Vitamin D status in female dogs with mammary gland tumors.

Background: Little information exists about vitamin D status in bitches with mammary tumors.

Objectives: To determine whether low plasma vitamin D concentrations are found in bitches with mammary tumors.

Animals: Eighty-five client-owned bitches with mammary tumors (n = 21 benign, n = 64 malignant) and 39 age-matched healthy bitches.

Rapamycin downregulates α-klotho in the kidneys of female rats with normal and reduced renal function.

Both mTOR and α-klotho play a role in the pathophysiology of renal disease, influence mineral metabolism and participate in the aging process. The influence of mTOR inhibition by rapamycin on renal α-klotho expression is unknown. Rats with normal (controls) and reduced (Nx) renal function were treated with rapamycin, 1.

Oral Acid Load Down-Regulates Fibroblast Growth Factor 23.

Increased dietary acid load has a negative impact on health, particularly when renal function is compromised. Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that is elevated during renal failure. The relationship between metabolic acidosis and FGF23 remains unclear.

Structural and ultrastructural renal lesions in rats fed high-fat and high-phosphorus diets.

Background: Foods prone to deteriorate renal function are rich in fat and in phosphorus (P), but the interaction between these two factors is not well studied.

Method: Detailed structural and ultrastructural histopathological studies were performed on the kidneys of rats fed different amounts of fat and P: low (4%) fat (LF) and normal (0.6%) P (NP), LF and high (1.

Increased 1,25(OH)-Vitamin D Concentrations after Energy Restriction Are Associated with Changes in Skeletal Muscle Phenotype.

The influence of energy restriction (ER) on muscle is controversial, and the mechanisms are not well understood. To study the effect of ER on skeletal muscle phenotype and the influence of vitamin D, rats ( = 34) were fed a control diet or an ER diet. Muscle mass, muscle somatic index (MSI), fiber-type composition, fiber size, and metabolic activity were studied in tibialis cranialis (TC) and soleus (SOL) muscles.

Caloric Intake in Renal Patients: Repercussions on Mineral Metabolism.

The aim of this paper is to review current knowledge about how calorie intake influences mineral metabolism focussing on four aspects of major interest for the renal patient: (a) phosphate (P) handling, (b) fibroblast growth factor 23 (FGF23) and calcitriol synthesis and secretion, (c) metabolic bone disease, and (d) vascular calcification (VC). Caloric intake has been shown to modulate P balance in experimental models: high caloric intake promotes P retention, while caloric restriction decreases plasma P concentrations. Synthesis and secretion of the phosphaturic hormone FGF23 is directly influenced by energy intake; a direct correlation between caloric intake and FGF23 plasma concentrations has been shown in animals and humans.

Effect of caloric restriction on phosphate metabolism and uremic vascular calcification.

Caloric restriction (CR) is known to have multiple beneficial effects on health and longevity. To study the effect of CR on phosphorus metabolism and vascular calcification (VC), rats were fed normal or restricted calories (67% of normal). The phosphorus content of the diets was adjusted to provide equal phosphorus intake independent of the calories ingested.

Direct regulation of fibroblast growth factor 23 by energy intake through mTOR.

To test the hypothesis that fibroblast growth factor 23 (FGF23) is directly regulated by energy intake, in vivo and in vitro experiments were conducted. Three groups of rats were fed diets with high (HC), normal (NC) and low (LC) caloric content that resulted in different energy intake. In vitro, UMR106 cells were incubated in high (HG, 4.

Hypocaloric Diet Prevents the Decrease in FGF21 Elicited by High Phosphorus Intake.

The effect of dietary phosphorus (P) on fibroblast growth factor 21 (FGF21)/β-klotho axis was investigated in rats that were fed diets with: Normal (NP) or high P (HP) and either normal (NC), high (HC) or low calories (LC). Sampling was performed at 1, 4 and 7 months. Plasma FGF21 concentrations were higher ( < 0.

Increased Phosphaturia Accelerates The Decline in Renal Function: A Search for Mechanisms.

In chronic kidney disease (CKD), high serum phosphate concentration is associated with cardiovascular disease and deterioration in renal function. In early CKD, the serum phosphate concentration is normal due to increased fractional excretion of phosphate. Our premise was that high phosphate intake even in patients with early CKD would result in an excessive load of phosphate causing tubular injury and accelerating renal function deterioration.

Phosphorus restriction does not prevent the increase in fibroblast growth factor 23 elicited by high fat diet.

This study was designed to evaluate the influence of phosphorus (P) restriction on the deleterious effects of high fat diets on mineral metabolism. Twenty-four rats were allotted to 3 groups (n = 8 each) that were fed different diets for 7 months. Rats in group 1 were fed normal fat-normal P (0.

Vitamin E protects against extraskeletal calcification in uremic rats fed high fat diets.

Background: High fat diets are implicated in the pathogenesis of metabolic syndrome, obesity and renal disease. Previous studies have revealed that high fat diets promote vascular calcification in uremic rats. Moreover, vitamin E has been shown to prevent uremic calcifications in genetically obese Zucker rats fed standard diet.

Dietary magnesium supplementation prevents and reverses vascular and soft tissue calcifications in uremic rats.

Although magnesium has been shown to prevent vascular calcification in vitro, controlled in vivo studies in uremic animal models are limited. To determine whether dietary magnesium supplementation protects against the development of vascular calcification, 5/6 nephrectomized Wistar rats were fed diets with different magnesium content increasing from 0.1 to 1.

Obesity-induced discrepancy between contractile and metabolic phenotypes in slow- and fast-twitch skeletal muscles of female obese Zucker rats.

A clear picture of skeletal muscle adaptations to obesity and related comorbidities remains elusive. This study describes fiber-type characteristics (size, proportions, and oxidative enzyme activity) in two typical hindlimb muscles with opposite structure and function in an animal model of genetic obesity. Lesser fiber diameter, fiber-type composition, and histochemical succinic dehydrogenase activity (an oxidative marker) of muscle fiber types were assessed in slow (soleus)- and fast (tibialis cranialis)-twitch muscles of obese Zucker rats and compared with age (16 wk)- and sex (females)-matched lean Zucker rats ( = 16/group).

Mangiferin protects against adverse skeletal muscle changes and enhances muscle oxidative capacity in obese rats.

Obesity-related skeletal muscle changes include muscle atrophy, slow-to-fast fiber-type transformation, and impaired mitochondrial oxidative capacity. These changes relate with increased risk of insulin resistance. Mangiferin, the major component of the plant Mangifera indica, is a well-known anti-inflammatory, anti-diabetic, and antihyperlipidemic agent.

Energy-dense diets increase FGF23, lead to phosphorus retention and promote vascular calcifications in rats.

Rats with normal renal function (Experiment 1, n = 12) and uninephrectomized (1/2Nx) rats (Experiment 2, n = 12) were fed diets with normal P (NP) and either normal (NF) or high fat (HF). Rats with intact renal function (Experiment 3, n = 12) were also fed NF or HF diets with high P (HP). Additionally, uremic (5/6Nx) rats (n = 16) were fed HP diets with NF or HF.

Chronic Vitamin D Intoxication in Captive Iberian Lynx (Lynx pardinus).

To document the biochemical and pathologic features of vitamin D intoxication in lynx and to characterize mineral metabolism in healthy lynx, blood samples were obtained from 40 captive lynx that had been receiving excessive (approximately 30 times the recommended dose) vitamin D3 in the diet, and from 29 healthy free ranging lynx. Tissue samples (kidney, stomach, lung, heart and aorta) were collected from 13 captive lynx that died as a result of renal disease and from 3 controls. Vitamin D intoxication resulted in renal failure in most lynx (n = 28), and widespread extraskeletal calcification was most severe in the kidneys and less prominent in cardiovascular tissues.

Acid-base balance in uremic rats with vascular calcification.

Background/aims: Vascular calcification (VC), a major complication in humans and animals with chronic kidney disease (CKD), is influenced by changes in acid-base balance. The purpose of this study was to describe the acid-base balance in uremic rats with VC and to correlate the parameters that define acid-base equilibrium with VC.

Methods: Twenty-two rats with CKD induced by 5/6 nephrectomy (5/6 Nx) and 10 nonuremic control rats were studied.

Assessment of calcitonin response to experimentally induced hypercalcemia in cats.

Objective: To characterize the dynamics of calcitonin secretion in response to experimentally induced hypercalcemia in cats.

Animals: 13 healthy adult European Shorthair cats.

Procedures: For each cat, the calcitonin response to hypercalcemia (defined as an increase in ionized calcium concentration > 0.

Mineral metabolism in growing cats: changes in the values of blood parameters with age.

The purpose of this study was to describe changes in calcium, phosphorus, magnesium, parathyroid hormone, calcitriol and calcidiol in cats from 3 to 15 months of age. Fourteen European shorthair healthy cats of both sexes (seven males, seven females) belonging to a research colony were studied from 3 to 15 months of age. Plasma concentrations of total calcium, ionised calcium, albumin, phosphorus, magnesium, intact parathyroid hormone (I-PTH), whole parathyroid hormone (W-PTH), calcidiol and calcitriol were measured at 3, 6, 9, 12 and 15 months of age.

HLA-A, -B, and -DRB1 allelic and haplotypic diversity in a sample of bone marrow volunteer donors from Rio Grande do Sul State, Brazil.

The HLA A, B, and DRB1 allele, phenotype, and haplotype frequencies were studied in a sample of 5,000 volunteer bone marrow donors registered at the Brazilian Volunteer Bone Marrow Donor Registry. The participants live in the state of Rio Grande do Sul and were classified according to ethnic group (4,428 Caucasians, 324 mestizos [mixed race], and 248 blacks). Typing was performed using the polymerase chain reaction sequence-specific oligonucleotide method combined with Luminex technology.