Does pharmacological activation of 5-HT1A receptors improve urine flow rate in female rats?

2016 ◽  
Vol 311 (1) ◽  
pp. F166-F175 ◽  
Author(s):  
Shih-Ching Chen ◽  
Tsung-Hsun Hsieh ◽  
Wen-Jia Fan ◽  
Chien-Hung Lai ◽  
Chih-Wei Peng

The role of 5-HT1A receptors in regulating voiding functions remains unclear, particularly regarding the urine flow rate (UFR) during voiding. This study examined the effects of 5-HT1A receptors on regulating urethral functions in female rats and investigated underlying modulatory mechanisms. Intravesical pressure (IVP), external urethral sphincter-electromyography (EUS-EMG), and UFR were simultaneously recorded during continuous transvesical infusion to examine the effects of a 5-HT1A receptor agonist (8-OH-DPAT) and antagonist (WAY-100635) on bladder and urethral functions. In addition, this study evaluated the independent roles of urethral striated and smooth muscles in the UFR in rats after a neuromuscular blockade (NMB) treatment and bilateral hypogastric nerve transection. Our results revealed that 8-OH-DPAT significantly increased the maximal UFR but reduced the mean UFR. This discrepancy may be because 8-OH-DPAT markedly increased the maximal UFR during the initial segment of the flow duration and subsequently induced an approximately zero level of long oscillatory waves during the remaining flow duration. Thus the mean UFR was reduced because of the prolonged approximately zero level of the UFR. However, paralyzing the EUS with an NMB agent, 8-OH-DPAT, significantly increased the maximal and mean UFRs because the prolonged zero level of the oscillatory UFR did not continue. These results support the hypothesis that the increased UFR in female rats during voiding is due to the induction of urethral smooth muscle relaxation by 8-OH-DPAT. This paper provides a detailed understanding of the role of 5-HT1A receptors in controlling the UFR in female rats.

2014 ◽  
Vol 307 (10) ◽  
pp. R1239-R1250 ◽  
Author(s):  
Wen-Jia Fan ◽  
Shih-Ching Chen ◽  
Tsung-Hsun Hsieh ◽  
Chien-Hung Lai ◽  
You Shuei Lin ◽  
...  

This study extensively examined the role of a 5-HT1A receptor in controlling voiding function in anesthetized male rats. A simultaneous recording of the intravesical pressure (IVP), external urethral sphincter (EUS)-electromyography (EMG), and urine flow rate (UFR) during continuous cystometry was used. 8-Hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), a 5-HT1A receptor agonist, significantly improved the voiding efficiency, as detected by increases in the evoked contraction amplitude, EUS burst period, and silent period, and decreases in the volume threshold, pressure threshold, and residual volume. Interestingly, the UFR during voiding was reduced by 8-OH-DPAT, as evidenced by decreases in the maximal UFR and mean UFRs of the voiding period, spike duration, and interspike interval. Conversely, treating rats with WAY-100635, a 5-HT1A antagonist, produced effects opposite to those produced by 8-OH-DPAT. These findings suggest that 8-OH-DPAT improved the voiding efficiency by enhancing the detrusor contractile ability and prolonging EUS burst period, which would compensate for the lower UFR, resulting from urethral smooth muscle contractions and longer EUS silent periods during voiding. The present study contributes to our understanding of the role of 5-HT1A receptors in controlling the urine flow rate in male rats.


1983 ◽  
Vol 105 (1) ◽  
pp. 351-362 ◽  
Author(s):  
A. J. MCVICAR ◽  
J. C. RANKIN

1. Improved estimates of urine flow rates of lampreys in various salinities were obtained by the collection of urine for periods of up to 48 h from minimally-stressed, unanaesthetized fish, following catheterization of the urinogenital papilla. 2. The mean urine flow rate of freshwater lampreys was 200.7 ±14.3 ml kg−1 day−1. 3. Urine flow in freshwater lampreys was correlated with spontaneous changes in gill ventilation rate. MS222 anaesthesia reduced both ventilation and urine flow rates, but pronounced effects were only observed at concentrations greater than those needed to induce light anaesthesia (50–55 mg 1−1). Urine flow rate in unanaesthetized fish was extremely sensitive to rapid (6°Ch−1) changes in temperature and Q10 (6–16°C) was approximately 5. 4. Urine flow rate decreased rapidly as the osmotic difference between the body fluids and environment approached zero, and the rate of flow in 30% seawater lampreys was only 7.6% that of freshwater fish. 5. There was no evidence for an effect of environmental calcium concentration on branchial osmotic permeability. 6. Extensive tubular reabsorption of ions occurred in freshwater lampreys. The total daily excretion rate of sodium ions generally decreased in salinities hyperosmotic to the plasma, indicating enhanced reabsorption, but secretion of magnesium and sulphate ions was greatly increased. Urine osmolarity was significantly increased in lampreys in hyperosmotic salinities. 7. Present data compare favourably with data obtained previously from anaesthetized animals, indicating that renal function in lampreys is not significantly impaired by light MS222 anaesthesia.


1979 ◽  
Vol 57 (2) ◽  
pp. 187-193
Author(s):  
R. A. Norman ◽  
T. G. Coleman ◽  
P. R. Kastner

1. The purpose of this study was to determine the role of reinfused water, electrolytes and urea in the diuresis and natriuresis of urine reinfusion. 2. Three groups of rats underwent 5 h of urine reinfusion. The first group served as a control, and during urine reinfusion the urinary volume and sodium excretion increased to 10 or 12 times control values. 3. In a second group, urine reinfusion was followed by 2 h of infusion of Ringer solution at a rate equal to the urine flow rate; 71% of the diuresis and 75% of the natriuresis resulting from urine reinfusion were maintained. 4. In a third group, urine reinfusion was followed by infusion of Ringer solution with urea added. The infusion rate was equal to urine flow rate and the concentration of urea was equal to that in the urine; 98% of the diuresis and 102% of the natriuresis were maintained. 5. These results indicate that the majority of urine-reinfusion diuresis and natriuresis is due to reinfused volume and electrolytes, and the remainder, in these experiments at least, could be explained by the reinfused urea. Therefore there was no need to postulate additional urinary natriuretic factors to explain the results of urine reinfusion.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Mudi Awaisu ◽  
Muhammed Ahmed ◽  
Ahmad Tijjani Lawal ◽  
Abdullahi Sudi ◽  
Musliu Adetola Tolani ◽  
...  

Abstract Background The aim of the study is to find the correlation between the prostate volume and severity of lower urinary tract symptoms (LUTS) as measured by international prostate symptoms score and maximum urine flow rate among patients with benign prostatic hyperplasia (BPH). Methods The study was a prospective correlational study conducted between June 2016 and November 2017. A total of 290 patients who presented with LUTS suggestive of BPH and satisfied the inclusion criteria were consecutively recruited. Clinical evaluation including digital rectal examination of the prostate was done. Symptoms severity was assessed using the self-administered international prostate symptoms score (IPSS) questionnaire. Prostate volume was determined by transrectal ultrasound scan, and the urine flow rate was measured using uroflowmeter. Data were analyzed using SPSS version 20.0, and p value < 0.05 was taken to be statistically significant. Results The mean age of the patients was 64.22 ± 9.04 years with a range of 40 to 95 years. Most of the patients had moderate symptoms (55%) on IPSS with the mean IPSS value of 16.41 ± 7.43. The mean Qmax value was 16.55 ± 7.41 ml/s, and the median prostate volume (IQR) was 45.05 (35, 59). There was a positive significant correlation between prostate volume and IPSS (r = 0.179, p = 0.002) and a negative significant correlation between prostate volume and Qmax (r = − 0.176, p = 0.003). Conclusion This study showed a significant correlation between the prostate volume and IPSS, and also between prostate volume and maximum flow rate (Qmax).


1981 ◽  
Vol 241 (3) ◽  
pp. F224-F230 ◽  
Author(s):  
E. R. Serros ◽  
M. A. Kirschenbaum

The present experiments examined the role of prostaglandin biosynthesis in the increase in urine flow rate seen in rats with hypercalcemia induced by the administration of 1,25-dihydroxycholecalciferol. In a first group, rats receiving the vitamin D metabolite developed hypercalcemia, polyuria, and increased urine prostaglandin E excretion. Indomethacin resulted in a fall in urine prostaglandin E excretion. A second group was fluid restricted to ascertain whether increased thirst could be an etiologic mechanism of the polyuria. This resulted in a trivial fall in urine flow rate despite a fall in body weight and a rise in both urine and plasma osmolality. In a final group, prostaglandin inhibition restored the vasopressin sensitivity of the hypercalcemic kidney. Accordingly, the polyuria seen in hypercalcemic rats after the administration of 1,25-dihydroxycholecalciferol is associated with an increase in urine prostaglandin E excretion and can be reversed by inhibition of prostaglandin synthesis. In addition, this polyuria can occur independent of the thirst mechanism. Finally, there is evidence that the vasopressin resistance of the hypercalcemic kidney could be reversed by prostaglandin inhibition.


1972 ◽  
Vol 15 (4) ◽  
pp. 338-346 ◽  
Author(s):  
Herbert S. Diamond ◽  
Robert Lazarus ◽  
David Kaplan ◽  
David Halberstam

1988 ◽  
Vol 254 (2) ◽  
pp. R357-R380 ◽  
Author(s):  
L. Rabinowitz ◽  
D. M. Green ◽  
R. L. Sarason ◽  
H. Yamauchi

In unanesthetized adult sheep, following intake of a daily meal, there was a peak in K excretion. The maximum and minimum rates of K excretion following meals were directly related to meal K content. On days without meals, no peak in K excretion occurred. Changes in K excretion on fed and fast days occurred without changes in the low levels of plasma aldosterone and were poorly correlated with urine or blood pH, urine flow rate, Na excretion, or the filtered load of K, but they correlated well with fractional K excretion. Plasma K did not change on fast days. Plasma K increased on some, but not all, fed days. Increases in plasma K that occurred on fed days were insufficient to account for the concurrent kaliuresis. Infusion of aldosterone or isotonic NaCl failed to alter K excretion in fed or fasted sheep. Infusion of isotonic NaCl + aldosterone hypertonic Na2SO4 + aldosterone increased K excretion in fasted but not fed sheep. Infusion of K in the rumen of fed and fasted sheep elevated rumen K concentration and led to increases in K excretion that could not be explained by increases in plasma K. The mechanisms responsible for the homeostatic changes in K excretion on fed and fast days were not ascertained but may importantly depend on sensors of enteric K content.


Author(s):  
Katja M. Gist ◽  
Jamie Penk ◽  
Eric L. Wald ◽  
Laura Kitzmiller ◽  
Tennille N. Webb ◽  
...  

AbstractA standardized, quantified assessment of furosemide responsiveness predicts acute kidney injury (AKI) in children after cardiac surgery and AKI progression in critically ill adults. The purpose of this study was to determine if response to furosemide is predictive of severe AKI in critically ill children outside of cardiac surgery. We performed a multicenter retrospective study of critically ill children. Quantification of furosemide response was based on urine flow rate (normalized for weight) measurement 0 to 6 hours after the dose. The primary outcome was presence of creatinine defined severe AKI (Kidney Disease Improving Global Outcomes stage 2 or greater) within 7 days of furosemide administration. Secondary outcomes included mortality, duration of mechanical ventilation and length of stay. A total of 110 patients were analyzed. Severe AKI occurred in 20% (n = 22). Both 2- and 6-hour urine flow rate were significantly lower in those with severe AKI compared with no AKI (p = 0.002 and p < 0.001). Cutoffs for 2- and 6-hour urine flow rate for prediction of severe AKI were <4 and <3 mL/kg/hour, respectively. The adjusted odds of developing severe AKI for 2-hour urine flow rate of <4 mL/kg/hour was 4.3 (95% confidence interval [CI]: 1.33–14.15; p = 0.02). The adjusted odds of developing severe AKI for 6-hour urine flow rate of <3 mL/kg/hour was 6.19 (95% CI: 1.85–20.70; p = 0.003). Urine flow rate in response to furosemide is predictive of severe AKI in critically ill children. A prospective assessment of urine flow rate in response to furosemide for predicting subsequent severe AKI is warranted.


1991 ◽  
Vol 260 (3) ◽  
pp. H698-H701 ◽  
Author(s):  
J. L. Dinerman ◽  
D. L. Lawson ◽  
J. L. Mehta

To evaluate the role of endothelium in nitroglycerin (NTG)-mediated vascular relaxation, epinephrine-contracted rat thoracic aortic segments with and without intact endothelium were exposed to NTG (10(-10) to 10(-5) M). Aortic segments with intact (endo+, n = 15) and denuded endothelium (endo-, n = 9) exhibited typical NTG-induced relaxation. However, the mean effective concentration of NTG was lower for endo- than for endo+ segments (P less than 0.001). To determine if this phenomenon related to nitric oxide (NO) generation by endothelium, six endo+ segments were treated with NG-monomethyl-L-arginine (L-NMMA), an inhibitor of NO production. These endo+ segments exhibited greater (P less than 0.001) relaxation in response to NTG than the untreated endo+ segments. Oxyhemoglobin, an inhibitor of guanylate cyclase activation, greatly diminished NTG-mediated relaxation of all aortic segments. To determine if the enhanced NTG-mediated relaxation of endo- segments was unique to the guanosine 3',5'-cyclic monophosphate-dependent vasodilator NTG, other endo+ and endo- segments were exposed to adenosine 3',5'-cyclic monophosphate-dependent vasodilator papaverine (10(-8) to 10(-4) M), and no difference in EC50 was noted between endo+ and endo- segments. Thus endothelium attenuates NTG-mediated vasorelaxation, and this attenuation is abolished by inhibition of endothelial NO production with L-NMMA. These observations indicate that endothelium is a dynamic modulator of vascular smooth muscle relaxant effects of NTG. This modulation appears to result from a competitive interaction between endothelial NO and NTG.


1995 ◽  
Vol 7 (5) ◽  
pp. 1311 ◽  
Author(s):  
EM Wintour ◽  
R Riquelme ◽  
C Gaete ◽  
C Rabasa ◽  
E Sanhueza ◽  
...  

Samples of maternal and fetal plasma, fetal urine, and amniotic fluid were collected from 8 chronically cannulated pregnant llamas, in the last third of gestation. The samples were obtained for up to 18 days post-surgery. Osmolality, sodium (Na), potassium (K), chloride (Cl), and urea were measured on 40 samples collected on days 1, 2, 3, 4-5, 6-7, 8-9, and 10-19. The osmolalities of maternal and fetal plasma, fetal urine and amniotic fluid, averaged over these 7 time periods, were, respectively, 312 +/- 2, 311 +/- 1, 484 +/- 14, and 317 +/- 1 mosmol kg-1. Values are given as mean +/- s.e. The major differences from fetal fluid values in the ovine fetus (from previously published values) were the higher osmolality and urea concentration of llama fetal urine. Urine flow rate measured in 6 fetuses, 4.5-6.5 kg body weight, was 5.8 +/- 0.4 mliter h-1; urea clearance rate was 55.5 +/- 11.8 mliter h-1. Glomerular filtration rate (GFR), measured with 51Cr-EDTA in 5 fetuses on 1-4 occasions, was 111.4 +/- 23.3 mliter h-1. Fractional reabsorptions (FR) of Na, K and Cl were 97.9 +/- 1, 75.9 +/- 13.5 and 97.7 +/- 0.4% respectively. The GFR (25 mliter kg-1 h-1) and urine flow rate (1 mL kg-1 h-1) were less than half and about one-tenth the respective values in ovine fetuses. As Na reabsorption is the major oxygen-consuming activity of the kidney, the llama fetal kidney requires only half the oxygen needed by the ovine fetal kidney to reabsorb the filtered sodium load. The reason for the formation of hypertonic, rather than hypotonic, urine in the fetal llama may be due to both greater morphological maturity of the kidney and the excretion of as yet unidentified osmotically active organic substances.


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