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T C Moore

Publications and source records attributed to T C Moore.

160 records · Page 9Linked to original sources
PubMed1967

Biosynthesis of (-)-Kaurene in Cell-free Extracts of Immature Pea Seeds.

Mevalonate-(14)C was incorporated into (-)-kaurene-(14)C in cell-free extracts of immature pea (Pisum sativum L.) seeds. The identification of (14)C-product as (-)-kaurene was based on: A) comparison with authentic (-)-kaurene on thin-layer and gas-liquid chromatography; and B) oxidation of (14)C-product and (-)-kaurene with osmium tetroxide to form the common derivative kaurane-16,17-diol. The enzyme system is heat labile and is dependent upon ATP and Mg(2+) or Mn(2-), with Mn(2+) being a more effective activator than Mg(2+). The reaction rate was proportional to enzyme concentration in reaction mixtures containing 0.45 to 1.8 mg protein n/ml, and was linear with time through 120 minutes in standard reaction mixtures. Enzyme preparations from immature seeds of tall and dwarf peas appeared to synthesize (-)-kaurene at the same rate. Synthesis of (-)-kaurene was readily inhibited by Amo-1618. (2-Chloroethyl)-trimethylammonium chloride (CCC) also inhibited (-)-kaurene synthesis; however, approximately 1000-fold higher concentrations of CCC were required to evoke the same percentages of inhibition as Amo-1618.

Journal Article↗
PubMed1967

Biosynthesis of Indoleacetic Acid from Tryptophan-C in Cell-free Extracts of Pea Shoot Tips.

A 2-step, 1-dimensional thin-layer chromatographic procedure for isolating indoleacetic acid (IAA) was developed and utilized in investigations of the biosynthesis of IAA from tryptophan-(14)C in cell-free extracts of pea (Pisum sativum L.) shoot tips. Identification of a (14)C-product as IAA was by (a) co-chromatography of authentic IAA and (14)C-product on thin-layer chromatography, and (b) gas-liquid and thin-layer chromatography of authentic and presumptive IAA methyl esters. Dialysis of enzyme extracts and addition of alpha-ketoglutaric acid and pyridoxal phosphate to reaction mixtures resulted in approximately 2- to 3-fold increases in net yields of IAA over yields in non-dialyzed reaction mixtures which did not contain additives essential to a transaminase reaction of tryptophan. Addition of thiamine pyrophosphate to reaction mixtures further enhanced net biosynthesis of IAA. It is concluded that the formation of indolepyruvic acid and its subsequent decarboxylation probably are sequential reactions in the major pathway of IAA biosynthesis from tryptophan in cell-free extracts of Pisum shoot tips. Comparison of maximum net IAA biosynthesis in extracts of shoot tips of etiolated and light-grown dwarf and tall pea seedlings revealed an order, on a unit protein N basis, of: light-grown tall > light-grown dwarf > etiolated tall congruent with etiolated dwarf. It is concluded that the different rates of stem elongation among etiolated and light-grown dwarf and tall pea seedlings are correlated, in general, with differences in net IAA biosynthesis and sensitivity of the tissues to IAA.

Journal Article↗
PubMed1967

Kinetics of growth retardant and hormone interactions in affecting cucumber hypocotyl elongation.

The capacities of indole-3-acetic acid (IAA) and gibberellin A(3) (GA(3)) to counteract the inhibitory effects of (2-chloroethyl) trimethylammonium chloride (CCC), 2-isopropyl-4-dimethylamino-5-methylphenyl-1-piperidinecarboxylate methyl chloride (Amo-1618), and N,N-dimethylaminosuccinamic acid (B-995) on hypocotyl elongation in light-grown cucumber (Cucumis sativus L.) seedlings were investigated. One mug of GA(3) applied to the shoot tip was sufficient to completely nullify the effect of 10 mug of Amo-1618 or 25 mug of B-995 applied simultaneously to the shoot tip, and 10 mug of GA(3) completely counteracted the effect of 10(-3)m CCC added to the root medium. One mug of IAA counteracted the effect of 10(-3)m CCC in the root medium, but IAA did not nullify the action of either Amo-1618 or B-995. Experiments were conducted using 2 growth retardants simultaneously, which indicated that Amo-1618 and CCC inhibit a common process, namely GA biosynthesis, essential to hypocotyl elongation. However, since the effect of CCC was overcome by applications of both GA and IAA, growth retardation resulting from treatment with CCC apparently is not due solely to inhibition of GA biosynthesis. B-995 did not interact additively with either Amo-1618 or CCC, which suggests that B-995 affects a process different from those affected by the other 2 retardants. Thus, while inhibition evoked by B-995 is reversible by applied GA, the action of B-995 does not appear to be inhibition of GA biosynthesis.

Journal Article↗
PubMed1966

Inhibition of the growth of peas by tris-(2-diethylaminoethyl)-phosphate trihydrochloride.

The effects of Tris-(2-diethylaminoethyl)-phosphate trihydrochloride (SK&F 7997-A(3)) on the development of 4 varieties of Pisum sativum were investigated. The compound inhibited shoot elongation of all 4 varieties by as much as 50% or more when seeds were soaked in solutions of the inhibitor for 12 hours before planting. Seed treatment also affected flowering by causing an increase in the number of nodes to the first flower in the early varieties Little Marvel and Alaska. The number of nodes preceding the first flower in the late varieties Dwarf and Tall Telephone was not affected by high concentrations of SK&F 7997-A(3), but low concentrations appeared to cause a slight reduction in the number of nodes to flower.The inhibitor had little effect on growth when applied to established seedlings; some slight inhibition was noted when high doses were applied to the shoot tip.SK&F 7997-A(3) suppressed the growth response of dwarf and tall peas to exogenous GA(3). The compound did not inhibit biosynthesis of gibberellin by Fusarium moniliformc when present in shaken liquid cultures at concentrations as high as 10 mg/ml. The inhibitor suppressed the action of applied GA(3) on shoot elongation when the 2 chemicals were applied in 3 ways: 1) inhibitor on lowermost compound leaf and GA(3) on shoot tip; 2) GA(3) on lowermost leaf and inhibitor on shoot tip; and 3) soaking of seeds in the 2 compounds combined for 12 hours prior to planting. The third method of dual treatment yielded evidence that SK&F 7997-A(3) interacts noncompetitively with GA(3) in the regulation of shoot elongation.

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PubMedDate not supplied

In vivo depression of lymphocyte traffic in sheep by VIP and HIV (AIDS)-related peptides.

Core pentapeptides and an octapeptide (Peptide T) computer deduced from amino acid sequences from vasoactive intestinal peptide (VIP) and the 120 gp external envelope of the HIV (AIDS) virus and synthesized have been reported to have important in vitro and in vivo activity including inhibition of HIV binding to CD4 surface antigens of brain cells and lymphocytes and limitation of HIV infectivity. Two of these core pentapeptides, peptide TTNYT (Peptide T [4-8]) and peptide TDNYT (VIP [7-11]), are reported here, on acute infusion into cannulated afferent popliteal lymphatics of sheep, to produce prompt and marked depressions in the output of both small recirculating and blast lymphocytes into popliteal lymph node efferent lymph. As with a prior VIP infusion study, there appeared to be a selective effect on T4 (CD4) lymphocytes, with a marked predominance of T4 (CD4) lymphocytes in the lymphocyte depleted efferent lymph.

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PubMedDate not supplied

Prompt elevations of PGE2 and thromboxane A2 metabolites in peripheral node efferent lymph of sheep following drainage area immunization.

In the past decade, the main interest in the involvement of prostaglandin E2 (PGE2) in the immune response has been concerned with its role in immunomodulation (suppression) both in vitro and in vivo. Comparatively little attention has been devoted to its immunostimulatory role. It has been suggested that PGE2, like histamine, may function as a 'double agent', initially triggering, facilitating and augmenting a stimulatory immune response and later modulating, limiting and contributing to the turning off of this response. We here report an early (within minutes) immunostimulatory involvement of PGE2 (and thromboxane A2) in the sheep, with prompt elevations in levels of PGE2 and thromboxane B2 in popliteal lymph node efferent lymph following drainage area immunization with killed Salmonella muenchen bacteria. These elevations were associated with an increase in efferent lymph flow and an equally prompt but limited depression of lymphocyte outputs into efferent lymph ('shutdown', 'recruitment'). Local increases in blood flow and vascular permeability probably play important roles in these events.

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PubMedDate not supplied

Substance P increases and prolongs increased output of T4 (CD4) lymphocytes from lymph nodes of sheep in vivo: is it a mediator of immunological memory?

There are receptors on lymphocytes for substance P which are found both on small recirculating and on blast lymphocytes. The principal effect of substance P on lymphocytes appears to be a stimulating one, both in vitro and in vivo. The in vivo administration of substance P to sheep by acute infusion into cannulated afferent lymphatics of peripheral lymph nodes has been found to stimulate efferent lymph flow and the output into efferent lymph of both small recirculating and blast lymphocytes. We here report that substance P both enhances and prolongs the enhancement of the output of T4 (CD4) lymphocytes from lymph nodes of sheep in vivo. This output-stimulating effect appears to be specific to T4 (CD4) lymphocytes and is associated with a depressant effect on the output of T8 (CD8) and B lymphocytes. The output-stimulating effect on small T4 (CD4) lymphocytes is quite prolonged, lasting in excess of 96 h after a single 50 micrograms acute infusion. A brief post-infusion depression in T4 (CD4) lymphocyte output is associated with an equally brief, but marked, elevation in the output into efferent lymph of the arachidonic acid metabolite, thromboxane B2. The output-stimulating effect of substance P on blast T lymphocytes is confined to the T4 (CD4) blast lymphocytes. Substance P or a similar molecule may be of value when a specific T4 (CD4) lymphocyte output stimulant effect is desired. A single prior (6 days) acute infusion of substance P into a popliteal lymph node via its cannulated afferent lymphatic produced profound changes in the response to nodal drainage area immunization with killed S. muenchen bacteria. The latent period prior to increased antibody production was abolished, as was the standard post-immunization 'shutdown' period of decreased output of lymphocytes into efferent lymph. These changes were accompanied by a marked and progressive increase in antibody production. The findings reported here suggest substance P-induced long-term potentiation (LTP) of the immune response and raise the question of an involvement of substance P as a major mediator of immunological memory.

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PubMedDate not supplied

In vivo influences of phorbol ester and calcium ionophore on lymphocyte traffic, lymph flow and efferent lymph levels of thromboxane B2 in sheep.

In vitro systems have provided increasing evidence of significant lymphocyte transmembrane signalling by plasma membrane receptors which utilize antigen and other ligand activation of the inositol phosphate dual second messenger system of intracellular signalling. Elevation of intracellular Ca2+ and activation of protein kinase C are important products of these signals and appear to provide a complete set of mitogenic signals for both T and B cells. Calcium inophore and phorbol ester have been found to mimic these events in vitro and are here employed in vitro to study their effects on lymphocyte traffic and efferent lymph flow through primary peripheral lymph nodes of sheep and on the output into efferent lymph of the arachidonic acid metabolite, thromboxane B2. Calcium ionophore and phorbol ester were given alone or in combination to popliteal lymph nodes of sheep by drainage area injection or by acute infusion into cannulated afferent lympatics of study popliteal lymph nodes whose efferent lymphatic was chronically cannulated for study. The findings resembled those of drainage area immunization with an early increase in efferent lymph flow and prompt and marked depressions in the output into efferent lymph of both small recirculating and blast lymphocytes ('shutdown', 'recruitment'), followed by a marked increase in the output into efferent lymph of both small recirculating and blast lymphocytes. The greatest elevation in both small recirculating and blast lymphocyte outputs was at 24 and 48 h following phorbol ester and calcium ionophore administration. Acute phorbol ester and calcium ionophore administration was associated with a prompt and marked elevation in efferent lymph levels of thromboxane B2 which were of short duration. The findings observed here with lymph node drainage area infusion/injection of both phorbol ester and calcium ionophore are quite similar to those encountered in this sheep lymphocyte traffic model following popliteal lymph node drainage area immunization with killed Salmonella muenchen antigen.

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