1. We investigated the mechanism of decreased transmucosal calcium transport in the gut of the diabetic rat by comparing calcium uptake by brush border membrane vesicles from control and streptozotocin diabetic rats at 5 days. Brush border calcium uptake consists of saturable and non-saturable components. Saturable uptake is mediated by a specific mobile carrier mechanism and is defined by Vmax (saturable uptake of calcium at infinite medium calcium concentration) and KT (calcium concentration at Vmax/2). Non-saturable uptake is defined by kD (rate constant for non-saturable uptake per unit calcium concentration), and comprises both diffusive and surface binding components of calcium uptake. 2. We found both saturable and non-saturable calcium uptake to be decreased (P < 0.05) in diabetes. Comparing control and diabetic, Vmax was 247 compared to 152 (data are pmol/mg protein per 3 s); kD was 285 compared to 172 (data are pmol/mg protein per 3 s at 1 mmol/L calcium); and KT (mmol/L) did not differ between groups, 0.070 compared to 0.057. 3. The decreased Vmax in the setting of unchanged KT in vesicles from diabetics is consistent with decreased calcium transporter specific activity, rather than with altered transporter function. 4. Since (i) Vmax is decreased by vitamin D deficiency in the normal rat, and (ii) circulating 1 alpha, 25-dihydroxycholecalciferol is decreased in the diabetic rat, decreased Vmax in the diabetic may be related to the low 1 alpha,25-dihydroxycholecalciferol.(ABSTRACT TRUNCATED AT 250 WORDS)
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1111/j.1440-1681.1995.tb01993.x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Core-Shell Nanoparticles with Sequential Drug Release Depleting Cholesterol for Reverse Tumor Multidrug Resistance.
ACS Appl Mater Interfaces
January 2025
School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China.
Multidrug resistance (MDR) facilitates tumor recurrence and metastasis, which has become a main cause of chemotherapy failure in clinical. However, the current therapeutic effects against MDR remain unsatisfactory, mainly hampered by the rigid structure of drug-resistant cell membranes and the uncontrolled drug release. In this study, based on a sequential drug release strategy, we engineered a core-shell nanoparticle (DOX-M@CaP@ATV@HA) depleting cholesterol for reverse tumor MDR.
View Article and Find Full Text PDFRetrospectively diagnosed familial hypocalciuric hypercalcaemia following total parathyroidectomy in an asymptomatic patient.
EJIFCC
December 2024
Department of Chemical Pathology, Inkosi Albert Luthuli Central Hospital, National Health Laboratory Service and University of KwaZulu Natal, Durban, South Africa.
Background: Familial hypocalciuric hypercalcemia (FHH) is a rare, benign condition that shares characteristics with primary hyperparathyroidism (PHPT), a more sinister condition that requires surgical intervention. This case report demonstrates misdiagnosis of FHH and highlights important learning points to prevent this in the future.
Case Presentation: Hypercalcaemia was incidentally discovered in a 21-year-old patient who had no symptoms of hypercalcaemia and no significant family history.
Evaluating the bioavailability of rare earth elements in paddy soils and their uptake in rice grains for human health risk.
Environ Geochem Health
January 2025
Department of Agricultural Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
Rare earth elements (REEs) are a critical global focus due to their increasing use, raising concerns about their environmental distribution and human exposure, both vital to food safety and human health. Surface soil (0-30 cm) and corresponding rice grain samples (n = 85) were collected from paddy fields in Taiwan. This study investigated the total REE contents in soil through aqua regia digestion, as well as their labile forms extracted using 0.
View Article and Find Full Text PDFPrebiotics as modulators of colonic calcium and magnesium uptake.
Acta Physiol (Oxf)
February 2025
Institute for Molecular Medicine, Health and Medical University Potsdam, Potsdam, Germany.
Ca and Mg are essential nutrients, and deficiency can cause serious health problems. Thus, lack of Ca and Mg can lead to osteoporosis, with incidence rising both in absolute and age-specific terms, while Mg deficiency is associated with type II diabetes. Prevention via vitamin D or estrogen is controversial, and the bioavailability of Ca and Mg from supplements is significantly lower than that from milk products.
View Article and Find Full Text PDFFoliar application of nitrates limits lead uptake by Cucumis sativus L. plants.
J Trace Elem Med Biol
January 2025
Department of Molecular Plant Physiology, Institute of Environmental Biology, Faculty of Biology, University of Warsaw, Ilji Miecznikowa 1, Warszawa 02-096, Poland.
Lead is a toxic heavy metal, which accumulates in the soil and is readily absorbed by plant roots. The uptake of toxic elements by crops is a serious threat to human health. For this reason, it is important to prevent the incorporation of heavy metals into the food chain.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!