Effects of whey protein hydrolysate ingestion on post-exercise muscle protein synthesis compared with intact whey protein in rats

Abstract

BackgroundIt is well known that ingestion of protein sources can stimulate muscle protein synthesis (MPS). The intake of whey protein is highly effective especially for accelerating MPS. Whey protein hydrolysate (WPH) can raise postprandial plasma concentration of amino acids, which impact stimulation of MPS more rapidly and highly than intact whey protein. However, it is unclear which is more effective for stimulating MPS, WPH or intact whey protein. The aim of the present study was to compare the effects of the WPH and whey protein on MPS in rats after exercise.MethodsRats were first subjected to a 2 h. swimming protocol. After this, in experiment 1, we evaluated time-dependent changes in the fractional synthetic rate (FSR) of the triceps muscle in Male Sprague-Dawley rats after ingestion of intact whey protein (30, 60, 90 or 120 min after ingestion). Then in experiment 2, at the time point that the results of Experiment 1 revealed postprandial FSR was highest (60 min after ingestion), we measured the FSR after ingestion of the WPH or whey protein at two different doses (0.5 or 2.0 g protein/kg body weight), or with deionized water (control), again after exercise. Plasma components and mammalian target of rapamycin (mTOR) signaling were also measured.ResultsIn experiment 1, postprandial FSR was highest 60 min after whey protein was administered. In experiment 2, the FSR 60 min after ingestion of the WPH was higher than that of whey protein (significant treatment main effect). Moreover, at a lower dose, only the WPH ingestion caused greater MPS and phosphorylated 4E-binding protein 1 (4E-BP1) levels compared with the control group.ConclusionThese results indicate that ingestion of the WPH was associated with greater post-exercise MPS compared with intact whey protein, especially at lower doses.

The role of protein hydrolysates for exercise-induced skeletal muscle recovery and adaptation: a current perspective

“…Specifically, following a 2-h swimming protocol, MPS 60 min following ingestion of the whey protein hydrolysate was significantly higher compared with a control intact whey protein. Interestingly, the whey protein hydrolysate caused greater MPS and phosphorylated 4E-binding protein 1 (4E-BP1) levels compared with the control whey protein only at the lower dose (i.e., 0.5 g·kg −1 ·day −1 ) [ 129 ], which supports the notion that whey protein hydrolysates may be more efficacious under conditions of suboptimal protein intakes and in relative proximity of exercise, albeit in rodents. Similar findings have been also observed with anabolic signaling markers and the attenuation of muscle loss with whey hydrolysates compared with its constituent AAs and/or non-hydrolysed forms [ 130 – 132 ].…”

“…A recent study using a rodent model investigating the effects of whey protein hydrolysate (0.5 and 2.0 g·kg −1 ·day −1 ) compared with an intact whey protein on postexercise MPS has produced interesting findings with regards to the muscle anabolic potential of hydrolysates [ 129 ]. Specifically, following a 2-h swimming protocol, MPS 60 min following ingestion of the whey protein hydrolysate was significantly higher compared with a control intact whey protein.…”

Krill Protein Hydrolysate Provides High Absorption Rate for All Essential Amino Acids—A Randomized Control Cross-Over Trial

“…Furthermore, independently of absorption kinetics, hydrolyzed protein may have beneficial physiological effects. In a study with rats, it was shown that hydrolyzed whey protein stimulated MPS more efficiently than intact whey protein, even though lower aminoacidemia was observed after ingestion of the hydrolysate [40]. This finding is possibly related to a higher plasma insulin concentration observed after ingestion of the whey protein hydrolysate compared to the intact whey protein, since insulin may support MPS when the AA availability is sufficient [41].…”

Effects of soy protein hydrolysates on antioxidant activity and inhibition of muscle loss

“…The enzymatic hydrolysis of proteins is an effective method widely used to produce bioactive peptides with multifunctional properties (Panyam and Kilara, 1996). In the case of whey protein (Nakayama et al, 2019), protein hydrolysate has been reported to stimulate muscle protein synthesis more effectively than the original protein. Alcalase and Flavourzyme have been mostly used to hydrolyse different plant proteins, such as rice or soy protein, to produce bioactive peptides (Ahmadifard et al, 2016;Gomes and Kurozawa, 2020).…”