Shinn-Nan Lin

The norepinephrine tissue concentration and neuropeptide Y immunoreactivity in genitourinary organs of the spontaneously hypertensive rat

Tissue concentration of norepinephrine and neuropeptide-Y immunoreactivity (NPY-IR) were measured in the urinary bladder, urethra, prostate and corpus cavernosum of the spontaneously hypertensive rat, as well as the normotensive Wistar-Kyoto rat. The results showed significantly increased tissue norepinephrine concentrations in the urinary bladder, urethra and prostate of the spontaneously hypertensive rat when compared to those of the normotensive rat (hypertensive, n = 18: 18.3 +/- 2.1, 14.9 +/- 1.7, 22.6 +/- 2.3 vs. normotensive, n = 18: 11.2 +/- 1.9, 10.4 +/- 1.3, 16.7 +/- 2.4 nmol/g tissue, respectively, P < 0.05 in each case). No difference was noted in the cavernosal tissue (hypertensive, n = 18: 11.3 +/- 1.6 vs. normotensive, n = 18: 10.1 +/- 1.8 nmol/g tissue, P > 0.01). Correspondingly, tissue NPY-IR was significantly increased in the bladder, urethra and prostate tissue of the spontaneously hypertensive rat (hypertensive, n = 18: 39.7 +/- 5.6, 25.3 +/- 3.4, 31.5 +/- 2.8 vs. normotensive, n = 18: 27.4 +/- 3.1, 18.6 +/- 2.7, 24.2 +/- 3.2 pmol/g tissue, respectively, P < 0.05 in each case). Again, no significant difference was observed in the cavernosal tissue (hypertensive, n = 18: 15.9 +/- 2.2 vs. normotensive, n = 18: 14.8 +/- 2.6 pmol/g tissue, P > 0.01). It is therefore concluded that increased tissue concentration of norepinephrine and NPY-IR were present in the urinary bladder, urethra and prostate of the spontaneously hypertensive rat. The significance of such biochemical findings needs further investigation but may suggest increased sympathetic innervation or activity. On the contrary, no corresponding changes were observed in the corpus cavernosum of the hypertensive rat.

Alterations in urinary bladder synaptosomal neurotransmitter concentrations in two-week streptozotocin-induced diabetic rats.

Three-month-old male Wistar rats were rendered diabetic with a single intravenous injection of streptozotocin (60 mg/kg body weight). Two weeks after induction of diabetes, synaptosome-rich fractions were prepared from urinary bladder tissue homogenate of the diabetic rats and control rats by differential centrifugation (1000 x g, 17,000 x g and 100,000 x g) with discontinuous sucrose gradient. Synaptosomal acetylcholine, norepinephrine, epinephrine and dopamine were measured by the method of high-performance liquid chromatography. The respective neurotransmitter concentrations for the diabetic rats were 1537.8 +/- 65.3, 4757.7 +/- 361.9, 3720.7 +/- 276.1, and 2447.8 +/- 196.8 pmol/mg synaptosomal protein, respectively; those for the control rats were 338.1 +/- 25.0, 1009.0 +/- 54.6, 645.3 +/- 52.2, and 1426.1 +/- 123.9 pmol/mg protein, respectively. Thus, the synaptosomal concentrations for all the measured neurotransmitters were significantly higher in the diabetic rats (P < 0.05 for each comparison). In conclusion, it has been demonstrated that the vesicle-bound acetylcholine and catecholamines in the synaptosome-rich fraction of the urinary bladder were significantly increased in 2-week diabetic rats. This finding would suggest impaired neurotransmitter release from both the bladder sympathetic and parasympathetic efferent nerve endings in early streptozotocin-induced diabetes.

Comparisons of neurotransmitter concentrations in the synaptosomal preparation of the normotensive and hypertensive rat urinary bladder

Synaptosome-rich fractions were prepared from tissue homogenate of the urinary bladder of the spontaneously hypertensive rat and normotensive Wistar-Kyoto rat by differential centrifugation (1000 x g, 17 000 x g and 100 000 x g) with discontinuous sucrose gradient. Synaptosomal acetylcholine, norepinephrine, epinephrine and dopamine were measured by the method of high-performance liquid chromatography. The respective neurotransmitter concentrations for the normotensive rats were 300.4 +/- 30.1, 962.8 +/- 58.5, 617.3 +/- 59.8, and 1354.8 +/- 144.2 pmol/mg synaptosomal protein. For the hypertensive rats, the acetylcholine concentration (203.8 +/- 23.0 pmol/mg protein) was significantly lower (P < 0.05), while the norepinephrine, epinephrine and dopamine concentrations (1459.0 +/- 180.3, 971.3 +/- 62.2, and 2161.0 +/- 243.4 pmol/mg protein, respectively) were significantly higher (P < 0.05 for all) than those of the normotensive rats. In conclusion, it has been demonstrated that the vesicle-bound catecholamines in the synaptosome-rich fraction of the urinary bladder were significantly increased in hypertensive rats. On the contrary, the synaptosomal acetylcholine concentration was significantly decreased. These findings are suggestive of increased sympathetic innervation and decreased parasympathetic innervation in the urinary bladder of the spontaneously hypertensive rat.

Dark-Cycle Video Surveillance of Sexual Performances of Normal and Diabetic Rats

Clinically, a 59% prevalence of impotence was reported among diabetic male patients. Neurological, vascular, endocrinologic and psychological factors are probably involved. Previous reports with the rat model found deterioration of sexual behavior and reproductive function caused by streptozotocin (STZ)-induced diabetes. The purpose of the present study was to develop the dark-cycle video recording methodology for the observation of rat sexual activities and to study the effect of STZ-induced diabetes on sexual performances of the rat. Adult male Wistar rats were rendered diabetic with intraperitoneal injection of STZ (60 mg/kg body weight). In the 4th week a diabetic rat or a control rat was caged with an adult ovariectomized female rat during the dark cycle. The female had been brought into behavioral estrus with intramuscular injection of 0.1 mg estradiol benzoate 3 days before and 1.0 mg progesterone 3 h before testing. Infrared-light-illuminated video recording was performed to evaluate the sexual performances. The mounting latency and frequency, intromission latency and frequency, the hit rate as well as the post-ejaculatory period of the diabetic rats were significantly deteriorated when compared with the controls (p < 0.05). However, the ejaculatory latency showed no significant difference between the two groups (p > 0.05). In conclusion, it has been demonstrated that with this methodology, behavioral studies on nocturnal animals like the rat can be carried out conveniently. It was shown that the sexual arousal mechanism and copulation-ejaculatory mechanism were both depressed in STZ-induced diabetic rats. The same study model can be used for further pathophysiological and pharmacological researches on the sexual behaviors of diabetic rats.

Effect of Alpha-Chymotrypsin on the Nonadrenergic, Noncholinergic Contraction of the Rat Urinary Bladder in vitro

The role of peptides in mediating the nonadrenergic, noncholinergic (NANC) response of the rat urinary bladder was studied. Electrical stimulation of muscle strips from 3-month-old female Wistar rat urinary bladders in the presence of autonomic blockers (atropine 10(-6) mol/l, propanolol 10(-6) mol/l, phentolamine 10(-6) mol/l, and guanethidine 10(-6) mol/l) showed NANC contraction accounting for 60% of the maximum contractile responses at 40 Hz. Frequency-response studies showed that in the presence of alpha-chymotrypsin (2 U/ml, 30-min incubation), the NANC contractile responses to electrical stimulation at lower frequencies (3-10 Hz) were enhanced (p < 0.05; n = 9). However, no significant differences were observed at higher frequencies (20-40 Hz). With repetitive 4-Hz stimulation, alpha chymotrypsin caused a 19% increase in the NANC contractile response (p < 0.05; n = 8). It is postulated that the NANC response of the rat bladder smooth muscle is composed of an excitatory (contractile) and an inhibitory (relaxant) component. Some peptide(s) is/are responsible for mediating the inhibitory response.

Isolation of synaptosomes from the rat urinary bladder

Synaptosomes are nerve-end particles (NEP) isolated by using the technique of differential centrifugation. The synaptosome offers a good model for biochemical and pharmacological studies of the nerve endings. No report has been made on synaptosome isolation from the urinary bladder. The purpose of our work was to develop the use of synaptosome in the research of neurophysiology and neuropharmacology of the urinary bladder. Synaptosome-rich fraction was prepared from tissue homogenate of male Wistar rat urinary bladder by differential centrifugation (1000, 17,000 and 100,000 g) with discontinuous sucrose gradient. Electron microscopy showed synaptosomes as thin-walled bags containing a large number of synaptic vesicles. Two types of synaptosomes were easily discerned: those containing small agranular vesicles, and those containing dense-cored vesicles. The acetylcholine, norepinephrine, epinephrine and dopamine contents in the preparation were measured by the method of high-performance liquid chromatography. The respective concentrations were 300.4 +/- 30.1, 962.8 +/- 58.5, 617.3 +/- 59.8 and 1354.8 +/- 144.2 pmol/mg synaptosomal protein. In conclusion, it has been demonstrated that synaptosome-rich fractions can be prepared from the rat urinary bladder. Thus it is possible to apply this methodology for the investigation of the neurobiology of urinary bladders.

Pheochromocytoma of the Urinary Bladder: Report of a Case and Review of the Literature

A pheochromocytoma of urinary bladder in a 75-year-old female is reported ans the literature is reviewed. The absence of elevation in urine vanillylmandelic acid (VMA) does not exclude the presence of pheochromocytoma. Besides, the characteristic history of micturtional attacks of headache, hypertension or incerased sweating may not occurred. Computed tomography and sonography were especially suitable for diagnostic localization. The neoplasm was diagnosed by cystoscopic biopsy.

Computed Tomography in Evaluation of Blunt Renal Trauma

Over one and half years, 16 patients admitted to this hospital with the diagnosis of blunt renal trauma were selected to perform computed tomography (CT) scanning. By the CT, renal injuries were categorized into minor and major injury. The minor in-juries included contusion of the kidney, shallow cortical laceration and forniceal disrup-tion. The major injuries consisted of renal pedical injury, deep laceration (into medulla), multiple lacerations (shattered kidney) and collecting system injury. There were 4 pa-tients with minor injuries and 12 ptients with major injuries in the CT finding. Among the 16 patients, only 4 patients could not achieve stable vital signs despite massive blood transfusion and finally they must receive surgical exploration for life sav-ing. These 4 patients were all in the group of major injury, of them 1 with deep lac-eration and the other 3 with multiple lacerations (shattered kidney). All of the 4 surgical patients and only 1 of 12 conservative treatment patients were present pararenal hematoma. The outcome of the patients were all good success. In conclusion, the CT findings will be helpful to the urologist to make decision for management of renal trauma. If the CT scanning revealed major injuries associat-ed with pararenal hematoma, surgical exploration for life saving must be considered. (J Urol R.O.C., 2:392-397, 1991)

Urodynamic Studies in Women Complaining of Stress Urinary Incontinence

From October 1988 to December 1989, thirty-two female patients with subjective symptoms of involuntary urine loss during abdominal straining underwent urodynamic studies of lower urinary tract. The urodynamic evaluation included uroflowmetry, cystometry and stress urethral pressure profilometry (SUPP). Cystometry showed 88% (28/32) of the patients had stable bladder storage function, 6% (2/32) had detrusor instability and 6% (2 had low bladder compliance. The uroflowmetry showed low flow in 26% (6/32) and normal uroflow in 74% (17/32). Seventy-two percent (23/32) of the patients were found to have incomplete bladder emptying. SUPP revealed 78% (25/32) of the patients had negative urethral closure pressure during cough. The percentage of patients with abnormal urodynamic findings other than positive SUPP revealed 78% (25/32) of the patients had negative urethral closure pressure during cough. The percentage of patients with abnormal urodynamic findings other than positing cough. The percentage of patients with abnormal urodynamic findings other than positive SUPP only was 47. Thus it can be concluded that urodynamic studies are useful in making diagnosis and preoperative evaluation for patients with stress urinary incontinence.