Effect of suramin on urinary excretion of diabetes-induced glomerular and tubular injury parameters in rats

Diabetes mellitus causes changes in metabolism of extracellular nucleotides acting through P2 receptors (P2Rs). This affects renal function and may lead to glomerular and tubular disturbances. We measured urinary excretion of nucleotides (ATP, ADP, AMP, UTP, UDP, UMP) in streptozotocin-induced diabetic rats (65 mg/kg, i.p., day 0) and the effects of P2Rs' blockade by suramin (10 mg/kg, i.p., days +7, +14) on glomerular P2×7R expression and urinary excretion of glomerular (albumin, nephrin) and tubular (KIM-1, NGAL) injury markers, electrolytes, and oxidative stress markers (TBARS, 8-OHdG). Concentrations of nucleotides, specific proteins, electrolytes, and oxidative stress markers in 24-h urine samples collected in metabolic cages at days -1, +6 and +20 were measured using ion-paired reversed-phase HPLC, immunoenzymatic and fluorometric methods, and flame photometry, respectively. Expression of KIM-1 and P2×7R was examined by immunohistochemistry or immunoblotting. Diabetes was associated with increased urinary excretion of ATP, ADP, UTP, UDP and glomerular P2×7R expression. Suramin attenuated P2×7R expression but did not affect urinary excretion of nucleotides. Urinary excretion of albumin, nephrin, NGAL, and 8-OHdG were increased in diabetic rats and were not affected by suramin. TBARS was higher in diabetic rats and suramin attenuated the excretion dynamics in this group. KIM-1 excretion was higher in diabetic rats and suramin further increased excretion of KIM-1 in both diabetic and non-diabetic rats. Furthermore, suramin attenuated the diabetes-induced natriuresis and kaliuresis. It is possible that suramin affects both glomerular and tubular functions in diabetic rats.

Higher responsiveness to rosuvastatin in polygenic versus monogenic hypercholesterolaemia: a propensity score analysis

Background

The underlying monogenic defect in familial hypercholesterolemia (FH) can be detected in ∼40% of cases. The majority of mutation-negative patients have a polygenic cause of high LDL-cholesterol (LDL-C) due to having inherited a greater than average number of common LDL-C raising single nucleotide polymorphisms (SNPs).

Purpose

We sought to investigate, whether the monogenic or polygenic defect in FH is associated with the response to rosuvastatin.

Methods

Individuals with a clinical diagnosis of FH were tested for mutations in LDLR and APOB genes. A previously established LDL-C-specific polygenic risk score (PRS) was used to examine the possibility of polygenic hypercholesterolemia in mutation negative patients. The propensity score analysis was performed to evaluate the variables associated with the response to rosuvastatin. The type of hypercholesterolemia (polygenic or monogenic) and following variables: age, gender, LDL-baseline, statin intolerance, ezetimibe use, rosuvastatin dose, diabetes and cardiovascular disease (CVD), were examined to minimize the bias of this observational study.

Results

LDLR/APOB mutation was found in 47 (42%) patients, whereas polygenic hypercholesterolemia was diagnosed in 65 (58%) of patients. Mean age was comparable in both groups (54±13 vs 51±13, p=0.134). CVD was diagnosed in ≈26% of individuals in both cohorts (p=0.343). There was no difference in the distribution of CV risk factors, such as arterial hypertension, smoking, diabetes, body mass index and in rate of statin intolerance. Monogenic subjects had higher baseline LDL-C compared to polygenic (Table 1). Adjusted model showed a lower percentage of change in LDL-C after rosuvastatin treatment in monogenic vs. polygenic subjects (46% vs 55%, p<0.001) (Figure 1). The probability of achieving LDL-C targets in monogenic FH was lower than in polygenic subjects (0.075 vs. 0.245, p=0.004). Polygenic patients were more likely to achieve LDL-C goals, compared to mutation-positive patients (OR 3.28; 95% CI:1.23–8.72).

Conclusion

Our findings indicate an essentially higher responsiveness to rosuvastatin in patients with a polygenic cause, as compared to those carrying monogenic mutations.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): 1. Polish Ministry of Science and Higher Education European Regional Development Fund under the Programme Innovative Economy 2007–2013 (POIG.01.01.02-22-079/09). 2. British Heart Foundation (PG 08/008). 3. The National Institute for Health Research, University College London Hospitals, Biomedical Research Centre. 4. The Foundation Leducq Transatlantic Networks of Excellence Program grant (no. 14 CVD03)

Disposition of cimicoxib in plasma and milk of whelping bitches and in their puppies

BACKGROUND

Caesarean section of bitches is a well recognized painful condition in dogs and it can be classified as a soft tissue surgery. Cimicoxib, a newly registered NSAID in European Union has a claim for the relief of pain in peri-operative conditions. However, in case of caesarean section, the main concerns of using NSAIDs are the transfer of the drugs into milk and its impact on the suckling pups. Thus, the aim of the present work was to evaluate the transfer of cimicoxib into the milk of 6 lactating bitches after a single oral administration of the drug on day 0 (just after whelping) and on day 28 at the target dose of 2 mg/kg. Another aim of the study was to evaluate the transfer of the drug from the milk into the suckling pups. Blood and milk samples were collected from the bitches after each administration on day 0 and day 28 and blood samples were drawn from the pups after suckling on day 28.

RESULTS

All bitches whelped without any complication and gave birth to 38 pups. After administration on D0, the mean observed plasma Cmax in bitches was 0.5323 μg/mL and the mean area under the concentration-time curve extrapolated to the infinity, AUCINF, was 2.411 μg.h/mL. After administration on D28, only AUCINF was significantly higher with a value of 3.747 μg.h/mL. In milk, after administration on D0, the mean observed Cmax was 0.9974 μg/mL and the mean area under the concentration-time curve until the last measurable time point, AUClast, was 4.205 μg.h/mL. Out of 24 sampled pups on D28, only 2 animals had a sample with very low cimicoxib concentrations slightly above the limit of quantification (0.01 μg/mL).

CONCLUSION

The presented data show that cimicoxib given by oral route to lactating bitches at a single dose of 2 mg/kg had a high transfer rate into the milk with a milk to plasma ratio of 1.7 to 1.9. The transfer rate to the suckling pups was low and no clinical abnormalities were detected in both bitches and pups.

Use of anti-infective agents during lactation, Part 3: Antivirals, antifungals, and urinary antiseptics

Because many antibiotics are excreted into the breast milk, it can be difficult for a practitioner to choose an antibiotic for a lactating patient that will have minimal risks to her nursing infant. This article is the last of a three-part series discussing the use of anti-infective agents during lactation. The authors review general information with regard to use and common side effects for several classes of antibiotics. They summarize information, including available safety data, documented milk concentrations, milk-to-plasma ratios, and other pharmacokinetic properties, to help practitioners choose antibiotics that may be considered safe to use in the lactating mother.

Use of anti-infective agents during lactation: Part 2--Aminoglycosides, macrolides, quinolones, sulfonamides, trimethoprim, tetracyclines, chloramphenicol, clindamycin, and metronidazole

Because many antibiotics are excreted into breast milk, it can be difficult for a practitioner to choose an antibiotic for a lactating patient that will have minimal risks to her nursing infant. This article is the second of a three-part series discussing the use of anti-infective agents during lactation. The authors review general information regarding use and common side effects for several classes of antibiotics. They also summarize information, including documented milk concentrations, milk-to-plasma ratios, and other pharmacokinetic properties, in a table that can help practitioners choose antibiotics that may be considered safe to use in the lactating mother.