Distribution of lactoferrin in the normal and inflamed human prostate: an immunohistochemical study

A polyclonal rabbit antibody to lactoferrin was used to localize the distribution of lactoferrin within the different zones of the normal human prostate as well as within the inflamed human prostate. Cases of normal central zone, peripheral zone, periurethral glandular tissue, as well as cases in which foci of moderate to severe inflammation, along with varying degrees of inflammation-related atrophy, were studied. In cases with inflammation, the staining pattern of lactoferrin was compared to the staining pattern of prostate-specific antigen. Within the central zone, lactoferrin staining occurred in numerous individual cells peppered throughout the epithelium as well as within multiple intraepithelial lumens (lacunae). These lacunae were often numerous enough to give the central zone epithelium a fenestrated appearance; they were not seen in any of the other regions of the prostate. With the exception of an occasional individual cell or isolated positive gland, normal peripheral zone exhibited very little lactoferrin activity. Staining within the transition zone was similar to that seen in the peripheral zone. Staining within the urethral lining of the epithelium in the periurethral glands showed a distinct pattern of frequent intense staining involving the entire gland; frequent individual positive cells were also often seen. Three patterns of staining were identified in prostatic inflammation. Mild periglandular chronic inflammation produced foci of epithelial lactoferrin positivity that coincided precisely with the areas of inflammation. Severe acute inflammation produced strong staining within luminal secretions while cytoplasmic staining was limited to the luminal surface of the epithelium. Post-inflammatory atrophy showed intense diffuse lactoferrin staining in the scant cytoplasm of the atrophic epithelium. In 12 of the 17 cases of inflammation that were studied, areas of post-inflammatory atrophy or severe inflammation commonly showed absence of prostate specific antigen staining and epithelium that was strongly lactoferrin-positive. Within the normal human prostate, lactoferrin appears to be produced primarily within the epithelium of the central zone, periurethral glands, and lining epithelium of the prostatic urethra. Lactoferrin-filled central zone lacunae appear to be structures unique to the central zone. The distribution of lactoferrin in the periurethral glands and urethral lining epithelium, along with the intense production of lactoferrin in the presence of inflammation, and the preservation of lactoferrin production in severe inflammation or atrophy suggest that lactoferrin may be a key component of the inflammatory response within the human prostate.

Mechanical irritation induces neurogenic inflammation in the rat urethra

A catheter was inserted into the urethral meatus of urethane-anaesthetized rats and rotated (30 rotations/minute) during a three minute period. One hour later, microvascular permeability in the distal urethra was evaluated by means of the Evans Blue leakage technique. Dye extravasation increased significantly (74 +/- 12 ng./mg. of wet tissue weight, p less than 0.05), as compared to control values (18 +/- 2 ng./mg.). The effect of catheterism was prevented by about 50% by systemic pretreatment with capsaicin performed in either adult or newborn rats, as well as by bilateral removal of pelvic ganglia. Furthermore, pretreatment with capsaicin of adult rats, combined to pelvic ganglionectomy, virtually abolished the inflammatory response produced by mechanical irritation of the urethra. These results indicate that: 1) the increase of vascular permeability produced by mechanical irritation is nerve-mediated, 2) capsaicin-sensitive afferents participate in the inflammatory process and 3) capsaicin-insensitive nerves, which pass through the pelvic ganglia, contribute to the overall response.

Studies on binding sites, contents, and effects of AVP in isolated bladder and urethra from rabbits and humans

The binding sites, contents, and effects of arginine vasopressin (AVP) were studied in isolated bladder and urethral preparations from rabbits and humans. In all tissues, higher levels of AVP-like immunoreactivity (AVP-LI) were detected than those normally found in plasma. Radioligand membrane binding studies using [3H]AVP as the ligand revealed the existence of a single population of binding sites in the rabbit bladder, and displacement experiments indicated that the receptor was of the V1 subtype. By autoradiography, [3H]AVP binding sites in the rabbit bladder were shown to be located on both circularly and longitudinally oriented smooth muscle cells, as well as in the submucosa at the part adjacent to the urothelium. In the rabbit urethra, the binding sites were confined mainly to the circular smooth muscle layer. Neither radioligand membrane binding studies nor autoradiography revealed any specific [3H]AVP binding sites in the human bladder. AVP contracted rabbit bladder and urethral preparations concentration dependently. The contractions were inhibited by the V1-receptor selective antagonist A16 in a noncompetitive manner. However, A16 had no effects on contractions elicited by electrical-field stimulation. In preparations of the human bladder and urethra, AVP in concentrations up to 10(-5) M did not have any contractile effects. These results suggest that in the rabbit and human lower urinary tract, AVP-LI is synthesized locally and/or extracted from the circulation. It is unlikely that AVP is directly involved in the neurotransmission in these tissues, although in the rabbit bladder and urethra a modulatory role cannot be excluded.

[Roles of prostaglandin on rabbit vesicourethral smooth muscle contraction]

The effects of prostaglandin (PG) E1, E2 and F2 alpha on isolated smooth muscles of rabbit bladder and urethra were studied by in vitro techniques for recording contractile activities. To examine the mechanism of PGs' effect, intracellular cyclic AMP content was also measured by radioimmunoassay. Spontaneous contractile force of muscle strips isolated from rabbit urinary bladder dome and base was increased dose-dependently by administration of PGE1, E2 or F2 alpha. Isolated muscle strips from bladder dome responded to PG more markedly than those from bladder base. The rank order of potency to induce contractile responses was PGF2 alpha greater than PGE2 greater than PGE1 in both dome and base muscles. Spontaneous contractile force of muscle strips isolated from rabbit urethra was increased dose-dependently by administration of PGF2 alpha, and, in contrast, was decreased dose-dependently by PGE1 or E2. These effects were not affected by pretreatment with atropine, phentolamine, propranolol and tetrodotoxin, but were significantly inhibited by pretreatment with verapamil, a Ca-antagonist. Cyclic AMP accumulation in urethral muscle strips significantly increased after administration of PGE1. These results demonstrated that contractile response of rabbit bladder smooth muscle to PG was mainly induced by Ca2+ influx and that cyclic AMP was related to the relaxation of rabbit urethral smooth muscle by PGE1.

Human papillomavirus infection of the male diagnosed by Southern-blot hybridization and polymerase chain reaction: comparison between urethra samples and penile biopsy samples

A group of 108 healthy men aged 18 to 23 years underwent penoscopy after application of acetic acid. In 39 (37%) aceto-white lesions were found and a biopsy was taken. From 105 patients a urethra sample was collected with a brush. The prevalence of HPV-DNA by dot-blot and Southern-blot hybridizations (DBH/SBH) and polymerase chain reaction (PCR) as well as the correlation between results from urethra samples and penile aceto-white epithelium were examined. In urethra, HPV-DNA was detected in four of the 66 patients (6%) with normal epithelium and in three of the 39 (8%) with aceto-white epithelium by using DBH/SBH. By PCR the corresponding findings were eight (12%) and 10 (26%) HPV-DNA-positive patients, respectively. Out of the 39 biopsy samples HPV-DNA was detected in six (15%) by DBH/SBH and in 17 (44%) by PCR. Twenty-two (56%) of the patients with aceto-white lesions were by PCR positive in either the urethra sample or biopsy. All samples positive by DBH/SBH were also positive by PCR except for one biopsy with HPV 35, a type not tested for by PCR. HPV 11 was the most common finding in urethra and HPV 6 and 16 in aceto-white epithelium.

Immunohistochemical evidence of estrogen and progesterone receptors in the female lower urinary tract and comparison with the vagina

Tissue biopsies from the lower urinary tract and the vagina were obtained from 51 and 45 women, respectively, during incontinence surgery or other gynecological operation procedures in order to calculate hormone receptor content. We compared the results between premenopausal, postmenopausal patients with and those without hormonal treatment. Utilizing the enzyme immunohistochemical assay we were able to demonstrate nuclear estrogen and progesterone receptors in the smooth muscle of the trigone and the posterior part of the bladder neck. But only in about 50% of the patients receptor proteins were detected in the frozen thin sections of these tissues. Biopsies from the anterior part of the bladder neck and the bladder vault were never receptor positive. In the vagina the rate of receptor-positive tissues was about 80%; in comparison, a smaller number of patients had receptor-positive cells in the bladder. From 29 patients we obtained specimens from the trigone and the vagina as well. The correlation of receptor-positive and -negative tissues of both organs was only 66%. Thus tissue biopsies obtained from the vagina only are not sufficient to discuss the probability of hormonal influence of the lower urinary tract.

Presence of a low capacity androgen receptor in the gubernaculum of the pig fetus

The aim of our study was to investigate the theory that the gubernaculum is an androgen-responsive structure responsible for fetal testicular descent. Using 3H-methyltrienolone (3H-R1881) as ligand, we performed a seven-point Scatchard analysis of androgen receptor binding in the gubernaculum, prostate, urethra and striated muscle tissue obtained from pig fetuses between 60 and 109 days of gestation. The gubernaculum demonstrated androgen receptor binding with an affinity and capacity significantly lower than that of fetal pig prostate and urethra, but not significantly different from that of striated muscle taken from both male and female fetuses. A marked increase in the size and mass of the gubernaculum of male (but not female) fetuses is known to accompany testicular descent. If the dramatic increase in the mass of the gubernaculum observed in male (but not female) fetuses were the result of androgen stimulation, it may be expected that the striated muscle mass (and therefore total body mass) of male fetuses should be greater than that of female fetuses, since the androgen receptor affinity and capacity of the gubernaculum is similar to that of striated muscle. However, we found no significant difference in total body mass between male and female pig fetuses at the same period of gestation. These findings raise doubt concerning the theory that growth of the gubernaculum during descent is the result of androgen stimulation.