Incidence and clinical features of priapism in Japan: 46 cases from the Japanese diagnosis procedure combination database 2006-2008.

We investigated the incidence and clinical features of priapism in Japan, using a national administrative claims database, the Diagnosis Procedure Combination database. Priapism patients were identified using the International Classification of Diseases and Related Health Problems, 10th Revision code, N483 (priapism). Verified patient characteristics included age, comorbidities and management of priapism. Among 6.93 million inpatients, 46 patients with priapism were identified. Four had two admissions each for repeated events. The median age was 41.5 years (range, 11-89 years). A total of 21 patients had comorbidities; 3 had haematological malignancies, 4 had haemodialysis, 1 had a renal transplant, 2 had neurological problems, 4 had non-haematological malignancies, 3 had trauma and 6 had psychoses (2 cases had two comorbidities). All patients with non-haematological malignancies were over the age of 70 years, indicating that close attention is required to search for associated malignancies in elderly patients. The medical treatments included 6 vascular embolizations, 11 Winter method surgeries and 18 other operations. The incidence was estimated to be 0.13 (95% confidence interval, 0.097-0.17) per 100,000 person-years. This incidence was lower than that reported in other parts of the world.

Lower incidence of inguinal hernia after radical prostatectomy using open gasless endoscopic single-site surgery.

Inguinal hernia is one of the long-term complications requiring surgical interventions after retropubic radical prostatectomy (RRP), and its incidence has been reported to range from 12 to 21%. The number of open gasless laparoendoscopic single-site surgery, especially minimum incision endoscopic radical prostatectomy (MIES-RRP) is increasing in Japan. The incidence of post-operative inguinal hernia was compared between conventional RRP and MIES-RRP. The medical records of 333 patients who underwent conventional RRP (n=214) or MIES-RRP (n=119) with pelvic lymphadenectomy at our hospital were retrospectively evaluated. There were no significant differences between the two groups in age, pre-operative PSA levels, or previous major abdominal surgery (cholecystectomy, gastrectomy and colectomy), appendectomy or inguinal hernia repair. MIES-RRP was carried out with a 5-8-cm lower abdominal midline incision. Inguinal hernia developed postoperatively in 41 (19%) of the 214 men undergoing conventional RRP during mean follow-up of 58 months (range: 7-60 months). In contrast, 7 (5.9%) of the 119 men receiving MIES-RRP, developed inguinal hernia during mean follow-up of 21 months (range: 13-31 months). The hernia-free survival was significantly higher after MIES-RRP than after conventional RRP (P=0.037). Our results suggest that MIES-RRP is less associated with post-operative inguinal hernia than conventional RRP.

Maximum tumor diameter: a simple independent predictor for biochemical recurrence after radical prostatectomy.

Previous studies have suggested that maximum tumor diameter (MTD) is a predictor of PSA recurrence or biochemical recurrence (BCR) in prostate cancer after radical prostatectomy (RP). The significance of MTD in BCR prediction was evaluated using RP specimens of 364 patients with a BCR of 18% (n=66) during a mean follow-up of 37.4 months (range: 10-109 months). MTD was defined as the largest diameter of the largest tumor, and its median MTD was 15 mm (range: 0.9-50 mm). MTD was significantly associated with pre-operative PSA levels, pathological T stage, Gleason's score and positive surgical margin. In a univariate analysis, pathological T stage, Gleason's score, positive surgical margin and MTD were associated significantly with the risk of BCR. Patients with >20 mm MTD had a significantly higher risk of BCR than did those with < or =20 mm MTD (P<0.001). Cox multivariate models indicated that pathological stage, Gleason's score, positive surgical margin and MTD were independent prognostic factors for BCR. MTD would be a useful tool for predicting BCR, as calculation of MTD is a simple and reliable measure.

Final report on low-dose estramustine phosphate (EMP) monotherapy and very low-dose EMP therapy combined with LH-RH agonist for previously untreated advanced prostate cancer.

PURPOSE: In order to assess the efficacy and toxicity of oral estramustine phosphate (EMP) administration, low-dose EMP monotherapy (study 1) and very low-dose EMP therapy with luteinizing hormone-releasing hormone (LH-RH) agonist (study 2) were conducted in previously untreated prostate cancer and long-term outcomes were compared between the 2 study groups. MATERIALS AND METHODS: Studies 1 and 2 were independently performed beginning in June 1999 and November 2001, respectively. Study 1 was composed of 87 patients including 85 assessable patients. All 108 patients recruited for study 2 were assessable. Low-dose EMP monotherapy (2 capsules/day or 280 mg/day) was used in study 1 and very low-dose EMP (1 capsule/day or 140 mg/day) combined with LH-RH agonist was adopted in study 2. RESULTS: Overall prostate specific antigen (PSA) -response rates in studies 1 and 2 were 92.3% and 94.2%, respectively, and overall toxicity rates were 54.1% and 38.9%, respectively. EMP discontinuation due to side effects was encountered more often in study 1 (45.9%) than in study 2 (27.8%). Among the adverse side effects gastrointestinal toxicity was most prevalent in both studies. One patient died of acute pulmonary embolism in study 1, but no one died in study 2. There were 6 cancer deaths in the gastrointestinal tract in study 1 but only 2 cancer deaths in study 2. CONCLUSION: Our data indicate that the overall PSA response rate was comparable between both studies. However, rates in overall toxicity and drug discontinuation were higher in study 1 than in study 2. We consider that study 2 is more promising for the treatment of previously untreated advanced prostate cancer, although the rate of adverse side effects is still high as compared with other hormonal therapies. In order to overcome the high toxicity rate, especially the gastrointestinal toxicity, we recently elaborated a method employing tailor-made medicine using SNPs of 1A1 gene in cytochrome P-450 for decreasing the rate of gastrointestinal toxicity. Using this method of patient selection, study 3 has been successfully launched on September 2005 with high drug compliance. Better clinical results are being accumulated.

The effect of combined androgen blockade on bone turnover and bone mineral density in men with prostate cancer.

UNLABELLED: Our study and previous reports suggest that castration results in increased bone turnover and lowered BMD and that these changes might be attenuated by anti-androgens, such as BL and EMP. INTRODUCTION: Recent studies have shown that castration for PC decreases bone mineral density (BMD), while estrogen therapy or bicalutamide (BL) monotherapy maintains BMD. However, the effect of combined androgen blockade (CAB) on bone turnover is not well studied. METHODS: A total of 204 men were evaluated in the study (control group: n = 56, castration group: n = 102, 'CAB with BL' group: n = 22, 'CAB with estramustine phosphate (EMP)' group: n = 24). We measured steroid hormone levels, BMD (measured at one-third distal radius), bone turnover markers (levels of urinary N-telopeptide cross links of type 1 collagen (u-NTx) and deoxypyridinoline (u-DPD), serum concentrations of osteocalcin (OC)) in order to assess differences between groups. RESULTS: The BMD % Z score of the castration group was significantly lower than that of the control group or the 'CAB with EMP' group (90.6% vs. 95.5%, 98.6%; p < 0.042, p < 0.044, respectively). Levels of u-NTx, u-DPD, OC of the castration group were the highest followed by the control group, then the 'CAB with BL' group and the 'CAB with EMP' group. CONCLUSIONS: Our study and previous reports suggests that castration results in increased bone turnover and lowered BMD and that these changes might be attenuated by anti-androgens, such as BL and EMP.

Engineered IGF-I expression induces glandular enlargement in the murine prostate.

IGF-I has been implicated as a factor that may predispose one to prostate cancer and to benign prostatic hypertrophy (BPH). We established murine IGF-I transgenic mice under the control of rat probasin promoter and analysed the histology of the murine IGF-I-overexpressing prostate. Immunohistochemically, IGF-I was expressed in prostatic epithelial cells or basement membranes of the ventral, dorsal and lateral lobes in a line of IGF-I transgenic mice, but not in their control littermates. The anterior lobe did not express IGF-I. IGF-binding protein-3 (IGFBP-3), inhibitory to the mitogenic action of IGF-I, was detected in epithelial cells of prostatic ventral lobes, but not in those of the dorsal, lateral or anterior lobes of IGF-I transgenic mice. In controls, IGFBP-3 was not detected in epithelial cells of any prostatic lobe. Macroscopic prostatic size and the appearance of IGF-I transgenic mice were comparable with those of their control littermates of the same age. With a computed morphometric analysis, epithelial glands and intraglandular lumens in the prostatic lobes except the ventral lobe were smaller at 17 Months of age than at 14 Months both in IGF-I transgenic mice and controls. Glands and intraglandular lumens in the ventral prostatic lobes of IGF-I transgenic mice expressing more IGF-I protein in the prostate than controls were dense and enlarged similar to cysts compared with those of non-transgenic littermates without showing epithelial growth. Glands and lumens in the dorsal and lateral lobes of the IGF-I transgenic mice were also larger than controls at 14 and/or 17 Months of age. Glands in the anterior prostatic lobe of the IGF-I transgenic mice were not morphologically or morphometrically different from those of non-transgenic littermates. In conclusion, IGF-I transgenic mice under the control of rat probasin promoter showed more dense and enlarged epithelial glands in their prostatic ventral, dorsal and lateral lobes.

The modified Spitzy shelf operation for patients with dysplasia of the hip. A 24-year follow-up study.

We evaluated the long-term results of a modified Spitzy shelf operation for secondary osteoarthritis in 119 hips with a mean follow-up of 23.8 years. The mean age of the patients at the time of surgery was 25 years. Preoperative osteoarthritic change, the age at operation and shelf height were important factors in determining the outcome. Of the 61 hips in the pre-stage (three) and the initial stage (58) of osteoarthritis, 53 (87%) had good results, compared with only 30 (51%) of 58 hips with advanced osteoarthritis. Of the latter, 72% of those aged less than 25 years had good results compared with only 40% of patients aged over 25 years. The shelf height in the group with good results was significantly lower than in those with poor results. This operation is a safe procedure and indicated for acetabular dysplasia or subluxation of the hip with early osteoarthritic change in patients aged less than 25 years.

Renal damage and salt-dependent hypertension in aged transgenic mice overexpressing endothelin-1.

The recent development of endothelin-1 (ET-1) antagonists and their potential use in the treatment of human disease raises questions as to the role of ET-1 in the pathophysiology of such cardiovascular ailments as hypertension, heart failure, renal failure and atherosclerosis. It is still unclear, for example, whether activation of an endogenous ET-1 system is itself the primary cause of any of these ailments. In that context, the phenotypic manifestations of chronic ET-1 overproduction may provide clues about the tissues and systems affected by ET-1. We therefore established two lines of transgenic mice overexpressing the ET-1 gene under the direction of its own promoter. These mice exhibited low body weight, diminished fur density and two- to fourfold increases in the ET-1 levels measured in plasma, heart, kidney and aorta. There were no apparent histological abnormalities in the visceral organs of young (8 weeks old) transgenic mice, nor was their blood pressure elevated. In aged (12 months old) transgenic mice, however, renal manifestations, including prominent interstitial fibrosis, renal cysts, glomerulosclerosis and narrowing of arterioles, were detected. These pathological changes were accompanied by decreased creatinine clearance, elevated urinary protein excretion and salt-dependent hypertension. It thus appears that mild, chronic overproduction of ET-1 does not primarily cause hypertension but triggers damaging changes in the kidney which lead to the susceptibility to salt-induced hypertension.

A test model of hip brace for prevention of dislocation after total hip arthroplasty (Zetton Band).

Hip dislocations remain an intractable problem in patients with soft tissue impairment, particularly in those with muscle weakness around the hip, such as those who have undergone revision total hip arthroplasty (THA). At the authors' hospital, postoperative dislocations were observed in 10 of 154 hips between January 1985 and June 1988. Five hips required re-replacement. Conventional measures to prevent or treat post-THA dislocations have been anti-dislocation pants for soft fixation and a cast or abduction-forcing braces for firm fixation. However, the anti-dislocation pants for soft fixation were not as effective as indicated by the above 10 postoperative dislocations. The firm fixation techniques are considered to cause a reduction in muscle strength, causing psychological stress and poor activity of daily living (ADL). The authors devised a soft brace for easy application and prepared its test model to prevent muscle weakening, allow stability of the hip during rotation and avoid restrictions in ADL. This brace was applied to a patient who had 3 dislocations in a short period after being discharged who sustained a postoperative dislocation and achieved good results.

Elevated sympathetic nervous activity in mice deficient in alphaCGRP.

alpha-Calcitonin gene-related peptide (alphaCGRP) is a pleiotropic neuropeptide implicated in a variety of physiological processes. To better understand the biological functions of alphaCGRP, we developed an alphaCGRP-null mouse model using a gene targeting approach. Recordings of mean arterial pressure (MAP) and heart rate (HR) showed that basal MAP and HR were significantly higher in both anesthetized and conscious, unrestrained alphaCGRP-null mice than in corresponding wild-type mice. The elevated MAP in alphaCGRP-null mice was shown to be the result of elevated peripheral vascular resistance by alpha-adrenergic blockade with prazosin and by transthoracic echocardiogram, which revealed no significant differences between alphaCGRP-null and wild-type mice in the stroke volume, fractional shortening, and ejection fraction. Moreover, evaluation of autonomic nervous activity by measuring HR after pretreatment of atropine and/or atenolol and by analyzing arterial baroreceptor reflexes showed sympathetic nervous activity to be significantly elevated in alphaCGRP-null mice; elevated levels of urinary catecholamine metabolites and decreased HR variability in mutant mice were also consistent with that finding. These findings suggest that alphaCGRP contributes to the regulation of cardiovascular function through inhibitory modulation of sympathetic nervous activity.

Vascular abnormalities and elevated blood pressure in mice lacking adrenomedullin gene.

BACKGROUND: Adrenomedullin (AM) is a vasodilating peptide involved in the regulation of circulatory homeostasis and in the pathophysiology of certain cardiovascular diseases. Levels of AM are markedly increased in the fetoplacental circulation during pregnancy, although its function there remains unknown. To clarify the physiological functions of AM, we chose a gene-targeting strategy in mice. METHODS AND RESULTS: Targeted null mutation of the AM gene is lethal in utero: the mortality rate among AM(-/-) embryos was >80% at E13.5. The most apparent abnormality in surviving AM(-/-) embryos at E13.5 to E14.0 was severe hemorrhage, readily observable under the skin and in visceral organs. Hemorrhage was not detectable at E12.5 to E13.0, although the yolk sac lacked well-developed vessels. Electron microscopic examination showed endothelial cells to be partially detached from the basement structure at E12.5 in vitelline vessels and hepatic capillaries, which allowed efflux of protoerythrocytes through the disrupted barrier. The basement membrane was not clearly recognizable in the aorta and cervical artery, and the endothelial cells stood out from the wall of the lumen, only partially adhering to the basement structure. AM(+/-) mice survived to adulthood but exhibited elevated blood pressures with diminished nitric oxide production. CONCLUSIONS: AM is indispensable for the vascular morphogenesis during embryonic development and for postnatal regulation of blood pressure by stimulating nitric oxide production.

Endothelial nitric oxide synthase is essential for the HMG-CoA reductase inhibitor cerivastatin to promote collateral growth in response to ischemia.

HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase inhibitors, or statins, are prescribed widely to lower cholesterol. Accumulating evidence indicates that statins have various effects on vascular cells, which are independent of their lipid-lowering effect. Here, we tested the hypothesis that statins may augment collateral flow to ischemic tissues. We induced hind-limb ischemia in wild-type mice and treated them with either saline or cerivastatin. Cerivastatin enhanced the blood flow recovery dramatically as determined by Laser Doppler imaging. The mice treated with saline displayed frequent autoamputation of the ischemic toe, which was prevented completely by cerivastatin. Anti-CD31 immunostaining revealed that cerivastatin significantly increased the capillary density. Endothelial nitric oxide synthase (eNOS) activity was enhanced markedly in the mice treated with cerivastatin. The angiogenic effect of cerivastatin was abrogated in eNOS deficient (eNOS-/-) mice. These results indicate that eNOS is essential for cerivastatin to promote collateral growth in response to ischemia.

Adrenomedullin induces endothelium-dependent vasorelaxation via the phosphatidylinositol 3-kinase/Akt-dependent pathway in rat aorta.

To study the mechanisms by which adrenomedullin (AM) induces endothelium-dependent vasorelaxation, we examined whether AM-induced endothelium-dependent vasodilation was mediated by the phosphatidylinositol 3-kinase (PI3K)/Akt-dependent pathway in rat aorta, because it was recently reported that PI3K/Akt was implicated in the activation of endothelial NO synthase. AM-induced vasorelaxation in thoracic aorta with intact endothelium was inhibited by pretreatment with PI3K inhibitors to the same level as that in endothelium-denuded aorta. AM elicited Akt phosphorylation in a time- and dose-dependent manner. AM-induced Akt phosphorylation was inhibited by pretreatment with a calmodulin-dependent protein kinase inhibitor as well as with PI3K inhibitors. When an adenovirus construct expressing a dominant-negative Akt mutant (Ad/dnAkt) was injected into abdominal aortas so that the mutant was expressed predominantly in the endothelium layer, AM-induced vasodilation was diminished to the same level as that in endothelium-denuded aortas. Finally, AM-induced cGMP production, which was used as an indicator for NO production, was suppressed by PI3K inhibition or by Ad/dnAkt infection into the endothelium. These results suggested that AM induced Akt activation in the endothelium via the Ca(2+)/calmodulin-dependent pathway and that this was implicated in the production of NO, which in turn induced endothelium-dependent vasodilation in rat aorta.

Silencing of the caspase-1 gene occurs in murine and human renal cancer cells and causes solid tumor growth in vivo.

Renal cell cancer is a unique solid tumor that occasionally shows spontaneous regression even at an advanced stage, of which the underlying mechanism is not well understood. To investigate a potential role of the pro-apoptotic molecule caspase-1 in the growth regulation of renal cell cancer, we created transfectants expressing exogenous caspase-1 from a murine renal cancer cell line, Renca. Overexpression of caspase-1 did not affect the growth of Renca cells in vitro at the exponential phase but induced apoptotic cell death at 50% to 75% confluence, whereas control cells underwent apoptosis only after reaching 100% confluence. When implanted into the flank of a syngeneic BALB/c mouse, caspase-1-overexpressing Renca cells did not effectively establish growth as a solid tumor, forming a measurable tumor in only 7 of 11 (64%) animals, whereas control cells formed a tumor in 6 of 6 (100%) animals. The growth of tumors from caspase-1-overexpressing cells slowed down markedly after the tumors reached 5 to 10 mm in diameter, and histological examination of such tumors revealed numerous apoptotic cells positively stained by TUNEL assay. Interestingly, endogenous caspase-1 was not detected in the tumors from control cells, which re-expressed caspase-1 when they were re-cultured and exposed to a demethylation reagent, 5-aza-2'-deoxycytidine. Furthermore, treatment of a human renal cancer cell line, ACHN, with 5-aza-2'-deoxycytidine also caused recovery of caspase-1 expression, which was not detected before treatment. These data suggest that silencing of caspase-1 through DNA methylation may be involved in the oncogenesis of some renal cell cancers growing as a solid tumor.

Transcriptional activation of the cyclin D1 gene is mediated by multiple cis-elements, including SP1 sites and a cAMP-responsive element in vascular endothelial cells.

In an attempt to examine the mechanisms by which transcriptional activity of the cyclin D1 promoter is regulated in vascular endothelial cells (EC), we examined the cis-elements in the human cyclin D1 promoter, which are required for transcriptional activation of the gene. The results of luciferase assays showed that transcriptional activity of the cyclin D1 promoter was largely mediated by SP1 sites and a cAMP-responsive element (CRE). DNA binding activity at the SP1 sites, which was analyzed by electrophoretic mobility shift assays, was significantly increased in the early to mid G(1) phase, whereas DNA binding activity at CRE did not change significantly. Furthermore, Induction of the cyclin D1 promoter activity in the early to mid G(1) phase depended largely on the promoter fragment containing the SP1 sites, whereas the proximal fragment containing CRE but not the SP1 sites was constitutively active. Finally, the increase in DNA binding and promoter activities via the SP1 sites was mediated by the Ras-dependent pathway. The results suggested that the activation of the cyclin D1 gene in vascular ECs was regulated by a dual system; one was inducible in the G(1) phase, and the other was constitutively active.

Effects of intracavernous administration of adrenomedullin on erectile function in rats.

We have reported that adrenomedullin (AM)-induced vasodilation is at least in part nitric oxide (NO)-cGMP-dependent in the rat. Although it is well known that NO is much involved in the erectile function, it is controversial as to whether AM influences the erectile function. Thus, we examined the effects of AM on intracavernous pressure (ICP) during penile erection. The left carotid artery of rats was cannulated to monitor of mean arterial pressure (MAP). Bipolar electrodes were positioned on the cavernous nerve. The right cavernous body was cannulated with a needle connected to a pressure transducer to monitor ICP. Electrical stimulation (ES) increased ICP in a voltage-dependent manner. Elevation of ICP continued during ES. The intracavernous injection of 0.5 nmol AM significantly potentiated ES-induced increases in both maximal developed ICP/MAP and area under the curve (ICP trace; AUC). Since AM slightly lowered MAP, ICP was normalized by MAP. i.v. administration of N(omega)-nitro-L-arginine, a NO synthase inhibitor, markedly decreased AM/ES-induced ICP elevation. However, in the presence of E-4021, a cGMP-specific phosphodiesterase inhibitor, AM further increased both ICP/MAP and AUC. These results suggest that a NO-cGMP pathway is involved in the regulation of AM-induced rat cavernous vasorelaxation.

Effects of vasodilatory antihypertensive agents on endothelial dysfunction in rats with ischemic acute renal failure.

Ischemic acute renal failure is associated with vascular endothelial dysfunction. We examined whether vasodilatory antihypertensive agents would improve endothelial function in rats with ischemia/reperfusion renal injury. Rat kidneys were isolated and perfused after clipping of the bilateral renal arteries for 45 min and reperfusion for 24 h, and renal perfusion pressure and nitric oxide concentration in the venous effluent (chemiluminescence assay) were monitored. Preischemic administration of celiprolol (a beta-blocker; 100 mg/kg p.o.), benidipine (a calcium channel blocker; 1 mg/kg p.o.), or imidapril (an angiotensin converting-enzyme inhibitor; 3 mg/kg p.o.) restored endothelial function in rats subjected to acute renal ischemia (deltarenal perfusion pressure [10(-8) M acetylcholine]: sham -42+/-3%, ischemia -31+/-1%, ischemia +celiprolol -39+/-1%*, ischemia+benidipine -38+/-2%*, ischemia+imidapril -42+/-2%*; *p<0.05 vs. ischemia). Serum urea nitrogen and creatinine levels were also lower in the treated groups. Furthermore, ischemia-induced decreases in the response to acetylcholine and renal excretory function were smaller in SHR than in deoxycorticosterone-salt hypertensive rats, in which endothelial damage was marked. These results suggest that preischemic endothelial function may influence the degree of ischemic renal injury. Calcium channel blockers, converting-enzyme inhibitors, and endothelial NO synthase-activating beta-blockers had beneficial effects on renovascular endothelial dysfunction due to ischemia.

Cyclin A downregulation and p21(cip1) upregulation correlate with GATA-6-induced growth arrest in glomerular mesangial cells.

The GATA-6 transcription factor is reported to be expressed in vascular myocytes. Because glomerular mesangial cells (GMCs) and vascular myocytes have similar properties, we examined whether GATA-6 was expressed in cultured GMCs and whether overexpression of GATA-6 induced cell cycle arrest in GMCs, using a recombinant adenovirus that expresses GATA-6 (Ad GATA-6). GATA-6 expression in GMCs was downregulated when quiescent GMCs were stimulated by serum to reenter the cell cycle. [(3)H]thymidine uptake was inhibited in GMCs infected with Ad GATA-6 in a dose- and time-dependent manner. The expression of cyclin A protein was decreased and that of the cyclin-dependent kinase inhibitor p21(cip1) was increased in GMCs infected with Ad GATA-6. Although the expression of p21(cip1) transcripts did not change remarkably, p21(cip1) protein was stabilized in GMCs infected with Ad GATA-6, suggesting a post-transcriptional regulation of p21(cip1) expression. Northern blot analysis showed that expression of the cyclin A transcript was decreased in Ad GATA-6-infected cells, whereas this decrease of cyclin A was not observed in GMCs derived from p21(cip1) null mice. Our results demonstrate that GATA-6 is endogenously expressed in GMCs and that overexpression of GATA-6 can induce cell cycle arrest. Our results also show that GATA-6-induced cell cycle arrest is associated with inhibition of cyclin A expression and p21(cip1) upregulation. Finally, our results indicate that the GATA-6-induced suppression of cyclin A expression depends on the presence of p21(cip1).

Contractile properties of urethral smooth muscles of young and aged female dogs: morphological and pharmacological aspects.

BACKGROUND: Alpha1-adrenoceptors are highly concentrated in the urethral smooth muscles and may play an important role in the contraction of this area. However, detailed examinations of age-related changes of the properties of urethral smooth muscle have rarely been undertaken. METHODS: The contractile properties of urethras from young non-parous and old parous female beagles were determined with a urethral function study, macroscopic autoradiography for urethras using [3H]-labeled tamsulosin and morphometry of the urethral muscles. RESULTS: The antagonistic effect (pA2) of prazosin for norepinephrine was 7.76+/-0.13 in young dogs and 7.62+/-0.06 in aged dogs. The specific binding of [3H]-tamsulosin (a relatively selective alpha1A-adrenoceptor antagonist) was recognized diffusely in proximal urethras with in vitro autoradiography. The density of binding in smooth muscles was approximately 60 and 40% in circular longitudinal layers, respectively, for both dogs. CONCLUSIONS: The female canine urethra had alpha1A, and alpha1L-adrenoceptors. No age-related changes were seen in the function of the proximal urethra, distribution of alpha1-adrenoceptor binding sites and smooth muscle densities.

Adrenomedullin and nitric oxide inhibit human endothelial cell apoptosis via a cyclic GMP-independent mechanism.

Adrenomedullin, which was discovered as a vasodilating peptide, has been reported to be produced in various organs, in which adrenomedullin regulates not only vascular tone but also cell proliferation and differentiation in an autocrine/paracrine manner. We evaluated the effect of adrenomedullin on endothelial cell apoptosis. Human umbilical vein endothelial cells underwent apoptosis when cultured in serum-free medium. Treatment with adrenomedullin reduced the number of cells with pyknotic nuclei (Hoechst 33258 staining) and inhibited cell death (dimethylthiazol-diphenyltetrazolium bromide assay) in a dose-dependent manner. The administration of adrenomedullin did not alter the expression levels of Bcl-2 family proteins. Experiments with analogs of cAMP or a cAMP-elevating agonist demonstrated that elevation of the intracellular cAMP concentration does not mediate the antiapoptotic effect of adrenomedullin. The coadministration of N-nitro-L-arginine methyl ester (2 mmol/L), an inhibitor of nitric oxide synthase, abrogated the effect of adrenomedullin. Lower doses of sodium nitroprusside (1 to 10 micromol/L), a nitric oxide donor, mimicked the antiapoptotic effect of adrenomedullin. The antiapoptotic effect of sodium nitroprusside was not attenuated by the inhibition of soluble guanylyl cyclase with 1 micromol/L oxadiazolo-quinoxalin-1-one nor could apoptosis be inhibited by the incubation of human umbilical vein endothelial cells with 1 mmol/L 8-bromo-cGMP, a cell-permeant cGMP analog. These results indicate that adrenomedullin and nitric oxide inhibit endothelial cell apoptosis via a cGMP-independent mechanism.