Effect of Aging on the Absorption of Small Peptides in Spontaneously Hypertensive Rats

Abstract

In the present study, we aimed to evaluate the effect of aging on the absorption of small peptides in spontaneously hypertensive rats (SHRs). Three kinds of dipeptides, glycyl-sarcosine (Gly-Sar), Trp-His, and captopril (a dipeptidomimetic drug), a Gly-Sar-Sar tripeptide, a Gly-Sar-Sar-Sar tetrapeptide, and a Gly-Sar-Sar-Sar-Sar pentapeptide were administered at doses of 10 mg/kg each to 8- and 40-week-old SHRs. The peptides were all detected in their intact forms in the blood. There was a significantly promoted absorption of di/tripeptides in aged SHRs compared with young SHRs. In contrast, the absorption of tetra/pentapeptides was not affected by aging. PepT1 expression in the mid-jejunum was significantly increased in 40-week-old SHRs compared with 8-week-old SHRs, whereas aging did not alter the expression of claudin-1, a tight junction related protein. Thus, the present results suggest that SHR aging may enhance the absorption of di/tripeptides through the enhanced PepT1 transport route, although oligopeptides may be absorbed in an age-independent manner.

Intestinal absorption of small peptides: a review

“…The extent of absorption (AUC 0–90 min ) of Gly‐Sar and Gly‐Sar‐Sar were 569.83 ± 68.5 pmol h mL −1 mg −1 ‐dose and 430 ± 53.5 pmol h mL −1 mg −1 ‐dose, respectively. Though data were not shown, in vivo absorption of peptides were shown to be in a peptide‐length‐dependent manner (up to pentapeptides, Hanh et al ., ), which correlated with the in vitro findings that chain lengths could be a determining factor for peptide absorption. Besides in the synthetic peptides with N ‐methylated peptide bonds, the C max of di‐/tripeptides was at pmol order in rat blood.…”

“…(SHRs) and compared them to 8-week young SHRs. We discovered that the expression of intestinal PepT1 was significantly (~1.5-fold) higher in the 40-week SHRs, which could indicate its enhanced absorption (Hanh et al, 2017; Fig. 3).…”

“…In a recent study, we reported enhanced absorption of dipeptides Gly‐Sar and Trp‐His in 40‐week‐old spontaneously hypertensive rats (SHRs) and compared them to 8‐week young SHRs. We discovered that the expression of intestinal PepT1 was significantly (~1.5‐fold) higher in the 40‐week SHRs, which could indicate its enhanced absorption (Hanh et al ., ; Fig. ).…”

Current understanding of transport and bioavailability of bioactive peptides derived from dairy proteins: a review

“…In another study of peptide bioavailability in rats, after oral administration with Trp-His, Gly-Sar, Gly-Sar-Sar, Gly-Sar-Sar-Sar and Gly-Sar-Sar-Sar-Sar, all the peptides were detected intact in rat blood. The rank of their plasma concentration from high to low was Gly-Sar > Gly-Sar-Sar > Gly-Sar-Sar-Sar > Gly-Sar-Sar-Sar-Sar, suggesting that the peptide size could influence their bioavailability (Hanh et al, 2017). Moreover, animal aging could enhance the bioavailability of di/tripeptide through increasing PepT1 transport route, but not oligopeptides (Hanh et al, 2017).…”

Absorption and Metabolism of Peptide WDHHAPQLR Derived from Rapeseed Protein and Inhibition of HUVEC Apoptosis under Oxidative Stress

“…Discussion in this section focuses on the use of Triple TOF MS/MS to scan the rat serum samples via mass spectrometry to verify the effectiveness of the Caco-2 cell monolayer model. Due to the complex ingredients of the animal serum that contains a variety of endogenous substances, 39 pretreatment of serum is particularly important. The free protein, lipids, and inorganic salts in rat serum were removed using the method in Section 2.5.…”