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PubMed1995

[Postoperative bronchial stenosis associated with IAA complex and transendoscopic resection of intrabronchial granulation].

Problem with stenosis of the left bronchus was encountered in a patient with type B interrupted aortic arch complex after the arch reconstruction and pulmonary artery banding. Bronchoscopic study disclosed the intraluminal granulation of left bronchus and transendoscopic resection of the granulation successfully relieved the stenosis and brought the patient to full recovery.

Airway Obstruction↗
PubMed1999

Effect of Brassinolide on Growth and Shikonin Formation in Cultured Onosma paniculatum Cells.

The effect of brassinolide (BR) on cell growth and shikonin and its derivative formation in Onosma paniculatum cell culture was studied. BR addition with IAA and BAP (+BR/+IAA/+BAP) in B(5) medium slightly increased the cell growth at 0.01-0.1 ppb concentration compared with a growth control (-BR/+IAA/+BAP). Only BR addition (+BR/-IAA/-BAP) at 0.001-100 ppb in B(5) medium significantly increased the cell fresh weight compared with a growth control (-BR/-IAA/-BAP). The same concentration of BR tested at 0-1000 ppb increased the cell fresh weight of +IAA/+BAP significantly more than that of -IAA/-BAP. BR at 0.001-0.1 ppb with IAA and BAP added (+BR/+IAA/+BAP) in M(9) medium increased shikonin and its derivative content markedly by 31-87%, compared with its control (-BR/+IAA/+BAP). BR at 0.001-1000 ppb without IAA and BAP added to M(9) medium (+BR/-IAA/-BAP) also increased shikonin and its derivative content compared with its control (-BR/-IAA/-BAP). However, the amount of shikonin and derivative formed of +IAA/+BAP was greater than that of -IAA/-BAP only at the same concentration of BR at 0-1 ppb. These combined results show that BR at 0.01 ppb with IAA and BAP added was the best for cell growth and shikonin formation. Formation of shikonin and its derivative by adding BR at 0.01 ppb with IAA and BAP (+BR/+IAA/+BAP) in M(9) medium was significantly enhanced 4 days after BR addition compared with a production control (-BR/+IAA/+BAP). In contrast, +BR/-IAA/-BAP vs. -BR/-IAA/-BAP was not as effective as +BR/+IAA/+BAP vs. -BR/+IAA/+BAP for the shikonin formation. The time course study for shikonin formation also showed that +BR/+IAA/+BAP and -BP/+IAA/+BAP only slightly increased cell growth in M(9) medium. Similarly, soluble protein content in the cells treated by BR at 0.01 ppb with IAA and BAP (+BR/+IAA/+BAP) exceeded that of the control (-BR/+IAA/+BAP) 4 days after BR addition. And +BR/-IAA/-BAP only slightly increased the soluble protein content over that of -BR/-IAA/-BAP.

Journal Article↗
PubMed2004

Prooxidant activity and cytotoxic effects of indole-3-acetic acid derivative radicals.

Previously, it was shown that indole-3-acetic acid (IAA) is a nontoxic prodrug that forms a radical, toxic to tumor cells when activated by peroxidase. Because of this, IAA and peroxidase conjugated to an antibody specific to an extracelluar tumor antigen are currently in phase II clinical trials. In the following, the prooxidant activities of the radicals formed were compared when IAA or its derivatives were metabolically oxidized by peroxidase/H(2)O(2). In general, it was found that the effectiveness of IAA analogues for catalyzing the cooxidation of ascorbate, NADH, or GSH increased as the IAA derivatives were more readily oxidized by HRP/H(2)O(2). The order of effectiveness of IAA derivatives at cooxidizing NADH, ascorbate, GSH, and hepatocyte GSH was 5MeO-2Me-IAA > 2Me-IAA > 5MeO-IAA > IAA. The rates of NADH and ascorbate cooxidation were faster at pH 7.4 than at pH 6.0, whereas GSH cooxidation was faster at pH 6.0 than at pH 7.4. Furthermore, NADH, ascorbate, and GSH prevented the oxidation of IAA derivatives, which suggested that the indolyl cation radical was responsible for the prooxidant activity. The effectiveness of IAA derivatives in catalyzing lipid peroxidation at pH 7.4 was similar and also correlated with the rate of oxidation of IAA derivatives by HRP-I and the one-electron potential of these compounds. The IAA derivative-induced lipid peroxidation was faster at pH 6.0 than at pH 7.4. IAA derivative effectiveness at catalyzing microsomal and hepatocyte lipid peroxidation or hepatocyte reactive oxygen species formation at pH 6.0 was IAA > 5MeO-2Me-IAA > 2Me-IAA > 5MeO-IAA, but at pH 7.4, it was 5MeO-2Me-IAA > 2Me-IAA > 5MeO-IAA > IAA. Previously, the rate of radical cation decarboxylation to skatole radicals and (skatole) peroxyl radicals was reported to be faster at an acid pH with IAA being more effective than the derivatives. This suggests that IAA skatole and/or (skatole) peroxyl radicals catalyze lipid peroxidation at pH 6.0. Incubation of isolated rat hepatocytes with IAA analogues/H(2)O(2)/peroxidase also resulted in cytotoxicity with 5MeO-2Me-IAA being the most effective at pH 7.4 and IAA being the most effective at pH 6.0. Cytotoxicity was also prevented by antioxidants.

Animals↗
PubMed1989

Changes in Amide-Linked and Ester Indole-3-Acetic Acid in Cotton Fruiting Forms during Their Development.

The concentration of free indoleacetic acid (IAA) is high in cotton (Gossypium hirsutum L.) fruiting forms before anthesis, but is low at and for a few days after anthesis. Amide-linked and ester IAA were measured in fruiting forms at 9, 6, and 3 days before anthesis; at anthesis; and at 2, 4, 7, and 9 days after anthesis to determine if free IAA decreased because it was converted to a conjugated form. That did not appear to be the case. While the major decrease in free IAA occurred during the 6 days before anthesis, ester IAA increased only a small amount and amide-linked IAA decreased even more than free IAA. During the 6 days before anthesis free IAA decreased from 0.62 to 0.12 micrograms per gram and amide-linked IAA decreased from 19.14 to 1.16 micrograms per gram dry weight. No evidence was found that a large amount of amide-linked IAA was converted to an insoluble form; flowers contained less than 1 microgram per gram of insoluble IAA. The free and amide-linked IAA must have been converted to other forms, perhaps by oxidation. Soluble amide-linked IAA remained low after anthesis. No ester IAA was detected 6 days before anthesis and only 0.08 microgram per gram dry weight was measured at anthesis. The concentration of ester IAA increased thereafter to 4.43 micrograms per gram at 9 days after anthesis. Therefore, amide-linked IAA was the major form of IAA in flower buds and ester IAA was the major form in young fruits (bolls). Minimum concentrations of free and total IAA occurred during the 4 days after anthesis, a stage when cotton fruiting forms are most likely to abscise. The large decreases in free and amide-linked IAA during the 6 days before anthesis may indicate a rapid turnover of IAA in flower buds. But, the decrease in free IAA was not accompanied by a comparable increase in ester or amide-linked IAA.

Journal Article↗
PubMed2000

The relative importance of tryptophan-dependent and tryptophan-independent biosynthesis of indole-3-acetic acid in tobacco during vegetative growth.

A quantitative study of indole-3-acetic acid (IAA) turnover, and the contribution of tryptophan-dependent and tryptophan-independent IAA-biosynthesis pathways, was carried out using protoplast preparations and shoot apices obtained from wild-type and transgenic, IAA-overproducing tobacco (Nicotiana tabacum L.) plants, during a phase of growth when the level of endogenous IAA was stable. Based on the rate of disappearance of [13C6]IAA, the half-life of the IAA pool was calculated to be 1.1 h in wild-type protoplasts and 0.8 h in protoplasts from the IAA-overproducing line, corresponding to metabolic rates of 59 and 160 pg IAA (microg Chl)(-1) h(-1), respectively. The rate of conversion of tryptophan to IAA was 15 pg IAA (microg Chl)(-1) h(-1) in wild-type protoplasts and 101 pg IAA (microg Chl)(-1) h(-1) in protoplasts from IAA-overproducing plants. In both instances, IAA was metabolised more rapidly than it was synthesised from tryptophan. As the endogenous IAA pools were in a steady state, these findings indicate that IAA biosynthesis via the tryptophan-independent pathway was 44 pg IAA (microg Chl)(-1) h(-1) and 59 pg IAA (microg Chl)(-1) h(-1), respectively, in the wild-type and transformed protoplast preparations. In a parallel study with apical shoot tissue, the presumed site of IAA biosynthesis, the rate of tryptophan-dependent IAA biosynthesis exceeded the rate of metabolism of [13C6]IAA despite the steady state of the endogenous IAA pool. The most likely explanation for this anomaly is that, unlike the protoplast system, injection of substrates into the apical tissues did not result in uniform distribution of label, and that at least some of the [2H5]tryptophan was metabolised in compartments not normally active in IAA biosynthesis. This demonstrates the importance of using experimental systems where labelling of the precursor pool can be strictly controlled.

Carbon Isotopes↗
PubMed2000

Expansion rates and outcomes for iliac artery aneurysms.

PURPOSE: The expansion rates and outcomes of iliac artery aneurysms (IAAs) were determined. METHODS: A retrospective chart review was conducted to identify patients in whom IAAs had been diagnosed between June 1990 and March 1999 in a vascular surgery service at a large university-affiliated Veterans Affairs medical center. The patients were veterans, 187 men and two women, in whom the diagnosis of an IAA was made, as defined by the Ad Hoc Committee on Reporting Standards of The Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter (IAA >/= 1.5 cm). Expansion rates relative to the size of IAAs and clinical outcomes were noted for all patients. RESULTS: One hundred eighty-nine patients (mean age, 72.3 +/- 0.5 years) with 323 IAAs (mean size, 2.34 +/- 0.7 cm) were found. The mean follow-up (96% of patients with B mode ultrasound scanning) period was 31.4 months, with each patient undergoing a mean of 4.2 studies. The 4-year life-table survival rate was 78.2%, with no patient deaths related to their IAAs. Symptoms were noted in six of 189 patients (3.1%; two ruptures, four chronic pain), who all had IAAs larger than 4 cm. IAAs were repaired in 34 of 189 patients (18%), in 25 of the 34 patients because of their associated abdominal aortic aneurysms and in nine of 34 patients because of their IAAs alone. All nine patients requiring operative treatment of indications related to the IAA had an IAA larger than 4 cm. Expansion rates were slow for IAAs smaller than 3 cm (0.11 +/- 0.02 cm/year) and significantly greater (P <.003) for IAAs 3 to 5 cm (0.26 +/- 0.1 cm/year). The correlation between B mode ultrasound scanning and computed tomography scanning was excellent. The size of the IAAs was underestimated by 0.03 +/- 0. 06 cm by means of B mode ultrasound scanning. CONCLUSION: The IAAs followed up by this contemporary Veterans Affairs vascular surgery service were small, rarely caused symptoms or rupture, and expanded at a slow rate. IAAs smaller than 3 cm could be followed up safely on an annual basis with B mode ultrasound scanning. IAAs that are 3 cm or larger and smaller than 3.5 cm should be carefully followed with B mode ultrasound scanning at 6-month intervals, whereas elective repair should be considered for IAAs 3.5 cm or larger in good-risk patients. Based on this report and currently available evidence and recommendations, asymptomatic IAAs that are 4 cm or larger and all other symptomatic IAAs should be considered for operative repair. Also, the reported high rupture rate of IAAs that are 5 cm or larger mandates prompt operative repair.

Aged↗
PubMed2005

Effect of indole-3-acetic acid derivatives on neuroepithelium in rat embryos.

Indole-3-acetic acid (IAA), a natural auxin, induces microencephaly in rats exposed to IAA during gestation days (Days) 12-14, corresponding to the early stage of cerebral cortex development. The purpose of this study was to examine the effects of 5 IAA derivatives administration in pregnant rats on neuroepithelial cells in the embryos. N-Methylindole-3-acetic acid (1Me-IAA), 2-Methylindole-3-acetic acid (2Me-IAA), 2-Methyl-5-methoxyindole-3-acetic acid (2Me-5MeO-IAA), 5-Methoxyindole-3-acetic acid (5MeO-IAA), Indole butyric acid (IBA), and IAA were administered at 1,000 mg/kg except for 2Me-IAA at 500 mg/kg on Days 12, 13 and 14, and then embryos/fetuses were harvested on Day 14.5 or 21. The dams in the 1Me-IAA and 2Me-IAA groups exhibited rigidity and a decrease in locomotor activity. Although a decrease in the absolute brain weight was observed in the 1Me-IAA, 5MeO-IAA, IBA and IAA groups, a decrease in the relative brain weight was observed in only the IAA group. Histopathologically, apoptotic cells were observed mainly in the medial and dorsal layer of the neuroepithelium in the 5MeO-IAA and IAA groups on Day 14.5. The degree of induced neuroepithelial cell apoptosis was less in the 5MeO-IAA group than in the IAA group. However, it was confirmed that the histopathological changes induced by 5MeO-IAA were quite similar to the lesions induced by IAA and may have resulted from the same mechanisms.

Administration, Oral↗
PubMed2000

Characterization of auxin conjugates in Arabidopsis. Low steady-state levels of indole-3-acetyl-aspartate, indole-3-acetyl-glutamate, and indole-3-acetyl-glucose.

Amide-linked indole-3-acetic acid (IAA) conjugates constitute approximately 90% of the IAA pool in the dicot Arabidopsis, whereas ester-linked conjugates and free IAA account for approximately 10% and 1%, respectively when whole seedlings are measured. We show here that IAA-aspartate Asp, IAA-glutamate (Glu), and IAA-glucose (Glc) are present at low levels in Arabidopsis. Nine-day-old wild-type Arabidopsis seedlings yielded 17.4 +/- 4.6 ng g(-1) fresh weight IAA-Asp and 3.5 +/- 1.6 ng g(-1) fresh weight IAA-Glu, and IAA-Glc was present at 7 to 17 ng g(-1) fresh weight in 12-d-old wild-type seedlings. Total IAA content in 9-d-old Arabidopsis seedlings was 1, 200 +/- 178 ng g(-1) fresh weight, so these three IAA conjugates together made up only 3% of the conjugate pool throughout the whole plant. We detected less than wild-type levels of IAA-Asp and IAA-Glu (7.8 +/- 0.4 ng g(-1) fresh weight and 1.8 +/- 0.3 ng g(-1) fresh weight, respectively) in an Arabidopsis mutant that accumulates conjugated IAA. Our results are consistent with IAA-Asp, IAA-Glu, and IAA-Glc being either minor, transient, or specifically localized IAA metabolites under normal growth conditions and bring into question the physiological relevance of IAA-Asp accumulation in response to high concentrations of exogenous IAA.

Arabidopsis↗
PubMed2002

Specificity of auxin regulation of gibberellin 20-oxidase gene expression in pea pericarp.

During early pea fruit growth, the physiological roles of 4-chloroindole-3-acetic acid (4-Cl-IAA) and IAA, natural pea auxins, in regulating gibberellin (GA) 20-oxidase gene expression (PsGA20ox1) were tested with 4-position, ring-substituted auxins that have a range of biological activities (fruit growth). The effect of seeds, and natural and synthetic auxins (4-Cl-IAA, and IAA; 4-Me-IAA, 4-Et-IAA and 4-F-IAA, respectively), and auxin concentration (4-Cl-IAA) on PsGA20ox1 mRNA levels in pea pericarp were investigated over a 24 h treatment period. The ability of the 4-substituted auxins to increase PsGA20ox1 mRNA levels in deseeded pericarp was correlated with their ability to stimulate pericarp growth. The greatest increase in pericarp PsGA20ox1 mRNA levels and growth was observed when deseeded pericarps were treated with the naturally occurring pea auxin, 4-Cl-IAA; however, IAA was not effective. Silver thiosulfate, an ethylene action antagonist, did not reverse IAA's lack of stimulation of PsGA20ox1 over the control treatment. 4-Me-IAA was the second most active auxin in stimulating PsGA20ox1 and was the second most biologically active auxin. Application of the 4-substituted IAA analogs, 4-Et-IAA and 4-F-IAA, to deseeded pericarps resulted in minimal or no increase in PsGA20ox1 transcript levels or pericarp growth. Pericarp PsGA20ox1 mRNA levels increased with increasing 4-Cl-IAA concentration and showed transitory increases at low 4-Cl-IAA treatments (30 to 300 pmol). These results support a unique physiological role for the auxin 4-Cl-IAA in the regulation of GA metabolism by effecting PsGA20ox1 expression during early pea fruit growth.

Blotting, Northern↗
PubMed2002

Indole acetic acid distribution coincides with vascular differentiation pattern during Arabidopsis leaf ontogeny.

We used an anti-indole acetic acid (IAA or auxin) monoclonal antibody-based immunocytochemical procedure to monitor IAA level in Arabidopsis tissues. Using immunocytochemistry and the IAA-driven beta-glucuronidase (GUS) activity of Aux/IAA promoter::GUS constructs to detect IAA distribution, we investigated the role of polar auxin transport in vascular differentiation during leaf development in Arabidopsis. We found that shoot apical cells contain high levels of IAA and that IAA decreases as leaf primordia expand. However, seedlings grown in the presence of IAA transport inhibitors showed very low IAA signal in the shoot apical meristem (SAM) and the youngest pair of leaf primordia. Older leaf primordia accumulate IAA in the leaf tip in the presence or absence of IAA transport inhibition. We propose that the IAA in the SAM and the youngest pair of leaf primordia is transported from outside sources, perhaps the cotyledons, which accumulate more IAA in the presence than in the absence of transport inhibition. The temporal and spatial pattern of IAA localization in the shoot apex indicates a change in IAA source during leaf ontogeny that would influence flow direction and, consequently, the direction of vascular differentiation. The IAA production and transport pattern suggested by our results could explain the venation pattern, and the vascular hypertrophy caused by IAA transport inhibition. An outside IAA source for the SAM supports the notion that IAA transport and procambium differentiation dictate phyllotaxy and organogenesis.

Arabidopsis↗
PubMed1992

The decrease in auxin polar transport down the lupin hypocotyl could produce the indole-3-acetic Acid distribution responsible for the elongation growth pattern.

The variation of indole-3-acetic acid (IAA) transport along Lupinus albus L. hypocotyls was studied using decapitated seedlings and excised sections. To confirm that the mobile species was IAA and not IAA metabolites, dual isotope-labeled IAAs, [5-(3)H]IAA + [1-(14)C]IAA, were used. After apical application to decapitated seedlings, the longitudinal distribution of both isotopes at different transport periods showed that the velocity of IAA transport was higher in the apical, elongating region than in the basal, non-growing region. This variation in velocity was not a traumatic consequence of decapitation because after application of IAA to the basal region of decapitated seedlings, both the velocity and intensity of IAA transport were lower than in the apical treatment. The variation in IAA transport down the hypocotyl was confirmed when it was measured in excised sections located at different positions along the hypocotyl. The velocity and, to a greater extent, the intensity of IAA transport decreased from the apical to the basal sections. Consequently, if the amount of IAA reaching the apical zones of lupin hypocotyl were higher than the IAA transport capacity in the basal zones, accumulation of mobile IAA might be expected in zones located above the basal region. In fact, an IAA accumulation occurred in the elongating region during the first 4-h period of transport after apical treatment with IAA. It is proposed that the fall in IAA transport along the hypocotyl might be responsible for the IAA distribution and, consequently, for the growth distribution reported in this organ. An indirect proof of this was obtained from experiments that showed that the excision of the slowly transporting basal zones strongly reduced the growth in the remaining part of the organ, whereas excision of the root caused no significant modification in growth during a 20-h period.

Journal Article↗