Comparative studies on the localization of esteroproteases and kallikrein-like activity in primate organs

Summary Various organs of three species of monkey were screened histochemically for esteroproteases usingN-acethyl-l-methionine--naphthylester ( N-O-met) as the substrate and also for enzymes with kallikrein-like activity usingd-Val-Leu-Arg-4-methoxy-2-naphthylamide as the substrate. Characteristic differences were found in the localization of the reaction products obtained with both substrates. In the main salivary glands, esteroproteases ( N-O-met reactivity) were found in mucous cells (submandibular gland), intercalated duct cells (parotid gland), acinar cells (sublingual gland), striated and interlobular duct cells (all glands). They were also localized in superficial lining epithelial cells of the digestive system, in liver cells, and acinar cells of the pancreas.Enzymes with kallikrein-like activity were found only in the striated and interlobular duct cells of salivary glands, in acinar cells of the pancreas, and in proximal tubular cells of the kidney. Free cells (including mast cells) normally distributed in the connective tissue of various organs showed reactivity towards N-O-met. Some of these cells were also reactive against Val-Leu-Arg-4-MNA.     

Electron microprobe analysis of frog skin epithelium: Evidence for a syncytial sodium transport compartment

Summary For elucidation of the functional organization of frog skin epithelium with regard to transepithelial Na transport, electrolyte concentrations in individual epithelial cells were determined by electron microprobe analysis. The measurements were performed on 1-m thick freeze-dried cryosections by an energy-dispersive X-ray detecting system. Quantification of the electrolyte concentrations was achieved by comparing the X-ray intensities obtained in the cells with those of an internal albumin standard.The granular, spiny, and germinal cells, which constitute the various layers of the epithelium, showed an identical behavior of their Na and K concentrations under all experimental conditions. In the control, both sides of the skin bathed in frog Ringer's solution, the mean cellular concentrations (in mmole/kg wet wt) were 9 for Na and 118 for K. Almost no change in the cellular Na occurred when the inside bathing solution was replaced by a Na-free isotonic Ringer's solution, whereas replacing the outside solution by distilled water resulted in a decrease of Na to almost zero in all layers. Inhibition of the transepithelial Na transport by ouabain (10^–4 m) produced an increase in Na to 109 and a decrease in K to 16. The effect of ouabain on the cellular Na and K concentrations was completely cancelled when the Na influx from the outside was prevented, either by removing Na or adding amiloride (10^–4 m). When, after the action of ouabain, Na was removed from the outside bathing solution, the Na and K concentration in all layers returned to control values. The latter effect could be abolished by amiloride.The other cell types of the epithelium showed under some experimental conditions a different behavior. In the cornified cells and the light cells, which occurred occasionally in the stratum granulosum, the electrolyte concentrations approximated those of the outer bathing meium under all experimental conditions. In the mitochondria-rich cells, the Na influx after ouabain could not be, prevented by adding amiloride. In the gland cells, only a small change in the Na and K concentrations could be detected after ouabain.The results of the present study are consistent with a two-barrier concept of transepithelial Na transport. The Na transport compartment comprises all living epithelial layers. Therefore, with the exception of some epithelial cell types, the frog skin epithelium can be regarded as a functional syncytium for Na.     

Chloride conductive and cotransport mechanisms in cultures of canine tracheal epithelial cells measured by an entrapped fluorescent indicator

Summary To study Cl conductive and cotransport mechanisms, primary cultures of canine tracheal cells were grown to confluency on thin glass cover slips and on porous filters. Transepithelial resistance was >100 ·cm², and short circuit current (I _sc=2–20 A/cm²), representing active secretion of Cl, increased >threefold with addition of 10 m isoproterenol to the serosal solution. Cells made transiently permeable in hypotonic solution were loaded with the Cl-sensitive fluorophore 6-methoxy-N-(3-sulfopropyl) quinolinium (SPQ) (5mm, 4 min, 150 mOsm). The electrical properties of the cell monolayers were not altered by the loading procedure. Intracellular SPQ fluorescence was monitored continuously by epifluorescence microscopy (excitation 360±5 nm, emission>410 nm). SPQ leakage from the cells was <10% in 60 min at 37°C. Intracellular calibration of SPQ fluorescencevs. [Cl] (0–90mm) was carried out using high-K buffers containing the ionophores nigericin (5 m) and tributyltin (10 m); SPQ fluorescence was quenched with a Stern-Volmer constant of 13m ^–1. Intracellular Cl activity was 43±4mm. Cl flux was measured in response to addition and removal of 114mm Cl from the bathing solution. Addition of 10 m isoproterenol increased Cl efflux from 0.10 to 0.27mm/sec. The increase was inhibited by the Cl-channel blocker diphenylamine-2-carboxylic acid (1mm). In the absence of isoproterenol, removal of external Na or addition of 0.5mm furosemide, reduced Cl influx by >fourfold. In ouabain-treated monolayers, removal of external K in the presence of 5mm barium diminished Cl influx by >twofold, suggesting that Cl entry is in part K dependent. These results establish an accurate optical method for the realtime measurement of intracellular Cl activity in tracheal cells that does not require an electrically tight cell monolayer. The data demonstrate the presence of an isoproterenol-regulated Cl channel and a furosemide-sensitive cation-coupled transport mechanism.     

Morphology of the exocrine glands of the frog skin

Frog skin contains three distinct types of exocrine glands: granular (poison), mucous, and seromucous. The granular gland forms a syncytial secretory compartment within the acinus, which is surrounded by smooth muscle cells. The mucous and seromucous glands are easily identifiable as distinct glands. The serous and mucous secretory cells are arranged in a semilunar configuration opposite the ductal end and are filled with granules. Within the acinus, located at the ductal pole of the gland, are distinct groups of cells with few or no granules in the cytoplasm. In both the mucous and seromucous gland there is a cell type with abundant mitochondria; the one in the mucous gland is located in the region adjacent to the secretory cells. The duct of these glands is two-layered, with the individual cells appearing morphologically similar to the layers of the skin epithelium as the duct traverses the skin. The duct appears to be patent throughout its length. The morphological heterogeneity and distinct distribution of the cell types within the gland acinus may be indicative of a functional heterogeneity that allows the production of distinctly different types of secretion from the same gland type, depending on the type of stimulus.     

Prostaglandin E2-stimulated glandular ion and water secretion in isolated frog skin (Rana esculenta)

Summary Prostaglandins are known to stimulate the active sodium absorption in frog skin. In this paper it is shown that prostaglandin E₂ (PGE₂) stimulates an active secretion of Cl^–, Na⁺, and K⁺ from the skin glands inRana esculenta. The active Cl secretion is enhanced more than the Na and K secretion. Therefore, in skins where the Na absorption is inhibited by amiloride, the addition of PGE₂ results in an increase in the short-circuit current (SCC). The PGE₂-stimulated Cl secretion could be inhibited by the presence of ouabain or furosemide in the basolateral solution or diphenylamine-2-carboxylate in the apical solution. The PGE₂-stimulated Cl secretion was enhanced by the phosphodiesterase inhibitor, theophylline, indicating that the effect of PGE₂ was caused by an increase in the intracellular cAMP level in the gland cells. The calcium ionophore A23187, which increases the PGE₂ synthesis in frog skin, stimulated the glandular Cl secretion. This secretion could be blocked by the prostaglandin synthesis inhibitor indomethacin, indicating that A23187 acts by increasing the prostaglandin synthesis and not by a direct action of Ca²⁺ ionsper se. The net water flow (J _w) and the Cl secretion were measured simultaneously under the conditions outlined above. The stimulation, inhibition, and the time-course of the outward-directedJ _w were similar to the change observed for the Cl secretion. These results show that PGE₂ stimulates a glandular secretion of Cl and water in frog skin, probably by increasing the cAMP level in the gland cells.     

Histochemistry of the glands associated with the reproductive tract ofLymnaea stagnalis

Summary The albumen gland, the muciparous gland and the oöthecal gland of female genital tract of Lymnaea stagnalis, collected in spring, autumn and winter have been studied.The reactions for polysaccharides, proteins and RNA have been performed in order to characterise the secretion of the glands.The albumen gland secretion consists almost exclusively of slightly acid polysaccharides whose histochemical reactions, according to Lison and Grainger and Shillitoe confirm the presence of galactogen. Proteins are also present in the secretion. The muciparous gland secretion consists of strongly acid mucopolysaccharides (non sulphated) produced by large cells among which small cells containing sulphated mucopolysaccharides are present.In the oöthecal gland two zones are present, one with a single type of cells containing acid mucopolysaccharides, and the other with two different types of cells: the first with mucopolysaccharides and the second with sulphated mucopolysaccharides, proteins and glycogen at the basis of the cell. Sialic acids are not present in the secretion of the glands studied.The polysaccharidic composition of the secretion of the glands is different from gland to gland. The secretion of the glands gradually changes and gets acid according to the composition of the various membranes and envelopes wrapping up the eggs.     

Ion and water transport by isolated cockroach salivary glands

Summary When the isolated salivary glands of the cockroachNauphoeta cinerea Olivier are stimulated by dopamine, the putative neurotransmitter, they secrete a fluid containing (mm): Na, 121; K, 47; Cl, 143. Stimulation of glands by 5-hydroxytryptamine or the neurotransmitter evokes a secretion identical in Na composition to this. Dopamine-evoked secretion is abolished in the absence of extracellular Na. The relationship between the rates of fluid secretion and Na transport is linear. However, at very low rates of secretion the Na concentration falls. Calcium, K and Cl ions can be removed from the bathing solution without abolishing fluid secretion. Our evidence suggests that (i) the primary secretion is formed by active transport of Na in the acini, and (ii) the ionic composition of this secretion is modified by re-absorption of Na and an independent secretion of K in the ducts.     

Defective fluid secretion and NaCl absorption in the parotid glands of Na+/H+ exchanger-deficient mice

Multiple Na(+)/H(+) exchangers (NHEs) are expressed in salivary gland cells; however, their functions in the secretion of saliva by acinar cells and the subsequent modification of the ionic composition of this fluid by the ducts are unclear. Mice with targeted disruptions of the Nhe1, Nhe2, and Nhe3 genes were used to study the in vivo functions of these exchangers in parotid glands. Immunohistochemistry indicated that NHE1 was localized to the basolateral and NHE2 to apical membranes of both acinar and duct cells, whereas NHE3 was restricted to the apical region of duct cells. Na(+)/H(+) exchange was reduced more than 95% in acinar cells and greater than 80% in duct cells of NHE1-deficient mice (Nhe1(-/-)). Salivation in response to pilocarpine stimulation was reduced significantly in both Nhe1(-/-) and Nhe2(-/-) mice, particularly during prolonged stimulation, whereas the loss of NHE3 had no effect on secretion. Expression of Na(+)/K(+)/2Cl(-) cotransporter mRNA increased dramatically in Nhe1(-/-) parotid glands but not in those of Nhe2(-/-) or Nhe3(-/-) mice, suggesting that compensation occurs for the loss of NHE1. The sodium content, chloride activity and osmolality of saliva in Nhe2(-/-) or Nhe3(-/-) mice were comparable with those of wild-type mice. In contrast, Nhe1(-/-) mice displayed impaired NaCl absorption. These results suggest that in parotid duct cells apical NHE2 and NHE3 do not play a major role in Na(+) absorption. These results also demonstrate that basolateral NHE1 and apical NHE2 modulate saliva secretion in vivo, especially during sustained stimulation when secretion depends less on Na(+)/K(+)/2Cl(-) cotransporter activity.     

Ultrastructure of the male reproductive accessory glands in the medfly Ceratitis capitata (Diptera: Tephritidae) and preliminary characterization of their secretions

The morphology and the ultrastructure of the male accessory glands and ejaculatory duct of Ceratitis capitata were investigated. There are two types of glands in the reproductive apparatus. The first is a pair of long, mesoderm-derived tubules with binucleate, microvillate secretory cells, which contain smooth endoplasmic reticulum and, in the sexually mature males, enlarged polymorphic mitochondria. The narrow lumen of the gland is filled with dense or sometimes granulated secretion, containing lipids. The second type consists of short ectoderm-derived glands, finger-like or claviform shaped. Despite the different shape of these glands, after a cycle of maturation, their epithelial cells share a large subcuticular cavity filled with electron-transparent secretion. The ejaculatory duct, lined by cuticle, has epithelial cells with a limited involvement in secretory activity. Electrophoretic analysis of accessory gland secretion reveals different protein profiles for long tubular and short glands with bands of 16 and 10 kDa in both types of glands. We demonstrate that a large amount of accessory gland secretion is depleted from the glands after 30 min of copulation.     

Indirect effects of adenosine triphosphate on chloride secretion in mammalian colon

Summary The effects of adenosine triphosphate (ATP) on shortcircuit current (SCC) in rat colonic epithelium are described. ATP caused a large increase in inward-going current and was considerably more potent in this respect than ADP. AMP or adenosine. The response to ATP was sided, there being only minor effects when the nucleotide was added to the apical side of the tissue. The effects of ATP were not modified by the cyclooxygenase inhibitor, indomethacin, eliminating eicosanoid formation as a mechanism. The effects of ATP were potentiated by theophylline and not blocked by ,-methylene ATP. The data are consistent with the effect being dependent on the activation of adenylate cyclase, but it has not been possible to classify the receptors intoP ₁ orP ₂ categories. Using inhibitors of NaCl cotransport (piretanide), carbonic anhydrase (acetazolamide), and chloride channels (diphenylamine-2-carboxylate), it was concluded that the SCC response to ATP was due to chloride secretion with, perhaps, a minor contribution from bicarbonate. Flux measurements with²²Na and³⁶Cl confirmed this view, there being approximate equivalence of chloride secretion with the SCC responses. Additionally, flux measurements revealed an inhibition of electroneutral NaCl absorption in response to ATP.The effects of ATP were antagonized by tetrodotoxin (TTX), greater than 50% inhibition being achieved with 10nm TTX. This result suggests that ATP does not act directly on receptors in the epithelial cells but rather on neuronal elements in the lamina propria. It will be necessary to re-examine other secretagogues for indirect effects of this kind and to search for the final effector neurotransmitter which evokes secretion.     

Stoichiometry and ion affinities of the Na−K−Cl cotransport system in the intestine of the winter flounder (Pseudopleuronectes americanus)

Summary Na–K–Cl cotransport stoichiometry and affinities for Na, K and Cl were determined in flounder intestine. Measurement of simultaneous NaCl and RbCl influxes resulted in ratios of 2.2 for Cl/Na and 1.8 for Cl/Rb. The effect of Na and Rb on Rb influx showed first order kinetics withK _1/2 values of 5 and 4.5mm and Hill coefficients of 0.9 and 1.2, respectively. The effect of Cl on rubidium influx showed a sigmoidal relationship withK _1/2 of 20mm and a Hill coefficient of 2.0. The effects of variations in Na and Cl concentration on short-circuit current (I _sc) were also determined. TheK _1/2 for Na was 7mm with a Hill coefficient of 0.9 and theK _1/2 for Cl was 46mm with a Hill coefficient of 1.9. Based on the simultaneous influx measurements, a cotransport stoichiometry of 1Na1K2Cl is concluded. The Hill coefficients for Cl suggest a high degree of cooperativity between Cl binding sites. Measurements of the ratio of net Na and Cl transepithelial fluxes under short-circuit conditions (using a low Na Ringer solution to minimize the passive Na flux) indicate that the Cl/Na flux ratio is approximately 21. Therefore Na recycling from serosa to mucosa does not significantly contribute to theI _sc. Addition of serosal ouabain (100 m) inhibited Rb influx, indicating that Na–K–Cl cotransport is inhibited by ouabain. This finding suggests that a feedback mechanism exists between the Na–K-ATPase on the basolateral membrane and the apical Na–K–2Cl cotransporter.     

Active chloride secretion by rabbit colon: Calcium-dependent stimulation by ionophore A23187

Summary Addition of Ca ionophore, A23187, to the solution bathing the mucosal surface of descending rabbit colon resulted in a reversal of active Cl absorption to active Cl secretion, a twofold increase in short-circuit current and a 40% increase in tissue conductance without affecting the rate of active Na absorption. These alterations in electrolyte transport are quantitatively similar to those previously observed in response to cyclic 3,5-AMP (cAMP) (R.A. Frizzell, M.J. Koch & S.G. Schultz,J. Membrane Biol. 27:297, 1976). When medium Ca concentration was reduced to 10^–6 m, the secretory response to A23187 was abolished but the response to cAMP was unaffected. The ionophore did not influence the cAMP levels of colonic mucosa. Addition of cyclic AMP to colonic strips preloaded with⁴⁵Ca elicited a reversible increase in Ca efflux from the tissue. These results suggest that an increase in intracellular Ca concentration stimulates colonic electrolyte secretion and that the secretory response to cAMP may be due, at least in part, to a release of Ca from intracellular stores.     

Clcn2 encodes the hyperpolarization-activated chloride channel in the ducts of mouse salivary glands

Transepithelial Cl(-) transport in salivary gland ducts is a major component of the ion reabsorption process, the final stage of saliva production. It was previously demonstrated that a Cl(-) current with the biophysical properties of ClC-2 channels dominates the Cl(-) conductance of unstimulated granular duct cells in the mouse submandibular gland. This inward-rectifying Cl(-) current is activated by hyperpolarization and elevated intracellular Cl(-) concentration. Here we show that ClC-2 immunolocalized to the basolateral region of acinar and duct cells in mouse salivary glands, whereas its expression was most robust in granular and striated duct cells. Consistent with this observation, nearly 10-fold larger ClC-2-like currents were observed in granular duct cells than the acinar cells obtained from submandibular glands. The loss of inward-rectifying Cl(-) current in cells from Clcn2(-/-) mice confirmed the molecular identity of the channel responsible for these currents as ClC-2. Nevertheless, both in vivo and ex vivo fluid secretion assays failed to identify significant changes in the ion composition, osmolality, or salivary flow rate of Clcn2(-/-) mice. Additionally, neither a compensatory increase in Cftr Cl(-) channel protein expression nor in Cftr-like Cl(-) currents were detected in Clcn2 null mice, nor did it appear that ClC-2 was important for blood-organ barrier function. We conclude that ClC-2 is the inward-rectifying Cl(-) channel in duct cells, but its expression is not apparently required for the ion reabsorption or the barrier function of salivary ductal epithelium.     

Intracellular ion concentrations in the frog cornea epithelium during stimulation and inhibition of Cl secretion

Summary The intracellular electrolyte concentrations in the isolated cornea of the American bullfrog were determined in thin freeze-dried cryosections using energy-dispersive X-ray microanalysis. Stimulation of Cl secretion by isoproterenol resulted in a significant increase in the intracellular Na concentration but did not change the intracellular Cl concentration. Similar results were obtained when Cl secretion was stimulated by the Ca ionophore A23187. Inhibition of Cl secretion by ouabain produced a large increase in the intracellular Na concentration and an equivalent fall in the K concentration. Again, no increase or decrease in the intracellular Cl concentration was detectable. Clamping of the transepithelial potential to ±50 mV resulted in parallel changes in the transepithelial current and intracellular Na concentration, but, with the exception of the outermost cell layer, in no changes of the Cl concentration. Only when Cl secretion was inhibited by bumetanide or furosemide, together with a decrease in the Na concentration, was a large fall in the Cl concentration observed. Application of loop diuretics also produced significant increases in the P concentration and dry weight, consistent with some shrinkage of the epithelial cells. The results suggest the existence of a potent regulatory mechanism which maintains a constant intracellular Cl concentration and, thereby, a constant epithelial cell volume. Through the operation of this system any variation in the apical Cl efflux is compensated for by an equal change in the rate of Cl uptake across the basolateral membrane. Cl uptake is sensitive to loop diuretics, directly coupled to an uptake of Na, and dependent on the Na and K concentration gradients across the basolateral membrane. Isoproterenol and A23187 seem to increase the Cl permeability of the apical membrane and thus stimulate Cl efflux. Ouabain inhibits Cl secretion by abolishing the driving Na concentration gradient for Cl uptake across the basolateral membrane.     

The cytochemistry of glycoconjugates in the planum nasolabial gland of the goat as studied by electron microscopic methods

Summary In the planum nasolabial glands of the goat, glycoconjugates of glandular and duct cells have been studied by means of a series of electron microscopic cytochemical methods. In the glandular cells glycoconjugates with vicinal diol groupings were present in secretory granules, certain elements of the Golgi complex, lysosome-like dense bodies, the surface coat of the plasma membrane, the majority of intracellular cytomembranes, glycogen particles and the basal lamina. In duct cells, glycoconjugates with the same properties were localized in similar ultrastructures, except for secretory granules, which were not detected in these cells. By lectin cytochemistry, glycoconjugates in glandular cell secretory granules contained a variety of saccharide residues such as -d-mannose, -d-glucose,N-acetyl-d-glucosamine and -l-fucose. The cytochemical properties of the secretory glycoconjugates are discussed in relation to the physiological functions performed by the planum nasolabial glands in the goat.     

Transepithelial transport in cell culture:d-Glucose transport by a pig kidney cell line (LLC-PK1)

Summary The pig kidney cell line LLC-PK₁ cultured on a collagen coated membrane filter formed a continuous sheet of oriented asymmetrical epithelial cells joined by occluding junctions. A transepithelial electrical potential (PD) and short-circuit current (SCC) were dependent on the presence of Na and sugar in the apical bathing solution. In the presence of 5.5mm d-glucose, a PD of 2.8 mV, apical surface negative, a SCC of 13 A cm^–2 and transepithelial resistance of 211 ohm·cm² were recorded. The SCC was promptly reduced by the addition of phlorizin to the apical bath but unaffected when placed in the basolateral bath. The effect on SCC of various sugars was compared by the concentrations required for half-maximal SCC: 0.13mm -methyl-d-glucoside, 0.28mm d-glucose, 0.65mm -methyl-d-glucoside, 0.77mm 6-deoxy-d-glucose, 4.8mm d-galactose, and 29mm 3-O-methyl-glucose. When [Na] was reduced, the concentration ofd-glucose required for half-maximal SCC increased. Isotopically labeled³H and¹⁴Cd-glucose were used to simultaneously determine bidirectional fluxes; a resultant net apical-to-basolateral transport was present and abolished by phlorizin. The transported isotope cochromatographed with labeledd-glucose, indicating negligible metabolism of transported glucose. The pig kidney cell line, LLC-PK₁, provides a cell culture model for the investigation of mechanisms of transepithelial glucose transport.     

Potential therapeutic effects of induced pluripotent stem cells on induced salivary gland cancer in experimental rats

Salivary gland neoplasms exhibit complex histopathology in a variety of tumor types and treatment options depend largely on the stage of the cancer. Induced pluripotent stem cells (iPS) have been investigated for treating induced salivary gland cancer and for restoring salivary gland function. We investigated iPS treatment for salivary gland cancer both in vitro and in vivo. For our study in vitro, we re-programmed human skin fibroblasts to form iPS cells using a plasmid containing Oct4, Sox2, L-MYC and LIN28. For our study in vivo, we used 30 white male albino rats divided into the following groups of 10: group 1 (control): rats were injected with phosphate-buffered saline (PBS), group 2 induced squamous cell carcinoma (SCC): rat submandibular glands were injected with squamous carcinoma cells (SCC), group 3 (induced SCC/iPS): SCC treated rats treated with 5 × 106 iPS cells. Submandibular glands from rats of all groups were examined histologically and real time PCR was performed for amylase, and COX I and COX II gene expression. We confirmed that submandibular gland specimens included tumor tissue before starting treatment with iPS. iPS treated cases exhibited regeneration of salivary glands, although minor degenerative and vascularization changes remained. The acinar cells regained their proper organization, but continued to exhibit abnormal activity including hyperchromatism. iPS cells may be useful for treating salivary gland carcinomas.     

The effects of thermally-induced activity in vivo upon the ultrastructure and Na, K and Cl composition of the epithelial cells of sweat glands from patients with cystic fibrosis

The secretory cells of the fundus of sweat glands from cystic fibrosis (CF) patients had higher Na and Cl contents and showed more granule depletion, cellular disruption and dilated intercellular canaliculi than normal. The cells of the coiled duct also had higher cytoplasmic levels of Na and Cl but were structurally normal. Thermal stimulation produced ultrastructural changes in the CF fundus comparable to normal, including further dilatation of the basolateral clefts, but did not induce the marked changes in the coiled duct which normally occur. The elevated Na and fall in K in the fundus and raised Na and Cl in the coiled duct upon activation, were not observed in the CF glands in which no significant changes were detected.     

关于野大豆盐腺问题的探讨

以中国3个省的盐生野大豆(Glycine soja Sieb. et Zucc.)为材料,在沙基培养、溶液培养和大田种植3种种植条件下用不同浓度的盐处理,观测了茎叶表面附着物的形态分布和腺毛的超微结构,测定了叶片腺毛分泌物中和叶片组织内部Na^ 和Cl^-的含量变化,并对腺毛的3个细胞以及表皮细胞和叶肉细胞内的Na^ 相对含量变化进行了X射线微区分析。结果发现：盐生野大豆茎叶表皮上生长的附着物中只有表皮毛和腺毛,腺毛的形态类似于禾本科植物中的一些盐腺,叶片上的腺毛均生长在叶脉上;腺毛细胞内部结构具有一般盐腺的特点,如有大液泡,稠密的细胞质,大量的线粒体、叶绿体、胞间连丝以及较厚的细胞壁等。通过测定在无盐对照、盐处理和盐处理加盐腺泌盐抑制剂条件下盐生野大豆叶片腺毛分泌物中和叶片组织内部的Na^ 和Cl^-含量,结果显示,盐生野大豆腺毛具有泌盐功能,加入泌盐抑制剂后,其泌盐作用停止;腺毛的3个细胞以及表皮细胞和叶肉细胞内的Na^ 在不同的盐浓度下的微区定位分析结果表明,盐生野大豆叶片的腺毛细胞有较强的积累Na^ 的能力。综合分析认为,盐生野生大豆的腺毛就是具有泌盐功能的盐腺,没有发现其他类型的盐腺。