Short-term urogenital effects of raloxifene, tamoxifen, and estrogen

The potential of hormones and selective oestrogen receptor modulators in preventing voiding dysfunction in rats

OBJECTIVE

To investigate whether oestrogen, selective oestrogen receptor modulators (SERMs), and growth hormone (GH) can prevent the development of voiding dysfunction in a postpartum postmenopausal rat model of voiding dysfunction.

MATERIALS AND METHODS

Immediately after spontaneous delivery, nine primiparous Sprague-Dawley rats served as uninjured controls (sham group) and 54 underwent intravaginal balloon dilation. On day 7, the 54 subject rats underwent bilateral ovariectomy. A week later, six treatment groups of nine rats were randomized to receive: normal saline (injured control group), 17beta-oestradiol (E(2)), raloxifene, levormeloxifene, GH, or GH + E(2). The treatment groups received daily subcutaneous injections for 3 weeks. The effects of hormone treatment were examined by conscious cystometry at the end of the study. Voiding dysfunction was defined to include overactive bladder and sphincter deficiency.

RESULTS

The sham rats had a mean (sd) voiding frequency of 3 (0.87) times in 10 min and a bladder capacity of 0.43 (0.13) mL with smooth cystometry curves. The number of rats in each treatment group (each group contained nine rats) that had voiding dysfunction was as follows: E(2), three; raloxifene, six; levormeloxifene, four; and controls, four (P > 0.05 among the groups). Only one rat in the GH-treated group and no rats in the GH + E(2)-treated group had voiding dysfunction, which was significantly less in the GH + E(2)-treated group than in the controls (P = 0.041).

CONCLUSION

This functional data suggest that the development of voiding dysfunction can be prevented by short-term administration of GH and GH + E(2) in our rat model. SERMs and E(2) alone seem to have no therapeutic effect.

Morphometric analysis of the urethra of castrated female rats treated with tamoxifen

OBJECTIVES

The aim of this study was to evaluate the effects of tamoxifen on the weight and thickness of the urethral epithelium of castrated female rats.

METHODS

Forty castrated adult female Wistar-Hannover rats were randomly divided into two groups: Group I (n=20) in which the animals received only the vehicle (propylene glycol) and Group II (n=20) in which the rats received tamoxifen 250microg/day by gavage. After 30 days of treatment, all animals were sacrificed and the urethra was immediately removed for weighing. Next, the urethra was divided into the proximal and distal segments, which were fixed in 10% formaldehyde and submitted to routine histological techniques for morphometric study. The data were analyzed using the weighted minimum mean-square error method and Student's t-test for two independent samples (p<0.05).

RESULTS

There was a significant increase in the mean weight of the urethra in the rats of Group II compared to the control group, 32.0+/-2.0mg and 22.0+/-1.6mg, respectively (p<0.001). The mean thickness of the distal urethral epithelium of the animals treated with tamoxifen was significantly greater than that of the control group, 42.8+/-2.0microm and 36.6+/-1.5microm, respectively (p<0.001). There was no statistically significant difference between the two groups with respect to the epithelial thickness of the proximal urethra (p=0.514).

CONCLUSION

Treating castrated adult rats with 250microg/day of tamoxifen for 30 days may increase the weight of the urethra and the thickness of the distal urethral epithelium.

The effect of raloxifene in association with vitamin D on vaginal maturation index and urogenital symptoms in postmenopausal osteoporotic women

In elderly women with osteoporosis, raloxifene treatment with vitamin D supplementation improves vaginal maturation index and vaginal pH.

Comparison of levator ani muscle defects and function in women with and without pelvic organ prolapse

BACKGROUND

To compare levator ani defects and pelvic floor function among women with prolapse and controls.

METHODS

Levator ani structure and function were measured in a case-control study with group matching for age, race, and hysterectomy status among 151 women with prolapse (cases) and 135 controls with normal support (controls) determined by pelvic organ prolapse quantification examination. Magnetic resonance imaging was used to determine whether there were "major" (more than half missing), "minor" (less than half of the muscle missing), or no defects in the levator ani muscles. Vaginal closure force at rest and during maximal pelvic muscle contraction was measured with an instrumented vaginal speculum.

RESULTS

Cases were more likely to have major levator ani defects than controls (55% compared with 16%), with an adjusted odds ratio of 7.3 (95% confidence interval 3.9-13.6, P<.001) but equally likely to have minor defects (16% compared with 22%). Of women who reported delivery by forceps, 53% had major defects compared with 28% for the nonforceps women, adjusted odds ratio 3.4 (95% confidence interval 1.95-5.78). Women with prolapse generated less vaginal closure force during pelvic muscle contraction than controls (2.0 Newtons compared with 3.2 Newtons P<.001), whereas those with defects generated less force than women without defects (2.0 Newtons compared with 3.1 Newtons, P<.001). The genital hiatus was 50% longer in cases than controls (4.7+/-1.4 cm compared with 3.1+/-1.0 cm, P<.001).

CONCLUSION

Women with prolapse more often have defects in the levator ani and generate less vaginal closure force during a maximal contraction than controls.

LEVEL OF EVIDENCE

II.

Cystoscopy in women with recurrent urinary tract infection

OBJECTIVE

To investigate if women with recurrent urinary tract infection (UTI) warrant cystoscopy to exclude an abnormality of the lower urinary tract. This is particularly relevant given that non-invasive imaging has often been performed to exclude abnormality. Our further aims were to correlate imaging and risk factors with cystoscopic findings to determine their predictive value in finding pathology.

PATIENTS AND METHODS

A database of women undergoing cystoscopy with recurrent UTI has been maintained at our institution for 10 years. We retrospectively examined this and patient records for patient demographics, and investigative and operative data.

RESULTS

A total of 118 patients (mean 55 years) having recurrent UTI (mean 4.7 infections/year) were available. There were nine patients (8%) with significant abnormalities at cystoscopy: urethral stricture (six), bladder calculus (one), bladder diverticulum (one) and colovesical fistula (one). The negative predictive value (NPV) of imaging was 99% and significant (P < 0.01). Women with no risk factors for UTI had a NPV of 93% for normal cystoscopy (P > 0.05). The positive predictive value was low for imaging and risk factors in predicting cystoscopy findings.

CONCLUSIONS

In our study, 8% of women had significant abnormalities detected during cystoscopy with most over 50 years. Women without risk factors for recurrent UTI and with normal imaging could have a cystoscopy omitted. Younger women are less likely to have pathology and this must be factored into decisions to perform cystoscopy.

Uterine effects of tamoxifen: a prospective study

The purpose of the study was to evaluate tamoxifen-associated changes in the vagina and uterus in postmenopausal breast cancer patients. Between June 1994 and December 1998, 45 patients enrolled in a prospective study before commencing tamoxifen therapy. Patients with endometrial thickness >5 mm or neoplasia were excluded. Transvaginal ultrasonography, vaginal maturation indexes (VMI), and endometrial biopsy were performed at baseline and repeated at 6 months (n= 42), 1 year (n= 39), 2 years (n= 32), 3 years (n= 26), 4 years (n= 19), and 5 years (n= 15). For the 39 patients followed for 1 year, VMI (% parabasal/intermediate/superficial) was 21/71/8 at baseline compared with 1/90/9 at 1 year (P value = 0.0008/0.001/0.78). At baseline, mean endometrial thickness and uterine volume were 2.6 mm and 64 cm(3), respectively, compared with 5.8 mm and 84 cm(3) at 1 year (P= 0.0002, 0.002). At baseline, 80% of patients had atrophic endometrium and 9% proliferative endometrium compared with 61% and 26% at 1 year, respectively (P= 0.04). No cases of endometrial hyperplasia or adenocarcinoma were detected. Findings observed at 6 months persisted through 5 years of follow-up. Tamoxifen exerts a weak estrogenic effect on the vagina and uterus in highly prescreened postmenopausal women without preexisting endometrial pathology.

Lasofoxifene enhances vaginal mucus formation without causing hypertrophy and increases estrogen receptor β and androgen receptor in rats

OBJECTIVE

Lasofoxifene, a new selective estrogen-receptor modulator (SERM), shows efficacy in vaginal and vulvar atrophy in postmenopausal women. Here, we sought to explore the possible mechanisms of action for this effect in comparison with other SERMs using an immature ovariectomized rat model.

DESIGN

SERMs (lasofoxifene, raloxifene, and tamoxifen) and 17alpha-ethinyl estradiol were administered orally to immature ovariectomized rats daily for 1 or 4 days. Vaginal and uterine tissues were weighed and processed for histomorphometric measurements, vaginal mucopolysaccharide staining, and immunohistochemistry of 5-bromo-2'-deoxyuridine and steroid receptors. Receptor quantification was determined by a novel ultrasensitive enzyme-linked immunosorbent assay method.

RESULTS

Lasofoxifene and raloxifene showed a minimal increase in vaginal and uterine weight, epithelial cell proliferation, and epithelial thickness in comparison with estradiol and tamoxifen. Lasofoxifene significantly enhanced vaginal mucus formation in a dose-dependent manner. Vaginal progesterone receptor protein was increased fivefold by estradiol and all three SERMs tested. 17alpha-Ethinyl estradiol caused a significant decrease in estrogen receptor alpha, but no change with other treatments. Only lasofoxifene significantly increased vaginal estrogen receptor beta and androgen receptor protein levels.

CONCLUSIONS

These results demonstrated that lasofoxifene stimulated vaginal mucus formation without causing cell proliferation in the rat reproductive tract. These effects may be due to the increased vaginal estrogen receptor beta and androgen receptor levels. This cellular and molecular profile of lasofoxifene in the vagina may account for its efficacy in the treatment of vaginal and vulvar atrophy in postmenopausal women.

A comparison of raloxifene and calcium plus vitamin D on vaginal atrophy after discontinuation of long-standing postmenopausal hormone therapy in osteoporotic women. A randomized, masked-evaluator, one-year, prospective study

OBJECTIVES

We assessed the effects of the discontinuation of long-standing transdermal estrogen replacement therapy (>4 years) and substitution of this treatment by calcium or raloxifene on the vaginal epithelium and climateric symptoms in a study population of osteoporotic women.

METHODS

A total of 136 women (mean age 55.5 years) were randomized to calcium (500 mg elemental calcium, 400 IU Vitamin D3) (n=40), raloxifene (60 mg/day) (n=48), or estrogen patches (3.9 mg estradiol) and progesterone (100 mg/day) (n=48). Treatment was given for 1 year. The vaginal maturation value (VMV), serum estradiol levels, and climateric symptoms using a 12-item modification of the SF-36 quality of life questionnaire were evaluated at baseline and at 6 and 12 months.

RESULTS

At 6 months, mean VMV decreased significantly (P<0.001) in the calcium (-51.8%) and raloxifene (-18.6%) groups compared with baseline and the estrogen/progesterone group. At 12 months, significant decreases of mean VMV in the calcium (-38.7%) and raloxifene groups (-32%) (P<0.001) were also observed. Serum estradiol levels and changes of VMV correlated significantly at 6 months (rho=0.361, P<0.01) and at 12 months (rho=0.269, P<0.035). A significantly higher number of patients complained of hot flushes and palpitations in the calcium and raloxifene groups than in the estrogen/progesterone group. Raloxifene-treated women reported a significantly higher number of adverse events at 6 months compared to the other treatment groups.

CONCLUSIONS

Withdrawal and change of long-standing transdermal hormone replacement therapy by treatment with calcium or raloxifene resulted in worsening of vaginal atrophy assessed by the VMV, although it was not clinically perceived by the patients. However, increases in dyspareunia and urinary leaks were reported. Menopausal complaints related to vasomotor symptoms worsened in the calcium- and raloxifene-treated groups and persisted throughout the study period.

Classification and evaluation of prolapse

Pelvic organ prolapse is prevalent among older women. Milder stages of prolapse, cranial to the hymen, are common and usually symptomless. A specific symptom is a bulge outside the vagina. Functional symptoms from the bladder, bowel and sexual life frequently coexist without a known cause/effect relationship to prolapse. Prolapse should be measured by the validated internationally approved pelvic organ prolapse quantification (POPQ) system that can measure prolapse in the three compartments and three levels of the vagina. We should work on a common classification system and agreement in which symptoms should be recorded as related to prolapse and expected to improve by prolapse surgery.

Effects of Resveratrol, Raloxifene, Tibolone and Conjugated Equine Estrogen on Vaginal Squamous Cell Maturation of Ovariectomized Rats

OBJECTIVE

The effects of estrogen replacement therapy, selective estrogen receptor modulators, or tibolone on vaginal squamous cell maturation in postmenopausal women are not well established. Resveratrol (3,5,4'-trans-trihydroxystilbene) has been shown to bind the estrogen receptor in rat uteri. The aim of this study was to cytologically evaluate vaginal smears from ovariectomized rats treated with resveratrol, raloxifene, tibolone and conjugated equine estrogen, and to compare each drug with regard to vaginal epithelial maturation.

MATERIAL AND METHODS

Forty-two bilaterally ovariectomized Wistar albino rats were equally randomized into 6 groups: (1) control sham-operated rats; (2) ovariectomized rats administered 0.1% ethanol; (3) ovariectomized rats administered resveratrol at a dose of 5 mg/kg/day p.o.; (4) ovariectomized rats administered conjugated equine estrogen (CEE) at a dose of 0.1 mg/kg/day p.o.; (5) ovariectomized rats administered tibolone at a dose of 0.25 mg/kg/day p.o., and (6) ovariectomized rats administered raloxifen at a dose of 1 mg/kg/day p.o. Administration of drugs started 5 days after bilateral ovariectomy and continued for 35 days. After 35 days of treatment a vaginal smear was obtained from each rat. Smears were stained with the usual Papanicolaou method, and observed with a light microscope by an experienced cytopathologist. Cytological grading was made according to the extent of parabasal, intermediate, superficial and anuclear squamous cells.

RESULTS

Ovariectomized rats had lower scores for superficial and anuclear cells when compared to sham-operated rats (p < 0.05). The CEE group had higher scores for superficial and anuclear cells than those of the ovariectomized, raloxifene and tibolone groups (p < 0.05). The resveratrol-treated rats had higher scores for superficial cells but lower scores for parabasal cells than ovariectomized rats (p < 0.05). The raloxifene and tibolone groups had the same scores for intermediate, superficial and anuclear cells but lower scores for parabasal cells compared to ovariectomized rats.

CONCLUSION

The results of our study suggest that resveratrol offsets the reduction in vaginal stratification generally observed after oophorectomy.

Vaginal thickness, cross-sectional area, and perimeter in women with and those without prolapse

OBJECTIVE

Use axial magnetic resonance imaging to test the null hypothesis that no difference exists in apparent vaginal thickness between women with and those without prolapse.

METHODS

Magnetic resonance imaging studies of 24 patients with prolapse at least 2 cm beyond the introitus were selected from an ongoing study comparing women with prolapse with normal control subjects. The magnetic resonance scans of 24 women with prolapse (cases) and 24 women without prolapse (controls) were selected from those of women of similar age, race, and parity. The magnetic resonance files were imported into an experimental modeling program, and 3-dimensional models of each vagina were created. The minimum transverse plane cross-sectional area, mid-sagittal plane diameter, and transverse plane perimeter of each vaginal model were calculated.

RESULTS

Neither the mean age (cases 58.6 years +/- standard deviation [SD] 14.4 versus controls 59.4 years +/- SD 13.2) nor the mean body mass index (cases 24.1 kg/m(2)+/- SD 3.3, controls 25.7 kg/m(2)+/- SD 3.7) differed significantly between groups. Minimum mid-sagittal vaginal diameters did not differ between groups. Patients with prolapse had larger minimum vaginal cross-sectional areas than controls (5.71 cm(2)+/- standard error of the mean [SEM] 0.25 versus 4.76 cm(2)+/- SEM 0.20, respectively; P = .005). The perimeter of the vagina was also larger in the prolapse group (11.10 cm +/- SEM 0.24) compared with controls (9.96 cm +/- SEM 0.22) P = .001. Subgroup analysis of patients with endogenous or exogenous estrogen showed prolapse patients had larger vaginal cross-sectional area (P = .030); in patients without estrogen group differences were not significant (P = .099).

CONCLUSION

Vaginal thickness is similar in women with and those without pelvic organ prolapse. The vaginal perimeter and cross-sectional areas are 11% and 20% larger in prolapse patients, respectively. Estrogen status did not affect differences found between groups.

The effects of hormone replacement on the biomechanical properties of the uterosacral and round ligaments in the monkey model

OBJECTIVE

The purpose of this study was to determine effects of ovariectomy (OVX) and conjugated equine estrogens plus medroxyprogesterone acetate (CEE/MPA), or ethinyl estradiol plus norethindrone acetate (EE/NA) on biomechanics of uterosacral (USL) and round (RL) ligaments in postmenopausal (PMP) monkeys.

STUDY DESIGN

This was a randomized, triple blind, placebo-controlled study. OVX monkeys received 12 months no treatment (Pbo) (n = 19), CEE/MPA (n = 19), or EE/NA (n = 21). USL and RL step strains and stress-relaxation data were curve-fitted, giving strain-dependent tensile modulus (TM) from 0% to 30%.

RESULTS

(1) USL: TM for both treatment groups was greater than Pbo for strains from 0% to 12% (P < .04). (2) RL: TM for both treatment groups was smaller than Pbo for strains from 12% to 30% (P < .05). No differences were found between treatment regimens.

CONCLUSION

CEE/MPA and EE/NA both affect functional biomechanical properties by increasing tensile stiffness in the USL and decreasing it in the RL.

Estrogen increases collagen I and III mRNA expression in the pelvic support tissues of the rhesus macaque

OBJECTIVE

Our aim was to study the effect of estradiol and raloxifene on collagen synthesis, by measuring the expression collagen I and III mRNA.

STUDY DESIGN

Nineteen nulliparous young adult rhesus macaques underwent oophorectomy and were treated for 5 months with estradiol alone, raloxifene, or no hormone. Tissue samples were acquired from the lateral vaginal wall, and included the paravaginal attachment and levator ani muscle. Expression of mRNA for collagen I and III was measured by in situ hybridization.

RESULTS

Estradiol increased mRNA for collagen I and III compared with no hormone and raloxifene treatment (ANOVA, P < .05). Collagen mRNA was localized to fibroblasts in the vaginal connective tissue and the connective tissue investments of striated muscle. Collagen mRNA was not expressed in epithelial, smooth, and striated muscle cells.

CONCLUSION

Estrogen, but not raloxifene, increases collagen gene transcription and indicates stimulation of collagen synthesis in pelvic floor connective tissues.

Effects of tamoxifen on Doppler velocimetry parameters of periurethral vessels in postmenopausal women

The purpose of the present study was to assess the effect of tamoxifen on periurethral vessels by Doppler velocimetry examination. Increase in the number of these vessels as well as decrease in resistance and pulsatility indices by tamoxifen were observed.