Transmembrane channel-like 4 is involved in pH and temperature-dependent modulation of salty taste

Human susceptibility to NaCl varies depending on temperature and pH, the molecular mechanisms of which remain unclear. The voltage-dependent chloride channel, transmembrane channel-like 4 (TMC4), is activated at approximately 40 °C and is suppressed at pH 5.5. As these are similar in character to human sensory evaluations, hTMC4 may be involved in human salt taste reception.

Genetic Variation in Taste Receptor Genes (SCNN1B, TRPV1) and Its Correlation with the Perception of Saltiness in Normotensive and Hypertensive Adults

Background. Different taste preferences correlated with genetic variations may lead to food consumption patterns that contribute to nutrient-related health outcomes such as hypertension. Objectives. The aim of this study was to determine whether single nucleotide polymorphisms (SNPs) in the salt taste receptor genes SCNN1B and TRPV1 affect salt taste perception among normotensive and hypertensive people. Materials and Methods. We conducted a cross-sectional case control study by design consisting of a normotensive and hypertensive group. Participants were 253 adults with age range of 20–82 residing in Mississippi, USA. For each of 128 normotensives and 125 hypertensives, the salt taste recognition threshold and salt taste receptor genotype were determined. Results. The hypertensive group had a higher salt taste recognition threshold than the normotensive group ( P < 0.001 ). The polymorphism of TRPV1, rs4790522, with the AA genotype was associated with a higher salt recognition threshold (lower salt taste sensitivity) in people with hypertension and obesity. Moreover, the polymorphism of TRPV1, rs8065080, and SCNN1B, rs239345, genes were associated with a risk of hypertension ( P = 0.016 and P = 0.024 ). Conclusion. Correlations between SNPs, salt taste sensitivity, and hypertension risk were observed. People with hypertension had a higher salt taste threshold than those with normotension.

Association of Single Nucleotide Polymorphisms in Salt Taste Receptor Genes With Dietary Salt Intake and Blood Pressure Among Iranian Adults Population

Objectives So far, few researches has examined how genetic variation in salt taste receptors affects food intake in Iranian population. Thus, in this study, we aimed to investigate associations of single nucleotide polymorphisms (SNPs) in salt taste receptors genes with dietary salt intake and blood pressure. Methods This cross-sectional study was carried out among 116 randomly selected adults aged 18 years and over in Isfahan city, Iran. Subjects with diabetes insipidus, renal insufficiency, a special dietary regimen, fasting or menstruating on the day of sampling, using diuretics and oral contraceptives or pregnant and lactating women as well as participants who had incomplete 24-h urine collection were excluded. A 24-h urine collection and blood pressure measurement were done. Whole blood was collected to extract DNA and measure SNP rs239345 in the ENaC and rs224534, rs4790151 and rs8065080 in the TRPV1 gene. Results Homozygous carriers of the T allele for rs239345 were found to consume significantly more sodium (4414.7 ± 1943.8 mg/day) compared to the AA genotype (3887.4 ± 1709.1 mg/day). Further, they also had higher diastolic blood pressure compared to subjects with the AA genotype (81.3 ± 9.7 vs. 75.3 ± 8.3 mmHg). Compared to subjects with the CC genotype, those with homozygous carriers of the T allele for rs8065080 in the TRPV1 had higher sodium intake (3592.6 ± 1645.2 mg/day vs. 4604.2 ± 2013.5 mg/day) and systolic blood pressure (118.1 ± 11.3 mmHg vs. 123.4 ± 11.5 mmHg). No differences were found in dietary sodium intake and blood pressure with the rs224534 and rs4790151 SNPs. Conclusions These findings suggest that genetic variation in the ENaC and TRPV1 genes may contribute to inter-individual differences in salt intake and blood pressure. Funding Sources The National Institute for Medical Research Development (NIMAD) was funded this study via grant number of 977,549.