Characteristics of the active transport of peptides and amino acids by germinating barley embryos

Use of two different assays involving either radioactively labelled substrates or a fluorescent-labelling procedure, gave good agreement for the rates of transport of peptides and amino acids into the scutellum of germinating grains of barley (Hordeum vulgare cv. Maris Otter, Winter). However, evidence was obtained for the enzymic decarboxylation of transpored substrate, which can cause underestimates of transport rates when using radioactively labelled substrates. The peptide Gly-Phe, was shown to be rapidly hydrolysed after uptake, and autoradiography of transported Gly-[U-¹⁴C]Phe indicated a rapid distribution of tracer, i.e. [U-¹⁴C] phenylalanine into the epithelium and sub-epithelial layers of the scutellum. The developmental patterns of transport activity indicate that peptide transport is more important nutritionally during the early stages of germination (1–3 d) whereas amino acids become relatively more important later (4–6 d). A range of amino acids is shown to be actively transported and several compete for uptake. At physiological concentrations, e.g. 2mM, transport of peptides and amino acids is inhibited about 80% by protonophore uncouplers, but at higher concentrations (10–100 mM) passive uptake predominates.Abbreviations Gly glycine - Leu leucine - Phe phenylalanine - Pro proline     

The impact of SELP gene Thr715Pro polymorphism on sP-selectin level and association with cardiovascular disease in Saudi diabetic patients: A cross-sectional case-control study

BackgroundCardiovascular diseases (CVD) are leading cause of mortality in patients with type 2 diabetes mellitus (T2DM). Increased soluble sP-selectin and 715Thr > Pro polymorphism were studied in CVD and T2DM, but association between them hasn’t been explored in Saudi Arabia. We aimed to assess sP-selectin levels in T2DM and T2DM-associated CVD patients in comparison to healthy control cohort. Also, we sought to investigate relationship between Thr715Pro polymorphism and sP-selectin levels and disease state.MethodsThis is a cross-sectional case-control study. sP-selectin level (measured by Enzyme-linked immunosorbent assay) and prevalence of Thr715Pro polymorphism (assessed by Sanger sequencing) were investigated in 136 Saudi participants. The study comprised 3 groups: group1 included 41 T2DM patients; group 2 (48 T2DM patients with CVD), and group 3 (47 healthy controls).ResultssP-selectin levels were significantly higher in diabetics and diabetics + CVD groups as compared to the corresponding control. In addition, results showed that the prevalence of 715Thr > Pro polymorphism is 11.75 % in the study population amongst the three study groups (9.55 % Thr/Pro, and 2.2 % Pro/Pro). No statistical difference was found between sP-selectin levels in subject carrying the wildtype genotype of this polymorphism and these who carry the mutant gene. There could be an association between this polymorphism and T2DM, whilst the polymorphism may protect diabetic patients from having CVD. However, odds ratio is not statistically significant in both cases.ConclusionOur study supports the previous researches’ results that Thr715Pro is neither influencing the sP-selectin level nor the risk of CVD in T2DM patients.