Cholinergic and adrenergic innervation of lingual salt glands of the estuarine crocodile, Crocodylus porosus

2005 ◽  
Vol 53 (6) ◽  
pp. 345 ◽  
Author(s):  
Craig E. Franklin ◽  
Greg Taylor ◽  
Rebecca L. Cramp
Keyword(s):  
Neural Control ◽  
Salt Water ◽  
Cholinergic Neurons ◽  
Secretory Activity ◽  
Salt Gland ◽  
Adrenergic Innervation ◽  
Chloride Ions ◽  
Adrenergic Nerve ◽  
Salt Glands ◽  
Crocodylus Porosus

Many marine reptiles and birds possess extrarenal salt glands that facilitate the excretion of excess sodium and chloride ions accumulated as a consequence of living in saline environments. Control of the secretory activity of avian salt glands is under neural control, but little information is available on the control of reptilian salt glands. Innervation of the lingual salt glands of the salt water crocodile, Crocodylus porosus, was examined in salt water-acclimated animals using histological methods. Extensive networks of both cholinergic and adrenergic nerve fibres were identified close to salt-secreting lobules and vasculature. The identification of both catecholamine-containing and cholinergic neurons in the salt gland epithelium and close to major blood vessels in the tissue suggests the action of the neurotransmitters on the salt-secreting epithelium itself and the rich vascular network of the lingual salt glands.

Secretory activity in salt glands of birds and turtles: stimulation via cyclic AMP

1987 ◽  
Vol 252 (2) ◽  
pp. R428-R432
Author(s):  
T. J. Shuttleworth ◽  
J. L. Thompson
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Calcium Ionophore ◽  
Secretory Activity ◽  
Second Messenger ◽  
Salt Gland ◽  
Ionophore A23187 ◽  
O2 Consumption ◽  
Salt Glands ◽  
Tissue Slices

O2 consumption in tissue slices from the nasal salt gland of the duck and the lachrymal salt gland of Malaclemys is stimulated by methacholine, a stimulation that is inhibited by bumetanide and by ouabain. In addition, the calcium ionophore A23187 mimics the action of methacholine in stimulating this secretion-related O2 consumption in both glands, suggesting a second-messenger role for this ion in the cholinergic response. However, the adenylate cyclase activator, forskolin, and the cyclic AMP analogue, 8-cpt-cAMP, also stimulate ouabain-sensitive and bumetanide-sensitive O2 consumption in both the duck gland and the Malaclemys gland. It is suggested that the mechanism of salt secretion in the Malaclemys lachrymal gland conforms to that previously described for other extrarenal salt-secreting tissues in nonmammalian vertebrates and, as in the bird gland, is subject to a cholinergic regulation potentially acting via changes in intracellular calcium. In addition to this, secretory activity in both the avian and the turtle glands can be stimulated by a previously undisclosed adenylate cyclase-cyclic AMP system. The identity of the primary signal for such a system is not known, nor is the nature of any interrelationship between the two second-messenger systems that have been identified in these glands.

scholarly journals A novel gene LbHLH from the halophyte Limonium bicolor enhances salt tolerance via reducing root hair development and enhancing osmotic resistance

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xi Wang ◽  
Yingli Zhou ◽  
Yanyu Xu ◽  
Baoshan Wang ◽  
Fang Yuan
Keyword(s):  
Salt Tolerance ◽  
Root Hair ◽  
Salt Gland ◽  
Nacl Stress ◽  
35S Promoter ◽  
Osmotic Resistance ◽  
Salt Glands ◽  
Limonium Bicolor ◽  
Root Hair Development ◽  
Hair Development

Abstract Background Identifying genes involved in salt tolerance in the recretohalophyte Limonium bicolor could facilitate the breeding of crops with enhanced salt tolerance. Here we cloned the previously uncharacterized gene LbHLH and explored its role in salt tolerance. Results The 2,067-bp open reading frame of LbHLH encodes a 688-amino-acid protein with a typical helix-loop-helix (HLH) domain. In situ hybridization showed that LbHLH is expressed in salt glands of L. bicolor. LbHLH localizes to the nucleus, and LbHLH is highly expressed during salt gland development and in response to NaCl treatment. To further explore its function, we heterologously expressed LbHLH in Arabidopsis thaliana under the 35S promoter. The overexpression lines showed significantly increased trichome number and reduced root hair number. LbHLH might interact with GLABRA1 to influence trichome and root hair development, as revealed by yeast two-hybrid analysis. The transgenic lines showed higher germination percentages and longer roots than the wild type under NaCl treatment. Analysis of seedlings grown on medium containing sorbitol with the same osmotic pressure as 100 mM NaCl demonstrated that overexpressing LbHLH enhanced osmotic resistance. Conclusion These results indicate that LbHLH enhances salt tolerance by reducing root hair development and enhancing osmotic resistance under NaCl stress.

scholarly journals Salt-tolerance screening in Limonium sinuatum varieties with different flower colors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaojing Xu ◽  
Yingli Zhou ◽  
Ping Mi ◽  
Baoshan Wang ◽  
Fang Yuan
Keyword(s):  
Salt Tolerance ◽  
Photosynthetic Rate ◽  
Large Scale ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Salt Gland ◽  
Salt Glands ◽  
Chlorophyll Contents ◽  
Relative Water ◽  
Whole Plants

AbstractLimonium sinuatum, a member of Plumbaginaceae commonly known as sea lavender, is widely used as dried flower. Five L. sinuatum varieties with different flower colors (White, Blue, Pink, Yellow, and Purple) are found in saline regions and are widely cultivated in gardens. In the current study, we evaluated the salt tolerance of these varieties under 250 mmol/L NaCl (salt-tolerance threshold) treatment to identify the optimal variety suitable for planting in saline lands. After the measurement of the fresh weight (FW), dry weight (DW), contents of Na+, K+, Ca2+, Cl−, malondialdehyde (MDA), proline, soluble sugars, hydrogen peroxide (H2O2), relative water content, chlorophyll contents, net photosynthetic rate, and osmotic potential of whole plants, the salt-tolerance ability from strongest to weakest is identified as Pink, Yellow, Purple, White, and Blue. Photosynthetic rate was the most reliable and positive indicator of salt tolerance. The density of salt glands showed the greatest increase in Pink under NaCl treatment, indicating that Pink adapts to high-salt levels by enhancing salt gland formation. These results provide a theoretical basis for the large-scale planting of L. sinuatum in saline soils in the future.

Biogenesis of Plasma Membranes in Salt Glands of Salt-Stressed Domestic Ducklings: Localization of Acyltransferase Activity

1972 ◽  
Vol 11 (3) ◽  
pp. 855-873
Author(s):  
A. M. LEVINE ◽  
JOAN A. HIGGINS ◽  
R. J. BARRNETT
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Specific Activity ◽  
Salt Gland ◽  
Secretory Cells ◽  
Salt Glands ◽  
Acyltransferase Activity ◽  
Structural Localization ◽  
Differentiated Cells ◽  
Golgi Membranes

In response to salt water stress there is a marked increase in the plasma membranes of the epithelial secretory cells of the salt glands of domestic ducklings. In the present study, the fine-structural localization of the acyltransferases involved in synthesis of phospholipids has been investigated in this tissue during this increased biogenesis of plasma membranes. The specific activity of the acyltransferases of the salt gland rose in response to salt stress, and this preceded the rapid increase in weight and cellular differentiation. After the weight increase of the gland became established, the specific activity of the acyltransferases declined, but the total activity remained constant. Salt gland tissue fixed in a mixture of glutaraldehyde and formaldehyde retained 35% of the acyltransferase activity of unfixed tissue. Cytochemical studies of the localization of acyltransferase activity in fixed and unfixed salt gland showed reaction product associated only with the lamellar membranes of the Golgi complex. This localization occurred in partially differentiated cells from salt-stressed glands to the greatest extent; and to only a small extent in cells of control tissue from unstressed salt glands. Omission of substrates resulted in absence of reaction product in association with the Golgi membranes. In addition, vesicles having limiting membranes morphologically similar to the plasma membrane occurred between the Golgi region and the plasma membrane in the partially differentiated cells. The phospholipid component of the plasma membrane appears therefore to be synthesized in association with the Golgi membranes and the membrane packaged at this site from which it moves in the form of vesicles to fuse with the pre-existing plasma membrane.

Methyl jasmonate improves tolerance to high salt stress in the recretohalophyte Limonium bicolor

2019 ◽  
Vol 46 (1) ◽  
pp. 82 ◽  
Author(s):  
Fang Yuan ◽  
Xue Liang ◽  
Ying Li ◽  
Shanshan Yin ◽  
Baoshan Wang
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Methyl Jasmonate ◽  
Salt Gland ◽  
Underlying Mechanism ◽  
Photosynthetic Parameters ◽  
Salt Glands ◽  
Plasma Membrane Permeability ◽  
Limonium Bicolor ◽  
Relative Electrical Conductivity

Limonium bicolor is a typical recretohalophyte with salt glands in the epidermis, which shows maximal growth at moderate salt concentrations (100mM NaCl) but reduced growth in the presence of excess salt (more than 200mM). Jasmonic acid (JA) alleviates the reduced growth of L. bicolor under salt stress; however, the underlying mechanism is unknown. In this study we investigated the effects of exogenous methyl jasmonate (MeJA) application on L. bicolor growth at high NaCl concentrations. We found that treatment with 300mM NaCl led to dramatic inhibition of seedling growth that was significantly alleviated by the application of 0.03mM MeJA, resulting in a biomass close to that of plants not subjected to salt stress. To determine the parameters that correlate with MeJA-induced salt tolerance (assessed as the biomass production in saline and control conditions), we measured 14 physiological parameters relating to ion contents, plasma membrane permeability, photosynthetic parameters, salt gland density, and salt secretion. We identified a correlation between individual indicators and salt tolerance: the most positively correlated indicator was net photosynthetic rate, and the most negatively correlated one was relative electrical conductivity. These findings provide insights into a possible mechanism underlying MeJA-mediated salt stress alleviation.

scholarly journals Anatomical and histological study of the kidneys and salt glands in great flamingos (Phoenicopterus roseus)

2016 ◽  
Vol 40 (1) ◽  
pp. 140-146
Author(s):  
Ali Faris Reshag
Keyword(s):  
Histological Study ◽  
Left Kidney ◽  
Relative Weight ◽  
Single Layer ◽  
Salt Gland ◽  
Total Body Weight ◽  
Peripheral Zone ◽  
Salt Glands ◽  
Connective Tissue Capsule ◽  
Collecting Ducts

     This study was designed to explain the anatomy and histology of kidneys and salt glands in Great Flamingos. Eight adult healthy Great Flamingos of both sexes have been used. The results showed that the kidneys in Great Flamingos consist of three separated lobes. The right kidney was longer 8.9±0.3 mm than the left kidney 8.4±0.4mm. The ratio of the kidneys weight to the total body weight was 0.39%. The salt gland was very large crescent shape, and occupied the supraorbital fossa and has 20.8±0.2mm long and 3.9±0.2mm in diameter. The volume of cortex was 60-70% and the medulla was 30-40%. Within the middle region of cortex there were numerous large corpuscles (mammalian type) and few of small corpuscles (reptilian type). There was a variation between the means diameters of mammalian type 59±1µm and reptilian type 42±0.9µm. The proximal and distal convoluted tubules and collecting ducts were lined by simple cuboidal epithelium and their means diameters were 46±0.9, 44±1 and 55.1±0.7µm, respectively. Within medulla the thick and thin segments were arranged at the peripheral zone of medullary cone while the collecting ducts were at the central part of cone and all were lined with simple cuboidal epithelium except thin segments were lined with squamous cells. The salt gland were consisted of lobules surrounded by thick connective tissue capsule and each has mass of branched tubuloacinar secretory unites. The latter were made up by single layer of cuboidal cells. The tubules lead into central duct lined by double layer of cuboidal cells while the main duct lined with stratified cuboidal epithelium. The secretory units of salt gland gave negative reaction to PAS and combined AB (pH 2.5) and PAS stains and this indicate the absence of neutral mucosubstances. The results concluded that the kidneys in great flamingo was small size organ with low relative weight in compare to birds size and the salt glands was active organ.

Degeneration and Regrowth of Adrenergic Nerve Fibers in the Rat Peripheral Tissues after 6-Hydroxydopamine

1971 ◽  
Vol 49 (4) ◽  
pp. 345-355 ◽  
Author(s):  
J. de Champlain
Keyword(s):  
Ganglion Cells ◽  
Adrenergic Innervation ◽  
Nerve Fibers ◽  
Adrenergic Nerve ◽  
High Dose ◽  
Rat Tissues ◽  
Peripheral Tissues ◽  
Endogenous Noradrenaline ◽  
6 Hydroxydopamine ◽  
Noradrenaline Levels

Histofluorescent and biochemical changes in the adrenergic nervous system were followed up in rat tissues after one single intravenous injection of a high dose of 100 mg/kg of 6-hydroxydopamine (6-OH-DA). This treatment results in the rapid disappearance of terminal and preterminal fibers in the iris, atria, and small arteries of rats, whereas endogenous noradrenaline pools of the heart are 95% depleted. The capacity of the adrenergic nerve to take up and accumulate tritiated noradrenaline is reduced proportionally to the reduction in endogenous noradrenaline levels. These changes are compatible with the concept of a complete sympathectomy induced by the specific toxic action of 6-OH-DA on the adrenergic fibers. This sympathectomy is not permanent, however, and numerous bundles of preterminal fibers start to grow in the iris and atria within 4 to 5 days following injection. Progressively, in the following weeks, these fibers distribute over the whole organ and give birth to terminal fibers which form a new adrenergic plexus in these tissues. A completely normal innervation is restored 2 to 3 months after administration of 6-OH-DA. The endogenous noradrenaline levels rise progressively in parallel to the development of the new plexus of fibers. Since a complete regeneration of the adrenergic innervation can be demonstrated in the weeks following injection of 6-OH-DA, it appears that this compound can selectively destroy the adrenergic terminal and preterminal fibers without causing a degeneration of the adrenergic ganglion cells.

Salt glands in flowering culms of Eriochloa species (Poaceae)

Bothalia ◽  
1992 ◽  
Vol 22 (1) ◽  
pp. 111-117 ◽  
Author(s):  
M. O. Arriaga
Keyword(s):  
Basal Cell ◽  
Apical Cell ◽  
Salt Gland ◽  
Salt Glands ◽  
X Ray ◽  
Large Pore ◽  
Micro Analysis

Salt glands were found in Eriochloa (Paniceae-Poaceae):  E. monte\idensis, E. pseudoacrotricha and E. punctata.  They occur on the culms, rachises and secondary ramifications of the inflorescence. The glands are bicellular structures with endodermal tissue at the base. They consist of a basal cell and an apical cell, which is a collecting chamber with a large pore at the top. It is proposed to conserve the term salt gland to designate excretory structures associated with endodermal collecting tissue. The elements present in the glands (detected by the use of X-ray micro-analysis) are: Na. Mg. P. S. Cl. K with an increase of the elements from the endodermal tissue to the cap cell. Because of energy needed to transport and excrete salts, salt glands are situated at the base of the inflorescence, which is the zone of maximal development of Kranz structure. It is inferred that  Eriochloa is a facultative halophytic genus, derived recently from a halophytic ancestor.

Study on the Concrete in Chloride Environment Based on Electrochemical Impedance Spectroscopy

2019 ◽  
Vol 34 (06) ◽  
pp. 2059017
Author(s):  
Fengjiao Jiang ◽  
Jinxin Gong ◽  
Jichao Zhu ◽  
Huan Wang
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Electric Double Layer ◽  
Electrochemical Impedance ◽  
Pore Solution ◽  
Salt Water ◽  
Chloride Ions ◽  
Double Layer Capacitance ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Electric Double Layer Capacitance

In this paper, the effect of water-cement ratio and chloride ions on the concrete meso-structure was studied. Three kinds of concrete cubes with different water-cement ratios were immersed in fresh water and salt water, respectively. Then, the Electrochemical Impedance Spectroscopy (EIS) analysis of various test cubes were carried out by using electrochemical workstation. The results show that the salt water can improve electric double layer capacitance in the test cubes with the same water-cement ratio, but it can reduce some other parameters such as resistance of pore solution, resistance to transfer the hydrated electron, coefficient of diffusion impedance of concreter, which shows that the chloride ions diffused into the concrete in salt water and increase the ionic concentration in pore solution and C-S-H gel. However, the phase angle index is constant whether in fresh water or salt water, which shows chloride ions cannot affect the concrete meso-structure even though they can improve the ion concentration of pore structure. For the concrete test cubes which has different water-cement ratio in salt water, with the reduction of water-cement ratio, the electric double-layer capacitance of concrete remains unchanged, which indicates when the water-cement ratio becomes smaller, the porosity becomes lower, and the internal structure of concrete becomes denser.

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