Effect of CKD-MBD therapies on the gastrointestinal expression of phosphate transporters

Background: Chronic kidney disease-mineral and bone disorder (CKD-MBD) is prevalent and encompasses biochemical abnormalities, bone alterations, and vascular calcifications. CKD-MBD treatments include phosphate binders and calcimimetics that effectively lower phosphorus and PTH, respectively, but the impact of these treatments on phosphate transporters in the gastrointestinal tract is still unknown. NaPi2B is considered the primary intestinal phosphate transporter. However, NaPi2B inhibition shows limited effectiveness, thus the importance of PIT1 and PIT2 requires further investigation. Methods: We tested the effects phosphate binders (ferric citrate (FC) and calcium gluconate (Ca)) and the calcimimetic KP2326 (KP) in (Cy/+ male rat; CKD) and untreated normal littermates (NL). Treatments lasted 10 weeks until euthanasia at 28 weeks (moderate-to-advanced CKD), where we collected mucosa samples from duodenum, jejunum, and ileum. Blood was collected for biochemistry measurements. Total RNA was isolated, and qPCR performed to assess phosphate transporters expression (NaPi2B, PIT1, PIT2) normalized to b-actin. Results were analyzed via 2-way ANOVA. Results: As expected, CKD had abnormal plasma concentrations of phosphorus, PTH, and FGF23. FC and KP effectively lowered phosphorus. KP and Ca lowered PTH, but Ca increased FGF23. NaPi2B was expressed in the duodenum and jejunum but not in the ileum, and its expression was upregulated with FC compared to NL. PIT1 was expressed in all segments, but the expression was the highest in the ileum, while PIT2 was constitutively expressed in all segments. Ca led to higher PIT1 and PIT2 expression in the duodenum and jejunum compared to NL, CKD, or KP. KP led to higher expression of PIT1 in the ileum compared to CKD, FC, and Ca. Conclusions: CKD-MBD therapies differentially impacted biochemistries and phosphate transporters expression. The effect of Ca on gastrointestinal expression of PIT1 and PIT2 may explain the higher plasma phosphorus and should be further explored.

EFFECT OF PHOSPHORUS SUPPLEMENTATION ON PREGNANCY IN WHITE FULANI (BUNAJI) CATTLE

THE effect of bone meal supplementation on pregnancy and plasma phosphorus level in White Fulani (Bunaji) cattle was investigated over a 13-month period. The monthly mean plasma levels of inorganic phosphorus for supplemented Cows varied from 4.63mg/100ml in dry season to 8.09mg/100ml in the rainy season in contrast to 3.07 to 7.09/100ml in the dry and rainy seasons respectively, for the controls. Bonemeal supplementation resulted in earlier conception and calving. Fifty percent of the supplemented cows calved by the end of the period of supplementation in contrast to 25 percent of the controls. By two months after the study period, 100% of cows that received the supplementation had conceived compared with 87.50% of the controls. It is concluded from the study that bonemeal is a practical method for improving the fertility of White Fulani cattle in the grazing areas of Nigeria where soil and forage are deficient in phosphorus

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. After 50 days of CR, rats had negative phosphorus balance, lower plasma phosphorus, glucose, triglycerides, and leptin, and higher adiponectin than rats fed normal calories. Uremia was induced by 5/6 nephrectomy (Nx). After Nx, rats were treated with calcitriol (80 ng/kg ip every other day) and high-phosphorus diets (1.2% and 1.8%). No differences in aortic calcium content were observed between rats that ate normal or restricted calories before Nx in either rats that received 1.2% phosphorus (11.5 ± 1.7 vs. 10.9 ± 2.1 mg/g tissue) or in rats that received 1.8% phosphorus (12.5 ± 2.3 vs. 12.0 ± 2.9 mg/g of tissue). However, mortality was significantly increased in rats subjected to CR before Nx in both the 1.2% phosphorus groups (75% vs. 25%, P = 0.019) and 1.8% phosphorus groups (100% vs. 45%, P < 0.001). After calcitriol administration was stopped and phosphorus intake was normalized, VC regressed rapidly, but no significant differences in aortic calcium were detected between rats that ate normal or restricted calories during the regression phase (5.7 ± 2.7 and 5.2 ± 1.5 mg/g tissue). In conclusion, CR did not prevent or ameliorate VC and increased mortality in uremic rats.

Comparative Plasma Endocrine, Metabolic and Mineral Profile of Cyclic, Acyclic, Endometritic and Pregnant Buffaloes

Circulating concentrations of hormones, metabolites, and minerals reflect the physio-pathological status of reproduction in animals. This study was carried out on infertile (anestrus, endometritic), normal healthy cyclic and pregnant buffaloes to evaluate the comparative plasma progesterone (P4) and estrogen (E2) hormones, plasma total protein, total cholesterol, calcium, and phosphorus profile. The study showed higher mean plasma E2 and lower P4 levels in the follicular phase of estrous cycle in buffaloes. Significantly (p less than 0.05) higher mean plasma P4 level and lower E2 levels were recorded during the luteal phase and in endometritic and pregnant buffaloes. Total plasma protein concentration was non-significantly higher in normal cyclic than acyclic and endometritic buffaloes. It was also comparatively lower in buffalo with 9 months of pregnancy than 3 and 6 months of pregnancy. The mean plasma total cholesterol level was significantly (p less than 0.05) higher in pregnant than acyclic and endometritic buffaloes. Cyclic buffaloes had significantly (p less than 0.05) higher mean plasma calcium levels than acyclic buffaloes. Plasma phosphorus concentration, however, did not show any significant difference between different stages of the reproductive cycle.

Effect of Fibrinolytic Microbes and Enzymes on Biochemical Blood Parameters in Crossbred Calves

Twenty crossbred (HF x Kankrej) calves were allotted randomly to five groups (each had one male and three female calves) almost with similar body weight (85.70±6.37 kg) and age (167.55±21.70 days). Experimental calves of the control group were offered hybrid napier untreated, and the other four groups were offered hybrid napier treated with (i) fungus- Aspergillus spp. (1×107 per g feed), (ii) fibrolytic bacteria- Escherichia spp. (106 CFU per g feed), (iii) xylanase (50 mL/kg having xylanase 1.2 IU/mL), and (iv) consortium of 1/3rd dose of fungus + bacteria + enzyme as treatments for 140 days. The blood samples were collected from each calf at a biweekly intervals in the EDTA vacuttee. Nutrients offered to crossbred calves were sufficient to satisfy the nutrients requirements. Bacteria fed calves had significantly higher (plessthan0.05) mean hemoglobin levels than control. Blood plasma glucose of calves in fibrolytic microbes and enzyme groups was statistically similar to control. Feeding of fungus, bacteria, enzyme, and consortium was without a significant effect on plasma total proteins.In comparison to control (7.53 mg/dL), the plasma phosphorus was significantly (plessthan0 0.05) higher in calves fed enzyme (7.87 ± 0.20 mg/dl) and lower in group fed fungus (7.13 mg/dL). In contrast, in bacteria (7.57 mg/dL) and consortium group (7.60 mg/dL) it was statistically similar to control. Plasma glutamic pyruvic transaminase concentration of crossbred calves was lower ( pless than 0.05) in enzyme and higher (p lessthan 0.05) in fungus, bacteria, and consortium groups than in control, while plasma glutamic oxaloacetate transaminase concentration in all groups was statistically similar. In conclusion, all blood parameters of different groups were within normal range and without adverse effect on the overall performance of calves.

Hypophosphatemia after High Dosage Iron Substitution with Ferric Carboxymaltose (FCM) and Iron Isomaltoside (IM) — the Randomised Controlled Home Afers 1 Trial

In iron deficiency anaemia patients, intravenous administration of either ferric carboxymaltose (FCM) or iron isomaltoside (IM) both allow high dosage iron substitution within a single outpatient visit. In contrast, other iron compounds require repetitive, low dosage infusions. Recently, FCM was reported to frequently induce acute, reversible hypophosphatemia. It remains enigmatic whether these hypophosphataemic effects of FCM are substance-specific, or whether they generally occur after high dosage iron substitution. A direct comparison of phosphorus regulation after high dosage iron substitution with either FCM or IM is clinically important, as hypophosphatemia after FCM has anecdotally been associated with osteomalacia and bone fractures. In the HOMe AFers 1 (HOMburg evaluations on application of Ferrum study 1) trial, we recruited normophosphatemic women with gynaecological bleeding and subsequent iron deficiency anaemia, in whom we assessed the longitudinal biochemical response over 28 days to a single intravenous injection of equivalent doses of randomly-assigned FCM and IM (1000 mg). The primary study hypothesis was that the incidence of hypophosphatemia - defined as plasma phosphorus < 2.0 mg/dl at least out of three post-infusion study time points (day 1, day 8, and week 5) - differs between FCM and IM. HOMe AFers 1 initially planned to recruit 60 women. An interim analysis was pre-specified and scheduled in July 2018, with the option to stop further patient recruitment if the incidence of hypophosphatemia differs significantly at this interim analysis. At the time point of the interim analysis, 26 patients have been recruited. One patient withdrew her acceptance to participate after day 1, leaving 25 patients for our per protocol interim analysis. Baseline plasma phosphorus did not differ significantly between FMC (3.3 ± 0.4 mg/dl) and IM (3.6 ± 0.6 mg/dl; p = 0.135). Analysis on the primary endpoint demonstrated that significantly more women developed hypophosphatemia < 2.0 mg/dl after FMC infusion (9 out of 12 patients) than after IM infusion (1 out of 13 patient) (p=0.001). Further, the minimum plasma phosphorus during any of the three post-infusion study time points was lower after FMC (1.8 ± 0.3 mg/dl) than after IM (2.7 ± 0.6 mg/dl; p < 0.001). As expected, ferritin and haemoglobin increased in both study groups after iron infusion. No severe adverse events occurred in either group. In conclusion, while both FCM and IM provide efficient iron substitution in iron deficiency anaemia, FCM induced a substantially higher incidence of hypophosphatemia. Disclosures Emrich: Pharmacosmos: Consultancy, Honoraria, Research Funding. Stilgenbauer:Mundipharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmcyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genzyme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Hoffmann La-Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Brandenburg:Pharmacosmos: Consultancy, Honoraria, Research Funding; Vifor: Consultancy, Honoraria. Heine:Pharmacosmos: Consultancy, Honoraria, Research Funding.