Exploring the Interactive Role of Parathyroid Hormone and Sodium Intake in Inducing Cardiac Hypertrophy in Rats: A Novel Study.

Background and objectives Previous research has suggested that hyperparathyroidism and excessive salt intake may contribute to the development of cardiac hypertrophy. This study aimed to investigate the relationship and underlying mechanisms between parathyroid hormone (PTH) and salt intake in the development of left ventricular hypertrophy (LVH). Additionally, the study sought to determine whether captopril intervention could reduce the impact of sustained PTH stimulation and excessive salt intake on LVH. Methodology We employed 40 eight-week-old male Sprague-Dawley rats, which were randomly assigned to eight groups: a sham group, a PTH group, a low-salt group (0.6% NaCl), a high-salt group (8% NaCl), a PTH + low-salt group, a PTH + high-salt group, a PTH + low salt + captopril group, and a PTH + high salt + captopril group. The rats were continuously infused with recombinant PTH (1-34) (2 pmol/kg per hour) via an osmotic pump for two weeks and were administered varying concentrations of saline for gavage over two weeks, according to their group. We monitored changes in blood pressure, measured heart weight, left ventricular wall thickness, and myocardial histological morphology, and assessed the relative expression of type III collagen. Results The PTH + high-salt group displayed a significant increase in blood pressure, heart weight, and left ventricular posterior wall thickness (P＜0.05), in addition to myocardial cell hypertrophy and increased Col III expression (P＜0.05), compared to other groups. Captopril intervention significantly reduced blood pressure (P＜0.05), ameliorated myocardial tissue morphology changes, and significantly decreased Col III expression (P＜0.05) but did not entirely reverse the increase in heart weight and left ventricular posterior wall thickness (P＞0.05). Conclusions Our findings suggest that the co-intervention of PTH and high salt can lead to an increase in blood pressure, heart weight, myocardial cell hypertrophy, LVH, and myocardial fibrosis levels in Sprague-Dawley rats. Captopril intervention can lower blood pressure and alleviate pathological myocardial tissue changes and myocardial fibrosis but cannot completely reverse LVH.

Characteristics of gut microbiota in male periadolescent rats with irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder, however, its effect on gut microbiota during the periadolescent period remains unclear. In this study, our objective was to investigate the characteristics of gut microbiota in male periadolescent rats with IBS induced by neonatal maternal separation (NMS). We evaluated visceral sensitivity by electromyography (EMG), analyzed gut microbiota composition using 16S rDNA gene sequencing, and examined intestinal pathological changes between control and IBS-like groups. The IBS-like group had significantly higher discharge amplitude of the external oblique muscle of the abdomen during colorectal distension (CRD) at 40- and 60 mmHg pressures. We observed differences in gut microbiota composition, with an increase in Bacteroidetes abundance and a decrease in Firmicutes in IBS-like rats. Beta-diversity analysis revealed the gut microbiota of the IBS-like group displayed higher consistent, while that of the control group exhibited substantial variation. Linear discriminant analysis effect size (LEfSe) detected 10 bacterial taxonomic clades showing statistically significant differences (7 increased and 3 decreased) in the IBS-like group. Functional analysis revealed that aminoacyl-tRNA biosynthesis and fatty acid biosynthesis were significantly altered, leading to changes in gene expression. Our findings demonstrate a definite correlation between gut microbiota dysbiosis and IBS during the male periadolescent period, with Alloprevotella and Bacteroide positively associated with high risk of IBS. The effects of specific bacterial genera may provide new insights for the development of treatments for IBS.

No significant association of serum klotho concentration with blood pressure and pulse wave velocity in a Chinese population.

Klotho, an important anti-aging protein, may be related to elevated blood pressure (BP) and arterial stiffness. We aimed to investigate associations between the serum klotho concentration and peripheral/central BP and arterial stiffness based on the carotid-femoral pulse wave velocity (cfPWV) in a Chinese population. We invited all inhabitants aged ≥ 18 years in two Dali communities for participation. The SphygmoCor system was used to record radial arterial waveforms. Aortic waveforms were derived using a generalized transfer function. The central BP was assessed by calibrating the brachial BP, which was measured using an oscillometric device. The serum klotho concentration was measured using an enzyme-linked immunosorbent assay and logarithmically transformed. Of the 716 participants (mean age: 51.9 ± 12.6 years), 467 (65.2%) were women. The median serum klotho concentration was 381.8 pg/mL. The serum klotho concentration did not significantly differ between patients with and without hypertension (P > 0.05) and between those with and without arterial stiffness (cfPWV ≥ 10 m/s) (P > 0.05). After adjusting for confounders, the serum klotho concentration was not significantly associated with the peripheral or central BP (P > 0.05) and cfPWV (P > 0.05). Our data indicated that the serum klotho concentration was not associated with BP or cfPWV in the general Chinese population.

Association of thyroid hormones with blood pressure and arterial stiffness in the general population: The Dali study.

Thyroid dysfunction plays a role in blood pressure (BP) regulation. However, the associations between thyroid function and BP and arterial stiffness in the general Chinese population without thyroid disease are unknown. This population-based cross-sectional study aimed to investigate the association between thyroid function and peripheral and central BP and arterial stiffness in Chinese individuals. After excluding those who had thyroid diseases or incomplete clinical measurements, this study included 691 participants. Of the participants, 444 (64.2%) were women and 215 (31.1%) had hypertension. After adjustment for covariates, serum FT3 was significantly associated with a higher pulse rate in both sexes. In men, each 2.72-fold increase in serum FT4 levels was associated with higher peripheral systolic BP (+10.82 mmHg, p = .005) and pulse pressure (+5.71 mmHg, p = .03). Each 2.72-fold increase in serum FT4 levels was associated with higher central systolic BP (+8.03 mmHg, p = .03) and pulse pressure (+3.89 mmHg, p = .05). In women, serum FT4 was only associated with a higher central pulse pressure (+2.96 mmHg, p = .04). After adjustment for covariates, serum FT4 was significantly associated with a faster cfPWV exclusively in men. Our study showed that serum FT4 is associated with higher peripheral and central BP and faster cfPWV in men, whereas serum FT3 is positively associated with a higher pulse rate in both sexes, indicating that the effects of thyroid function on BP and arterial stiffness are more significant in men than in women.