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Since platelets accumulate taurine, they provide a model for studying the taurine transport in anisosmotic disorders. Thus, in this work we studied the taurine concentration and uptake in the platelets of Brattleboro rats, homozygous (DI) and heterozygous (HZ) for hereditary hypothalamic diabetes insipidus, and Long Evans (LE) normal rats after free water intake and after dehydration induced by water deprivation for 24 h. The decreased ability of the DI rats to concentrate urine led to plasma hypernatremia and hyperosmolality despite excessive drinking. Water deprivation in the DI rats induced drastic dehydration with exacerbated hypernatremia and hyperosmolality. Plasma hypernatremia and hyperosmolality resulted in a significant elevation of the taurine concentration and uptake by platelets of the DI rats. Kinetic assays showed that plasma hypernatremia and hyperosmolality did not alter the affinity of taurine to platelet membrane carrier, as expressed by Km, but caused a profound increase in the maximal transport capacity, Vmax. After free water intake the Vmax of the DI rats was about two times higher than that in the HZ and LE rats and after water deprivation it was about three times higher. Water deprivation doubled the Vmax of the DI rats without changing the Km.

The use of ligand-binding methods to study neurotransmitter-receptor sites has made its impact on almost all aspects of biological pursuits including research on aging and neurodegenerative diseases. In the past, most of the research in biochemical gerontology has largely centered around changes in various neurotransmitters and enzymatic activities. The molecular basis of aging and neurodegeneration at the level of neurotransmitter-receptor interactions has been highly appreciated in the last two decades as a result of receptor binding studies. It is now possible to obtain information about the regional distribution of neurotransmitter receptors in the brain, the pharmacological and biochemical characteristics of these sites, and the functional interrelationships between different neuronal systems in normal and pathological conditions. The passage of time after maturity is accompanied by measurable physiologic decline in virtually all systems. It is the aim of this work to discuss the practical aspects of neurotransmitter and/or drug (ligand)-receptor binding studies, highlighting some examples of their applications to geriatric neuropharmacology research, with special consideration to learning impairment and memory loss in normal and in pathological aging processes.

We observed differences in the capillary architecture of the skeletal muscles that have different fiber metabolism. The soleus, the vastus intermedius and the tibialis anterior muscles of adult Wistar rats were prepared using two different techniques. Samples for adenosine triphosphatase (ATPase) staining were prepared following Dubovitz's method, and the distributions of fiber type, Types 1, 2A and 2B, were analyzed. Then, corrosion casts of capillary architecture of these muscles prepared following Murakami's method were observed with a scanning electron microscope (SEM) and compared with the fiber distribution. The fiber type composition of the soleus muscle showed Type 1 (slow-twitch) dominance and that of the vastus intermedius and the tibialis anterior muscle showed Type 2 (fast-twitch) dominance. The capillaries of the soleus muscle were tortuous, and this was thought to be advantageous for blood supply. In contrast, the capillaries of the vastus intermedius and tibialis anterior muscles had a relatively parallel pattern. Additionally, two different patterns of capillary architecture that appeared to correspond to certain metabolic characteristic of different muscle fiber types were preserved with corrosion casting. In conclusion, comparative studies on capillary architecture of the skeletal muscles are useful for analyses of its function.

In the pathophysiology of lumbosacral radiculopathy, inflammation of the nerve root is of critical importance. Additionally, free radicals have been shown to be associated with some inflammatory process. This study was designed to investigate whether free radicals participate in the pathophysiology of nerve root involvement. We measured superoxide dismutase (SOD) activity in cerebrospinal fluid (CSF) of 31 patients with unilateral lumbosacral radiculopathy caused by a herniated disc using electron spin resonance (ESR) spectrometry. Then SOD activity was compared with the type of nerve root compression as seen on preoperative myelography. SOD activity in the normal control group was 7U/ml, while that in the hernia group remarkably decreased. The concentration gradient of SOD activity was different between central herniation and centrolateral herniation. Our findings indicate that free radicals are generated after nerve root compression. Under severe deficiency of SOD activity in CSF, serum SOD penetrates into CSF after further compression. In addition, SOD in CSF may play an important role in protecting against nerve root involvement.

We conducted a clinicopathological analysis of chondrosarcomas in 17 patients treated in our institute. The 5- and 10-year overall survival rates of the patients were 72.3% and 61.9%, respectively. The significant prognostic factors were size and histologic grade of the tumor. Sex, age, location of the primary tumor, or the presence of a preceding exostosis did not affect the treatment results significantly. Chondrosarcomas of histologic grades I and II did not metastasize, while all grade III and dedifferentiated chondrosarcomas metastasized to the lung. The local recurrence rate depended on the surgical margin. Wide excision with an adequate surgical margin is important to achieve local control of the chondrosarcoma.

We report here the time-course of electron microscopic changes induced by gamma-interferon (IFN-gamma) in the human erythromyeloid leukemia cell line K562. In K562 cells treated with IFN-gamma for 6h, the nuclei were polygonal in shape and microvilli were far more abundant on cell membranes compared with control K562 cells, and invaginations were often seen in the cell membranes. There was a reduction in the number of cell-membrane microvilli and an increase in the number of lysosomal bodies in the cytoplasm of K562 cells treated with IFN-gamma for 12h. After treatment with IFN-gamma for 24h, the cell membrane microvilli disappeared, large numbers of cellular organelles were observed, such as mitochondria and lysosomes, and the cytoplasm became electron-dense. Cytoplasmic vesicles and vacuoles were also observed. These vesicles may correspond to an intermediate step in the ultimate cellular disintegration associated with apoptosis caused by IFN-gamma.

In order to evaluate a clinical use of omeprazole suspension, we examined the pharmacokinetics of omeprazole after oral administration in rats. Although the administration of omeprazole suspension buffered by NaHCO3 solution did not produce a significant increase in the area under the concentration-time curve (AUC) value compared with non-buffered group, the administration of NaHCO3 buffer immediately after dosing of omeprazole suspension buffered by NaHCO3 caused a significant increase in the AUC value. These results suggest that the NaHCO3 treatment following the administration of omeprazole buffered suspension effectively decreased the degradation of the compound by gastric acid. Therefore, the successive administration of NaHCO3 solution after the omeprazole dosing seems to be a simple and useful method for the administration to patients who cannot receive tablets.

Effects of HR-592, a new derivative of indole, on conditioned avoidance and intracranial self-stimulation behavior were investigated in rats using a shuttle box and a Skinner box, respectively. The oral administration of HR-592 at doses of 3-10 mg/kg caused a dose-dependent suppression of the conditioned avoidance response. Even the escape response was slightly suppressed in the group administered 10 mg/kg of HR-592. The self-stimulation behavior was suppressed dose-dependently from 1 to 8 h after the administration of 6-10 mg/kg of HR-592. These results indicate that the action of HR-592 on conditioned avoidance response and intracranial self-stimulation behavior is similar to the action of neuroleptics.

The plasma level of isosorbide dinitrate intraperitoneally administered to rats stressed by foot-shock was almost the same as that in non-stressed control rats. However, levels of its metabolites, 5-isosorbide mononitrate and 2-isosorbide mononitrate, were lower in stressed rats than in non-stressed rats, suggesting that stress may influence the metabolism and/or excretion of the metabolites.

We studied the effect of endogenous prostaglandin E2 (PGE2) on interleukin 1 (IL-1) production by peripheral blood monocytes from patients with rheumatoid arthritis (RA). IL-1 production by RA monocytes was not different from that of monocytes from normal controls, when the cells were either unstimulated or stimulated with lipopolysaccharide (LPS, 20 micrograms/ml), as measured by two different bioassays (thymocyte or fibroblast proliferation assay) and enzyme-linked immunosorbent assay. However, IL-1 production by LPS-stimulated monocytes from RA patients cultured in medium containing indomethacin, an inhibitor of PGE2 synthesis, was significantly greater than that of monocytes from normal controls. In addition, the levels of PGE2 in culture supernatants of unstimulated or LPS-stimulated monocytes from RA patients were higher than in culture supernatants of monocytes from normal controls. Moreover, the increase of in vitro IL-2 production by RA T cells stimulated by phytohemagglutinin (PHA) was observed when monocytes were removed from peripheral blood mononuclear cells. These results indicated that peripheral blood monocytes from RA patients could produce IL-1 in excess in vitro, but that in vivo IL-1 production by RA monocytes and IL-2 induction by RA T cells might be negatively regulated by endogenous PGE2.

Peptides and proteins in the extracellular space in the central nervous system were investigated in vivo using an intracerebral microdialysis probe. The molecular cut-off of the hollow fiber which was used for the probe was approximately 100 kDa. We examined recovery rates of several compounds in vitro. The recovery rates of proteins and peptides were between 7-28%, with the exceptions of substance P and insulin-like growth factor I. The recovery rates of monoamines and their metabolites were 22-40%. In in vivo studies, two major proteins with apparent molecular weights of 62 kDa and 12 kDa, and several minor proteins (28 kDa, 43 kDa, 52 kDa and 70 kDa) were detected by SDS-polyacrylamide gel electrophoresis in the dialysate from a probe implanted in the striatum of anesthetized rats. These results suggest that the newly developed, intracerebral microdialysis probe might be useful for investigating the dynamic changes of peptides and proteins in the central nervous system.

To select a suitable medium for serum-free primary culture of adult rat hepatocytes, ten commercially-available synthetic media were compared for their ability to maintain the cells under serum-free and serum-supplemented conditions with special reference to attachment, survival and albumin secretion. It was found that Williams' medium E and DM-160 medium were the best among the ten media for maintaining hepatocytes under serum-free conditions in primary culture.

A method for the simultaneous determination of hypotaurine and taurine was developed. The method consisted of the elimination of urea, which interfered with the determination of hypotaurine, by immobilized urease, and determination of hypotaurine and taurine with an amino acid analyzer. The analyzer equipped with a cation-exchange column was operated at 32 degrees C with 0.2 M sodium citrate buffer, pH 2.8. Using this method, the dynamics of hypotaurine and taurine in blood plasma of rats was studied after the intraperitoneal injection of L-cysteine. The concentration of cysteine reached the maximum 1 h after L-cysteine loading. The concentration of hypotaurine and taurine increased in parallel and reached the maximum 2 h after L-cysteine loading. These changes seem to indicate the precursor-product relationship of these substances and the rapid conversion of hypotaurine to taurine in vivo.

We studied the brains of two cases of amyotrophic lateral sclerosis with dementia. Bunina bodies were found in the motor neurons of cranial nerve nuclei (trigeminal, facial and hypoglossal nerves) as well as in the spinal motoneurons. They appeared mostly in the cytoplasm and occasionally in the neuronal processes. However, the present electron microscopic study disclosed clearly that Bunina bodies were present not only in the cell body but also in the dendrites. No Bunina bodies were observed in the axons. It is inferred that the Bunina bodies were degenerative products formed as a result of a protein metabolism disorder.

Capsaicin-sensitive and hexamethonium-insensitive contractile and relaxatory motor responses of circular muscle induced by mesenteric nerve stimulation were studied. Desensitization to substance P or to neurokinin A, or the substance P antagonist, spantide largely reduced the initial contractile response. Desensitization to calcitonin gene-related peptide moderately reduced the late prolonged relaxation response. These results indicate that both responses of the circular muscle to mesenteric nerve stimulation may be attributed to a release of neuropeptides evoked by the 'efferent' stimulation of capsaicin-sensitive sensory nerves.

A case of hepatocellular carcinoma is reported in which the main tumor, intrahepatic metastases and a tumor thrombus in the portal vein were necrotized completely after Lipiodol chemoembolization. In this case, the tumor thrombus seemed to act as a portal embolus. This phenomenon is interesting because Lipiodol chemoembolization alone usually can not necrotize intra- or extra-capsular invasion, intrahepatic metastasis or tumor thrombus in the portal vein. This case is considered to be suggestive of a possible therapy for hepatocellular carcinoma.

The excretion of 3-mercaptolactate-cysteine mixed disulfide [S-(2-hydroxy-2-carboxyethylthio)-L-cysteine, HCETC], sulfate and taurine in the urine of normal adults was investigated before and after oral administration of L-cysteine and related sulfur-containing amino acids. Before the loading of amino acids, the excretion (mean +/- SD) per kg of body weight per day of HCETC, free sulfate and taurine was 0.096 +/- 0.042, 305.7 +/- 66.1 and 31.9 +/- 8.7 mumols, respectively. After the loading of L-cysteine (800 mumols/kg of body weight), the average excretion in the 24-h urine of HCETC increased 2-fold and that of taurine increased 1.6-fold. The average excretion of free sulfate after the L-cysteine loading was 989.4 +/- 145.1 and 388.8 +/- 51.6 mumols/kg per day in the first and second 24-h urine, respectively, indicating that the sulfur corresponding to 85% of the L-cysteine loaded was excreted as free sulfate in 24 h. Administration of L-cystine (400 mumols/kg) resulted in similar results. The increase in HCETC after L-cysteine or L-cystine administration indicates that L-cysteine is metabolized in part through the transamination pathway (3-mercaptopyruvate pathway) and that an equilibrium exists between the intake and excretion of sulfur in humans.

In the extrinsically denervated smooth muscle esophagus of the hen anesthetized with urethane (1 g/kg, i. m.), it was studied whether peptidergic neurons in the intramural plexus are involved in the intrinsic reflex. Ascending and descending contractions, and descending relaxation were induced by electrical stimulation of a narrow segment of the esophagus. Naloxone (1 microM), desensitization to substance P (0.3 microM) and spantide (20 microM) inhibited the ascending and descending contractions, respectively. The degree of the inhibition of the contractile response by a combination of naloxone and substance P was nearly the same as that by a single administration of naloxone or substance P. The ascending and descending contractions were reduced to one-third of the control by hexamethonium (100 microM) and abolished by atropine (10 microM). The descending relaxation was abolished after desensitization to vasoactive intestinal peptide (0.3 microM). Taken together the results suggest that in the hen's esophagus, opioid- and substance P-containing neurons in the intramural plexus may act as preganglionic neurons of cholinergic motor neurons in the ascending and descending excitatory pathways and that vasoactive intestinal peptide-containing neurons are involved in the descending inhibitory pathway.

<p>Tissue contents and urinary excretion of taurine were studied in rats after the administration of L-cysteine and its derivatives. Average taurine content in the liver of rats fed a 25% casein diet for 7 days increased 2-fold 2h after the intraperitoneal administration of 5 mmol of L-cysteine per kg of body weight, whereas that in rats fed a 5% casein diet for 2 days increased only slightly. The difference in the liver taurine contents between these two groups was discussed in relation to cysteine dioxygenase. Taurine contents in the heart, brain and blood did not differ significantly between these two groups or between the control and the group of rats which received L-cysteine. The increase in liver taurine concentrations after L-cysteine administration was much higher than that after L-cystine administration, suggesting a difference in their absorption. The intraperitoneal administration of 5 mmol/kg of L-2-oxothiazolidine-4-carboxylate (OTCA) resulted in a 3-fold increase in liver taurine content. The average increase in taurine excretion in the 24-h urine after OTCA administration corresponded to about 6.0% and that in the next 24-h urine to about 2.6% of OTCA administered, suggesting that nearly 10% of OTCA was metabolized to taurine and excreted in the urine.</p>