensive approach — it provides the signal to build, but the substrate (protein) and stimulus (activity) must also be present.
Boost provides targeted leucine supplementation (30 mg per chewy) that complements the leucine already present in your dog’s diet. When combined with Bonza Superfoods & Ancient Grains, which provides a complete amino acid profile including dietary leucine, the total leucine intake supports the mTOR signalling threshold needed for optimal muscle protein synthesis.
Research from the WALTHAM Centre for Pet Nutrition demonstrated that BCAA supplementation (including leucine) improved cognitive performance in senior dogs during exercise, with greater benefit to older dogs.⁶ This effect is believed to involve modulation of neurotransmitter balance at the blood-brain barrier, supporting sustained mental performance.
Related Reading
- The Gut-Metabolic Axis in Dogs – Powerful Health Regulator
- The Gut-Immune Axis in Dogs – How Gut Health Supports Immune Health
- The Dog Gut Microbiome — Vital Key to Dog Health
- Best Probiotics for Dogs: Canine Nutritionist’s Guide to Real Gut Impact
- Best Prebiotics for Dogs: Canine Nutritionist’s Complete Guide
References
- Duan Y, Li F, Li Y, Tang Y, Kong X, Feng Z, Anthony TG, Watford M, Hou Y, Wu G, Yin Y. The role of leucine and its metabolites in protein and energy metabolism. Amino Acids. 2016;48(1):41–51. doi:10.1007/s00726-015-2067-1
- Suryawan A, Jeyapalan AS, Orellana RA, Wilson FA, Nguyen HV, Davis TA. Leucine stimulates protein synthesis in skeletal muscle of neonatal pigs by enhancing mTORC1 activation. Am J Physiol Endocrinol Metab. 2008;295(4):E868–E875. doi:10.1152/ajpendo.90314.2008
- Pagano TB, Wojcik S, Costagliola A, De Biase D, Iovino S, Iovane V, Russo V, Papparella S, Paciello O. Age related skeletal muscle atrophy and upregulation of autophagy in dogs. Vet J. 2015;206(1):54–60. doi:10.1016/j.tvjl.2015.07.005
- Guo Y, Fu X, Hu Q, Chen L, Zuo H. The effect of leucine supplementation on sarcopenia-related measures in older adults: a systematic review and meta-analysis of 17 randomized controlled trials. Front Nutr. 2022;9:929891. doi:10.3389/fnut.2022.929891
- Kopke MA. Sarcopenia and weight management in older dogs. Vet Focus. Royal Canin. Available at: https://vetfocus.royalcanin.com/en/scientific/sarcopenia-and-weight-management-in-older-dogs
- Fretwell LK, McCune S, Fone JV, Yates DJ. The effect of supplementation with branched-chain amino acids on cognitive function in active dogs. J Nutr. 2006;136(7):2069S–2071S. doi:10.1093/jn/136.7.2069S
- Song B, Zheng C, Zha C, Hu S, Yang X, Wang L, Xiao H. Dietary leucine supplementation improves intestinal health of mice through intestinal SIgA secretion. J Appl Microbiol. 2020;128(2):574–583. doi:10.1111/jam.14464
- Mao X, Ren M, Chen D, Yu B, Che L, He J, Luo J, Luo Y, Wang J, Sun H. Leucine modulates the IPEC-J2 cell proteome associated with cell proliferation, metabolism and phagocytosis. Anim Nutr. 2018;4(3):316–321. doi:10.1016/j.aninu.2018.03.006
- Hu J, Nie Y, Chen S, Xie C, Fan Q, Wang Z, Long B, Yan G, Zhong Q, Yan X. Leucine reduces reactive oxygen species levels via an energy metabolism switch by activation of the mTOR-HIF-1α pathway in porcine intestinal epithelial cells. Int J Biochem Cell Biol. 2017;89:42–51. doi:10.1016/j.biocel.2017.05.026
- Goichon A, Chan P, Lecleire S, Coquard A, Cailleux AF, Walrand S, Lerebours E, Vaudry D, Déchelotte P, Coëffier M. An enteral leucine supply modulates human duodenal mucosal proteome and decreases the expression of enzymes involved in fatty acid beta-oxidation. J Proteomics. 2013;78:535–544. doi:10.1016/j.jprot.2012.10.024
- Miller BF, Ehrlicher SE, Drake JC, Peelor FF 3rd, Biela LM, Pratt-Phillips S, Davis M, Hamilton KL. Assessment of protein synthesis in highly aerobic canine species at the onset and during exercise training. J Appl Physiol. 2015;118(7):811–817. doi:10.1152/japplphysiol.00982.2014
- Ban H, Shigemitsu K, Yamatsuji T, Haisa M, Nakajo T, Takaoka M, Nobuhisa T, Gunduz M, Tanaka N, Naomoto Y. Arginine and leucine regulate p70 S6 kinase and 4E-BP1 in intestinal epithelial cells. Int J Mol Med. 2004;13(4):537–543. doi:10.3892/ijmm.13.4.537
- Mao X, Liu M, Tang J, Chen H, Chen D, Yu B, He J, Yu J, Zhang P, Mao Q, Wu D. Dietary leucine supplementation improves the mucin production in the jejunal mucosa of the weaned pigs challenged by porcine rotavirus. PLOS One. 2015;10(9):e0137380. doi:10.1371/journal.pone.0137380
- Ren M, Zhang S, Liu X, Li S, Mao X, Zeng X, Qiao S. Different lipopolysaccharide branched-chain amino acids modulate porcine intestinal endogenous β-defensin expression through the Sirt1/ERK/90RSK pathway. J Agric Food Chem. 2016;64(17):3371–3379. doi:10.1021/acs.jafc.6b00968
Editorial Information
| Last reviewed | February 2026 |
| Next review due | February 2027 |
| Author | Glendon Lloyd, Dip. Canine Nutrition (Dist.), Dip. Canine Nutrigenomics (Dist.) |
| Medical disclaimer | This article is for informational purposes only and does not constitute veterinary advice. Always consult a qualified veterinarian before making changes to your dog’s diet or supplement regimen. |
