Nanopore Sequencing with GraphMap for Comprehensive Pathogen Detection in Potato Field Soil.

Early detection of causal pathogens is important to prevent crop loss from diseases. However, some diseases, such as soilborne diseases, are difficult to diagnose due to the absence of visible or characteristic symptoms. In the present study, the use of the Oxford Nanopore MinION sequencer as a molecular diagnostic tool was assessed due to its long-read sequencing capabilities and portability.

Effect of progesterone on aldosterone secretion in rats.

In both human and animal studies high progesterone states are associated with elevated aldosterone production but variable changes in PRA. These experiments were designed to test the hypothesis that progesterone has an effect similar to a low sodium diet on the glomerulosa cell: increasing aldosterone synthase messenger RNA activity and aldosterone production. Ovariectomized (OVX) rats were injected with progesterone (1 mg/100 g) or vehicle (SHAM) for 5 days.

Sodium restriction increases aldosterone biosynthesis by increasing late pathway, but not early pathway, messenger ribonucleic acid levels and enzyme activity in normotensive rats.

To determine whether changes in dietary sodium intake modify the early and/or late pathways of aldosterone biosynthesis, we studied in Sprague-Dawley rats the effect of sodium restriction on early (conversion of cholesterol to pregnenolone) and late (conversion of corticosterone to aldosterone) pathway activity and on the mRNA levels for the enzymes regulating these steps. Sodium restriction increased basal and angiotensin-II-stimulated aldosterone output from isolated zona glomerulosa cells by 5- to 9-fold. This increase in aldosterone output did not appear to be due to changes in the conversion of cholesterol to pregnenolone or in the mRNA levels of the early pathway enzyme, cholesterol side-chain cleavage cytochrome P-450.

Abnormal norepinephrine and aldosterone responses to upright posture in nonmodulating hypertension.

The subgroup of patients with nonmodulating hypertension demonstrates a number of abnormalities of the renin-angiotensin-aldosterone axis. We previously identified abnormalities in plasma and urinary dopamine in nonmodulators and posited that this may be in part due to a generalized defect in sympathetic nervous system activity. In the present study we assessed the state of activation of the renin-angiotensin system and the sympathetic nervous system in normal subjects and patients with modulating, nonmodulating, and low renin essential hypertension during sodium depletion and change from supine to upright posture.

Dose effect of adrenocorticotropin on aldosterone and cortisol biosynthesis in cultured bovine adrenal glomerulosa cells: in vitro correlate of hyperreninemic hypoaldosteronism.

In some critically ill patients, aldosterone secretion is diminished despite hyperreninemia. These same patients demonstrate appropriately elevated plasma ACTH and cortisol levels. In addition, infusion of ACTH or angiotensin-II (AII) fails to elicit the normal aldosterone response, implying that the defect is at the level of the zona glomerulosa (ZG) cell.

Dissociation in plasma renin and adrenal ANG II and aldosterone responses to sodium restriction in rats.

In rats, plasma renin activity (PRA) increases sharply, reaching a plateau within hours of sodium restriction. Plasma aldosterone increases gradually, not reaching a plateau for 1-2 days. To determine whether this dissociation is secondary to the time needed to modify adrenal sensitivity to angiotensin II (ANG II) and to assess the role of locally produced ANG II in this process, rats were salt restricted for 0-120 h.

Sodium-mediated modulation of aldosterone secretion: impact of converting enzyme inhibition on rat glomerulosa cell response to angiotensin-II.

Sodium restriction enhances the aldosterone response to angiotensin-II (AII) in normal rats, but not in spontaneously hypertensive rats (SHR). To determine whether a change and/or abnormality in the circulating or adrenal renin-angiotensin systems are responsible for these observations, three groups of animals were studied on a low sodium diet with and without the administration of a converting enzyme inhibitor (enalapril). Sprague-Dawley and Wistar-Kyoto (normotensive rat strains) and SHR were placed on low sodium (0.

Rate of activation of renin-angiotensin-aldosterone axis and sodium intake in rats.

When sodium intake in the rat is reduced abruptly from the typical high level to a very low level (0.02%), sodium excretion falls exponentially, with a half time of 2-3 h. The result is that the rat achieves external sodium balance, in which intake equals excretion, on the new low intake within a few hours.

Mass determination of polyphosphoinositides and inositol triphosphate in rat adrenal glomerulosa cells with a microspectrophotometric method.

A method is described for the assay of subnanogram amounts of phosphorus in phospholipids and organic phosphates. The formation of a complex with a high molar absorption coefficient at 600 nm when malachite green is added to phosphomolybdate at low pH and the adaptation of a microspectrophotometer to quantify the color in 10 microliters solution have made it possible for a dose-response curve from 0.1-1.

Kinetics of sodium homeostasis in rats: rapid excretion and equilibration rates.

In normal humans, when sodium intake is abruptly reduced from a high to a very low level, renal sodium excretion falls exponentially (half time approximately 24 h), and several days are required to achieve external sodium balance, where intake equals excretion. Because much of our knowledge of intrarenal mechanisms comes from the rat, we studied their capacity to handle sodium. In two strains of rat, Sprague-Dawley (SD) and Wistar-Kyoto (WKY), whether the sodium load was administered intravenously, by gavage, or by spontaneous feeding, the slope relating sodium excretion to time was 8-10 times more rapid than in humans, reflecting half times of 2-3 h, and external sodium balance was achieved in hours rather than days.

Comparative effect of angiotensin II, potassium, adrenocorticotropin, and cyclic adenosine 3',5'-monophosphate on cytosolic calcium in rat adrenal cells.

The present study compares changes in cytosolic calcium and steroidogenesis when rat adrenal cells are stimulated with potassium (K+), angiotensin II (AII), ACTH, and (Bu)2cAMP (cAMP). The calcium-sensitive fluorescent dye, quin 2, was used to determine cytosolic calcium concentrations. K+ and AII both induced parallel increases in cytosolic calcium and aldosterone output.

Unique calcium dependencies of the activating mechanism of the early and late aldosterone biosynthetic pathways in the rat.

This study compared the extracellular calcium dependency and the enzymatic locus of that dependency for N6 O2'-dibutyryl cyclic AMP (dbcAMP)-, angiotensin II- and potassium-stimulated aldosterone secretion in dispersed rat glomerulosa cells. The need for extracellular calcium, calcium influx, and specifically for calcium influx through the calcium channel was examined. dbcAMP, angiotensin II and potassium, in the presence of calcium (3.

Calcium, a "third messenger" of cAMP-stimulated adrenal steroid secretion.

This study examines the role of extracellular calcium and calcium mobilization from intracellular stores in mediating cAMP-stimulated steroid secretion by rat adrenal glomerulosa cells (GC) and fasciculata cells (FC). When GC were incubated acutely in a calcium-deficient buffer, cAMP failed to significantly increase aldosterone secretion above base line. Aldosterone secretion, however, rose from 17 +/- 2 to 32 +/- 4 ng/10(6) cells (P less than 0.

The effects of extracellular K+ and angiotensin II on cytosolic Ca++ and steroidogenesis in adrenal glomerulosa cells.

We evaluated changes in cytosolic calcium concentration (Ca++) and steroidogenesis in rat adrenal glomerulosa cells (GC) stimulated with potassium (K+) or angiotensin II (AII). Cytosolic Ca++ concentration was determined using the Ca++-sensitive, fluorescent dye QUIN 2. Raising extracellular K+ increased cytosolic Ca++ from 267 +/- 23 nM at 3.

Is the adrenal angiotensin receptor angiotensin II--or angiotensin III like?

In order to determine whether the adrenal receptor is primarily directed at angiotensin II (AII) or angiotensin III (AIII) the following in vitro experiments were performed examining aldosterone responsiveness in isolated glomerulosa cells. 1) Cells exposed to increasing doses (2.4 X 10(-10)M - 2.

Metoclopramide inhibits aldosterone biosynthesis in vitro.

Metoclopramide, a dopaminergic antagonist, has consistently elevated plasma aldosterone levels in vivo. To determine whether this was a direct action of metoclopramide on adrenal steroidogenesis, we examined the response of collagenase-dispersed rat adrenal glomerulosa cells to metoclopramide in vitro. The effect of increasing concentrations of metoclopramide (3 X 10(-10) to 3 X 10(-4) M) on basal as well as angiotensin II (2.

Decreased adrenal responsiveness to angiotensin II: a defect present in spontaneously hypertensive rats. A possible model of human essential hypertension.

30% of patients with essential hypertension have a decreased adrenal response to angiotensin II (A II) on a low but not a high sodium intake. They also have a compensatory increase in the activity of the renin-angiotensin system best documented in a sodium-restricted state.To assess whether such a mechanism could account for the hypertension in genetically hypertensive rats, adrenal responsiveness to A II was determined in three groups of rats; spontaneously hypertensive rats (SHR), normotensive Wistar rats (WKY), and normotensive Sprague-Dawley rats (SDR).

Angiotensin II's role in mediating angiotensin I- and tetradecapeptide-induced steroidogenesis by rat glomerulosa cells.

To evaluate the role of angiotensin II (A II) in mediating the steroidogenic response to angiotensin I (A I) and tetradecapeptide, rat glomerulosa cells were incubated with each peptide in the presence or absence of an angiotensin-converting enzyme inhibitor (captopril or the nonapeptide bradykinin-potentiating factor). Both A I and tetradecapeptide increased aldosterone secretion in a dose-dependent fashion, but were considerably less effective (P less than 0.001) than the same dose (2.

The effect of angiotensin II and saralasin on 18-hydroxy-11-deoxycorticosterone production by isolated human adrenal glomerulosa cells.

To assess the role of angiotensin II (AII) in regulating 18-hydroxy-11-deoxycorticosterone (18-OHDOC) secretion in man, isolated human adrenal glomerulosa cells were incubated with AII and/or its competitive antagonist, saralasin. AII 2.4 X 10(-8) M) elicited an 80% increase in 18-OHDOC levels as well as similar increases in aldosterone, 18-hydroxycorticosterone, and corticosterone (P less than 0.

Stimulation of 18-hydroxy-11-deoxycorticosterone secretion by angiotensin II and potassium.

The control of 18-hydroxy-11-deoxycorticosterone (18-OH-DOC) secretion is incompletely understood: ACTH seems to be the dominant regulator, the importance of angiotensin II (A-II) is uncertain, and the effect of potassium has not been investigated. The purpose of this study was to evaluate the 18-OH-DOC response to these three stimuli in vitro. Suspensions of isolated rat adrenal glomerulosa or fasciculata cells were stimulated with either alpha-1-24 ACTH (0.

Rat adrenal cell sensitivity to angiotensin II, alpha-1-24-ACTH, and potassium: a comparative study.

Rat adrenal glomerulosa and fasciculata-reticularis cell sensitivity to comparable molar doses of angiotensin II (AII) (2.4 X 10(-12) to 2.4 X 10(-4) M) and ACTH (alpha-1-24-adrenocorticotropin) (3.