Shigeharu Kurimoto

Detection of α1-adrenoceptor subtypes in human hypertrophied prostate byin situ hybridizationsubtypes in human hypertrophied prostate byin situ hybridization

SummaryAdrenergic stimulation induces contraction of hypertrophied prostatic tissue via the α1 adrenoceptor, and the results of pharmacological studies suggested the existence of adrenoceptor subtypes. Recently three subtypes (α1a, α1b, and α1d) were cloned. Using probes for these subtypes, we demonstrated their expression in the tissues of ten cases of benign prostatic hypertrophy, usingin situ hybridization. To determine the ratio between these subtypes, an RNase protection assay was also performed in three cases. Expression of the α1a and α1d adrenoceptors was diffuse in the smooth muscles of the interstitium, but was absent in glandular epithelial cells. On the contrary, the α1b adrenoceptor was hardly detectable. The RNase protection assay confirmed the absence of the α1b adrenoceptor, the ratio of α1a and α1d being 4∶1. These results supported the idea that the differences in prostatic contractile response to several adrenergic drugs are based on the affinities of these drugs for the different subtypes.Adrenergic stimulation induces contraction of hypertrophied prostatic tissue via the alpha 1 adrenoceptor, and the results of pharmacological studies suggested the existence of adrenoceptor subtypes. Recently three subtypes (alpha 1a, alpha 1b, and alpha 1d) were cloned. Using probes for these subtypes, we demonstrated their expression in the tissues of ten cases of benign prostatic hypertrophy, using in situ hybridization. To determine the ratio between these subtypes, an RNase protection assay was also performed in three cases. Expression of the alpha 1a and alpha 1d adrenoceptors was diffuse in the smooth muscles of the interstitium, but was absent in glandular epithelial cells. On the contrary, the alpha 1b adrenoceptor was hardly detectable. The RNase protection assay confirmed the absence of the alpha 1b adrenoceptor, the ratio of alpha 1a and alpha 1d being 4:1. These results supported the idea that the differences in prostatic contractile response to several adrenergic drugs are based on the affinities of these drugs for the different subtypes.

CO-EXPRESSION OF HEPATOCYTE GROWTH FACTOR AND ITS RECEPTOR IN HUMAN PROSTATE CANCER

Hepatocyte growth factor acts differently depending on the organs or tumours involved. It may be produced simultaneously with its receptor, c-Met, in several types of malignant tumour cells and may exercise an autocrine regulation. To analyse the effect of hepatocyte growth factor in human prostate cancer, we conducted immunohistochemistry, in situ hybridization and the reverse transcriptase polymerase chain reaction. The first two techniques revealed the growth factor in prostate cancer cells, and the polymerase chain reaction confirmed this expression. c-Met is expressed in prostate cancer cells, but not in interstitial cells. Hepatocyte growth factor is expressed in interstitial cells, especially in hormone-treated cancer tissue, indicating that the growth factor pathway changes with the hormonal status. Low-grade tumours expressed c-Met at the plasma membrane. Higher grade tumours tended to express it in the cytoplasm, suggesting that the role of c-Met as the hepatocyte growth factor receptor was blocked in higher grade tumours. The relationship between the growth factor and its receptor is thus influenced by hormonal status and differentiation in prostate cancer and is not explained simply in terms of autocrine or paracrine action.

ELECTRON MICROSCOPIC EVIDENCE FOR EPIDERMAL GROWTH FACTOR RECEPTOR (EGF‐R)‐LIKE IMMUNOREACTIVITY ASSOCIATED WITH THE BASOLATERAL SURFACE OF GASTRIC PARIETAL CELLS

Epidermal growth factor (EGF), in addition to its effects on cell growth, has a suppressive effect on gastric hydrochloride secretion. We recently demonstrated EGF‐receptor (EGF‐R)‐like immunoreactlvity on human gastric parietal cells by light microscopy. To reveal further the localization of this reaction an immuno‐electron microscopical study was performed. 5281gG, an anti‐EGF‐R murine monoclonal antibody and a polyclonal anti‐EGF antibody were employed for immunostaining using the avidin‐biotin method. Positive reaction against 5281gG was shown mostly on the outer membrane of parietal cells, except in the apical portion. No reaction was observed on most of the intracytoplasmic membranes including intracellular canaliculi, endoplasmic reticulum and other membranous components. In the basillar portion, the 5281 gG‐positive parietal cell membrane formed labyrinthine interdigitations. No reaction against anti‐EGF was demonstrated in any of the gastric mucosal cells, although a reaction was clearly shown on salivary gland cells. These findings suggest a blood‐mediated direct action of EGF on parietal cells.

Multidirectional contraction of human hypertrophied prostate.

1. The purpose of the present investigation is to evaluate muscle contraction in two directions (longitudinal and circumferential to urethra) physiologically and morphologically for alpha-adrenoceptor agonists. 2. Norepinephrine (10(-7)-10(-4) M), phenylephrine (10(-7)-10(-4) M) and clonidine (10(-7)-10(-4) M) induced contractions in a dose-dependent manner on human prostate from patients with benign prostatic hypertrophy (BPH). 3. No significant differences were observed between longitudinal and circumferential directions of human prostate in 50% of the maximal muscle contraction (EC50 values) and the maximal muscle contractions caused by any agents used. 4. Morphometric analysis for muscle in prostates was performed using formalin-fixed, paraffin-embedded sections stained by the Mallory-Azan method. 5. There was no significant difference in the density of the muscle area between longitudinal and circumferential directions of prostatic strips. 6. These results suggest that there are no significant differences in responsiveness of alpha-adrenoceptor agonists and the smooth muscle contents in longitudinal and circumferential directions to urethra, for human hypertrophied prostate.

Prolonged renal parenchymal retention of 99mTc mercaptoacetyltriglycine after nephron-sparing surgery

ObjectiveNephron-sparing surgery is a treatment in which a part of a diseased kidney is resected and some parenchyma of the kidney is spared. Impairment of spared renal parenchyma after the surgery may cause prolonged prarenchymal retention in renal scintigraphy with 99mTc mercaptoacetyltriglycine (99mTc-MAG3). The aim of this study was to determine whether or not parenchymal retention of 99mTc-MAG3 is prolonged after nephronsparing surgery. MethodsTwenty-two patients underwent a total of 29 99mTc-MAG3 studies within 1 year after nephron-sparing surgery. In 17 patients (23 examinations) who had bilateral kidneys, the presence of diffuse prolongation of parenchymal retention was determined for the operated kidney. In all patients, the presence of regional prolongation around the surgical margin was assessed. ResultsDiffuse prolongation was observed in four of 10 examinations performed within 1 month after surgery and in none of 13 examinations performed later than 1 month after surgery. Regional prolongation was shown in 10 of 14 examinations performed within 1 month after surgery and in three of 15 examinations performed later than 1 month after surgery. In five patients who were studied both prior to and later than 1 month after surgery, regional prolongation was noted on the first study. On the second study, regional prolongation was improved and initial renal uptake around the surgical margin was intensified. ConclusionsRenal parenchymal retention of 99mTc-MAG3 is frequently prolonged in the early period after nephron-sparing surgery. Renal scintigraphy with 99mTc-MAG3 may aid in characterizing acute renal damage after nephron-sparing surgery.

Age-related changes in alpha1-adrenoceptors in rat prostate

The age-related changes in the density of alpha1-adrenoceptors in the dorsolateral lobe of the rat prostate were evaluated in Wistar rats at 8, 52, and 104 weeks of age. [3H]YM617, a newly senthesized alpha1-adrenergic blocker, was used as the ligand. The mean maximum number of binding sites, or alpha1-adrenoceptor density (Bmax)±SE of 104-week-old rats (11.0±1.2 fmol/mg protein) was significantly lower than that in the 8-week-old rats (37.0±4.3 fmol/mg protein) and 52-week-old rats (37.2±3.4 fmol/mg protein) respectively, P<0.01. In contrast, mean affinity (Kd) values±SE of these groups showed no significant differences (8-week-old rats, 115.8±9.1; 52-week-old rats, 100.5±5.8; and 104-week-old rats, 116.4±9.8 pM). Mean volumes±SE of muscle cells of the prostate were 3.7±1.1x103 μm3 at 8 weeks, 30.0±6.2x103 μm3 at 52 weeks, and 18.6±8.2x103 μm3 at 104 weeks. Volumes for 8-week-old rats were significantly smaller than those for 52-week-old (P<0.01) and 104-week-old rats (P<0.05). However, the mean area density of the muscle cells showed no difference among the three groups: 20.1±2.2% at 8 weeks, 27.3±2.9% at 52 weeks and 20.3±3.4% at 104 weeks. In conclusion, the density of YM617-binding sites (alpha1-adrenoceptors) in 104-week-old rats was lower than in 8- and 52-week-old rats. Muscle volume in the rat prostate was larger in rats aged 52 and 104 weeks than in 8-week-old rats, but no correlation was found between alpha1-adrenoceptor density and the muscle volume or muscle density in aging.

Quantitative autoradiography of α1 adrenoceptors with [3H]tamsulosin in human hypertrophied prostate using computerized image analysis

SummaryFourteen specimens of human hypertrophied prostate were evaluated for the distribution of α1 adrenoceptors using autoradiography with a computerized image analysis system. The hypertrophied prostatic specimens, obtained at open prostatectomy, were dissected vertically to the urethra, and sectioned at 10 μm. They were immersed in 1 nM of specific α1 ligand, [3H]tamsulosin chloride ([3H]tamsulosin) and exposed to autoradiographic film. The images were analysed by a computerized image analysis system. The total binding of [3H]tamsulosin in the whole section (n = 14) was 0.82 ± 0.21 (mean ± se) nCi mg−1. The autographic data were correlated with data obtained in a membrane-binding assay. The prostatic tissue studied was divided into urethral, glandular and stromal zones, the latter two zones being further divided into the inner and outer areas. The total binding of [3H]tamsulosin in the urethral zone (n = 7) was 0.65 ± 0.32 nCi mg−1. The glandular zone contained significantly more abundant α1 adrenoceptors than the stromal zone and their densities (glandular vs stromal) were 1.15 ± 0.19 nCi mg−1 (n = 14) vs 0.72 ± 0.15 nCi mg−1 (n = 14), respectively (p < 0.05). The data from the whole section were not affected by prostatic weight. This method described enabled the distribution of the receptors in different sites to be evaluated both morphologically and quantitatively.

Detection of a glycosphingolipid antigen in bladder cancer cells with monoclonal antibody MRG-1

SummaryThe monoclonal antibody MRG-1 has been evaluated for the immunohistochemical detection of the type 3 chain of blood group A in human normal bladder epithelium and bladder tumours. Light microscope examination of paraffin sections demonstrated that this antigen was present in normal epithelium and superficial bladder tumour in patients with blood group A or AB, but was absent in the invasive type of bladder tumour. In normal epithelium, the plasma membrane was positive for this antigen, and the cytoplasm was diffusely stained. In superficial transitional cell carcinoma, the plasma membrane was negative, whereas the cytoplasm was intensely stained in the perinuclear region. This pattern was different from that observed for type 1 and 2 group A antigen, which was recognized mainly at the plasma membrane. However, in superficial transitional cell carcinoma, the staining was also seen on the plasma membrane. The pattern of the localization of this antigen in this carcinoma was influenced by the treatment of organic solvents. Electron microscopical observations confirmed that this antigen was localized on the plasma membrane and also in the Golgi apparatus of the superficial tumour.These results proved that the type 3 chain of blood group A is present in human bladder epithelium and low grade tumours in correspondence with the blood type, but disappears in tumours with high malignant potential. However, its expression is independent of the expressions of the other subtypes which have been studied. Furthermore, the changes in the staining pattern caused by pretreatment with organic solvents suggested possible differences in the microenvironment of the glycolipids containing this type of sugar chain.

Renal aging change of α1-adrenoceptor in wistar rats

Abstract 1. 1. The aging changes of density of the α 1 -adrenoceptors in the kidney were evaluated with Wistar rats of several ages (8, 52 and 104 weeks old). 2. 2. [ 3 H]prazosin and [ 3 H]YM617 (newly synthesized α 1 -blocker) were used for the ligand. The B max of [ 3 H]prazosin was 74.0 ± 9.5 fmol/mg/protein in 8 week, 52.1 ± 7.3 fmol/mg protein in 52 week, and 31.3 ± 4.2 fmol/mg/protein in 104 week rats, and that of [ 3 H]YM617 was 45.0 ± 6.6 fmol/mg/protein in 8 week, 32.4 ± 5.7 fmol/mg/protein in 52 week, and 19.3 ± 5.5 fmol/mg/protein in 104 week rats. 3. 3. The B max of both ligands for 104 week rats was significantly decreased compared to 8 week rats, however, 52 week rats showed no decrease of B max for both ligands. 4. 4. The K d values showed no difference in these three age groups for both ligands. 5. 5. Autoradiographic study supported the result above mentioned. Furthermore, the binding sites of α 1 -adrenoceptors were mainly in the cortex (vascular wall and peritubular area) and that α 1 -adrenoceptors were chiefly chlorethylclonidine dihydrochloride (CEC) insensitive.

Tiny nodule in the testicle: Case report of a sertoli cell tumor

Abstract Sex cord‐stromal tumors of the testis are rare. We report on a small Sertoli cell tumor in the testicle. According to published reports, a nodular lesion on the testicle has a variety of differential diagnoses. Preoperatively, it is very difficult to differentiate between a tumorous lesion and an inflammatory change. When a tiny nodule in the testicle is encountered, we propose limited, testicular‐sparing surgery according to the frozen section diagnosis.