A biochemical study of the cotton pellet granuloma in the rat. Effects of dexamethasone and indomethacin.

The subcutaneous implantation of a cotton pellet into a rat results in the formation of a granuloma at the site of the implant. The early events comprise an accumulation of fluid and protein-aceous material together with an infiltration of neutrophils. The granuloma formed by day 7 is characterized by the formation of a vascularized fibrous capsule containing fibroblasts and infiltrating mononuclear cells which are rich in N-acetyl-beta-D-glucosaminidase (NAG). Granuloma development was quantitated by dry weight measurements, and its cellular content was measured by assaying activity of NAG and total nucleic acid content. Nucleic acid determinations showed that cell infiltration into the granuloma took place at a virtually constant rate over a 7-day period. In contrast, the NAG activity did not change significantly until after day 5 when a large increase in the amount of enzyme extractable from the granuloma was seen. Systemic treatment of the animal with dexamethasone or indomethacin resulted in an inhibition of granuloma weight gain, NAG activity and nucleic acid levels. The data suggest that the two drugs acted during the early phase of granuloma development at the level of cell infiltration. Both drugs given on days 0-3 alone suppressed granuloma formation, whereas treatment on days 4-7 was without effect.

The biosynthesis of dimethyltryptamine in vivo.

The in vivo formation of dimethyltryptamine was studied in rabbits, rats and monkeys. When C14-labelled N-methyltryptamine was administered by intravenous injection to rabbits, C14-dimethyltryptamine was found in lung, the principle site of the methyltransferase that biosynthesizes this psychotogen. Unequivocal evidence for C14-dimethyltryptamine formation in rat tissues was not obtained. When rabbits were given non-radioactive N-methyltryptamine intravenously, dimethyltryptamine appeared in carotid arterail blood, peaking within the first minute after injection of the precursor. USing this assay procedure we could not demonstrate dimethyltryptamine synthesis in the rhesus monkey.

Dimethyltryptamine levels in blood of schizophrenic patients and control subjects.

A gas chromatographic-mass spectrometric determination of blood N,N-dimethyltryptamine in normal controls and schizophrenic patients was carried out with a sensitivity limit of 0.05 ng/ml whole blood. Although the results appear to suggest that the mean DMT level was higher in the total patient group, those patients with acute psychosis, female patients and patients with suspiciousness scores on the BPRS of 4 or over, the differences were not statistically significant.

Isolation of amylopectin granules and identification of amylopectin phosphorylase in the oocysts of Eimeria tenella.

Amylopectin granules were purified from Eimeria tenella oocysts following digestion with sodium dodecyl sulfate and pronase. The oval granules had a uniform size of 0.5 X 0.7 mum, and consisted of only glucose polymers. alpha-Amylase treatment yielded 235 nmoles of maltose from the granules from 10(6) unsporulated oocysts and 93 nmoles maltose from those from 10(6) sporulated oocysts. Amylopectin phosphorylase activity was detected in the cytoplasm of unsporulated oocysts of E. tenella. It had a specific activity of 13 U/mg protein in crude extracts, and a pH optimum of 6.0. The Km values determined were 9.1 mM for glucose-1-phosphate and 5.6 mM for glucose end groups in potato amylopectin. Enzyme activity declined at a linear rate during sporulation, sporulated oocysts containing less than 8% of the activity of unsporulated oocysts. No amylase-type activity was found in the parasite.