Estrogen and ghrelin increase number of submucosal urethral and anal canal blood vessels in ovariectomized rats

Ghrelin protects against renal damages induced by angiotensin-II via an antioxidative stress mechanism in mice

We explored the renal protective effects by a gut peptide, Ghrelin. Daily peritoneal injection with Ghrelin ameliorated renal damages in continuously angiotensin II (AngII)-infused C57BL/6 mice as assessed by urinary excretion of protein and renal tubular markers. AngII-induced increase in reactive oxygen species (ROS) levels and senescent changes were attenuated by Ghrelin. Ghrelin also inhibited AngII-induced upregulations of transforming growth factor-β (TGF-β) and plasminogen activator inhibitor-1 (PAI-1), ameliorating renal fibrotic changes. These effects were accompanied by concomitant increase in mitochondria uncoupling protein, UCP2 as well as in a key regulator of mitochondria biosynthesis, PGC1α. In renal proximal cell line, HK-2 cells, Ghrelin reduced mitochondria membrane potential and mitochondria-derived ROS. The transfection of UCP2 siRNA abolished the decrease in mitochondria-derived ROS by Ghrelin. Ghrelin ameliorated AngII-induced renal tubular cell senescent changes and AngII-induced TGF-β and PAI-1 expressions. Finally, Ghrelin receptor, growth hormone secretagogue receptor (GHSR)-null mice exhibited an increase in tubular damages, renal ROS levels, renal senescent changes and fibrosis complicated with renal dysfunction. GHSR-null mice harbored elongated mitochondria in the proximal tubules. In conclusion, Ghrelin suppressed AngII-induced renal damages through its UCP2 dependent anti-oxidative stress effect and mitochondria maintenance. Ghrelin/GHSR pathway played an important role in the maintenance of ROS levels in the kidney.

Activation of VEGF and ERK1/2 and improvement of urethral function by adipose-derived stem cells in a rat stress urinary incontinence model

OBJECTIVE

To investigate the injected autologous adipose-derived stem cells (ADSCs) in improving stress urinary incontinence in a rodent model of parturition-related stress incontinence and the possible mechanism.

METHODS

The 40 rats were developed stress urinary incontinence models by postpartum balloon dilation of the vagina for 4 hours followed by bilateral ovariectomy. ADSCs were isolated from the peri-ovarian fat and labeled with thymidine analog 5-ethynyl-2-deoxyuridine (EdU). Twenty stress urinary incontinence rats received peri-urethral injection of phosphate-buffered saline as the negative controls and the other 20 stress urinary incontinence rats received peri-urethral injection of EdU-labeled ADSCc. Twenty control rats underwent sham ovariectomy without balloon dilation and served as positive controls. Four weeks later, voiding function was assessed by cystometry. Urethral histologic examination (Masson trichrome stain, picrosirius red stain, Hart elastin stain, Gordon and Sweet stain, and immunohistochemical stain) and Western blot were performed on urethral tissues.

RESULTS

Both leak point pressure and bladder capacity were significantly increased in ADSC-treated rats, compared to the balloon-injured ovariectomized rats. Histologic examination revealed normalized appearance of the fibromuscular structure of the urethra as well as increased peri-urethral blood vessel density in ADSC-treated rats. On Western blot, vascular endothelial growth factor and P-extracellular signal-regulated kinases (ERKs)1/2 protein was expressed at a higher rate in tissues from ADSC-treated rats compared to phosphate-buffered saline-treated rats.

CONCLUSION

Peri-urethral injection of ADSCs is associated with more normal urinary function and urethral structure in rats with parturition-related incontinence. The activation of vascular endothelial growth factor and ERK1/2 may be responsible for the paracrine effects from ADSCs.

Evaluation of the ratio of collagen type III to collagen type I in periurethral tissues of sexually intact and neutered female dogs

OBJECTIVE

To determine the ratio of collagen type III to collagen type I in the periurethral tissues of sexually intact and neutered female dogs.

ANIMALS

8 neutered and 34 sexually intact female dogs.

PROCEDURES

Tissues were obtained from female dogs euthanized for non-urinary tract-related reasons. Indirect immunofluorescent antibody detection of type I and collagen type III was performed by use of confocal microscopy on 2 periurethral samples from each dog, and the ratios of collagen type III to type I area fraction and total area were determined.

RESULTS

No significant differences were detected in the collagen ratios of periurethral tissues between sexually intact and neutered female dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

In contrast to differences in periurethral collagen content found between pre- and postmenopausal women, such differences may not occur in dogs. This implies that changes in pelvic organ support structures may not play an important role in urinary incontinence in neutered female dogs. Further evaluation is needed to determine the role of age on collagen and pelvic organ support structures in the pathogenesis of canine urinary incontinence.

Effects of ovarian failure on submucosal collagen and blood vessels of the anal canal in postmenopausal women

BACKGROUND

Estrogen and progesterone receptors are expressed in the anal canal. Fecal control deteriorates after menopause. This phenomenon is related to decreased circulating levels of estrogen and progesterone due to ovarian failure at menopause.

AIM OF WORK

To study the effects of estrogen and progesterone on inflammatory cells, submucosal collagen fibers, and vascular plexus of the anal canal of postmenopausal women.

SUBJECTS AND METHODS

Experiments were performed on samples of anorectal tissue obtained from 40 women, 19 menstruating (group I), and 21 postmenopausal women (group II). Investigations included immunohistochemistry of estrogen and progesterone receptors and CD34.

RESULTS

In negative estrogen receptors (ER) and progesterone receptors (PR), inflammatory cells, submucosal blood vessels, collagen type I were nonsignificantly changed in postmenopausal women relative to menstruating women (P > 0.05) whereas, in positive ER and PR, inflammatory cells and collagen I were significantly increased and submucosal blood vessels were significantly decreased in postmenopausal women relative to menstruating women (P < 0.05).

CONCLUSION

Estrogen and progesterone, in menstruating women, produce beneficial effects by decreasing incidence of inflammation and increasing anal canal submucosal blood vessels number and collagen types I, thus both hormones have a positive effect on anal compliance and pressure.

Effects of raloxifene on the urethra of adult castrated female rats

OBJECTIVE

The objective of this study was to evaluate the effects of raloxifene on the weight and epithelial thickness of the urethra of castrated female rats.

METHODS

Forty castrated female rats were randomly separated into two groups: group I (control, n = 20) received only the vehicle, and group II (raloxifene, n = 20) received 750 microg/day of raloxifene for 30 days. On the 31st day, the animals were sacrificed and the urethras were removed for the study. A model for categorical data using the weighted minimum mean square error method and Student's t test were used for the data analysis (p < 0.05).

RESULTS

The mean weights of the urethras in groups I and II were 22 +/- 1.6 mg and 24 +/- 1.7 mg, respectively (p = 0.371). There was an increase in the mean epithelial thickness of the distal segments in group II compared to group I (50.7 +/- 1.9 microm vs. 45.3 +/- 1.6 microm, respectively) (p < 0.04). No statistically significant difference was found in the mean epithelial thickness of the proximal urethra between the two groups (p = 0.187).

CONCLUSION

Raloxifene administered to castrated female rats for 30 days increased the distal urethral epithelial thickness and did not alter the weight of the urethra.

Combined estrogen and ghrelin administration restores number of blood vessels and collagen type I/III ratio in the urethral and anal canal submucosa of old ovariectomized rats

We compare the effects of estrogen and/or ghrelin on vascular counts and collagen I/III ratio of urethral and anal canal submucosa in old vs young-adult ovariectomized rats. Ovariectomized Fisher 344 rats (18 and 3 months old, n = 24 x 2) received 42 daily intraperitoneal 17-ss estradiol (10 microg/kg), ghrelin (2 microg/kg), both, or vehicle (n = 6 x 4 per group). Blood vessel counts and collagen I/III ratio were measured, respectively, by light microscopy and Western blot analysis with immunohistochemistry of ghrelin receptors. Estrogen significantly increased urethral and anal vascular counts and collagen I/III ratio in young-adult rats. In old rats, only combined estrogen/ghrelin administration significantly increased both variables. This was not observed with estrogen or ghrelin separately. Ghrelin receptors were immunostained in urethral and anal submucosa of all samples. Combined estrogen/ghrelin administration restored postovariectomy urethral and anal canal submucosal vessel number and collagen I/III ratio in old rats suggesting independent ageing effect.

The effect of ovariectomy on biomarkers of urogenital ageing in old versus young adult rats

The aim of this study was to compare the effects of ageing and ovariectomy on biomarkers of urogenital ageing in old and young-adult rats. Fisher 344 rats (18- and 3-months-old, n = 6 x 2) underwent ovariectomy. Age-matched sham animals received no intervention (n = 6 x 2). One month later, biomarkers of urogenital ageing were evaluated (light microscopic count of urethral and anal canal submucosal blood vessels, Western blot analysis of urethral, and anal canal submucosal collagen I and III and cytoplasmic p27(kip1) expression in the striated urethral and anal sphincters and levator ani and gel electrophoresis of isomyosin I proportion in these muscles) and compared in all groups (n = 24). All biomarkers of urogenital ageing studied were significantly increased in old compared to young-adult sham rats. Ovariectomy significantly increased these changes further in old versus young-adult rats with either smaller or larger differential effect than ageing compared to young-adult sham animals. Ovariectomy significantly exacerbates normative urogenital ageing changes in rats.

Estrogen and ghrelin decrease cytoplasmic expression of p27kip1, a cellular marker of ageing, in the striated anal sphincter and levator muscle of ovariectomized rats

A study was carried out to investigate the effect of estrogen and/or ghrelin on the cellular marker of ageing, p27kip1, in pelvic floor muscles of ovariectomized rats. Virgin Wistar rats (13 months old) underwent ovariectomy followed (1 month) by 42 daily intraperitoneal 17-beta estradiol (10 microg/kg), ghrelin (2 microg/kg), both hormones, or placebo vehicle (n=6x4 groups). Six more age-matched animals underwent sham surgery without ovariectomy. Cytoplasmic expression of p27kip1 in the striated urethral and anal sphincters and levator muscle was measured by Western blot analysis in all animals (n=30). p27kip1 signal intensity significantly increased postovariectomy in all muscles compared to sham animals. In the anal sphincter and levator, signal intensity decreased to sham levels with ghrelin or estrogen and decreased further after estrogen or ghrelin and estrogen/ghrelin administration. Urethral sphincter signal intensity decreased without reaching sham levels after drug administration. Estrogen and/or ghrelin replacement reverses the ovariectomy-induced exacerbation of biochemical cellular ageing in the anal sphincter and levator muscle of middle-aged rats.