THE ACCUMULATION OF RADIOACTIVE ACETYLCHOLINE BY A SYMPATHETIC GANGLION AND BY BRAIN: FAILURE TO LABEL ENDOGENOUS STORES

Abstract— The accumulation of radioactively labelled acetylcholine (ACh) by perfused superior cervical ganglia of cats and by incubated brain slices from rats was studied in the presence of diisopropylphosphorofluoridate. Ganglia accumulated more labelled ACh than an extracellular marker (inulin), but the amount of ACh accumulated did not increase when ACh turnover was increased by preganglionic nerve stimulation. The ACh that accumulated in ganglia was not released when the preganglionic nerve was subsequently stimulated. Sliced cerebral cortex also accumulated labelled ACh but this was not released when the tissue was subsequently exposed to a high K⁺ medium. Thus accumulated ACh does not appear to mix with releasable transmitter stores. Chronically (7 days) decentralized ganglia lost most of their transmitter store but retained their ability to accumulate labelled ACh. Uptake of ACh by sliced cerebellum was not less than uptake of ACh by sliced cerebral cortex and the amount of ACh accumulated by synaptosomes isolated from cerebellum was similar to the amount of ACh accumulated by synaptosomes isolated from cerebral cortex. It is concluded that ACh uptake is not specifically into cholinergic nerve endings. Hexamethonium reduced ACh uptake by cerebral cortex slices but did not increase the amount of ACh collected from slices stimulated by raised K⁺.     

Pentose cycle and reducing equivalents in rat mammary-gland slices

1. Slices of mammary gland of lactating rats were incubated with glucose labelled uniformly with (14)C and in positions 1, 2, 3 and 6, and with (3)H in all six positions. Glucose carbon atoms are incorporated into CO(2), fatty acids, lipid glycerol, the glucose and galactose moieties of lactose, lactate, soluble amino acids and proteins. C-3 of glucose appears in fatty acids. The incorporation of (3)H into fatty acids is greatest from [3-(3)H]glucose. (3)H from [5-(3)H]glucose appears, apart from in lactose, nearly all in water. 2. The specific radioactivity of the galactose moiety of lactose from [1-(14)C]- and [6-(14)C]-glucose was less, and that from [2-(14)C]- and [3-(14)C]-glucose more, than that of the glucose moiety. There was no randomization of carbon atoms in the glucose moiety, but it was extensive in galactose. 3. The pentose cycle was calculated from (14)C yields in CO(2) and fatty acids, and from the degradation of galactose from [2-(14)C]glucose. A method for the quantitative determination of the contribution of the pentose cycle, from incorporation into fatty acids from [3-(14)C]glucose, is derived. The rate of the reaction catalysed by hexose 6-phosphate isomerase was calculated from the randomization pattern in galactose. 4. Of the utilized glucose, 10-20% is converted into lactose, 20-30% is metabolized via the pentose cycle and the rest is metabolized via the Embden-Meyerhof pathway. About 10-15% of the triose phosphates and pyruvate is derived via the pentose cycle. 5. The pentose cycle is sufficient to provide 80-100% of the NADPH requirement for fatty acid synthesis. 6. The formation of reducing equivalents in the cytoplasm exceeds that required for reductive biosynthesis. About half of the cytoplasmic reducing equivalents are probably transferred into mitochondria. 7. In the Appendix a concise derivation of the randomization of C-1, C-2 and C-3 as a function of the pentose cycle is described.     

Impaired Cellular Immunity in Kwashiorkor with Improvement after Therapy

Children with kwashiorkor showed a high incidence of deranged cellular immunity as evidenced by impairment of delayed cutaneous hypersensitivity reactions to candida and diphtheria toxoid antigens and of lymphocyte transformation after phytohaemagglutinin stimulation. This may contribute to their susceptibility to infection. A correlation was shown between the degree of impairment of tests of cellular immunity and the severity of the kwashiorkor. Once recovery was initiated the skin tests gave the expected positive results and the lymphocyte transformation index improved. Protein deprivation may result in impaired deoxyribonucleic acid (DNA) synthesis and in atrophy of both the thymus and the lymphoid tissue.     

Bacteriophage PBS2-induced inhibition of uracil-containing DNA degradation.

Degradation of uracil-containing DNA by Bacillus subtilis extracts and its inhibition after infection by the uracil-containing DNA phage PBS2 have been investigated to resolve differences between the published reports of Tomita and Takahashi (1975) and Friedberg et al. (1975, 1976). The product of hydrolysis of PBS2 DNA, tritium labeled in its uracil and cytosine residues, is solely uracil and not deoxyuridine. The degrading activity is completely inhibited within 7 min after PBS2 infection, before any other known PBS2-induced protein is detectable. The production of the PBS2 inhibitor (a small, heat-stable protein) continues until 10 to 20 min postinfection.     

Covalent chromatography — The isolation of tryptophanyl containing peptides by novel polymeric reagents

Specific polymeric reagents for reversible covalent binding of tryptophan residues have been developed. Polymers bearing Aryl-SxCl groups (x=2–3) were prepared by binding thioaryl groups to cross-linked polyacrylamide, and subsequently reacting the products with an excess of S₂Cl₂. The resulting polymers were allowed to react with various mixtures of amino acids and peptides (excluding cysteine and its peptides) in acidic media. It was found that tryptophan as well as tryptophan-containing peptides were selectively bound to the polymer. Upon reduction with thiols (e.g. dithiothreitol), 2-thiotryptophan or its peptide derivatives were cleaved from the polymeric matrix. The proposed method is used for a one step isolation of tryptophanyl-containing peptides from peptide mixtures as well as for introducing thiol groups at the tryptophanyl residues.     

Clinical and laboratory findings in primary generalized and multiple-myeloma-related amyloidosis.

Thirty-four patients with primary generalized amyloidosis (PGA) and 14 with multiple-myeloma-related amyloidosis (MRA) were studied. The commonest clinical manifestations in PGA were nephrotic syndrome, hepatomegaly and congestive heart failure, and in MRA, low back pain, plasmacytoma and rheumatoid-arthritis-like syndrome. Eight patients with PGA had limited clinical expression of the disease, such as involvement of only kidneys, joints, parotid glands or gastrointestinal tract; in one patient amyloidosis was limited to lymph nodes. Low serum concentrations of total protein and albumin were common. M components were detected in the serum of 91% of patients with PGA and 92% of patients with MRA: 70% of the M components in PGA and 25% of those in MRA had lambda light chains. Bence Jones proteinemia was detected in 56% of the patients with PGA and in 77% of those with MRA. The serum concentration of immunoglobulins was decreased substantially in more than two thirds of the patients with PGA. Proteinuria (greater than 250 mg/24 h) was observed in 78% of patients with PGA and in 93% of patients with MRA. Bence Jones proteinuria was noted in 75 and 77% of patients, respectively. Plasmacytic infiltration of the bone marrow was found in 90% of the patients with PGA. The mean survival time of the patients with PGA was 28 months and of those with MRA, 29 months from the time of diagnosis.