A retracting wire knife for cutting fiber bundles and making sheet lesions of brain tissue

A retracting knife which has two cutting wires for the transection of fiber bundles is described. The knife holds the fiber bundles of the stria terminalis between the two cutting wires and transects them by a shearing movement as the wires close. In addition, the feasability of such a knife producing a sheet lesion around the n. caudatus is also described.

Formation of 5-hydroxykynurenine and 5-hydroxykynurenamine from 5-hydroxytryptophan in rabbit small intestine

In order to clarify the role of indoleamine 2,3-dioxygenase [indole:oxygen 2,3-oxidoreductase (decyclizing), EC 1.13.11.17] in the metabolism of serotonin, DL-5-hydroxy[methylene-(14)C]tryptophan, a precursor of serotonin, was incubated with slices of rabbit ileum. Resulting metabolites were separated by DEAE-cellulose column and polyamide column chromatography and identified by various chromatographic techniques and enzymatic analysis. Metabolites obtained in significant amounts were serotonin, 5-hydroxyindoleacetic acid, 5-hydroxytryptophol, 5-hydroxykynurenine, 5-hydroxykynurenamine, and 4,6-dihydroxyquinoline, representing 13.2, 15.8, 7.0, 21.9, 1.3, and 2.6% of the total metabolites, respectively. The first three compounds were previously reported to be major metabolites produced from 5-hydroxytryptophan by the action of aromatic L-amino acid decarboxylase and monoamine oxidase, whereas the last three are formed by the cleavage of the indole ring by the action of indoleamine 2,3-dioxygenase. In the presence of pargyline, a monoamine oxidase inhibitor, the major metabolites obtained were serotonin, 5-hydroxykynurenine, and 5-hydroxykynurenamine, representing 29.6, 26.6, and 5.4% of the total metabolites, respectively. In the presence of RO4-4602, an aromatic amino acid decarboxylase inhibitor, 5-hydroxykynurenine was the sole major product. These results strongly suggest that the newly discovered metabolic pathway involving the cleavage of the indole ring of 5-hydroxytryptophan operates in vivo to a significant extent and that indoleamine 2,3-dioxygenase plays an important role in the regulation of serotonin levels in the small intestine of the rabbit.

Indoleamine 2,3-dioxygenase. Formation of L-kynurenine from L-tryptophan in cultured rabbit fineal gland

The distribution of the indoleamine 2,3-dioxygenase activity was investigated in various parts of the rabbit brain using the supernatant fraction (30,000 X g, 30 min) of homogenates. A low but significant activity was detected in all parts of the brain. The highest activity was associated with the pineal gland and choroid plexus. Specific activities of the supernatant fractions derived from the pineal gland and choroid plexus were 84.8 and 34.2 pmol/h/mg of protein at 37 degrees C, respectively, with L-tryptophan as substrate. When the pineal gland was cultured with L-[methylene-14C]tryptophan, L-[methylene-14C]kynurenine formed by the action of indoleamine 2,3-dioxygenase was found as one of the major products. It was isolated by DEAE-cellulose column chromatography and identified by thin layer chromatography with and without the treatment by kynureninase from a pseudomonad. The amount of kynurenine thus measured accounted for approximately one-third of the total amount of tryptophan metabolites, indicating that the kynurenine pathway is one of the major metabolic pathways of tryptophan in the rabbit pineal gland.

Unilateral cortical spreading depression in the rat: effects on feeding, drinking and other behaviors

The effects of unilateral cortical spreading depression (CSD) on feeding, drinking and other behaviors were studied in rats. CSD waves were elicited by a microinjection of KC1 solution through an implanted cannula. The animal's behavior and slow potential changes (SPC) accompanying CSD were then simultaneously monitored for 20 min. Intensive face grooming was observed while the CSD wave-front propagated across the sensorimotor cortex. Animals commenced their first feeding or drinking shortly after the invasion of the negative SPC into the frontal cortex of Krieg's area 6 and 10 [14] had reached its maximum height. A two-way switching effect between the first feeding or drinking and quiescence (freezing) and a close relationship between their onsets were observed. The results are discussed specifically in relation to cortico-hypothalamic pathways.

Effect of phenacetin and caffeine on the urinary bladder of rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine

The effect of phenacetin and caffeine on urinary bladder carcinogenesis in rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) was examined. Animals were given a high or low dose of BBN for 4 weeks and then phenacetin or caffeine was administered for 30 or 32 weeks, respectively. All the animals were examined histologically after 36 experimental weeks. The incidence of papillary or nodular hyperplasia, papilloma, and cancer of the urinary bladder was significantly higher in the groups treated with BBN and then with phenacetin than in those treated with BBN alone, especially with a high dose of BBN. Simple hyperplasia and papillary or nodular hyperplasia developed in the urinary bladder of rats treated with phenacetin alone. Papillary proliferative growth of the renal pelvis was seen in one rat treated with a low dose of BBN and phenacetin. Treatment with caffeine after BBN had no enhancing effect and caffeine alone caused no remarkable changes.

[A new method for assaying anti-inflammatory drugs. Quantitative analysis of pigment leakage into skin by Chromatoscanner CS-900 (author's transl)]

Although the pigment leakage method is one of the most conventional for determining vascular permeability, accuracy in macroscopic measurement of the diameter of the stained area with an arbitary scale leaves much to be desired. We developed a simple and beneficial method for quantitative assay using a densitometer (Chromatoscanner CS-900). Guinea pigs weighing 300 approximately 350 g were used. Formalin as a phlogistic, in a dose of 2.3 approximately 37 mg was injected intradermally in the shaved skin of the back, and 15 mg/kg of pontamine blue was then given into the femoral vein. One hour after the injection the animals were sacrificed and the skin of the back, which was stained by the leaked pigment, was stripped off and allowed to adhere to a wooden plate for 24 hours. Reflection and a zig-zag scanning technique were used to measure the volume of the leaked pigment. There was a liner relationship between the dose of formalin and the integrated values. A dose-dependent relationship was also obtained when histamine, serotonin, kallikrein and bradykinin were used as phlogistics. Representative anti-inflammatory drugs such as aspirin, hydrocortisone, oxyphenbutazone, benzydamine, diclofenac sodium, sodium salicylate and aminopyrine depressed the leakage due to formalin. Depression of leakage by aspirin in a dose of 400 mg/kg was the most remarkable. Pigment leakage elicited by histamine, serotonin, kallikrein and bradykinin was examined on the same individual animal. Aspirin more than the other agents depressed the leakages due to bradykinin and kallikrein. Hydrocortisone and oxyphenbutazone depressed the leakage due to bradykinin, serotonin and histamine, but enhanced that due to kallikrein. The results obtained were consistent with those of a previous study and as this method is simple and more reliable, it is applicable for assay of anti-inflammatory compounds.

Effect of iodoacetamide or Tween 60 on methylnitrosocyanamide carcinogenesis in rat glandular and forestomach

The effect of iodoacetamide or Tween 60 on carcinogenicity of methylnitrosocyanamide (MNC) in rats was examined. A significant increase in the incidence of the forestomach tumors (P less than 0.01) was observed in rats treated with MNC and iodoacetamide simultaneously. Moreover, there were 2 cases of glandular stomach tumors in rats treated with MNC and Tween 60 simultaneously. They were one well-differentiated adenocarcinoma and one polypoid hyperplasia. This result indicates that MNC under certain conditions is carcinogenic to the glandular stomach of rats in addition to the forestomach. Tween 60 might act by facilitating direct contact between MNC and the glandular stomach mucosa.