Pharmacological Properties of Propiverine Contribute to Improving Lower Urinary Tract Dysfunctions in Rats with Spinal Cord Injuries.

Patients with spinal cord injury (SCI) usually develop lower urinary tract dysfunctions, including detrusor overactivity which is also known to be a risk factor for upper urinary tract dysfunction. Antimuscarinic agents, such as propiverine, have been used clinically for the treatment of detrusor overactivity. Also, propiverine has been known to possess antagonistic activity against L-type Ca2+ channels and transient receptor potential vanilloid subtype 1 (TRPV1), in addition to activity against muscarinic receptors. These mechanisms of action may contribute to improving detrusor overactivity in SCI. We therefore investigated the effects of antagonists of these mechanisms on non-voiding contraction (NVC) in SCI rats that are similar to clinical cases of detrusor overactivity, and considered whether these action mechanisms contribute to the incidence of NVC in SCI. Cystometry was performed in rats 4 weeks after spinal transection. Urinary functions were evaluated before and after intravenous administration of propiverine and specific antagonists for muscarinic receptors (atropine), L-type Ca2+ channels (verapamil), and TRPV1 (capsazepine). Propiverine markedly decreased the amplitude pressure of NVC in SCI rats, which was partially inhibited by atropine. Verapamil also suppressed the amplitude pressure of NVC to the same degree as propiverine. NVC disappeared almost completely after C-fiber desensitization, although capsazepine exerted no evident effects. These findings suggest that muscarinic receptors, L-type Ca2+ channels, and C-fiber afferent nerves contribute to the incidence of detrusor overactivity in SCI, and a drug that has multiple antagonistic effects, such as propiverine, is very effective for the treatment of lower urinary tract dysfunctions in SCI.

[Effect of piracetam on urea-induced myoclonus in rats].

Piracetam [2-oxo-1-pyrrolidineacetamide], a cyclic GABA, has been used in Europe for the treatment of patients with cognitive disorders. We investigated the effect of piracetam on urea-induced myoclonus in rats. Myoclonus was induced by intraperitoneal injection of 4.5 g/kg urea, and was recorded with EMG and video apparatus. The incidence of induced myoclonus decreased significantly by intraperitoneal injection of 300 mg/kg piracetam and oral administration of 0.3-10 mg/kg clonazepam. Furthermore, the combined application of 100 mg/kg piracetam and 0.03-0.1 mg/kg clonazepam was effective in ameliorating the myoclonus, although separate administrations were not effective. These findings suggest that piracetam is an effective drug for treating myoclonus, particularly when it is used in combination with clonazepam.

[A pharmacological profile of piracetam (Myocalm), a drug for myoclonus].

Myoclonus is defined as shock-like, brief involuntary abnormal movements in muscle jerking caused by external stimuli; and it arises from progressive myoclonus epilepsy, post-anoxic encephalopathy and Alzheimer's disease, causing disabling symptoms. It is a rare syndrome but very difficult to control. Piracetam (2-oxo-1-pyrrolidineacetamide, Myocalm) was developed more than 30 years ago as a cyclic derivative of gamma-aminobutyric acid (GABA); it has been used in European countries for the treatment of memory loss and other cognitive defects in patients. Some reports have suggested that piracetam has anti-myoclonus activities, but the mechanisms of myoclonus are not well-identified, and thus there have been few preclinical studies on piracetam for the treatment of myoclonus. We investigated the effect of piracetam and clonazepam, an anti-epileptic drug, on high dosage urea-induced myoclonus using an electromyogram in rats. The incidence of myoclonus induced by urea 4.5 g/kg (i.p.) was significantly reduced by piracetam at 300 mg/kg (i.p.) and by clonazepam at 0.3 mg/kg (p.o.). The coadministration of piracetam 100 mg/kg (i.p.) and clonazepam at 0.03-0.1 mg/kg (p.o.) significantly reduced the incidence of myoclonus, although separate administration was not effective. After oral administration of piracetam, it is rapidly and completely absorbed and excreted almost unchanged in the urine; however, it does show a little binding to human serum protein. Repeated oral administration of piracetam for 7 days in phase-I trials did not show any accumulation of the drug. In the placebo-controlled double-blind crossover trial of piracetam conducted in the UK, there was a significant improvement in cortical myoclonus. In phase-II trials, piracetam inhibited myoclonus and showed an improvement in the quality of life (QOL) of the patients. These results show that piracetam has a beneficial use in clinics for severe myoclonus patients when it is combined with anti-epileptic drugs, demonstrating an improvement in the myoclonus and QOL of patients.

[Availability of 2VO rats as a model for chronic cerebrovascular disease].

We have established a chronic cerebral hypoperfusion model that is produced by permanent occlusion of bilateral common carotid arteries (2VO) in rats. 2VO rats exhibited rarefaction in the white matter, shrinkage of neurons in the cerebral cortex and hippocampus 1-3 days after 2VO and infarctions in the striatum 7 days after 2VO. These histological changes in the cortex and hippocampus were accompanied by a decrease in immunoreactivity for microtubule-associated protein 2 (MAP2). Immunoreactivity for glial fibrillary acid protein (GFAP) was observed at 3-7 days after 2VO. Marked increase in GFAP staining in astrocytes in the cerebral cortex and hippocampus was found 30 days after ligation. In the 8-arm radial maze performance, the 2VO rats showed a higher rate of errors than the sham-operated control during repeated training periods. THA (9-amino-1,2,3,4-tetrahydroacridine), a cholinesterase inhibitor and GTS-21 (3-(2,4-dimethoxybenzylidene)-anabaseine dihydrochloride), a central nicotinic acetylcholine-receptor agonist improved the learning impairment in the radical maze task of 2VO rats. GTS-21 administration exerted a protective effect against the neuropathological changes that followed 2VO. Taken together, the 2VO rat appears to be a useful model for investigating the pathophysiology of human dementia and to elucidate the therapeutic potential of drugs for this disease.

[A case of renal cell carcinoma associated with von Hippel-Lindau disease and the necessity for family genetic diagnosis].

We report a 47-year-old man who had bilateral renal cell carcinoma (RCC) associated with von Hippel-Lindau (VHL) disease. Surgical resection of hemangioblastomas and left nephrectomy for RCC had been done previously. This time, a small RCC was found in his right kidney and enucleation was performed to preserve renal function. His mother had retinal angioma, hemangioblastoma, and bilateral RCC. Hemangioblastoma was also found in his daughter. Genetic diagnosis was performed in his family and a germline VHL mutation was recognized. For improvement of the prognosis of VHL disease, genetic diagnosis and early clinical assessment are important.

A comparative study on the effects of nicotine and GTS-21, a new nicotinic agonist, on the locomotor activity and brain monoamine level.

Effects of GTS-21 [3-(2,4-dimethoxybenzylidene)-anabaseine dihydrochloride], a selective nicotinic agonist, on locomotor activity and dopamine turnover were examined and compared to those of nicotine to test if GTS-21 exhibits side effects similar to those of nicotine. GTS-21 had no effect on locomotor activity in mice or dopamine turnover in rats. In contrast, nicotine produced a biphasic effect on locomotor activity. It also enhanced dopamine turnover rates in the striatum and cerebral cortex, suggesting the involvement of dopaminergic systems in the nicotine-induced changes in locomotor activity. GTS-21 exhibits fewer adverse effects, suggesting that it has therapeutic potential for cognitive disorders related to central cholinergic dysfunction.

[Complete remission of liver metastasis from rectal cancer following continuous oral administration of tegafur-uracil after intrahepatic arterial single injection of CDDP and 5-FU].

An intrahepatic arterial injection of CDDP, 5-FU, followed by ten months of oral tegafur-uracil administration (2g/day), induced remission for 3 months or more in a 72-year-old male with rectal cancer and synchronous liver metastasis subsequent to anterior resection of the rectum. Tegafur-uracil showed an excellent anticancer effect against colorectal metastatic liver cancers without loss of QOL because a single-low dose of intraarterial anticancer injection was followed by continuous oral administration of tegafur-uracil, and the chemotherapy could be managed to obtain complete remission of the hepatic lesion.

Protective effect of GTS-21, a novel nicotinic receptor agonist, on delayed neuronal death induced by ischemia in gerbils.

The neuroprotective effects of GTS-21 [3-(2,4-dimethoxybenzylidene)-anabaseine dihydrochloride] were studied and compared with those of nicotine, 9-amino-1,2,3,4-tetrahydroacridine hydrochloride hydrate (THA) and pentobarbital-Na (PB) using a cerebral ischemia model in Mongolian gerbils. The learning performance and memory retention were elucidated by a step-through passive avoidance task at 2 and 3 days after ischemia-reperfusion. In this task, the ischemia-operated gerbils showed impairment of learning performance and memory retention. Neuronal cell death in the hippocampal CA1 area was observed at 7 days after ischemia. When administered i.p. 30 min before ischemia, GTS-21 (5 mg/kg), (-)-nicotine (1.5 mg/kg), THA (5 mg/kg) and PB (50 mg/kg) significantly attenuated the impairment of passive avoidance performance and the neuronal cell death induced by the ischemia. When administered orally twice daily for 2 weeks prior to the ischemia, GTS-21 (10 mg/kg) significantly suppressed both amnesia and neuronal cell death, while (-)-nicotine (10 mg/kg) and THA (10 mg/kg) suppressed only the amnesia. These results suggest that GTS-21 exerts a protective activity on not only impairment of learning and memory but also delayed neuronal death and that the underlying mechanism of GTS-21 differs from that of nicotine or THA.

Chronic cerebral hypoperfusion-induced neuropathological changes in rats.

We investigated the time courses of histopathological changes in various brain regions following permanent occlusion of the bilateral common carotid arteries (2VO) in rats. 2VO rats exhibited rarefaction in the white matter, shrinkage of neurons in the cerebral cortex and hippocampus CA1-3 and dentate gyrus areas 1-3 days after the operation. These histological changes in the cortex and hippocampus were accompanied by a decrease in immunoreactivity for microtubule-associated protein 2 (MAP2), a marker protein of neuronal dendrites. Immunoreactivity for glial fibrillary acid protein (GFAP) was observed at 3-7 days after the 2VO operation. A marked increase in GFAP staining of the astrocytes in the cerebral cortex and hippocampus was found 30 days after ligation. Eight-arm radial maze performance was tested from 14 days to 60 days after the operation. The 2VO rats showed fewer initial correct responses than sham-operated control rats during a repeated training period. These findings suggested that the loss in dendritic MAP2 immunoreactivity and an increase in astroglial staining and/or rarefaction of the white matter may cause neuronal death, infarction and learning impairment under conditions of chronic hypoperfusion.

GTS-21, a nicotinic agonist, attenuates multiple infarctions and cognitive deficit caused by permanent occlusion of bilateral common carotid arteries in rats.

We examined the effects of GTS-21 [3-(2,4-dimethoxybenzylidene)-anabaseine dihydrochloride], a nicotinic agonist, on histopathological changes of the brain and radial maze learning performance in rats with permanent occlusion of the bilateral common carotid arteries (2VO) and elucidated whether this compound has a protective effect against the neuronal degeneration and spatial cognitive deficit caused by chronic ischemia. Rats were administered GTS-21 (1 and 10 mg/kg, p.o.) or vehicle 24 hr and 30 min before the 2VO operation and then once daily for 2 months after the operation. The 2VO rats given vehicle had multiple infarctions in the cerebral cortex, hippocampus and striatum and rarefaction in the white matter at 2 months after the operation, although the number and distribution of infarctions varied among individual animals. In addition, the 2VO rats given vehicle showed a higher rate of errors in the acquisition trials of the 8-arm radial maze task than sham-operated controls. However, 2VO rats treated with GTS-21 (1 and 10 mg/kg, p.o.) showed significantly decreased neuropathological changes and less errors in the acquisition trials compared to the vehicle-treated 2VO rats. These results indicate that GTS-21 attenuates impairment of spatial cognitive deficit and progressive neuronal degeneration induced by 2VO and suggest that this compound is beneficial for the treatment of neurodegenerative diseases following chronic cerebral hypoperfusion.

GTS-21, a nicotinic agonist, protects against neocortical neuronal cell loss induced by the nucleus basalis magnocellularis lesion in rats.

Effect of subchronically administered GTS-21 [3-(2,4-dimethoxybenzylidene)-anabaseine dihydrochloride], a selective nicotinic agonist, on neuronal cell loss caused by nucleus basalis magnocellularis (nBM) lesion was studied in rats. After 2 weeks of bilateral nBM excitotoxic lesion, GTS-21 was orally administered once daily for 20 weeks. Neuronal cell loss was observed in layers II-III of the parietal cortex in the lesioned control rats. GTS-21 significantly attenuated the neuron loss in these layers. These results suggest that GTS-21 exhibits a protective action against the neuronal cell death in the parietal cortex and may have a beneficial effect on neurodegenerative disorders such as an Alzheimer-type disease.

[Anti-amnesic effect of prolyl endopeptidase inhibitors in mice].

Based on the results of a previous report that prolyl endopeptidase (PPCE) inhibitors facilitated the acquisition of active avoidance response and retarded the extinction of the response, further studies were made on the effect of PPCE inhibitors on learning and the memory process. Using mice, tests were performed both in the light-dark discrimination Y-maze task and the lever-press task of the water reinforcement schedule, and mice were also tested in the acquisition and retention of one-trial "step-through" passive avoidance task. The effect of PPCE inhibitors were investigated both in control and electroconvulsive shock- or scopolamine-induced amnesic animals. Z-Pro-p, the most potent inhibitor among 5 compounds tested in this study, and arginine vasopressin (AVP) facilitated the learning process and retarded the extinction of the acquired response in all tests. Suc-Pro-p was also effective in the Y-maze and passive avoidance test. Thus, the effect of the test compounds were parallel with their in vitro activities as PPCE inhibitor. These results suggest that the anti-amnesic effect of PPCE inhibitors is partially attributable to their effect on the breakdown of the biologically active peptides which are involved in the memory process, such as AVP, in the brain.

[Acquisition of a lever press behavior by mice in a water reinforcement situation].

An operant chamber for mice, consisting of two adjacent compartments of W 130 X L 120 X H 150 mm, with a liquid dispenser which is operated by lever press was prepared. Using the apparatus, the applicability of mice for the study of learning of lever press behavior in a water reinforcement situation was investigated. Animals were deprived of water in the home cage and water was only supplied in the operant chamber by the lever press. A session of 15 min training was performed daily. By continuous reinforcement schedule, animals learned the lever pressing by 3 sessions. With these trained animals which attained more than 150 responses further experiments with a fixed ratio (FR) schedule was made, from FR 1 to FR 20. The best increase in responses was observed when the FR was regularly and gradually stepped up from 1 to 20 by every 5 sessions. Scopolamine, 1 mg/kg ip, significantly suppressed the lever press at FR 1 sessions, and the latency time until the first lever press was also prolonged significantly in these sessions. Thus, the applicability of mice for the study of learning of lever press behavior and the experimental schedules were established.

Serum gastrin levels and lower oesophageal sphincter pressures in infants with congenital hypertrophic pyloric stenosis.

Serum gastrin levels in 16 patients with congenital hypertrophic pyloric stenosis (CHPS) were measured and oesophageal manometric studies were performed in 14 of these 16 patients before and after pyloromyotomy. Hypergastrinaemia was found in the patients with CHPS, and the 7th postoperative serum gastrin level was much higher than the preoperative pressure. However, there was no significant correlation between the LES pressure change and the serum gastrin change. These results indicate that competence of LES after pyloromyotomy in patients with CHPS is maintained not only by endogenous gastrin rise but also by other factors.