scholarly journals Modification of single Ca channel by adrenaline.

1986 ◽  
Vol 6 (1) ◽  
pp. 15-18
Author(s):  
RIKUO DAICHI
Keyword(s):  
Ca Channel ◽  
Single Ca Channel

Single Ca channel currents in mouse pancreatic B-cells

1988 ◽  
Vol 412 (6) ◽  
pp. 597-603 ◽  
Author(s):  
P. Rorsman ◽  
F. M. Ashcroft ◽  
G. Trube
Keyword(s):  
B Cells ◽  
Ca Channel ◽  
Pancreatic B Cells ◽  
Channel Currents ◽  
Single Ca Channel

scholarly journals P0828CKD STAGE DISTRIBUTION IN AN ITALIAN PROVINCE; SEVEN YEARS OF FOLLOW UP

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Alessandro Roggeri ◽  
Daniela Paola Roggeri ◽  
Carlotta Rossi ◽  
Marco Gambera ◽  
Rossana Piccinelli ◽  
...  
Keyword(s):  
Hospital Discharge ◽  
Administrative Database ◽  
Ca Channel ◽  
Dialysis Treatment ◽  
First Choice ◽  
Stage 4 ◽  
Ckd Stage ◽  
Significant Difference ◽  
Stage 1

Abstract Background and Aims Chronic kidney disease (CKD) is a chronic illness with important implications for the health of the population and for the commitment of resources by public health services. CKD staging makes it possible to assess the severity of the disease and its distribution in the population. The distribution of the stages of CKD diagnosed through hospitalization were analyzed using administrative database of the Local Health Authority of a province with a population of about 1 million inhabitants in northern Italy. Method Patients with hospital discharge with a diagnosis of CKD (ICD9CM 5851, 5852, 5853, 5854) in 2011- 2012 years, without dialysis treatment, neither transplantation procedure nor acute renal failure were selected. Demographic characteristics, comorbidities, dialysis treatment, drugs prescription and nephrological follow-up were investigated. This cohort of patients was examined over a 7-year period (2011-2017). Stage five was not considered to avoid possible misunderstanding with five D stage. Results 1808 patients diagnosed with CKD were extracted from the 2011-2017 administrative database; of these, 1267 had a diagnosis with the CKD stage specification. The distribution of 1267 patients in the CKD stages at the first hospital discharge was as follows: 7.4% stage 1, 30.9% stage 2, 42.3% stage 3, 19.3% stage 4. The 832 patients described in the study were still alive as of Jan. 1, 2013 while 435 (34.3%) died by Dec. 31, 2012. Until Dec. 31, 2017, 503 of the 832 patients died representing the 52.8% of stage 1 patients, 62% of stage 2 patients, 58.2% of stage 3 patients, 66.4% of stage 4 patients. Males were the most prevalent gender (58.5%), without any significant difference into CKD stages. Our patients have a fairly high age as can be seen from the table 1. The presence of co-morbidities was assessed either directly for the main risk factors or by the modified Charlson index (MCI) for CKD patients. The average value of the MCI is 3.8 ± 3.1 for all patients and 3.4 ±3.0 for stage 1, 4.1 ± 3.3 for stage 2, 3.7 ± 3.1 for stage 3, 3.7 ± 2.9 for stage 4, with maximum values of 12.0, 17.0, 16.0 and 14.0 respectively. About 40% of patients had diabetes mellitus, with the highest prevalence in stage 4 (49.3%) and the lowest in stage 1 (25%). Cardiovascular disease was distributed almost equally among all patients with a value between 82% in stage 1 and 86.3% in stage 4. Cancer were present in 26.3% of patients with similar values in all stages. Just about 9% of patients underwent dialysis treatment for achieving ESRD, with a percentage of 5.6% among patients in stage 1 and 17.1% among those in stage 4. Hemodialysis represented first choice treatment (86%) compared with peritoneal one (14%). Time from the diagnosis of CKD to the first dialysis was variable with an average of 3.4 ±1.7 years; the longest interval for patients in stage 1 (5.1±1.8) and the shortest (3.0 ±1.6) for patients in stage 4. The number of nephrological visits at renal units was analyzed for an assessment of the extent of follow-up and prevention upon reaching the ESRD (table2). More than 90% of patients had prescribed drugs antagonists of the renin angiotensin system, in all stages of CKD; other antihypertensive drugs (Ca channel blockers and peripheral vasodilators) had a similar prescription level. Anemia control drugs (ESA and iron) had an incremental prescription with stages of the disease from 51.4% in stage 1 to 74% in stage 4, similarly to Ca-P metabolism control drugs ranging from 44.4% in stage 1 to 67.8% in stage 4. Conclusion Correct staging of CKD is very important to assess the prognosis of patients, but the major determinants of outcome are comorbidities and age of the patients. The cohort examined has a high mortality rate, far higher than reported in the literature for CKD. It should be noted that the sample was identified by hospitalization for cardiovascular diseases more than 50% complicated by diabetes and hypertension, so death represents the main outcome and not ESRD.

Sodium-calcium exchange-mediated contractions in feline ventricular myocytes

1992 ◽  
Vol 263 (4) ◽  
pp. H1161-H1169 ◽  
Author(s):  
H. B. Nuss ◽  
S. R. Houser
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Ventricular Myocytes ◽  
Membrane Potentials ◽  
Exchange Mechanism ◽  
Ca Channel ◽  
Ca Current ◽  
Voltage Step ◽  
Reverse Mode ◽  
Sodium Calcium ◽  
Calcium Exchange

The hypothesis that Ca entry by the sarcolemmal Na-Ca exchange mechanism induces sarcoplasmic reticulum (SR) Ca release, loads the SR with Ca, and/or directly induces contractions by elevating cytosolic free Ca was tested in voltage-clamped feline ventricular myocytes. Intracellular Na concentration was increased by cellular dialysis to enhance Ca influx via "reverse-mode" Na-Ca exchange at positive membrane potentials, at which the "L-type" Ca current (ICa) should be small. Contractions were induced in the presence of Ca channel antagonists by depolarization to these potentials, suggesting that Ca influx via reverse-mode Na-Ca exchange was involved. These contractions had both phasic (SR related) and tonic components of shortening. They were smaller and began with more delay after depolarization than contractions which involved ICa. The magnitude of shortening was graded by the amount and duration of depolarization, suggesting that Ca influx via reverse-mode Na-Ca exchange has the capacity to induce and grade SR Ca release. Small slow contractions could be evoked in the presence of ryanodine (to impair SR function) and verapamil (to block ICa), supporting the idea that Ca influx via Na-Ca exchange is sufficient to directly activate the contractile proteins. Contractions induced by voltage steps to +10 mV, which were usually small when ICa was blocked, were potentiated if preceded by a voltage step to strongly positive potentials. This potentiation was inhibited by ryanodine, suggesting that Ca entry that occurs by Na-Ca exchange may be important for normal SR Ca loading.(ABSTRACT TRUNCATED AT 250 WORDS)

Cilnidipine, a N+L-type dihydropyridine ca channel blocker, suppresses the occurrence of ventricular premature arrythmia during ischemia and reperfusion in rabbits

2004 ◽  
Vol 10 (5) ◽  
pp. S165
Author(s):  
Nagai Hiroshi ◽  
Minatoguchi Shinya ◽  
Hirohito Onogi ◽  
Chen Xuehai ◽  
Maruyama Rumiko ◽  
...  
Keyword(s):  
Channel Blocker ◽  
Ischemia And Reperfusion ◽  
Ca Channel

scholarly journals Internal and external effects of dihydropyridines in the calcium channel of skeletal muscle.

1990 ◽  
Vol 95 (1) ◽  
pp. 1-27 ◽  
Author(s):  
H H Valdivia ◽  
R Coronado
Keyword(s):  
Skeletal Muscle ◽  
Lipid Bilayers ◽  
Radioligand Binding ◽  
Quantitative Agreement ◽  
Bay K 8644 ◽  
Single Channels ◽  
Ca Channel ◽  
Ca Channels ◽  
Receptor Sites ◽  
Internal Side

The agonist effect of the dihydropyridine (DHP) (-)Bay K 8644 and the inhibitory effects of nine antagonist DHPs were studied at a constant membrane potential of 0 mV in Ca channels of skeletal muscle transverse tubules incorporated into planar lipid bilayers. Four phenylalkylamines (verapamil, D600, D575, and D890) and d-cis-diltiazem were also tested. In Ca channels activated by 1 microM Bay K 8644, the antagonists nifedipine, nitrendipine, PN200-110, nimodipine, and pure enantiomer antagonists (+)nimodipine, (-)nimodipine, (+)Bay K 8644, inhibited activity in the concentration range of 10 nM to 10 microM. Effective doses (ED50) were 2 to 10 times higher when HDPs were added to the internal side than when added to the external side. This sidedness arises from different structure-activity relationships for DHPs on both sides of the Ca channel since the ranking potency of DHPs is PN200-110 greater than (-)nimodipine greater than nifedipine approximately S207-180 on the external side while PN200-110 greater than S207-180 greater than nifedipine approximately (-)nimodipine on the internal side. A comparison of ED50's for inhibition of single channels by DHPs added to the external side and ED50's for displacement of [3H]PN200-110 bound to the DHP receptor, revealed a good quantitative agreement. However, internal ED50's of channels were consistently higher than radioligand binding affinities by up to two orders of magnitude. Evidently, Ca channels of skeletal muscle are functionally coupled to two DHP receptor sites on opposite sides of the membrane.

Blockade of Dual T- and L-type Ca Channel Prevents Sudden Death in Mouse Model of Heart Failure Through both Direct and Indirect Cardiac Effects

2007 ◽  
Vol 13 (6) ◽  
pp. S30
Author(s):  
Hideyuki Kinoshita ◽  
Koichiro Kuwahara ◽  
Masaki Harada ◽  
Yasuaki Nakagawa ◽  
Michio Nakanishi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Sudden Death ◽  
Mouse Model ◽  
Ca Channel ◽  
Cardiac Effects
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