Induction of functional cytodifferentiation in the epithelium of tissue recombinants. I. Homotypic seminal vesicle recombinants

Development ◽  
1989 ◽  
Vol 106 (2) ◽  
pp. 219-234 ◽  
Author(s):  
S.J. Higgins ◽  
P. Young ◽  
J.R. Brody ◽  
G.R. Cunha
Keyword(s):  
Seminal Vesicle ◽  
Time Course ◽  
Full Range ◽  
Seminal Vesicles ◽  
Neonatal Rat ◽  
Secretory Proteins ◽  
Functional Variation ◽  
Adult Rats ◽  
Normal Functional

Functional cytodifferentiation of seminal vesicle epithelium was investigated in tissue recombinants. Neonatal rat and mouse seminal vesicles were separated into epithelium and mesenchyme using trypsin. Epithelium and mesenchyme were then recombined in vitro to form interspecific rat/mouse homotypic recombinants. Growth as renal grafts in adult male athymic mice resulted in seminal vesicle morphogenesis in 70% of the recombinants (the remaining 30% failed to grow). Functional cytodifferentiation was judged by the expression of the major androgen-dependent secretory proteins characteristic of the seminal vesicles of adult rats and mice. Antibodies specific for each of these proteins were used to screen tissue sections by immunocytochemistry and to probe protein extracts by immunoblotting techniques. The heterospecific recombinants synthesized the full range of seminal vesicle secretory proteins that typifies the species providing the epithelium of the recombinant, not the mesenchyme. There was little functional variation between individual recombinants. The time course of development corresponded to that of intact neonatal seminal vesicles grown under the same conditions. Morphogenesis and functional cytodifferentiation were not evident after one week, but were well advanced after two weeks. Seminal vesicle recombinants grown for three weeks were indistinguishable morphologically and functionally from normal adult seminal vesicles. In addition, the ability of adult seminal vesicle epithelium to be induced to proliferate was examined. In association with neonatal seminal vesicle mesenchyme, the epithelium of the adult seminal vesicle proliferated and retained its normal functional activity. Thus, seminal vesicle functional cytodifferentiation can be faithfully reproduced in homotypic tissue recombinants. The methods used in this study will be used to investigate seminal vesicle development in instructive inductions of heterotypic epithelia.

Induction of functional cytodifferentiation in the epithelium of tissue recombinants. II. Instructive induction of Wolffian duct epithelia by neonatal seminal vesicle mesenchyme

Development ◽  
1989 ◽  
Vol 106 (2) ◽  
pp. 235-250 ◽  
Author(s):  
S.J. Higgins ◽  
P. Young ◽  
G.R. Cunha
Keyword(s):  
Seminal Vesicle ◽  
Normal Development ◽  
Seminal Vesicles ◽  
Wolffian Duct ◽  
Secretory Proteins ◽  
Ductus Deferens ◽  
Tissue Sections ◽  
Duct Epithelium ◽  
Mouse Tissues ◽  
Renal Grafts

When grown as renal grafts in adult male hosts, the upper (cranial), middle and lower (caudal) portions of fetal mouse and rat Wolffian ducts developed into epididymis, epididymis plus ductus deferens, and seminal vesicle, respectively. In heterotypic tissue recombinants, the epithelia from upper and middle Wolffian ducts were instructively induced to undergo seminal vesicle morphogenesis by neonatal seminal vesicle mesenchyme. Functional cytodifferentiation was examined in these recombinants using antibodies against major androgen-dependent, seminal vesicle-specific secretory proteins. The instructively induced Wolffian duct epithelia synthesized normal amounts of all of the secretory proteins characteristic of mature seminal vesicles, as judged by immunocytochemistry on tissue sections and gel electrophoresis plus immunoblotting of secretions extracted from the recombinants. In heterospecific recombinants composed of rat and mouse tissues, the seminal vesicle proteins induced were specific for the species that had provided the epithelium. This showed that the seminal vesicle epithelium in the recombinants was derived from instructively induced Wolffian duct epithelium and not from epithelial contamination of the mesenchymal inductor. Upper Wolffian duct epithelium, instructively induced to undergo seminal vesicle morphogenesis, did not express epididymis-specific secretory proteins, showing that its normal development had been simultaneously repressed.

scholarly journals Regional distribution, developmental changes, and cellular localization of CNTF-mRNA and protein in the rat brain.

1991 ◽  
Vol 115 (2) ◽  
pp. 447-459 ◽  
Author(s):  
K A Stöckli ◽  
L E Lillien ◽  
M Näher-Noé ◽  
G Breitfeld ◽  
R A Hughes ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Olfactory Bulb ◽  
Cellular Localization ◽  
Time Course ◽  
Regional Distribution ◽  
Developmental Expression ◽  
Adult Rats

Ciliary neurotrophic factor (CNTF) is a potent survival molecule for a variety of embryonic neurons in culture. The developmental expression of CNTF occurs clearly after the time period of the physiological cell death of CNTF-responsive neurons. This, together with the sites of expression, excludes CNTF as a target-derived neuronal survival factor, at least in rodents. However, CNTF also participates in the induction of type 2 astrocyte differentiation in vitro. Here we demonstrate that the time course of the expression of CNTF-mRNA and protein in the rat optic nerve (as evaluated by quantitative Northern blot analysis and biological activity, respectively) is compatible with such a glial differentiation function of CNTF in vivo. We also show that the type 2 astrocyte-inducing activity previously demonstrated in optic nerve extract can be precipitated by an antiserum against CNTF. Immunohistochemical analysis of astrocytes in vitro and in vivo demonstrates that the expression of CNTF is confined to a subpopulation of type 1 astrocytes. The olfactory bulb of adult rats has comparably high levels of CNTF to the optic nerve, and here again, CNTF-immunoreactivity is localized in a subpopulation of astrocytes. However, the postnatal expression of CNTF in the olfactory bulb occurs later than in the optic nerve. In other brain regions both CNTF-mRNA and protein levels are much lower.

Growth hormone (GH) autofeedback action in the neonatal rat: involvement of GH-releasing hormone and somatostatin

1990 ◽  
Vol 124 (2) ◽  
pp. 199-205 ◽  
Author(s):  
S. G. Cella ◽  
V. De Gennaro Colonna ◽  
V. Locatelli ◽  
V. Moiraghi ◽  
S. Loche ◽  
...  
Keyword(s):  
Body Weight ◽  
Inhibitory Effect ◽  
Postnatal Period ◽  
Neonatal Rat ◽  
Gh Treatment ◽  
Adult Rats ◽  
Releasing Hormone ◽  
Term Administration

ABSTRACT It is known that in adult rats, GH by itself and by promoting secretion of the somatomedins acts at the level of the hypothalamus to trigger release of somatostatin and decrease output of GH-releasing hormone (GHRH), thereby inhibiting further secretion of GH. To assess whether these mechanisms are already operative in the early postnatal period, we have evaluated the effect of short-term administration of GH in 10-day-old rats. Twice-daily s.c. administration of 25 μg human GH/rat, from days 5 to 9 of life, significantly reduced pituitary content of GH, decreased hypothalamic levels of GHRH mRNA and abolished the in-vivo GH response to a challenge dose of GHRH (20 ng/100 g body weight, s.c.). GHRH (20 ng/100 g body weight, twice daily, s.c.) given concomitantly with the GH treatment, completely counteracted the inhibitory effect of the latter on pituitary content of GH and restored to normal the in-vivo GH response to the GHRH challenge. These data indicate that impaired secretion of GHRH is involved in the inhibitory effect elicited by GH treatment in infant rats. However, concomitant involvement of hypothalamic somatostatin as a result of GH treatment cannot be ruled out. In fact, pituitaries from rats pretreated with GH responded in the same manner as pituitaries from control rats to the GHRH challenge in vitro. Journal of Endocrinology (1990) 124, 199–205

Sulfated cholecystokinin octapeptide in the rat: pontomedullary distribution and modulation of the respiratory pattern

1999 ◽  
Vol 77 (7) ◽  
pp. 490-504 ◽  
Author(s):  
Howard H Ellenberger ◽  
Frank M Smith
Keyword(s):  
Respiratory Rhythm ◽  
Mean Amplitude ◽  
Neonatal Rat ◽  
Respiratory Pattern ◽  
Reticular Nucleus ◽  
Adult Rats ◽  
Cholecystokinin Octapeptide ◽  
Ventral Respiratory Group

We performed anatomical and physiological studies to determine the site and actions of sulfated cholecystokinin octapeptide (CCK8-S) on breathing. Peptide locations were determined by combined immunodetection of CCK8-S- containing synaptic varicosities and retrograde labeling of medullary neurons projecting to the ventral respiratory group. Retrogradely labeled neurons and CCK8-S immunolabeled varicosities overlapped within the nuclei of the solitary tract, ventral respiratory group, and the Kölliker-Fuse nucleus. Additional CCK8-S immunoreactive terminals were located in the rostroventrolateral medullary reticular nucleus, lateral paragigantocellular reticular nucleus, and the caudal pontine reticular nucleus. The respiratory effects of CCK8-S, which binds to CCKA and CCKB receptors, were examined by intravenous injection in adult rats and by bath application in the in vitro neonatal rat brainstem - spinal cord preparation. CCK8-S produced an increase in the mean amplitude of diaphragmatic electromyogram (EMG) of 28 ± 35% (SD) and a decrease in mean respiratory interval of 13 ± 4% in vivo. In vitro, CCK8-S significantly increased inspiratory duration and decreased respiratory interval, primarily by shortening expiratory duration. CCK8-unsulfated, a specific agonist for CCKB receptors, did not produce these effects. CCK8-S effects in the in vitro preparation were partially blocked by the CCK receptor antagonist lorglumide (final bath concentration 600 nM). These results suggest that CCK8-S modulates the respiratory rhythm via CCKA receptors within one or more medullary or pontine respiratory groups in both neonatal and adult rats.Key words: neuropeptide, ventral respiratory group, medulla, pons, respiratory network.

Neonatal seminal vesicle mesenchyme induces a new morphological and functional phenotype in the epithelia of adult ureter and ductus deferens

Development ◽  
1991 ◽  
Vol 111 (1) ◽  
pp. 145-158 ◽  
Author(s):  
G.R. Cunha ◽  
P. Young ◽  
S.J. Higgins ◽  
P.S. Cooke
Keyword(s):  
Epithelial Cells ◽  
Seminal Vesicle ◽  
Developmental Plasticity ◽  
Androgen Receptors ◽  
Seminal Vesicles ◽  
Neonatal Mouse ◽  
Secretory Proteins ◽  
Complete Spectrum ◽  
Ductus Deferens ◽  
Functional Phenotype

Mesenchyme from neonatal mouse and rat seminal vesicles (SVM) was grown in association with postnatal (adult) epithelial cells from the ureter (URE) and ductus deferens (DDE) in chimeric tissue recombinants composed of mouse mesenchyme and rat epithelium or vice versa. Functional cytodifferentiation was examined in these SVM + URE and SVM + DDE tissue recombinants with antibodies against major androgen-dependent seminal-vesicle-specific secretory proteins. Adult DDE and URE were induced to express seminal cytodifferentiation and produced the complete spectrum of major seminal vesicle secretory (SVS) proteins. The SVS proteins produced were specific for the species that provided the epithelium. In the case of SVM + URE recombinants, the URE, which normally lacks androgen receptors (AR), expressed AR. These results demonstrate that adult epithelial cells retain a developmental plasticity equivalent to their undifferentiated fetal counterparts and are capable of being reprogrammed to express a completely new morphological, biochemical and functional phenotype.

Electrophysiological properties of rat lateral parabrachial neurons in vitro

1999 ◽  
Vol 276 (3) ◽  
pp. R696-R706 ◽  
Author(s):  
Linda F. Hayward ◽  
Robert B. Felder
Keyword(s):  
Spatial Clustering ◽  
Distinct Type ◽  
Neonatal Rat ◽  
Intrinsic Properties ◽  
Adult Rats ◽  
Membrane Hyperpolarization ◽  
Electrophysiological Properties ◽  
Lateral Parabrachial Nucleus ◽  
A Current

Anatomical studies have demonstrated that the lateral parabrachial nucleus (LPBN) is composed of at least seven separate subnuclei distinguished by cell morphology, spatial clustering, and afferent and efferent connectivity. We hypothesized that neurons within the subnuclear clusters of the LPBN might have distinct electrophysiological properties that correlate with cellular morphology. An in vitro slice preparation was used to intracellularly record the intrinsic properties of 64 neurons located within the external lateral (EL) and central lateral (CL) subnuclei of the LPBN in adult rats. Analysis of intrinsic properties revealed that neurons in the EL subnucleus had significantly wider action potentials and on the average demonstrated more spike frequency adaptation during 2 s of depolarization compared with CL neurons. The majority of both EL and CL area neurons expressed delayed excitation (DE) after membrane hyperpolarization. DE was eliminated with the A-current blocker 4-aminopyridine (1.5–5 mM). Postinhibitory rebound was also observed in a subpopulation of EL and CL neurons. Morphological analysis of 11 LPBN neurons, which were electrophysiologically characterized and filled with 2% biocytin, failed to demonstrate an association between morphology and the electrophysiological profiles of LPBN neurons. The lack of distinct “type” of neuron within a single subnucleus of the LPBN is in agreement with recent findings reported from the neonatal rat.

scholarly journals Experimental and Modeling Studies of Novel Bursts Induced by Blocking Na+ Pump and Synaptic Inhibition in the Rat Spinal Cord

2002 ◽  
Vol 88 (2) ◽  
pp. 676-691 ◽  
Author(s):  
Aldo Rozzo ◽  
Laura Ballerini ◽  
Gilda Abbate ◽  
Andrea Nistri
Keyword(s):  
Spinal Cord ◽  
Time Course ◽  
Synaptic Depression ◽  
Neonatal Rat ◽  
Pump Operation ◽  
High K ◽  
Close Sequence ◽  
Activity Dependent ◽  
Dependent Processes

This study addressed some electrophysiological mechanisms enabling neonatal rat spinal networks in vitro to generate spontaneous rhythmicity. Networks, made up by excitatory connections only after block of GABAergic and glycinergic transmission, develop regular bursting (disinhibited bursts) suppressed by the Na+ pump blocker strophanthidin. Thus the Na+ pump is considered important to control bursts. This study, however, shows that, after about 1 h in strophanthidin solution, networks of the rat isolated spinal cord surprisingly resumed spontaneous bursting (“strophanthidin bursting”), which consisted of slow depolarizations with repeated oscillations. This pattern, recorded from lumbar ventral roots, was synchronous on both sides, of irregular periodicity, and lasted for ≥12 h. Assays of 86Rb+uptake by spinal tissue confirmed Na+ pump block by strophanthidin. The strophanthidin rhythm was abolished by glutamate receptor antagonists or tetrodotoxin, indicating its network origin. N-methyl-d-aspartate (NMDA), serotonin, or high K+ could not accelerate it. The size of each burst was linearly related to the length of the preceding pause. Bursts could also be generated by dorsal root electrical stimulation and possessed similar dependence on the preceding pause. Conversely, disinhibited bursts could be evoked at short intervals from the preceding one unless repeated pulses were applied in close sequence. These data suggest that rhythmicity expressed by excitatory spinal networks could be controlled by Na+ pump activity or slow synaptic depression. A model based on the differential time course of pump operation and synaptic depression could simulate disinhibited and strophanthidin bursting, indicating two fundamental, activity-dependent processes for regulating network discharge.

Ontogenesis of intestinal bile salt absorption in the neonatal rat

1980 ◽  
Vol 239 (4) ◽  
pp. G319-G323 ◽  
Author(s):  
J. M. Little ◽  
R. Lester
Keyword(s):  
Bile Salt ◽  
Steroid Treatment ◽  
Neonatal Rat ◽  
Metabolic Inhibitors ◽  
Ileal Mucosa ◽  
Adult Rats ◽  
Salt Absorption ◽  
Weanling Rats ◽  
Mucosal Uptake

In vitro uptake of taurocholate by weanling rat ileum was characterized. The neonatal development of the ileal mechanism was determined, and the effect of steroid treatment on this development was assessed. Mucosal uptake of taurocholate by ileum of 26-day-old and adult rats was linear with time and, when measured as a function of concentration, tended toward a plateau. Mucosal concentration of taurocholate was significantly reduced by metabolic inhibitors and was competitively inhibited by taurochenodeoxycholate. The capacity to concentrate taurocholate in ileal mucosa was undemonstrable in 12-day-old neonates, first appeared at 15 days, and reached adult levels by 26 days of age. Mucosal uptake of taurocholate by ileum of 12-day-old offspring of steroid-treated mothers or of 12-day-old neonates given dexamethasone directly was significantly increased over control values. The results indicate that the ileal bile salt absorption found in weanling rats is an active process that does not begin to develop in neonatal rats until 15 days after birth, and that the appearance of ileal active transport can be accelerated by maternal or neonatal steroid treatment.

Implantation increases tensile strength and collagen content of self-assembled tendon constructs

2010 ◽  
Vol 108 (4) ◽  
pp. 875-881 ◽  
Author(s):  
Sarah Calve ◽  
Ian F. Lytle ◽  
Karl Grosh ◽  
David L. Brown ◽  
Ellen M. Arruda
Keyword(s):  
Tensile Strength ◽  
Collagen Fiber ◽  
Fiber Diameter ◽  
Collagen Content ◽  
Neonatal Rat ◽  
Adult Rats ◽  
Autologous Cell ◽  
Lower Tensile Strength

Tissue-engineered tendons, derived from an autologous cell source, have the potential to provide an ideal replacement graft that is biologically compatible and has the ability to adapt to the specific mechanical requirements of the in vivo environment. Scaffold-free tendon constructs have been successfully engineered in vitro. However, when compared against native tendons the constructs demonstrate both a lower tensile strength and collagen content. We hypothesized that the in vitro environment lacks certain environmental stimuli and that implantation in vivo would facilitate the maturation of engineered tissues. Using primary Achilles tendon fibroblasts from adult rats, self-organizing constructs were created in vitro. Tendon constructs were implanted subcutaneously into the groins of adult rats for 4 wk, while controls remained in vitro. Implanted constructs increased in stiffness by three orders of magnitude when compared with the in vitro controls (7,500 vs. 22.3 kPa). This increase in tangent modulus correlated with a significant increase in collagen content, as measured by hydroxyproline concentration, from 3.9% for the in vitro controls to 22.7% in the in vivo conditioned group. In addition, collagen fiber diameter increased from 22.0 to 75.4 nm as a result of in vivo implantation. The tensile strength and collagen content of in vivo conditioned constructs were similar to the values determined for neonatal rat tibialis anterior tendons.

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