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Biomedical subjects

J E Stern

Publications and source records attributed to J E Stern.

At least 19 recordsLinked to original sources
PubMed2005

Expression of GABAB receptors in magnocellular neurosecretory cells of male, virgin female and lactating rats.

GABA is one of the key neurotransmitters that regulate the firing activity of neurones in the supraoptic (SON) and paraventricular (PVN) nuclei. In the present study, we used immunohistochemical techniques to study the distribution and subcellular localisation of metabotropic GABA(B) receptors in magnocellular neurones in the SON and PVN. Robust GABA(B) receptor immunoreactivity (GABA(B)R; both subunit 1 and subunit 2 of the heterodimer), was observed in the SON and PVN. At the light microcope level, GABA(B)R immonoreactivity displayed a clustered pattern localised both intracytoplasmically and at the plasma membrane. Densitometry analysis indicated that GABA(B)R immunoreactivity was significantly more intense in vasopressin cells than in oxytocin cells, both in male, virgin female and lactating rats, and was denser in males than in virgin females. Light and electron microscope studies indicated that cytoplasmic GABA(B)R was localised in various organelles, including the Golgi, early endosomes and lysosomes, suggesting the cycling of the receptor within the endocytic and trafficking pathways. Some smaller clusters at the level of the cell plasma membrane were apposed to glutamic acid decarboxylase 67 immunoreactive boutons, and appeared to be colocalised with gephyrin, a constituent protein of the postsynaptic density at inhibitory synapses. The presence of GABA(B)R immunoreactivity at synaptic and extrasynaptic sites was supported by electron microscopy. These results provide anatomical evidence for the expression of postsynaptic GABA(B) receptors in magnocellular neurosecretory cells.

Animals↗
PubMed2004

Activation of postsynaptic GABAB receptors modulate the firing activity of supraoptic oxytocin and vasopressin neurones: role of calcium channels.

Oxytocin and vasopressin release from neurohypophysial terminals is closely related to the firing activity of magnocellular neurones in the supraoptic (SON) and paraventricular nuclei. It is well established that activation of GABAA receptors potently inhibits the activity of SON neurones and, thus, hormone release. However, whether postsynaptic GABAB receptors are expressed in magnocellular neurones, and the role they play in controlling their firing activity, is still controversial. In the present work, we combined immunohistochemical and electrophysiological techniques to determine whether activation of GABAB receptors in identified oxytocin and vasopressin neurones modulates their firing activity. Patch-clamp recordings from SON neurones were obtained either in the slice preparation or from acutely dissociated neurones. Activation of GABAB receptors with the selective agonist baclofen (10 micro m) inhibited voltage-gated Ca2+ currents, reduced the duration of individual action potentials, as well as the magnitude of the hyperpolarizing after-potential. SON firing activity was reduced by baclofen, and effect that was accompanied by a small membrane hyperpolarization. The inhibition of firing discharge persisted in the presence of synaptic blockade media, and was also observed in acutely dissociated SON neurones. Finally, GABAB-mediated modulation of firing activity was largely blocked by the Ca2+ channel blocker Co2+ (2 mm). In general, baclofen modulatory actions were significantly larger, or observed more predominantly, in vasopressin neurones. In summary, these results support the expression of functional postsynaptic GABAB receptors in SON neurones, activation of which efficiently modulates neuronal excitability, in a Ca2+- and cell-type dependent manner.

Action Potentials↗
PubMed2003

Preautonomic neurons in the paraventricular nucleus of the hypothalamus contain estrogen receptor beta.

Central actions of estrogen (E2) include, among others, modulation of autonomic and cardiovascular function. Despite the well-known influence of sex steroid hormones on the incidence of cardiovascular disorders, little is known about the neural substrates and receptors mediating central E2 actions on autonomic function. The paraventricular nucleus of the hypothalamus (PVN) is an important site for the integration of neuroendocrine and autonomic function. Interestingly, while this region was originally found to lack the classical ERalpha receptor, recent studies demonstrated a high degree of expression of the ERbeta subtype. To determine specifically whether autonomic-related neurons in the PVN express ERbeta, thus constituting a neuronal substrate for central E2 actions on autonomic function, we carried out an immunohistochemical study of ERbeta expression in a subpopulation of PVN neurons that innervate the rostroventrolateral medulla (RVLM). ERbeta immunostained neurons were found in medial and caudal aspects of the PVN, overlapping with the distribution of RVLM-projecting neurons. Overall, approximately 50% of RVLM-projecting PVN neurons expressed ERbeta immunoreactivity. Interestingly, the degree of colocalization was found to be sex-dependent (higher expression in males), and varied according to the topographical distribution of neurons within the PVN. ERbeta immunoreactivity was also observed in magnocellular compartments of the PVN, although this appeared to be consistently weaker than that observed in autonomic-related subnuclei. These studies demonstrate for the first time ERbeta expression in identified autonomic-related neurons in the PVN, and suggest that these neurons constitute an important neuronal substrate mediating E2 actions on autonomic and cardiovascular control.

Animals↗
PubMed2003

Nitric oxide inhibits the firing activity of hypothalamic paraventricular neurons that innervate the medulla oblongata: role of GABA.

Nitric oxide (NO) has been shown to modulate autonomic function by acting both peripherally and centrally. A growing body of evidence indicates that the paraventricular nucleus of the hypothalamus (PVN), an important site for autonomic and endocrine homeostasis, constitutes an important locus mediating central NO actions. However, the cellular targets and mechanisms mediating NO actions within the PVN are not completely understood. Here, we examined whether NO influences the firing activity of identified PVN neurons that innervate two functionally different autonomic centers, the dorsal vagal complex (DVC) and the rostral ventrolateral medulla (RVLM). Perforated patch-clamp recordings were performed in hypothalamic slices containing retrogradely labeled PVN neurons innervating the DVC or the RVLM. Application of the NO donors dyethylamine- or 1-propanamine, 3-(2-hydroxy-2-nitroso-1-propylhydrazino) NONOate inhibited the firing activity of both DVC- and RVLM-projecting PVN neurons. Furthermore, application of 2-(4-carboxypheny)-4,4,5,5,-tetramethilimidazoline-1-oxyl-3-oxide (carboxy-PTIO), or the relatively selective neuronal nitric oxide synthase (nNOS) inhibitor 7-nitroindazole alone, increased their basal firing activity, suggesting the presence of an endogenous NO inhibitory tone. GABAergic synaptic activity in PVN neurons was potentiated by NO donors, an action that involved a presynaptic mechanism. Furthermore, the NO-mediated inhibition of firing activity was blocked by the GABA(A) receptor antagonist bicuculline, suggesting that NO-inhibitory actions involved potentiation of local GABAergic synaptic activity. Immunohistochemical studies showed that approximately 25% of DVC- and RVLM-projecting PVN neurons express nNOS, suggesting that a proportion of these medullary-projecting PVN neurons contribute to the cellular source of NO within the PVN. In summary, NO has been identified as an important molecule controlling autonomic function under physiological and pathological conditions. Here, we provide information on the cellular mechanisms mediating central NO actions. Our results demonstrate for the first time that NO modulates the activity of identified populations of PVN neurons that innervate the medulla oblongata, an action that is likely mediated by enhancing synaptic GABAergic function. This work suggests that NO-GABA interaction in PVN neurons that innervate the medulla constitutes an efficient cellular mechanism mediating NO central regulation of autonomic function.

Action Potentials↗
PubMed2003

Nitric oxide: a local signalling molecule controlling the activity of pre-autonomic neurones in the paraventricular nucleus of the hypothalamus.

AIM: The gas molecule nitric oxide (NO) has been shown to modulate autonomic function by acting both peripherally and centrally. Accumulating evidence indicates that the paraventricular nucleus (PVN) of the hypothalamus is an important locus mediating central NO actions on autonomic function, under both physiological and pathological conditions. However, the cellular targets and mechanisms mediating NO actions within the PVN are still poorly understood. RESULTS: By combining in vitro patch-clamp recordings with neuronal tract tracing techniques, we show that neuronal excitability of autonomic-related neurones in the PVN is tonically inhibited by an endogenous NO input. Furthermore, immunohistochemical studies show that approximately 25% of autonomic-related PVN neurones express neuronal nitric oxide synthase, suggesting that at least a proportion of them contribute to the cellular sources of NO within the PVN. CONCLUSION: In summary, this work suggests that NO modulation of the firing activity of autonomic-related PVN neurones constitutes an efficient mechanism mediated central NO regulation of autonomic function.

Action Potentials↗
PubMed2003

Determining access to assisted reproductive technology: reactions of clinic directors to ethically complex case scenarios.

BACKGROUND: Our aim was to increase understanding of how patient selection is handled by assisted reproductive technology (ART) clinicians. METHODS: Ethically complex case scenarios were evaluated by the directors of USA ART clinics. Scenarios included using a son as sperm donor for his father, sex selection without associated disease, treatment of morally irresponsible couples, and a dispute over embryo disposition. Respondents reviewed eight scenarios and gave their opinions on whether to offer treatment. Reasons given for these decisions were placed into one of 13 categories. RESULTS: Survey response rate was 57%. Between 3 and 50% of respondents would treat in each case. Of reasons given, 'conditional' responses (requiring counselling, blood tests or agreement to other 'conditions') were common (31.4%). Non-maleficence (risk) accounted for 29.4% of responses, philosophy of medicine 18.9%, respect for patient autonomy 5.9% and legal concerns 4.6%. Discrimination and threats were each significant in one case. Reasons evoking absolutist beliefs, personal discomfort, commitment to justice, religion and ethical relativism were rare. CONCLUSIONS: Clinicians felt conflict between a desire to respect patient autonomy and their discomfort over the risk associated with the procedure. They raised concerns about misuse of medical technology. Attempts to resolve complex issues through negotiation and compromise were common.

Abortion, Induced↗
PubMed2001

Electrophysiological and morphological properties of pre-autonomic neurones in the rat hypothalamic paraventricular nucleus.

1. The cellular properties of pre-autonomic neurones in the hypothalamic paraventricular nucleus (PVN) were characterized by combining in vivo retrograde tracing techniques, in vitro patch-clamp recordings and three-dimensional reconstruction of recorded neurones in adult hypothalamic slices. 2. The results showed that PVN pre-autonomic neurones constitute a heterogeneous neuronal population. Based on morphological criteria, neurones were classified into three subgroups. Type A neurones (52 %) were located in the ventral parvocellular (PaV) subnucleus, and showed an oblique orientation with respect to the third ventricle (3V). Type B neurones (25 %) were located in the posterior parvocellular (PaPo) subnucleus, and were oriented perpendicularly with respect to the 3V. Type C neurones (23 %) were located in both the PaPo (82 %) and the PaV (18 %) subnuclei, and displayed a concentric dendritic configuration. 3. A morphometric analysis revealed significant differences in the dendritic configuration among neuronal types. Type B neurones had the most complex dendritic arborization, with longer and more branching dendritic trees. 4. Several electrophysiological properties, including cell input resistance and action potential waveforms, differed between cell types, suggesting that the expression and/or properties of a variety of ion channels differ between neuronal types. 5. Common features of PVN pre-autonomic neurones included the expression of a low-threshold spike and strong inward rectification. These properties distinguished them from neighbouring magnocellular vasopressin neurones. 6. In summary, these results indicate that PVN pre-autonomic neurones constitute a heterogeneous neuronal population, and provide a cellular basis for the study of their involvement in the pathophysiology of hypertension and congestive heart failure disorders.

Action Potentials↗
PubMed2001

Access to services at assisted reproductive technology clinics: a survey of policies and practices.

OBJECTIVE: Our goal was to investigate policy on patient access to services at assisted reproductive technology clinics in the United States. STUDY DESIGN: Surveys asked about a variety of ethically and socially challenging cases and were mailed to directors of all Society for Assisted Reproductive Technology-associated assisted reproductive technology clinics. RESULTS: Written policies on access to services are present at 40% of assisted reproductive technology clinics. Universal agreement was not found on any issue; 79% of clinics treat single women, 27% treat patients with a history of schizophrenia, 10% treat patients who use alcohol excessively, 7% treat human immunodeficiency virus-positive women, and 2% would treat patients previously convicted of child abuse. A breakdown of the responses indicated that some clinics are more permissive in terms of access to services than others, whereas some are more restrictive. CONCLUSIONS: The data demonstrate considerable variability in policy among clinics on most access-to-services questions. The results highlight the importance of ongoing discussion of the ethical and legal issues related to access and the need to develop consistent methods to deal with complex cases.

Alcoholism↗
PubMed2001

NO inhibits supraoptic oxytocin and vasopressin neurons via activation of GABAergic synaptic inputs.

To study modulatory actions of nitric oxide (NO) on GABAergic synaptic activity in hypothalamic magnocellular neurons in the supraoptic nucleus (SON), in vitro and in vivo electrophysiological recordings were obtained from identified oxytocin and vasopressin neurons. Whole cell patch-clamp recordings were obtained in vitro from immunochemically identified oxytocin and vasopressin neurons. GABAergic synaptic activity was assessed in vitro by measuring GABA(A) miniature inhibitory postsynaptic currents (mIPSCs). The NO donor and precursor sodium nitroprusside (SNP) and L-arginine, respectively, increased the frequency and amplitude of GABA(A) mIPSCs in both cell types (P < or = 0.001). Retrodialysis of SNP (50 mM) onto the SON in vivo inhibited the activity of both neuronal types (P < or = 0.002), an effect that was reduced by retrodialysis of the GABA(A)-receptor antagonist bicuculline (2 mM, P < or = 0.001). Neurons activated by intravenous infusion of 2 M NaCl were still strongly inhibited by SNP. These results suggest that NO inhibition of neuronal excitability in oxytocin and vasopressin neurons involves pre- and postsynaptic potentiation of GABAergic synaptic activity in the SON.

Animals↗
PubMed2000

Enhanced neurotransmitter release at glutamatergic synapses on oxytocin neurones during lactation in the rat.

The increased release of oxytocin during lactation has been shown to be dependent upon glutamatergic transmission and is associated with an increased synaptic innervation of the supraoptic nucleus (SON). To determine whether the glutamatergic synaptic properties of oxytocin neurones are changed during lactation, we recorded excitatory postsynaptic currents (EPSCs) from identified oxytocin neurones in the SON of slices taken from adult virgin and lactating rats. The frequency of AMPA-mediated miniature EPSCs (mEPSCs) more than doubled during lactation. In addition, the decay time constant, but not the amplitude of the mEPSCs was significantly increased in both vasopressin and oxytocin neurones. Paired-pulse facilitation (PPF) was significantly reduced in oxytocin neurones during lactation, whereas no change was observed in vasopressin neurones. Elevating Ca(2+) reduced PPF in oxytocin neurones in virgin rats but did not alter PPF in oxytocin neurones from lactating rats. Collectively, our results suggest that excitatory glutamatergic transmission is strengthened in oxytocin neurones during lactation, probably by a combination of an increased number of terminals, slower decay kinetics, and an increase in the probability of release.

Animals↗
PubMed1999

Differences in the properties of ionotropic glutamate synaptic currents in oxytocin and vasopressin neuroendocrine neurons.

Oxytocin (OT) and vasopressin (VP) hormone release from neurohypophysial terminals is controlled by the firing pattern of neurosecretory cells located in the hypothalamic supraoptic (SON) and paraventricular nuclei. Although glutamate is a key modulator of the electrical activity of both OT and VP neurons, a differential contribution of AMPA receptors (AMPARs) and NMDA receptors (NMDARs) has been proposed to mediate glutamatergic influences on these neurons. In the present study we examined the distribution and functional properties of synaptic currents mediated by AMPARs and NMDARs in immunoidentified SON neurons. Our results suggest that the properties of AMPA-mediated currents in SON neurons are controlled in a cell type-specific manner. OT neurons displayed AMPA-mediated miniature EPSCs (mEPSCs) with larger amplitude and faster decay kinetics than VP neurons. Furthermore, a peak-scaled nonstationary noise analysis of mEPSCs revealed a larger estimated single-channel conductance of AMPARs expressed in OT neurons. High-frequency summation of AMPA-mediated excitatory postsynaptic potentials was smaller in OT neurons. In both cell types, AMPA-mediated synaptic currents showed inward rectification, which was more pronounced in OT neurons, and displayed Ca2+ permeability. On the other hand, NMDA-mediated mEPSCs of both cell types had similar amplitude and kinetic properties. The cell type-specific expression of functionally different AMPARs can contribute to the adoption of different firing patterns by these neuroendocrine neurons in response to physiological stimuli.

Animals↗
PubMed1998

Reorganization of the dendritic trees of oxytocin and vasopressin neurons of the rat supraoptic nucleus during lactation.

Oxytocin (OT) and vasopressin (VP) release from the neurohypophysis are correlated with the electrical activity of magnocellular cells (MNCs) in the supraoptic (SON) and paraventricular nuclei. Synaptic inputs to MNCs influence their electrical activity and, hence, hormone release. During lactation OT neurons display a synchronized high-frequency bursting activity preceding each milk ejection. In parallel to the adoption of this pattern of electrical activity, an ultrastructural reorganization of the SON has been observed during lactation. In the present study we performed a light microscopic, morphometric analysis of identified OT and VP neurons in the SON to determine whether the dendrites of these neurons participate in the plasticity observed during lactation. The dendritic trees of OT neurons shrunk during lactation ( approximately 41% decrease in the total dendritic length) because of a decreased dendritic branching concentrated at a distance of 100-200 microm from the soma. No changes in the maximal distal extension were observed. The distribution pattern of dendritic length into branch orders also was affected. Strikingly, opposite effects were observed in VP neurons. The dendritic trees during lactation elongated ( approximately 48% increase in the total dendritic length) because of an increased branching close to the soma. No changes in the maximal distal extension were observed. These results indicate that the length and geometry of the dendritic trees of OT and VP neurons are altered in opposite ways during lactation. These changes would influence the availability of postsynaptic space and alter the electrotonic properties of the neurons, affecting the efficacy of synaptic inputs.

Animals↗
PubMed1998

Electrophysiological distinctions between oxytocin and vasopressin neurons in the supraoptic nucleus.

Oxytocin and vasopressin neurons can be differentiated from one another, and from neurons in the immediately adjacent perinuclear zone, by their electrophysiological properties. In both sexes, oxytocin and vasopressin neurons are characterized by a prominent transient outward rectification which is conspicuously lacking in most perinuclear neurons. In addition, perinuclear neurons, some of which project to the supraoptic nucleus, exhibit a transient depolarization which underlies short bursts of spikes. Oxytocin neurons are characterized by: 1) the presence of a sustained outward rectifier above -50 mV, active below spike threshold; 2) a rebound depolarization following deactivation of the sustained rectification which can sustain short spike trains; and 3) a smaller transient outward rectification, probably associated with the potassium current, Ia. Vasopressin neurons show little of the sustained outward rectification and rebound depolarization, but have a stronger transient outward rectification. Although both cell types exhibit depolarizing afterpotentials, in vasopressin neurons these lead to plateau potentials underlying prolonged discharges. In oxytocin neurons, the depolarizing potential usually sustains a short spike discharge, but less often leads to prolonged bursts. These data suggest that the intrinsic properties of oxytocin and vasopressin neurons lead to quantitatively different forms of burst discharges, both of which may facilitate hormone release.

Animals↗
PubMed1998

Leukocytes in the cervix: a quantitative evaluation of cervicitis.

OBJECTIVE: To quantify the numbers of leukocytes in the normal cervix and relate these numbers to the diagnosis of cervicitis. METHODS: Isolated cell suspensions were prepared from cervical tissue recovered at hysterectomy from 37 women who had no obvious cervical disease. The percentages of CD45+ cells (leukocytes) in these preparations were determined using immunofluorescence-based flow cytometric analysis. These percentages were compared with the pathologist's assessment of cervicitis. RESULTS: Leukocytes were present in all cervical samples tested. For endocervical samples, the mean (+/- standard error of the mean [SEM]) percentage of CD45+ cells was 12.4 +/- 1.9% of cells in patients with a diagnosis of cervicitis (n = 16) and 9.1 +/- 1.1% in patients without cervicitis (n = 17). For ectocervical samples, the mean (+/- SEM) percentage was 14.8 +/- 3.0% in those with cervicitis (n = 16) and 9.5 +/- 1.6% in those without cervicitis (n = 19). The differences between samples from patients with cervicitis and those without cervicitis were not statistically significant at the .05 level. Intra- and interassay variabilities were 5.7 +/- 1.2% and 7.3 +/- 1.6%, respectively. CONCLUSION: Our study demonstrates there is a resident population of leukocytes in the cervix. Leukocyte number did not relate clearly and consistently to the diagnosis of cervicitis made by the pathologist. We suggest that the resident population of leukocytes, in the absence of other indicators of infection, may confuse determinations of cervicitis.

Cell Count↗
PubMed1998

Phenotypic and state-dependent expression of the electrical and morphological properties of oxytocin and vasopressin neurones.

Oxytocin and vasopressin secreting neurones of the hypothalamic supraoptic nucleus share many membrane characteristics and a roughly similar morphology. However, these two neurone types differ in the relative expression of some intrinsic and synaptic currents, and in the extent of their respective dendritic arbors. Spike depolarizing afterpotentials are present in both types, but more frequently give rise to prolonged burst discharges in vasopressin neurones. Oxytocin, but not vasopressin neurones, are characterized by a depolarization-activated, sustained outward rectifier which turns on near spike threshold, and which can produce prolonged spike frequency adaptation. When this sustained current is deactivated by small hyperpolarizing pulses, a rebound depolarization sufficient to evoke short spike trains follows the offset of these pulses. Both oxytocin and vasopressin neurones exhibit a transient outward rectification underlain by an Ia-type current. This transient rectifier delays spiking to depolarizing stimuli from a relatively hyperpolarized baseline, and is more prominent in vasopressin neurones. As a result, oxytocin neurones may be more reactive to depolarizing inputs. Both cell types receive glutamatergic, excitatory synaptic inputs and both possess R,S- alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptor subtypes. The AMPA receptor channel on both cell types is characterized by a relatively high calcium permeability and voltage-dependent rectification, characteristic of a diminished presence of the GluR2 AMPA subunit. However, AMPA-mediated synaptic transients are larger, and decay faster, in oxytocin compared with vasopressin neurones, suggesting a potential difference for synaptic integration. The characteristics of NMDA-mediated synaptic transients are similar in oxytocin and vasopressin neurones, but some data suggest NMDA receptors may be less involved in the glutamatergic activation of oxytocin neurones. In both cell types, synaptic release of glutamate often coactivates AMPA and NMDA receptors. The dendritic morphology of oxytocin and vasopressin neurones in female rats differs from one another and exhibits considerable plasticity as a function of endocrine state. In virgin rats, oxytocin neurones have more dendritic branches and a greater total dendritic length compared with lactation, when the arbor is much less extensive. A complementary change occurs in vasopressin dendrites, which are more extensive during lactation. This reorganization suggests that oxytocin neurones may be more electronically compact during lactation. In addition, such dramatic shifts in overall dendritic length imply that significant gains and losses in either the total number of synapses, or in synaptic density, are incurred by both cell types as a function of reproductive state.

Action Potentials↗
PubMed1998

Regulation by human uterine cells of PBMC proliferation: influence of the phase of the menstrual cycle and menopause.

To determine the influence of human uterine cells recovered at different stages of the menstrual cycle and following menopause on the proliferation of peripheral blood mononuclear cells (PBMC), whole cell suspensions of uterine tissues were co-cultured with autologous and heterologous PBMC. PBMC proliferation in response to tetanus toxoid (TT) or Con A was inhibited by uterine endometrial cells and was dependent on the phase of the menstrual cycle. Inhibition by cells from the proliferative phase was significantly greater than by cells from the secretory phase. Uterine cells isolated from post-menopausal women also inhibited proliferation of PBMC. Cell fractionation studies indicated that epithelial cells are the primary source of uterine inhibitory activity. When epithelial cells and PBMC were cultured in separate compartments, epithelial cells released a soluble factor(s) that inhibited the PBMC proliferation. These results suggest that uterine epithelial cells produce cytokines that down-regulate the proliferation of PBMC in response to antigens and mitogens. This may be important for the control of uterine immune responses, as well as the growth of the reproductive tract in preparation for implantation during the secretory phase of the menstrual cycle.

Adult↗
PubMed1998

Secretory component production by polarized epithelial cells from the human female reproductive tract.

At mucosal surfaces, the polymeric Ig receptor (pIgR) is responsible for transporting polymeric IgA across epithelial cells. The purpose of this study was to determine whether normal epithelial cells from the female reproductive tract form tight junctions and produce secretory component, the external domain of the pIgR. Uterine, cervical and vaginal tissues from women at different stages of the menstrual cycle and following menopause were used to prepare purified epithelial cell sheets, which were cultured in cell chambers. Transepithelial resistance was measured and the media from apical and basolateral compartments assayed for secretory component. Secretory component produced by uterine epithelial cells accumulated preferentially in apical compartment and correlated with increased transepithelial resistance. Seeding as epithelial sheets at 1 x 10(6) cells/cm2 of matrix coated cell chambers was required for growth. Epithelial cells from endo-cervix and ecto-cervix, but not the vagina, also showed preferential production and release of secretory component into the apical chamber. In conclusion, normal epithelial cells from the human female reproductive tract grow to confluence, become polarized and produce secretory component. Our results suggest that uterine and cervical epithelial cells play a key regulatory role in the control of IgA transcytosis from tissue into secretions.

Cell Polarity↗