The influence of high and low levels of estrogen on diurnal urine regulation in young women (original) (raw)
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Acta Physiologica, 2014
We investigated the influence of gender on the diurnal regulation of urine production with special focus on vasopressin, oxytocin and prostaglandin E2. Methods: Fifteen young women in mid-follicular phase and 22 young men (20-33 years) were included. All participants underwent a 24-h circadian inpatient study under standardized conditions for measurements of plasma vasopressin, oxytocin, sodium and osmolality. Urine was fractionally collected for measurements of electrolytes, aquaporin-2 and prostaglandin E2. Results: Plasma vasopressin expressed a diurnal rhythm with a night-time increase in both genders (P < 0.001). The ratio between mean daytime and mean night-time was 1.57 [95% CI: 1.33-1.84] P < 0.001 in men and 1.35 [95% CI: 1.11-1.64] P = 0.002 in women. P-vasopressin was higher in males during the night (P < 0.05). There was no difference in diuresis (P = 0.43), urine osmolality (P = 0.12) or aquaporin-2 excretion (P = 0.80) between genders. We found a trend towards a higher reabsorption of free water in males (P = 0.07). The excretion of prostaglandin E2 was higher in males (P < 0.001). There was no diurnal rhythm in p-oxytocin (P = 0.37) and no correlation to diuresis, urine osmolality or aquaporin-2 excretions. Conclusion: Similar urinary flows and osmolalities are associated with levels of plasma vasopressin and renal PGE2, which are higher in males than in females. Oxytocin does not seem to play a role in the diurnal urine formation, whereas prostaglandin E2 could represent a mediator of the gender difference, not only as a mediator of the vasopressin response, but also as an independent factor. These findings need further elucidation.
Journal of Urology, 2006
We investigated the circadian rhythm of solute excretion and regulating hormones as well as blood pressure in patients with monosymptomatic nocturnal enuresis. Materials and Methods: We included 15 patients with a mean age Ϯ SE of 13.4 Ϯ 0.9 years who had monosymptomatic nocturnal enuresis with at least 3 wet nights weekly and a control group of 10 healthy children with a similar age and sex distribution. During inpatient circadian studies urine was collected during 6 periods and blood was drawn at 7 time points during 24 hours. Heart rate and blood pressure was recorded with an ambulatory blood pressure monitor every 30 to 60 minutes. Results: The total patient group excreted a significantly larger nocturnal urine volume than controls (p Ͻ0.01). Five patients had marked nocturnal polyuria (nocturnal urine volume greater than the mean in the control group ϩ2 SD), whereas urine output in the remaining patients without polyuria were similar to controls. Nocturnal polyuria was caused mainly by increased nocturnal solute excretion, especially Na. Serum aldosterone and plasma angiotensin II showed a marked circadian rhythm in normal children with a nocturnal increase concomitant with a significant decrease in mean arterial blood pressure during sleep. In contrast, the group of patients with nocturnal polyuria showed a lack of circadian rhythm in all excretion variables as well as an attenuated rhythm in plasma angiotensin II and mean arterial blood pressure. Interestingly this group had normal circadian rhythms of the circadian rhythm markers plasma cortisol and heart rate. Conclusions: The study suggests that an abnormally large nocturnal excretion of Na caused by selectively attenuated circadian rhythms of Na regulating hormones might be an important pathogenic factor in monosymptomatic nocturnal enuresis.
Antidiuretic hormone regulation in patients with primary nocturnal enuresis
Archives of Disease in Childhood, 1995
Treatment of primary nocturnal enuresis using DDAVP is based upon the hypothesis that antidiuretic hormone (ADH) secretion is insufficient at night. The known efficacy of the treatment on the one hand, and persisting doubts about its theoretical basis on the other, formed the background of the present study. Ten children (mean age 10-5 years) with primary nocturnal enuresis were compared with a corresponding control group of eight patients. Diurnal and nocturnal urine production, ADH secretion, and plasma osmolality were determined. No differences between the two groups were found for urine production, ADH levels during day and night, or plasma osmolality. However, in order to regulate plasma osmolality the enuretic children required a markedly greater output of ADH: 2-87 (95% confidence interval 0-091 to 40.35) pg/ml/mmol/kg v 056 (0.08 to 1.03) in the controls (p<0.01). The results are consistent with the established fact that ADH secretion is a function of plasma osmolality, and they contradict the hypothesis that urine production is increased at night in enuretics because of lower ADH secretion. The findings do not solve the uncertainties in the pathogenesis of enuresis but they suggest there might be a difference between enuretic children and controls at the ADH receptor level.
Journal of Applied Physiology, 2008
Sims ST, Rehrer NJ, Bell ML, Cotter JD. Endogenous and exogenous female sex hormones and renal electrolyte handling: effects of an acute sodium load on plasma volume at rest. This study was conducted to investigate effects of an acute sodium load on resting plasma volume (PV) and renal mechanisms across the menstrual cycle of endurancetrained women with natural (NAT) or oral contraceptive pill (OCP) controlled cycles. Twelve women were assigned to one of two groups, according to their usage status: 1) OCP [n ϭ 6, 29 yr (SD 6), 59.4 kg (SD 3.2)], or 2) NAT [n ϭ 6, 24 yr (SD 5), 61.3 kg (SD 3.6)]. The sodium load was administered as a concentrated sodium chloride/ citrate beverage (164 mmol Na ϩ /l, 253 mosmol/kgH2O, 10 ml/kg body mass) during the last high-hormone week of the OCP cycle (OCP high) or late luteal phase of the NAT cycle (NAThigh) and during the low-hormone sugar pill week of OCP (OCP low) or early follicular phase of the NAT cycle (NAT low). The beverage (ϳ628 ml) was ingested in seven portions across 60 min. Over the next 4 h, PV expanded more in the low-hormone phase for both groups (timeaveraged change): OCP low 6.1% (SD 1.1) and NATlow 5.4% (SD 1.2) vs. OCP high 3.9% (SD 0.9) and NAThigh 3.5% (SD 0.8) (P ϭ 0.02). The arginine vasopressin increased less in the low-hormone phase [1.63 (SD 0.2) and 1.30 pg/ml (SD 0.2) vs. 1.82 (SD 0.3) and 1.57 pg/ml (SD 0.5), P ϭ 0.0001], as did plasma aldosterone concentration (ϳ64% lower, P ϭ 0.0001). Thus PV increased more and renal hormone sensitivity was decreased in the low-hormone menstrual phase following sodium/fluid ingestion, irrespective of OCP usage.
Diurnal Variation in Urodynamics of Rat
PLoS ONE, 2010
In humans, the storage and voiding functions of the urinary bladder have a characteristic diurnal variation, with increased voiding during the day and urine storage during the night. However, in animal models, the daily functional differences in urodynamics have not been well-studied. The goal of this study was to identify key urodynamic parameters that vary between day and night. Rats were chronically instrumented with an intravesical catheter, and bladder pressure, voided volumes, and micturition frequency were measured by continuous filling cystometry during the light (inactive) or dark (active) phases of the circadian cycle. Cage activity was recorded by video during the experiment. We hypothesized that nocturnal rats entrained to a standard 12:12 light:dark cycle would show greater ambulatory activity and more frequent, smaller volume micturitions in the dark compared to the light. Rats studied during the light phase had a bladder capacity of 1.4460.21 mL and voided every 8.261.2 min. Ambulatory activity was lower in the light phase, and rats slept during the recording period, awakening only to urinate. In contrast, rats studied during the dark were more active, had a lower bladder capacities (0.6560.18 mL), and urinated more often (every 3.760.9 min). Average bladder pressures were not significantly different between the light and dark (13.4062.49 and 12.1962.85 mmHg, respectively). These results identify a day-night difference in bladder capacity and micturition frequency in chronically-instrumented nocturnal rodents that is phase-locked to the normal circadian locomotor activity rhythm of the animal. Furthermore, since it has generally been assumed that the daily hormonal regulation of renal function is a major driver of the circadian rhythm in urination, and few studies have addressed the involvement of the lower urinary tract, these results establish the bladder itself as a target for circadian regulation.
Oestrogen effects on urine concentrating response in young women
The Journal of Physiology, 2003
In pre-menopausal women, the rate of progression of renal disease is slower than that in men of similar age (Neugarten et al. 2000; Dubey & Jackson, 2001). This sex difference is no longer apparent in menopausal women and oestrogen administration delays the onset of renal disease in older women (Silbiger & Neugarten, 1995; Neugarten et al. 2000). Moreover, oestrogen modulates whole body water and sodium at rest, and during perturbations of normal body fluid homeostasis such as dehydration, sodium loading and hyponatraemia (Ayus & Arieff, 1996; Calzone et al. 2001; Stachenfeld & Keefe, 2002). While these findings suggest an important function for oestrogen in renal water and sodium regulation, specific oestrogen actions in the kidney still need clarification. A number of studies have demonstrated that the osmotic threshold for arginine vasopressin (AVP) release is reduced when oestrogen is elevated (Spruce et al. 1985;
Acta Obstetricia et Gynecologica Scandinavica, 1998
Background. Circulating vasopressin and oxytocin are influenced by ovarian steroid blood levels, but the effect of estrogen and progestogen treatment on induced release of the posterior pituitary hormones is not clear. Methods. Eight postmenopausal women who had not been on hormonal replacement therapy for at least two months were included in the study. The women were treated for four weeks with transdermal administration of estradiol-17b in a daily dose of 100 mg with the addition of 5 mg tablets of medoxyprogesterone twice daily for the last two weeks. A 25 minute intravenous infusion of hypertonic saline (0.06 mg/kg/min) was given before hormonal treatment, and after two and four weeks with serial plasma sampling for assay of vasopressin and oxytocin. Results. The mean basal concentration of vasopressin, which was 0.83∫0.13 (SE) pmol/L before hormonal treatment, increased to a statistically significant degree after estradiol alone to 1.18∫0.11 pmol/L and decreased after combined estrogen/progestogen treatment to 0.31∫0.02 pmol/L. Sodium concentration and osmolality increased in a similar way during all three infusions, but the resultant increase in vasopressin concentration was significantly smaller and slower after treatment with estradiol alone than in the first experiment without pretreatment. The areas under the concentration curve for the second and third infusion were significantly smaller than when no hormone treatment was given. The induced hyperosmolality also caused a rise in oxytocin levels, but no influence of ovarian hormone treatment was observed. Conclusions. Ovarian hormone administration influences vasopressin secretion, affecting both the basal levels in plasma and the responses to an increase in plasma osmolality. The influence of ovarian hormones on oxytocin secretion is minimal.
Journal of Applied Physiology, 2009
Effects of oral contraceptives on body fluid regulation. J. Appl. Physiol. 87(3): [1016][1017][1018][1019][1020][1021][1022][1023][1025] 1999.-To test the hypothesis that estrogen reduces the operating point for osmoregulation of arginine vasopressin (AVP), thirst, and body water balance, we studied nine women (25 Ϯ 1 yr) during 150 min of dehydrating exercise followed by 180 min of ad libitum rehydration. Subjects were tested six different times, during the earlyfollicular (twice) and midluteal (twice) menstrual phases and after 4 wk of combined [estradiol-norethindrone (progestin), OC E ϩ P] and 4 wk of norethindrone (progestin only, OC P) oral contraceptive administration, in a randomized crossover design. Basal plasma osmolality (P osm ) was lower in the luteal phase (281 Ϯ 1 mosmol/kgH 2 O, combined means, P Ͻ 0.05), OC E ϩ P (281 Ϯ 1 mosmol/kgH 2 O, P Ͻ 0.05), and OC P (282 Ϯ 1 mosmol/kgH 2 O, P Ͻ 0.05) than in the follicular phase (286 Ϯ 1 mosmol/kgH 2 O, combined means). High plasma estradiol concentration lowered the P osm threshold for AVP release during the luteal phase and during OC E ϩ P [x-intercepts, 282 Ϯ 2, 278 Ϯ 2, 276 Ϯ 2, and 280 Ϯ 2 mosmol/kgH 2 O, for follicular, luteal (combined means), OC E ϩ P, and OC P, respectively; P Ͻ 0.05, luteal phase and OC E ϩ P vs. follicular phase] during exercise dehydration, and 17-estradiol administration lowered the P osm threshold for thirst stimulation [x-intercepts, 280 Ϯ 2, 279 Ϯ 2, 276 Ϯ 2, and 280 Ϯ 2 mosmol/kgH 2 O for follicular, luteal, OC E ϩ P, and OC P, respectively; P Ͻ 0.05, OC E ϩ P vs. follicular phase], without affecting body fluid balance. When plasma 17-estradiol concentration was high, P osm was low throughout rest, exercise, and rehydration, but plasma arginine vasopressin concentration, thirst, and body fluid retention were unchanged, indicating a lowering of the osmotic operating point for body fluid regulation. estrogen; progesterone; rehydration; osmolality; arginine vasopressin 1018 ESTROGEN, AVP, AND FLUID REGULATION
Circadian Rhythms in Urinary Functions: Possible Roles of Circadian Clocks?
International Neurourology Journal, 2011
Circadian clocks are the endogenous oscillators that harmonize a variety of physiological processes within the body. Although many urinary functions exhibit clear daily or circadian variation in diurnal humans and nocturnal rodents, the precise mechanisms of these variations are as yet unclear. In this review, we briefly introduce circadian clocks and their organization in mammals. We then summarize known daily or circadian variations in urinary function. Importantly, recent findings by others as well as results obtained by us suggest an active role of circadian clock genes in various urinary functions. Finally, we discuss possible research avenues for the circadian control of urinary function.