Recent studies have indicated that derangement of peritubular capillary (PTC) circulation with consequent tubulointerstitial hypoxia plays a pivotal role in the pathogenesis of renal injury. The present study was performed to determine whether azelnidipine, a new dihydropyridine calcium channel blocker, attenuates angiotensin II (AngII)-induced peritubular ischemia in anesthetized rats. The superficial PTCs were visualized directly using an intravital fluorescence videomicroscope system, and the PTC blood flow was evaluated by analyzing the velocity of fluorescein isothiocyanate-labeled erythrocytes. Intravenous infusion of AngII (50 ng/kg/min, 10 min) significantly increased mean arterial pressure (MAP) and renal vascular resistance (RVR) (by 35 +/- 3% and 110 +/- 32%, respectively), and decreased total renal blood flow (RBF) and PTC erythrocyte velocity (by -34 +/- 4 and -37 +/- 1%, respectively). Treatment with azelnidipine (5 microg/kg/min i.v., 10 min) had no effect on basal MAP, RBF, RVR, or PTC erythrocyte velocity. However, azelnidipine markedly attenuated the AngII-induced increases in MAP (7 +/- 3%) and RVR (40 +/- 4%) and decreases in RBF (-24 +/- 1%) and PTC erythrocyte velocity (-22 +/- 1%). Similar attenuation in the AngII-induced responses of MAP, RBF, RVR, and PTC erythrocyte velocity were observed in rats treated with a higher dose of azelnidipine (20 microg/kg/min i.v., 10 min), which significantly decreased basal MAP and RVR and increased RBF and PTC erythrocyte velocity. These data suggest that calcium channel blockade attenuates AngII-induced peritubular ischemia, which may be involved in its beneficial effects on renal injury.

Download full-text PDF

Source
http://dx.doi.org/10.1124/jpet.105.095331DOI Listing

Publication Analysis

Top Keywords

ptc erythrocyte
20
erythrocyte velocity
20
calcium channel
12
peritubular ischemia
12
channel blockade
8
renal injury
8
angii-induced peritubular
8
blood flow
8
+/-
8
rvr +/-
8

Similar Publications

Specific analysis of SOD1 enzymatic activity in CSF from ALS patients with and without SOD1 mutations.

Neurobiol Dis

November 2024

Department of Medical Biosciences, Clinical Chemistry, Umeå University, SE-901 85 Umeå, Sweden. Electronic address:

Mutations in superoxide dismutase-1 (SOD1) are a cause of hereditary amyotrophic lateral sclerosis (ALS) through a gain-of-function mechanism involving unfolded mutant SOD1. Intrathecal gene therapy using the antisense-oligo-nucleotide drug tofersen to reduce SOD1 expression delays disease progression and has recently been approved in the United States and the European Union. However, the discovery of children homozygous for inactivating SOD1 mutations developing the SOD1 Deficiency Syndrome (ISODDES) with injury to the motor system suggests that a too low SOD1 antioxidant activity may be deleterious in humans.

View Article and Find Full Text PDF

We aimed to explore the influence that the circadian blood pressure (BP) profile could exert on the correlation between some inflammatory markers and hypertension-mediated organ damage (HMOD). This was a cross-sectional study that included patients with primary arterial hypertension older than 18 years old. We included some parameters of 24 h ambulatory blood pressure monitoring collection and several inflammatory markers, as follows: platelet count (PTC), erythrocyte sedimentation rate (ESR), ultrasensitive C-reactive-protein, ferritin, fibrinogen, and uric acid.

View Article and Find Full Text PDF

Background: The primary endpoint was to analyze the preoperatory inflammatory markers and platelet indices in papillary thyroid cancer (PTC) patients compared with patients with benign thyroid pathology. The secondary endpoints were to analyze the relationship between these markers and the pathological features of PTC and to compare their pre- and postoperative levels in PTC patients.

Methods: In this retrospective case-control study, we analyzed the files of 1183 patients submitted to thyroidectomy between January 2012 and December 2018.

View Article and Find Full Text PDF

Silver nanoparticles (AgNPs) have been studied worldwide for their potential biomedical applications. Specifically, they are proposed as a novel alternative for cancer treatment. However, the determination of their cytotoxic and genotoxic effects continues to limit their application.

View Article and Find Full Text PDF
Article Synopsis
  • Nonsense-mediated RNA decay (NMD) is an essential process that degrades faulty mRNAs but its exact mechanisms and implications in health and disease are still being explored.
  • A new reporter system and genome-wide CRISPR-Cas9 screening revealed several factors that promote NMD, particularly components of the SF3B complex related to RNA splicing, and highlighted reduced NMD activity in certain cancer-related mutations.
  • The study suggests that targeting the NMD pathway could be a promising therapy for myelodysplastic syndromes and cancers with spliceosome mutations, as enhancing RNase H1 levels can help counteract the negative effects of these mutations.
View Article and Find Full Text PDF

Want 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!