Pacemaker Localization in the Renal Pelvis of the Unicalyceal Kidney

Hannappel, J.; Lutzeyer, W

doi:10.1159/000473948

Cited by 19 publications

(15 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast to the results of earlier investi gations in unicalyceal kidneys [5,7], we found spontaneous activity also in many ure teral preparations. As in rabbits, a frequency gradient from the proximal to the distal por tions of the pyeloureter also exists in the mul ticalyceal kidney of the pig if the average spontaneous frequency is calculated (fig.…”

Section: Resultscontrasting

confidence: 99%

“…In the past years, many investigations concerning the pacemaker processes in the pyeloureteral system and the origin of ure teral peristalsis have been published [1][2][3][4][5][6][7], All these papers presented results from ani mals with unicalvceal kidneys, such as rats, guinea pigs, cats, rabbits and dogs. Although there are great interspecies differences, the pacemaker of ureteral peristalsis in unicalyceal kidneys is localized in the most intrarenal parts of the pelvis.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pacemaker Process of Ureteral Peristalsis in Multicalyceal Kidneys

et al. 1982

View full text Add to dashboard Cite

The mechanical activity of isolated strips from different areas of the pyeloureteral system was investigated in 10 pigs: calyx, renal pelvis, pyeloureteral junction and ureter. Additionally, electrical activity was measured in some pyeloureteral preparations using the sucrose-gap technique. Regular spontaneous activity with an average frequency of 9.5/min was recorded in calyceal strips, decreasing to 5.4/min in renal pelvis, 5.7/min in pyeloureteral preparations and to 1.2/min in ureteral preparations. The activity of renal pelvis, pyeloureteral and ureteral preparations was less regular, and bursts of fast activity (near 10/min) could be observed in all these preparations. The membrane potential of pyeloureteral strips showed spontaneous generator oscillations of about 10/min. Variations in the pattern of ureteral peristalsis are due to different coupling ratios of membrane potential oscillations to contractions. Adrenaline (10^––5 mol/l) increased the frequency of the oscillations and enhanced their manifestation in the mechanical recordings, whereas tetraethylammonium (5–20 mmol/l) only increased the coupling ratio. The following concept for the generation of ureteral peristalsis in multicalyceal kidneys is developed: several (primary) oscillators exist in the calyces; in the pyeloureteral junction a (secondary) pacemaker exists which has an intrinsic frequency similar to that of the calyceal pacemakers; both processes cooperate in the generation of ureteral peristalsis.

show abstract

Section: Resultscontrasting

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Pacemaker Process of Ureteral Peristalsis in Multicalyceal Kidneys

et al. 1982

View full text Add to dashboard Cite

show abstract

“…In both uni-calyceal and multi-calyceal mammals, circumferentially cut strips of muscle wall dissected from the same region contract at the same frequency. However contraction frequency decreases with distance from the renal fornix as strips are dissected from the middle and lower calyces, renal pelvis and UPJ [14,[17][18][19][20][21][22][23]. Thus researchers have located the primary pacemaker in the most proximal calyceal regions of the renal pelvis, although there have been a few reports that have situated the primary pacemaker in the UPJ [24,25].…”

Section: Pelviureteric Contractilitymentioning

confidence: 99%

“…For the last 30 years the decreasing presence of 'atypical' SMC with distance from the renal fornix has been correlated with the decreasing frequency of pelvic contraction to suggest that atypical SMC are the pacemaker cells of the UUT [17,28,[30][31][32]. It has been envisaged that these atypical SMC drive neighbouring 'typical' SMC in the renal pelvis either directly [16,33] or indirectly [33].…”

Section: Electrical Recordings From Smc Of the Uutmentioning

confidence: 99%

Interstitial cell of Cajal-like cells in the upper urinary tract

Lang

Klemm

2005

J Cellular Mol Med

View full text Add to dashboard Cite

Autorhythmicity in the upper urinary tract (UUT) has long been considered to arise in specialized atypical smooth muscle cells (SMC) predominately situated in the most proximal regions of the pyeloureteric system. These atypical SMC pacemakers have been thought to trigger adjacent electrically-quiescent typical SMC to fire action potentials which allow an influx of Ca 2+ and the generation of muscle contraction. More recently, the presence of cells with many of the morphological, electrical and immunohistochemical characteristics of interstitial cells of Cajal (ICC), the pacemaker cells of the gastrointestinal tract, have been located in many regions of both the upper and lower urinary tract. This article reviews the evidence from the literature and from our laboratory supporting a role of both atypical SMC and ICC-like cells in the initiation and propagation of pyeloureteric peristalsis in the UUT. We propose a new model in which there are 2 populations of pacemaker cells, high frequency atypical SMC and lower frequency ICC-like cells, both of which can drive electrically-quiescent typical SMC. The relative presence of these 2 populations of pacemaker cells and the relatively-long refractoriness of typical SMC determines the decreasing frequency of contraction with distance from the renal fornix. In the absence of the proximal pacemaker drive from atypical SMC after pyeloureteral/ureteral obstruction or surgery, ICC-like cell pacemaking provides a compensatory mechanism allowing the ureter to maintain rudimentary peristaltic waves and movement of urine from the pyelon towards the bladder.

show abstract

“…Furthermore, whether there is a frequency gradient within the calyceal length remains the subject of further investiga tion. However, there is evidence (1,6) within the unicalyceal system of the rabbit and the dog that segmentation of the renal pelvis into strips produces a frequency gradient. It may be hypothesized that the structural integration of pacemaking cells responsible for the rhythmic activity of pyeloureteral smooth muscle pos sesses an organization which ensures a gradient of excitability.…”

Section: Discussionmentioning

confidence: 99%

Hydronephrotic Alterations in Calyceal and Renal Pelvic Pacemaker Function of thein vitroPyeloureteral System

M¹,

Djurhuus²,

Constantinou³

1980

Urol Int

View full text Add to dashboard Cite

There are regional variations of the amplitude, frequency and waveform of spontaneous contractions within the isolated renal pelvis and calyx of the multicalyceal pyeloureter of the pig. The contractility of these structures was studied in normal and hydronephrotic preparations. Tissues were obtained from normal and chronically obstructed animals. In 20 normal preparations, the contractile frequency of the renal pelvis was 4.9 ± 2.1 contractions/min, while that of the calyx was 9.5 ± 2.2 (mean ± SD). The recorded amplitude was 0.95 ± 0.92 and 0.45 ± 0.61 g, respectively. The waveform of the calyceal contractility approximated the sinusoid demonstrating a slow rise and fall in tension, while the waveform of renal pelvic smooth muscle demonstrated a faster increase in tension. Obstruction and hydronephrosis produced a minimal alteration in the frequency and amplitude of the calyceal structures, 9.1 ± 2.2 contractions/min and 0.71 ± 0.49 g, respectively. Hydronephrotic renal pelves demonstrated a significant increase in the frequency of spontaneous contractility 8.0 ± 4.2 contractions/min with no change in the mean amplitude of contraction 0.88 ± 0.90 g. These data suggest that obstruction alters the frequency of isolated renal pelvic contraction so that they approximate the frequency of isolated calyceal contractions.

show abstract

Pacemaker Localization in the Renal Pelvis of the Unicalyceal Kidney

Cited by 19 publications

References 5 publications

Pacemaker Process of Ureteral Peristalsis in Multicalyceal Kidneys

Pacemaker Process of Ureteral Peristalsis in Multicalyceal Kidneys

Interstitial cell of Cajal-like cells in the upper urinary tract

Hydronephrotic Alterations in Calyceal and Renal Pelvic Pacemaker Function of thein vitroPyeloureteral System

Contact Info

Product

Resources

About