The role of mesenchyme in the morphogenesis and functional differentiation of rat salivary epithelium

Development ◽  
1972 ◽  
Vol 27 (3) ◽  
pp. 497-513
Author(s):  
Kirstie A. Lawson
Keyword(s):  
Parotid Gland ◽  
Amylase Activity ◽  
Growth Control ◽  
Functional Differentiation ◽  
Initial Mass ◽  
Functional Product ◽  
Foetal Rat ◽  
Terminal Buds

The ability of foetal rat salivary epithelium, particularly from the parotid gland, to develop morphogenetically and functionally (amylase activity) in various mesenchymes, and the quantitative effects of altering mesenchymal mass on the development of the parotid epithelium, have been studied in vitro. Both parotid and submandibular epithelial rudiments were able to undergo morphogenesis and subsequent cytodifferentiation in their own and in the reciprocal mesenchyme. The growth of the explant and the arrangement of the acini were governed by the mesenchyme, submandibular mesenchyme supporting the development of more acini, which were more closely packed, than parotid mesenchyme. The functional product of the epithelium was not qualitatively affected, amylase activity being developed only by parotid epithelium, whether in its own or in submandibular mesenchyme. Amylase activity was greater when the epithelium from a single parotid rudiment was recombined with submandibular mesenchyme than with its own mesenchyme. Increasing the initial mass of either salivary mesenchyme also led to the development of more amylase activity. Parotid epithelium was able to develop in lung mesenchyme, but not so well as in its own mesenchyme. Stomach and pancreatic mesenchyme could support only limited histogenesis of parotid epithelium. The results are interpreted in terms of morphogenetic and growth control of salivary epithelium by mesenchyme, the subsequent cytodifferentiation of the terminal buds being typical of the organ from which the epithelium was derived.

Morphogenesis and functional differentiation of the rat parotid gland in vivo and in vitro

Development ◽  
1970 ◽  
Vol 24 (2) ◽  
pp. 411-424
Author(s):  
Kirstie A. Lawson
Keyword(s):  
Submandibular Gland ◽  
Amylase Activity ◽  
Functional Differentiation ◽  
Basal Nucleus ◽  
Early Postnatal Development ◽  
Rat Parotid ◽  
Terminal Buds ◽  
Branched Structure

In comparison with the submandibular and the sublingual glands, the parotid develops slowly in the rat. The foetal rudiment appears a day later than that of the submandibular gland and the formation of adenomeres is slower, leading to a more diffusely branched structure. Cytodifferentiation, in the form of traces of mucopolysaccharide in the tubules and terminal buds, begins at, or just before, birth. There is a transitory increase in mucopolysaccharide production for a few days after birth until the presumptive acinar cells become pyramidal in shape with basal nucleus and granular cytoplasm. Amylase activity of the gland begins to rise between the second and third day after birth and reaches the adult level at weaning. That of the submandibular gland remains at the foetal level. Parotid rudiments were cultivated on a film of agar over a medium of fowl plasma and chick embryo extract. The oxygen in the gas phase of air and 5% CO2 was increased to 50% after the first 9 days in vitro. Under these conditions the mass of the rudiments increased tenfold during 18 days cultivation and the initially unbranched rudiment formed adenomeres in which the cytodifferentiation followed the same course as in vivo. The rise in amylase activity of the explants was only slightly delayed compared with that in vivo, suggesting that systemic or environmental factors are not obligatory in the early postnatal development of the rat parotid.

TESTOSTERONE SECRETION BY FOETAL RAT TESTES IN VITRO

1976 ◽  
Vol 71 (2) ◽  
pp. 231-238 ◽  
Author(s):  
RÉGINE PICON
Keyword(s):  
Cyclic Amp ◽  
Synthetic Medium ◽  
Functional Differentiation ◽  
Dibutyryl Cyclic Amp ◽  
Testosterone Secretion ◽  
Testosterone Production ◽  
Foetal Rat

SUMMARY Testosterone secretion by foetal rat testes (13½–21½ days of gestation) explanted for 3 days in a synthetic medium was measured every 24 h by radioimmunoassay. During the first day of explantation, the foetal testis produced, respectively, 1013 ± 132, 8734 ± 1118, 9179 ± 2185 and 3886 ± 309 (s.e.m.) pg/testis when explanted at 14½, 16½, 18½ and 21½ days respectively. Testosterone production by 13½-day-old testes was not detectable on the first day of culture, but appeared on subsequent days. Daily testosterone secretion increased on the 2nd and 3rd days of culture in 14½-day-old testes and decreased in older stages. These results suggest that the functional differentiation of the testis is independent of stimulatory factors like gonadotrophins. Dibutyryl cyclic AMP was found to stimulate testosterone production significantly from 14½ days of gestation onwards.

scholarly journals Strategies for Developing Functional Secretory Epithelia from Porcine Salivary Gland Explant Outgrowth Culture Models

Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 657 ◽  
Author(s):  
Urkasemsin ◽  
Castillo ◽  
Rungarunlert ◽  
Klincumhom ◽  
Ferreira
Keyword(s):  
Salivary Gland ◽  
Parotid Gland ◽  
Calcium Influx ◽  
Amylase Activity ◽  
Smooth Muscle Actin ◽  
Dry Mouth ◽  
Muscarinic Agonists ◽  
Proliferation Markers ◽  
Epithelial Barrier Function

Research efforts have been made to develop human salivary gland (SG) secretory epithelia for transplantation in patients with SG hypofunction and dry mouth (xerostomia). However, the limited availability of human biopsies hinders the generation of sufficient cell numbers for epithelia formation and regeneration. Porcine SG have several similarities to their human counterparts, hence could replace human cells in SG modelling studies in vitro. Our study aims to establish porcine SG explant outgrowth models to generate functional secretory epithelia for regeneration purposes to rescue hyposalivation. Cells were isolated and expanded from porcine submandibular and parotid gland explants. Flow cytometry, immunocytochemistry, and gene arrays were performed to assess proliferation, standard mesenchymal stem cell, and putative SG epithelial stem/progenitor cell markers. Epithelial differentiation was induced and different SG-specific markers investigated. Functional assays upon neurostimulation determined α-amylase activity, trans-epithelial electrical resistance, and calcium influx. Primary cells exhibited SG epithelial progenitors and proliferation markers. After differentiation, SG markers were abundantly expressed resembling epithelial lineages (E-cadherin, Krt5, Krt14), and myoepithelial (α-smooth muscle actin) and neuronal (β3-tubulin, Chrm3) compartments. Differentiated cells from submandibular gland explant models displayed significantly greater proliferation, number of epithelial progenitors, amylase activity, and epithelial barrier function when compared to parotid gland models. Intracellular calcium was mobilized upon cholinergic and adrenergic neurostimulation. In summary, this study highlights new strategies to develop secretory epithelia from porcine SG explants, suitable for future proof-of-concept SG regeneration studies, as well as for testing novel muscarinic agonists and other biomolecules for dry mouth.

ROLE OF THE MESENCHYME IN THE INDUCTION OF THE RAT PROSTATE GLAND BY ANDROGENS IN ORGAN CULTURE

1979 ◽  
Vol 82 (1) ◽  
pp. 171-NP ◽  
Author(s):  
ILSE LASNITZKI ◽  
TAKEO MIZUNO
Keyword(s):  
Organ Culture ◽  
De Novo ◽  
Prostate Gland ◽  
Young Male ◽  
Free Medium ◽  
Foetal Rat ◽  
Rat Prostate ◽  
Do So

SUMMARY Rat prostate glands are induced de novo by androgens in 16·5-day-old male and female urogenital sinuses in vitro as epithelial buds projecting into the surrounding mesenchyme. The role of the mesenchyme in this process has been investigated in various epithelial-mesenchymal recombinations in organ culture. Isolated epithelium did not form buds but required the presence of the mesenchyme to do so. This requirement seemed to be specific; in the presence of testosterone or dihydrotestosterone only urogenital mesenchyme increased cell division in the urogenital epithelium and stimulated prostatic bud formation. In contrast, heterotypic mesenchyme did not affect epithelial mitosis and failed to induce buds while heterotypic epithelia did not respond to urogenital mesenchyme. In recombinants of urogenital mesenchyme pretreated with androgen and untreated urogenital epithelium, grown in androgen-free medium, the majority of explants developed prostatic buds while only a few buds were formed from epithelium pretreated with androgen when it was recombined with untreated mesenchyme. The role of the mesenchyme in the loss of androgen responsiveness of the older female sinuses was examined in heterochronic recombinants. It was found that the old female mesenchyme failed to induce buds in young epithelium while young male or female mesenchymes induced them in the old female epithelium. The results suggest that the urogenital mesenchyme is essential for the initiation of the foetal rat prostate gland and that it may be a target for androgens and complement or mediate their effect on the epithelium.

scholarly journals The Role of the Cell Volume-Area Ratio in Thermodynamic Analysis of the Cancer Growth Control for In Vitro Experiments

2018 ◽  
Author(s):  
Umberto Lucia ◽  
Giulia Grisolia
Keyword(s):  
Growth Control ◽  
Area Ratio ◽  
Point Of View ◽  
Cancer Growth ◽  
Cyclic Process ◽  
Cell Life ◽  
Starting Point ◽  
Cell Changes

From a thermodynamic point of view, living cell life is no more than a cyclic process. It starts with the newly separated daughter cells and restarts when the next generations grow as free entities. In this cycle the cell changes its entropy. In cancer the growth control is damaged. In this paper we analyze the role of the volume-area ratio in cell in relation to the heat exchange between cell and its environment in order to point out the effect on the cancer growth. The result holds to a possible control of the cancer growth based on the heat exchanged by the cancer towards its environment, and the membrane potential variation, with the consequence of controlling the ions fluxes and the related biochemical reactions. This second law approach could represent a starting point for a possible future support for the anticancer therapies, in order to improve their effectiveness for the untreatable cancers.

scholarly journals Elevated Fecal Candida Counts in Patients with Antibiotic-Associated Diarrhea: Role of Soluble Fecal Substances

2003 ◽  
Vol 10 (1) ◽  
pp. 167-168 ◽  
Author(s):  
Robert Krause ◽  
Günter J. Krejs ◽  
Christoph Wenisch ◽  
Emil C. Reisinger
Keyword(s):  
Candida Albicans ◽  
Growth Factors ◽  
Healthy Subjects ◽  
Growth Control ◽  
Antibiotic Associated Diarrhea ◽  
Phosphate Buffered Saline

ABSTRACT To assess the role of soluble fecal substances in the elevation of fecal Candida counts in patients with antibiotic-associated diarrhea (AAD), we investigated the growth of Candida albicans in vitro in serially diluted stool fluids from patients with AAD and healthy subjects. There were significantly higher Candida albicans counts in stool fluids diluted 1:10 from AAD patients than in healthy subjects and the phosphate-buffered saline growth control, which may be due to reduced soluble Candida inhibitors and increased availability of growth factors and nutrients.

scholarly journals E2F4 and E2F1 Have Similar Proliferative Properties but Different Apoptotic and Oncogenic Properties In Vivo

2000 ◽  
Vol 20 (10) ◽  
pp. 3417-3424 ◽  
Author(s):  
Dawei Wang ◽  
Jamie L. Russell ◽  
David G. Johnson
Keyword(s):  
Transgenic Mice ◽  
Cellular Response ◽  
Tumor Development ◽  
Growth Control ◽  
Mouse Skin ◽  
Keratin 5 ◽  
E2f Transcription Factors

ABSTRACT Loss of retinoblastoma (Rb) tumor suppressor function, as occurs in many cancers, leads to uncontrolled proliferation, an increased propensity to undergo apoptosis, and tumorigenesis. Rb negatively regulates multiple E2F transcription factors, but the role of the different E2F family members in manifesting the cellular response to Rb inactivation is unclear. To study the effect of deregulated E2F4 activity on cell growth control and tumorigenesis, transgenic mouse lines expressing the E2F4 gene under the control of a keratin 5 (K5) promoter were developed, and their phenotypes were compared to those of previously generated K5 E2F1 transgenic mice. In contrast to what has been observed in vitro, ectopically expressed E2F4 was found to localize to the nucleus and induce proliferation to an extent similar to that induced by E2F1 in transgenic tissue. Unlike E2F1, E2F4 does not induce apoptosis, and this correlates with the differential abilities of these two E2F species to stimulatep19ARF expression in vivo. To examine the role of E2F4 in tumor development, the mouse skin two-stage carcinogenesis model was utilized. Unlike E2F1 transgenic mice, E2F4 transgenic mice developed skin tumors with a decreased latency and increased incidence compared to those characteristics in wild-type controls. These findings demonstrate that while the effects of E2F1 and E2F4 on cell proliferation in vivo are similar, their apoptotic and oncogenic properties are quite different.

scholarly journals Indole-3-acetic acid (IAA) producing Pseudomonas isolates inhibit seed germination and α-amylase activity in durum wheat (Triticum turgidum L.)

2016 ◽  
Vol 14 (1) ◽  
pp. e0802 ◽  
Author(s):  
Samira Tabatabaei ◽  
Parviz Ehsanzadeh ◽  
Hassan Etesami ◽  
Hossein A. Alikhani ◽  
Bernard R. Glick
Keyword(s):  
Acetic Acid ◽  
Seed Germination ◽  
Durum Wheat ◽  
Triticum Turgidum ◽  
Amylase Activity ◽  
Inhibitory Effect ◽  
Bacterial Isolates ◽  
Indole 3 Acetic Acid

<p>The role of plant-associated bacteria in plant physiology and metabolism is well documented, but little has been known about the roles played by <em>Pseudomonas</em> in durum wheat (<em>Triticum turgidum</em> L. var <em>durum</em>) growth and development. An<em> in vitro</em>experiment was conducted to observe the effect of the inoculation of four indole-3-acetic acid (IAA)-producing <em>Pseudomonas </em>isolates<em> </em>and exogenous IAA on seed germination traits and α-amylase activity of durum wheat. The results showed inoculation with all bacterial isolates led to a decrease in the germination percent, although the extent of the depression varied with the isolate. A significant relationship between concentrations of bacterial IAA and the germination inhibition percent in durum wheat seeds by different bacteria strains was observed. The results of this assay showed the effect of bacterial isolates on α-amylase activity after six and 8 days of inoculation was significant, while effect of these isolates on α-amylase activity after two and 4 days of inoculation was not meaningful. In addition, the exogenously applied IAA displayed a concentration-dependent effect on seed germination attributes and α-amylase activity, consistent with the possibility that the inhibitory effect of bacterial inoculation on seed germination was in consequence of bacteria-produced IAA. Therefore, it may suggested that the inhibitory role of IAA in seed germination and α-amylase activity should be taken into account during the screening of IAA-producing <em>Pseudomonas</em> isolates for durum wheat growth promoting agents.</p>

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