Survival and reversion of a stable L form in soil

1978 ◽  
Vol 24 (1) ◽  
pp. 50-55 ◽  
Author(s):  
A. H. Horwitz ◽  
L. E. Casida Jr.
Keyword(s):  
High Salt ◽  
Salt Medium ◽  
Bacterial Form ◽  
Original Parent ◽  
Low Salt ◽  
Colonial Morphology

The stable L form of Agromyces ramosus reverted to a bacterial form when incubated in sterilized soil. The cellular and colonial morphology of this bacterial form resembled that of the original parent bacterial form. The two forms differed, however, in that the revertant maintained its bacterial form when transferred onto a low-salt (NaCl) medium but was virtually completely induced into the L-form state on a high-salt medium. The original parent bacterial form was not sensitive to salt. The possibility is discussed that an L-form ↔ bacterial-form cycle for this bacterium might occur naturally in soil. This cycle would be mediated by fluctuations in local salt concentrations in the soil.

scholarly journals Mitochondrial-reticular cytostructure in liver cells

1983 ◽  
Vol 214 (3) ◽  
pp. 795-813 ◽  
Author(s):  
J Katz ◽  
P A Wals ◽  
S Golden ◽  
L Raijman
Keyword(s):  
Endoplasmic Reticulum ◽  
High Speed ◽  
Citrate Synthase ◽  
Respiratory Control ◽  
High Salt ◽  
Marker Enzyme ◽  
Salt Medium ◽  
Low Speed ◽  
Low Salt ◽  
Specific Activities

This study examines the structural relationship of mitochondria and the endoplasmic reticulum in liver. Livers of rat and Japanese quail were homogenized and fractionated in media of 0.25 M-sucrose, either 5mM or 50 mM in sodium Hepes [4-(2-hydroxyethyl)-1-piperazine-ethanesulphonic acid], pH 7.4 (2.2 mM or 22 mM in Na respectively), designated here as low- and high-salt media. Three particulate fractions were prepared by sequential centrifugation. A nuclear pellet sedimenting at 300 g was obtained as described by Shore & Tata [(1977) J. Cell Biol. 72, 714-725], and from the resulting supernatant thereof a low-speed pellet (1100-1500 g) and a high-speed pellet (8000-10 000 g) were prepared. In the low-salt medium the yields of mitochondrial matrix enzymes (citrate synthase, glutamate dehydrogenase, ornithine carbamoyltransferase) and their specific activities in the low-speed pellet were over twice those in the high-speed pellet. In the high-salt medium the yield of matrix enzymes was 4-5 times, and the specific activities were up to 3 times, higher in the low-speed pellet than in the high-speed pellet. Oxygen uptake and respiratory control ratio were also much higher in the low-speed pellets in both media. Some 50-65% of the microsomal marker enzyme glucose 6-phosphatase was in the supernatant from the high-speed pellet, and the rest sedimented with the mitochondria. Repeated washing with the high-salt medium removes only a limited amount of reticulum. Washing with salt-free sucrose removes most of the reticulum, but a fraction remains strongly bound to mitochondria. Homogenates from quail and rat liver were fractioned isopycnically on Percoll gradients in either 0.25 M-sucrose or 0.25 M-sucrose/50 mM-sodium Hepes. Up to five particulate bands were separated and assayed. Mitochondria were present in two to three bands and were associated with endoplasmic reticulum. As seen in the phase-contrast microscope the mitochondria prepared in the low-salt medium consist of separate organelles. In the high-salt medium the mitochondria appear as chains of from three to ten organelles not touching each other. On addition of univalent ions at concentrations above 20 mM, the mitochondria aggregate into chains, and at higher ionic strength larger multidimensional aggregates are formed. The dispersion and aggregation of mitochondria are reversible. Negatively stained electron micrographs reveal a branched mitochondrial structure, with mitochondria held together by strands of reticulum.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Studies on halotolerance in a moderately halophilic bacterium. Effect of betaine on salt resistance of the respiratory system

1968 ◽  
Vol 109 (4) ◽  
pp. 687-691 ◽  
Author(s):  
Dvora Rafaeli-Eshkol ◽  
Y. Avi-Dor
Keyword(s):  
Sodium Chloride ◽  
Respiratory Rate ◽  
Respiratory System ◽  
Chloride Concentration ◽  
Salt Resistance ◽  
High Salt ◽  
Salt Medium ◽  
Sodium Chloride Concentration ◽  
Moderately Halophilic ◽  
Low Salt

The role of betaine as a factor influencing the salt resistance of the respiratory system in resting cells of the moderately halophilic halotolerant bacterium Ba1 was studied. Betaine accelerated succinate oxidation in cells obtained from low-salt medium, and stimulation of the respiratory rate was stronger the higher the sodium chloride concentration in the assay medium. The stimulatory effect also depended on the ratio of betaine concentration to the amount of bacteria present. Accumulation of labelled betaine by the bacterial cells was demonstrated; like the respiratory stimulation, it was favourably influenced by an increase in the sodium chloride concentration of the medium. In cells harvested from a high-salt medium and washed with 2·0m-sodium chloride, betaine caused no increase in the respiratory rate, nor was the already high salt resistance of the respiratory system further improved by the addition of betaine. When, however, these cells lost their salt resistance as a result of washing in the absence of sodium chloride, betaine was able to restore it to its original level. In contrast with respiration in low-salt-grown bacteria, that in high-salt-grown cells was not affected by betaine, even after they were washed in the absence of sodium chloride, when the sodium chloride concentration was optimum.

Effect of Salt Concentration and Incubation Temperature on Formation of Histamine, Phenethylamine, Tryptamine and Tyramine During Miso Fermentation

1986 ◽  
Vol 49 (6) ◽  
pp. 423-427 ◽  
Author(s):  
K.-D. HENRY CHIN ◽  
P. E. KOEHLER
Keyword(s):  
Salt Concentration ◽  
Incubation Temperature ◽  
High Salt ◽  
Soybean Paste ◽  
Salt Level ◽  
Low Salt ◽  
Two Factors

Two factors, salt concentration and incubation temperature, were examined for their effect on the formation of histamine, phenethylamine, tryptamine and tyramine during miso (soybean paste) fermentation. Misos containing 5 and 10% NaCl were prepared and incubated at 25 and 35°C. The effect of each factor was determined from the chemical and microbiological changes in the misos during fermentation. Salt level was a significant factor in the formation of amines. Higher amine levels were found in low-salt (5% NaCl) formulations than in high-salt (10% NaCl) misos. Incubation temperature within the range of 25 to 35°C during fermentation had little effect on amine formation in misos.

scholarly journals STRUCTURAL DIFFERENTIATION OF STACKED AND UNSTACKED CHLOROPLAST MEMBRANES

1971 ◽  
Vol 48 (3) ◽  
pp. 594-619 ◽  
Author(s):  
Ursula W. Goodenough ◽  
L. Andrew Staehelin
Keyword(s):  
Gene Mutation ◽  
Growth Conditions ◽  
Salt Medium ◽  
Wild Type ◽  
Dense Population ◽  
Structural Differentiation ◽  
Chloroplast Membranes ◽  
Particle Distributions ◽  
Low Salt

Wild-type chloroplast membranes from Chlamydomonas reinhardi exhibit four faces in freeze-etchreplicas: the complementary Bs and Cs faces are found where the membranes are stacked together; the complementary Bu and Cu faces are found in unstacked membranes. The Bs face carries a dense population of regularly spaced particles containing the large, 160 ± 10 A particles that appear to be unique to chloroplast membranes. Under certain growth conditions, membrane stacking does not occur in the ac-5 strain. When isolated, these membranes remain unstacked, exhibit only Bu and Cu faces, and retain the ability to carry out normal photosynthesis. Membrane stacking is also absent in the ac-31 strain, and, when isolated in a low-salt medium, these membranes remain unstacked and exhibit only Bu and Cu faces. When isolated in a high-salt medium, however, they stack normally, and Bs and Cs faces are produced by this in vitro stacking process. We conclude that certain particle distributions in the chloroplast membrane are created as a consequence of the stacking process, and that the ability of membranes to stack can be modified both by gene mutation and by the ionic environment in which the membranes are found.

scholarly journals Eplerenone inhibits aldosterone-induced renal expression of cyclooxygenase

2012 ◽  
Vol 13 (3) ◽  
pp. 353-359 ◽  
Author(s):  
MA Bayorh ◽  
A Rollins-Hairston ◽  
J Adiyiah ◽  
D Lyn ◽  
D Eatman
Keyword(s):  
Salt Intake ◽  
High Salt ◽  
Prostaglandin E ◽  
Renal Tubules ◽  
Protective Effects ◽  
High Salt Diet ◽  
Salt Diet ◽  
High Salt Intake ◽  
Low Salt ◽  
Cox 2

Introduction: The upregulation of cyclooxygenase (COX) expression by aldosterone (ALDO) or high salt diet intake is very interesting and complex in the light of what is known about the role of COX in renal function. Thus, in this study, we hypothesize that apocynin (APC) and/or eplerenone (EPL) inhibit ALDO/salt-induced kidney damage by preventing the production of prostaglandin E2 (PGE2). Methods: Dahl salt-sensitive rats on either a low-salt or high-salt diet were treated with ALDO (0.2 mg pellet) in the presence of EPL (100 mg/kg/day) or APC (1.5 mM). Indirect blood pressure, prostaglandins and ALDO levels and histological changes were measured. Results: Cyclooxygenase-2 (COX-2) levels were upregulated in the renal tubules and peritubular vessels after high-salt intake, and APC attenuated renal tubular COX-2 protein expression induced by ALDO. Plasma PGE2 levels were significantly reduced by ALDO in the rats fed a low-salt diet when compared to rats fed a high-salt diet. PGE2 was blocked by EPL but increased in the presence of APC. Conclusions: The beneficial effects of EPL may be associated with an inhibition of PGE2. The mechanism underlying the protective effects of EPL is clearly distinct from that of APC and suggests that these agents can have differential roles in cardiovascular disease.

Factors affecting Potassium Balance During Frusemide Administration

1984 ◽  
Vol 67 (2) ◽  
pp. 195-203 ◽  
Author(s):  
Christopher S. Wilcox ◽  
William E. Mitch ◽  
Ralph A. Kelly ◽  
Paul A. Friedman ◽  
Paul F. Souney ◽  
...  
Keyword(s):  
Salt Intake ◽  
Normal Subjects ◽  
Plasma Aldosterone ◽  
High Salt ◽  
Renin Angiotensin Aldosterone System ◽  
Plasma Aldosterone Concentration ◽  
Water Load ◽  
Renin Angiotensin ◽  
High Salt Intake ◽  
Low Salt

1. We investigated the effects of Na+ intake, the renin-angiotensin-aldosterone system and antidiuretic hormone (ADH) on K+ balance during 3 days of frusemide administration to six normal subjects. Subjects received 40 mg of frusemide for 3 days during three different protocols: Na+ intake 270 mmol/day (high salt); Na+ intake 20 mmol/day to stimulate the renin-angiotensin-aldosterone system (low salt); Na+ intake 270 mmol/day plus captopril (25 mg/6 h) to prevent activation of the renin-angiotensin-aldosterone system. In a fourth protocol, a water load was given during high salt intake to prevent ADH release and then frusemide was given. 2. During high salt intake, frusemide increased K+ excretion (UKV) over 3 h, but the loss was counterbalanced by subsequent renal K+ retention so that daily K+ balance was neutral. 3. During low salt intake, the magnitude of the acute kaliuresis following the first dose of frusemide and the slope of the linear relationship between UKV and the log of frusemide excretion were increased compared with that found during the high salt intake. In addition, low salt intake abolished the compensatory renal retention of K+ after frusemide and cumulative K+ balance over 3 days of diuretic administration was uniformly negative (−86 ± 7 mmol/3 days; P < 0.001). 4. Captopril abolished the rise in plasma aldosterone concentration induced by frusemide. The acute kaliuresis after frusemide was unchanged compared with that observed during high salt intake. The compensatory reduction in UKV occurring after the diuretic was slightly potentiated. In fact, captopril given without the diuretic induced a small positive K+ balance. 5. When a water load was given concurrently with frusemide, the acute kaliuresis was >30% lower compared with that seen with frusemide alone, even though the natriuretic response was unchanged. 6. We conclude that: (a) K+ balance is maintained when frusemide is given during liberal Na+ intake because acute K+ losses are offset by subsequent renal K+ retention; (b) this compensatory K+ retention can be inhibited by aldosterone release which could account for the negative K+ balance seen during salt restriction; (c) the short-term kaliuretic response to frusemide is augmented by release of both ADH and aldosterone whereas changes in K+ balance over 3 days of frusemide are dependent on plasma aldosterone concentration.

Abstract 495: A Novel Test for Low Salt Sensitivity: Angiotensin type-II Receptor Recruitment After Dopamine-1 Receptor Stimulation in Urine-Derived Renal Proximal Tubule Cells

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
John J Gildea ◽  
Staci A Keene ◽  
Dylan T Lahiff ◽  
Robert E Van Sciver ◽  
Cynthia D Schoeffel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Flow Cytometry ◽  
Clinical Study ◽  
Salt Sensitivity ◽  
High Salt ◽  
Salt Diet ◽  
Independent Events ◽  
Angiotensin Type 2 Receptor ◽  
Low Salt ◽  
Angiotensin Type

Salt-sensitivity of blood pressure is an inappropriate increase in blood pressure following high salt intake. Subjects in our clinical study were typed according to their salt-sensitivity status into 3 categories: High-Salt-Sensitive (HSS; ≥ 7 mmHg increase in mean arterial pressure (MAP) on a high salt diet of 300 mEq of sodium, 17% prevalence), Low-Salt-Sensitive (LSS:, who paradoxically showed a ≥ 7 mmHg increase in MAP on a low salt diet of 10 mEq of sodium, 11% prevalence), and Salt-Resistant (SR, individuals who showed no significant increase in blood pressure on either diet, 72% prevalence). We previously demonstrated that LSS subjects show increased recruitment of the natriuretic dopamine-1 receptor (D1R) to the plasma membrane following a salt stimulation as compared to HSS subjects. Stimulation of the D1R in RPTC with fenoldopam (dopaminergic agonist) results in recruitment of the natriuretic angiotensin type-2 receptor (AT2R) to the cell surface. We hypothesized that LSS individuals may also demonstrate an enhanced AT2R RPTC membrane recruitment compared to HSS individuals when challenged with fenoldopam. In order to gain access to fresh RPTC from each subject, we isolated exfoliated RPTC from randomly voided urine from SR, LSS, and HSS subjects from our clinical study. We measured three subjects from each category with a minimum of three voids for each subject. We counted individual cells as independent events using both the confocal microscope (n=245) and the flow cytometer (n=5344). We found an inverse correlation between AT2R recruitment and the degree of salt-sensitivity of blood pressure. Fenoldopam stimulated AT2R recruitment as measured by confocal microscopy (y = -0.0047x + 0.4966, R2 = 0.2488, P<0.0001) and flow cytometry (y =-0.057x + 1.5645, R2=0.2912, P=0.0185). Flow cytometry provided a more sensitive diagnostic for LSS than HSS subjects. AT2R recruitment was more predictive of LSS than HSS. AT2R recruitment may be used as a rapid method to test for LSS individuals who need to be identified and encouraged to increase their sodium intake in order to avoid paradoxical hypertension.

Prolonged NOS inhibition in the brain elevates blood pressure in normotensive rats

1998 ◽  
Vol 275 (2) ◽  
pp. R410-R417 ◽  
Author(s):  
Atsushi Sakima ◽  
Hiroshi Teruya ◽  
Masanobu Yamazato ◽  
Rijiko Matayoshi ◽  
Hiromi Muratani ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Salt Intake ◽  
High Salt ◽  
Salt Loading ◽  
Salt Diet ◽  
Intracerebroventricular Infusion ◽  
Air Jet ◽  
Sd Rats ◽  
Low Salt ◽  
The Brain

Systemic inhibition of nitric oxide synthase (NOS) evokes hypertension, which is enhanced by salt loading, partly via augmented sympathetic activity. We investigated whether inhibition of brain NOS elevates blood pressure (BP) in normotensive rats and, if so, whether the BP elevation is enhanced by salt loading. After a 2-wk low-salt (0.3%) diet, male Sprague-Dawley (SD) rats were divided into four groups. Groups 1 and 2 received a chronic intracerebroventricular infusion of 0.5 mg ⋅ kg−1 ⋅ day−1of N G-monomethyl-l-arginine (l-NMMA), and groups 3 and 4 were given artificial cerebrospinal fluid (aCSF). Groups 1 and 3 were placed on a high-salt (8%) diet, whereas groups 2 and 4 were on a low-salt diet. On day 9or 10, group 1 showed significantly higher mean arterial pressure (MAP) in a conscious unrestrained state (129 ± 3 mmHg vs. 114 ± 3, 113 ± 1, and 108 ± 3 mmHg in groups 2, 3, and 4, respectively, P < 0.05). On a high-salt diet, response of renal sympathetic nerve activity but not of BP to air-jet stress was significantly larger in rats givenl-NMMA than in rats given aCSF (29 ± 4% vs. 19 ± 3%, P < 0.05). When the intracerebroventricular infusions were continued for 3 wk, MAP was significantly higher in rats givenl-NMMA than in rats given aCSF irrespective of salt intake, although the difference was ∼7 mmHg. Thus chronic inhibition of NOS in the brain only slightly elevates BP in SD rats. Salt loading causes a more rapid rise in BP. The mechanisms of the BP elevation and its acceleration by salt loading remain to be elucidated.

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