ABSTRACT
The second GnRH form, originally identified in chickens (cGnRH-II or GnRH-II), is the most ubiquitous peptide of the GnRH neuropeptide family, being present from jawed fish to human beings. However, the presence of GnRH-II in such an important experimental model as the rat is still an object of discussion. Here we present chromatographic, immunologic and biologic activity evidence supporting the expression of GnRH-II in the rat. Olfactory bulb, hypothalamus, remnant brain and anterior pituitary from a pool of 50 female adult rats were extracted and subjected to RP-HPLC on a C-18 column. The fractions were collected and evaluated by using two different RIA systems, specific for GnRH-I and GnRH-II respectively. Under these conditions the GnRH-I standard eluted in fraction 21 (f21) was only detected with the GnRH-I RIA system, whereas the GnRH-II standard was only detected in the fraction 27 (f27) by using a GnRH-II RIA system. In the olfactory bulbs extract, the fractions analyzed by the GnRH-I RIA systems showed a single peak in f21, whereas by using the GnRH-II RIA system a single peak at f27 was observed. In the hypothalamus GnRH-I was detected in f21 meanwhile GnRH-II could not be detected. When the remnant brain and pituitary gland extracts were analyzed, both GnRH forms were detected. To the best of our knowledge, this is the first report concerning GnRH-II detection in a mammalian pituitary. Serial dilutions of f27 and GnRH-II presented similar displacement of radioiodinated-GnRH-II, demonstrating that both molecules share immunological properties. Moreover, after 60 min stimulation, both f27 and GnRH-II had similar LH and FSH releasing activity in 12 day-old rat pituitary primary cell cultures. However, we failed to characterize the GnRH-II gene in this model. These results provide strong evidence for the expression of GnRH-II in the rat brain and pituitary gland.
Subject(s)
Brain/metabolism , Gene Expression Regulation , Gonadotropin-Releasing Hormone/analogs & derivatives , Gonadotropin-Releasing Hormone/biosynthesis , Pituitary Gland/metabolism , Animals , Chromatography, High Pressure Liquid , Conserved Sequence , Female , Follicle Stimulating Hormone , Gonadotropin-Releasing Hormone/chemistry , Humans , Luteinizing Hormone/metabolism , Models, Genetic , Radioimmunoassay , Rats , Rats, Sprague-DawleyABSTRACT
GnRH has been suggested to participate in corpus luteum function. Here we studied the expression of GnRH mRNA and peptide in two models of rat luteinized tissues: ovarian cells from PMSG-hCG treated prepubertal rats (SPO) and from intrasplenic ovarian tumors (Luteoma). A GnRH autoregulatory effect was evaluated as well as its action on cell proliferation and apoptosis. GnRH mRNA was present in SPO, isolated corpora lutea from SPO and Luteoma from 1 week to 7 months of development. In vitro cultures of Luteoma cells expressed 2-fold higher GnRH mRNA and 10-fold higher GnRH peptide than SPO cells. Buserelin (GnRH analog) increased GnRH mRNA and peptide expression in SPO but not in Luteoma cells. While basal proliferation was very low in Luteoma cells, SPO cells showed a significant increase in cell number by both the thymidine and the MTS methods after 72 h in culture. Buserelin induced a decrease in cell number in both cell types to a similar degree. Although basal apoptosis levels were higher in SPO than in Luteoma cells, Buserelin-induced apoptosis was only detected in Luteoma cells after 48 h treatment. These results show that the two types of rat, luteinized tissues, Luteoma and SPO, markedly differed in some intrinsic properties and in their local GnRH systems. Luteoma cells proliferate very weakly, express and secrete high amounts of GnRH, do not show an autoregulatory effect and respond to the decapeptide with apoptosis stimulation. In contrast SPO cells proliferate significantly, secrete low levels of GnRH but possess a positive, autoregulatory mechanism and respond to GnRH stimulation with impairment of proliferation.
Subject(s)
Apoptosis/physiology , Cell Proliferation , Gonadotropin-Releasing Hormone/biosynthesis , Homeostasis , Ovary/metabolism , Animals , Cell Culture Techniques , Female , Luteinization , Luteoma/metabolism , Luteoma/pathology , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology , Ovary/cytology , Ovary/pathology , RNA, Messenger/analysis , Rats , Rats, Sprague-Dawley , Tumor Cells, CulturedABSTRACT
PURPOSE: Because of increasing interest in G protein regulation of cell growth, differentiation and oncogenesis, we studied the functionality and expression of different G protein subunits in human prostate adenocarcinoma. MATERIALS AND METHODS: Surgical prostate specimens from control patients with bladder cancer and patients with prostate cancer were used. The functionality of alphas and alphai G protein subunits was evaluated by studying somatostatin or guanyl-5'-yl-imidotriphosphate regulation of forskolin stimulated adenylyl cyclase activity. The expression of alphas, alphai and beta subunits was studied by reverse transcriptase-polymerase chain reaction and immunoblot analysis. RESULTS: Adenylyl cyclase sensitivity to somatostatin inhibition decreased in prostate cancer. Low guanyl-5'-yl-imidotriphosphate doses inhibited forskolin stimulated adenylyl cyclase, whereas the opposite was true at high concentrations, evidencing the functionality of alphai and alphas, respectively, in normal and cancer tissue samples. Reverse transcriptase-polymerase chain reaction revealed RNA encoding for alphas and alphai1,2,3 subclasses in normal and pathological conditions. However, immunoblot analysis showed that the level of beta subunits was maintained, whereas that of alphas and alphai subunits decreased 30% to 40% after neoplastic transformation. The levels of alphas and alphai1,2 subunits correlated inversely with serum prostate specific antigen in patients with prostate cancer. CONCLUSIONS: The functionality and expression of G protein subunits are selectively modified in human prostate adenocarcinoma. Low alphas and alphai levels in prostate cancer suggest an important regulatory role of G proteins for cell proliferation and neoplastic transformation in the human prostate and they may have prognostic value.
Subject(s)
Adenocarcinoma/metabolism , GTP-Binding Proteins/biosynthesis , Prostatic Neoplasms/metabolism , Aged , Humans , Male , Middle Aged , Urinary Bladder Neoplasms/metabolismABSTRACT
BACKGROUND: Tadenan (a Pygeum africanum extract) is a drug used in the treatment of benign prostatic hyperplasia. Its effects on prostate fibroblast proliferation and bladder function after partial outlet obstruction have been demonstrated in various pharmacological studies. However, its effects at the molecular level are poorly documented. METHODS: Tadenan was dissolved in peanut oil. Rats were orally given two daily doses of the drug (1 or 10 mg/kg b.w.) for 4 days. Vasoactive intestinal peptide (VIP) binding, adenylyl cyclase stimulation, and expression of G-protein subunits were studied in rat prostatic membranes by established procedures. RESULTS: Tadenan treatment of castrated/testosterone-replaced rats was performed in order to interfere with prostatic cell proliferation. This experimental approach resulted in increases of: 1) VIP effect on adenylyl cyclase stimulation through alpha(s) G-subunit; 2) alpha(i) activation by low Gpp[NH]p doses (in the presence of forskolin); and 3) alpha(s), alpha(i1/2), and alpha(i3/0) levels. However, there were no modifications in membranes from quiescent, nonproliferating prostates (untreated rats). CONCLUSIONS: The observed regulatory role of Tadenan on various prostatic components of the adenylyl cyclase system, together with previous findings on protein kinase C-mediated signal transduction, open a complex array of possibilities of direct actions of this phytotherapeutic agent in the prostate.
Subject(s)
Adenylyl Cyclases/drug effects , Fatty Alcohols/pharmacology , GTP-Binding Proteins/drug effects , Growth Inhibitors/pharmacology , Prostate/drug effects , Receptors, Vasoactive Intestinal Peptide/drug effects , Adenylyl Cyclases/metabolism , Administration, Oral , Animals , Cell Division , GTP-Binding Proteins/physiology , Male , Plant Extracts , Prostate/enzymology , Prostate/pathology , Rats , Rats, Wistar , Receptors, Vasoactive Intestinal Peptide/physiologyABSTRACT
The diaphragmatic eventration will be congenital or acquired; the damage to the phrenic nerve its for elongenest, cruch, gun ball or iatrogenic; this last one could be during cardiac surgery, birth trauma, venodissection and colocation of one thorax drill. We presented the case of one premature newborn of 32 weeks with 1374g of weight, with respiratory distress syndrome which evolutioned to bilateral pneumothorax and posteriorly left diaphragmatic eventration secondary to a phrenic nerve damage by the thorax drill which one reach to mediastinum. The diagnosis of these entity will suspect by abnormal elevation of the affected hemidiaphragm and confirmed by fluoroscopy. The treatment its a early diaphragmatic pleat.
Subject(s)
Hernia, Diaphragmatic/etiology , Phrenic Nerve/physiopathology , Respiratory Distress Syndrome, Newborn/complications , Hernia, Diaphragmatic/diagnostic imaging , Hernia, Diaphragmatic/therapy , Humans , Infant, Newborn , Male , Radiography, ThoracicABSTRACT
Seventeen VTIM pacers were implanted in seventeen patients. Average follow up were 16.7 months. This paper concerns TX track and TX on modes only. Sensing window period and slope, which determine the rate response, must be programmed carefully. Potential competitive rhythms, severe ventricular arrhythmias or inadequate rate response to physical stress may potentially develop under inadequate programming. Consequently, it is advisable to program the sensing window 20-25 ms longer than the QTE max (at LRL) and the slope at 100% of the whole value. No complications were detected. Figures 1, 2 and 3 show examples of competitive rhythms without heart stimulation and unsensed beats by abnormally long programmed SW values. When properly shortened, this interval allows proper measurement of the Stim.-T and no competitive rhythm, during almost the same spontaneous rhythm. This system fulfills the major conditions for pacing the heart: rate adaptation to neurohormonal release, to physical stress and operative mode as a close-loop system during the recovery period.
Subject(s)
Adaptation, Physiological , Cardiac Pacing, Artificial/methods , Electric Stimulation/methods , Heart Rate , Arrhythmias, Cardiac/etiology , Electrocardiography , Exercise Test , HumansABSTRACT
Seventeen VTIM pacers were implanted in seventeen patients. Average follow up were 16.7 months. This paper concerns TX track and TX on modes only. Sensing window period and slope, which determine the rate response, must be programmed carefully. Potential competitive rhythms, severe ventricular arrhythmias or inadequate rate response to physical stress may potentially develop under inadequate programming. Consequently, it is advisable to program the sensing window 20-25 ms longer than the QTE max (at LRL) and the slope at 100
of the whole value. No complications were detected. Figures 1, 2 and 3 show examples of competitive rhythms without heart stimulation and unsensed beats by abnormally long programmed SW values. When properly shortened, this interval allows proper measurement of the Stim.-T and no competitive rhythm, during almost the same spontaneous rhythm. This system fulfills the major conditions for pacing the heart: rate adaptation to neurohormonal release, to physical stress and operative mode as a close-loop system during the recovery period.
ABSTRACT
En 17 pacientes se implantaron 17 marcapasos con ajuste automático de la frecuencia (VTIM). El promedio de observación fue de 16,7 meses. La programación del período de detección del QTE (SW) y de la pendiente de respuesta debe ser cuidadaosa para evital ritmos competitivos, potenciales arritmias ventriculares e inapropiada adecuación al esfuerzo físico. En consecuencia, se aconseja para los modos operativos TX on y TX track de este sistema, la adición de 20-25 ms al QTE máximo y el valor de la pendiente programarla al 100% del valor obtenido. El presente trabajo se refiere exclusivamente a ambos modos de programación de este tipo de marcapasos. No se detectaron complicaciones. Este sistema posee adecuada asaptación de la frecuencia de marcapaseo a las descargas neurohormonales y a las necesidades metabólicas y permite un retorno fisiológico a la situación de reposo post-stress físico acorde con la magnitud del esfuerzo, edad, sexo y patología subyacente conformando una suerte de retroalimentación biológica en este período (AU)
Subject(s)
Humans , Cardiac Pacing, Artificial/methods , Electric Stimulation/methods , Heart Rate , Adaptation, Physiological , Exercise Test , Electrocardiography , Arrhythmias, Cardiac/etiologyABSTRACT
En 17 pacientes se implantaron 17 marcapasos con ajuste automático de la frecuencia (VTIM). El promedio de observación fue de 16,7 meses. La programación del período de detección del QTE (SW) y de la pendiente de respuesta debe ser cuidadaosa para evital ritmos competitivos, potenciales arritmias ventriculares e inapropiada adecuación al esfuerzo físico. En consecuencia, se aconseja para los modos operativos TX on y TX track de este sistema, la adición de 20-25 ms al QTE máximo y el valor de la pendiente programarla al 100% del valor obtenido. El presente trabajo se refiere exclusivamente a ambos modos de programación de este tipo de marcapasos. No se detectaron complicaciones. Este sistema posee adecuada asaptación de la frecuencia de marcapaseo a las descargas neurohormonales y a las necesidades metabólicas y permite un retorno fisiológico a la situación de reposo post-stress físico acorde con la magnitud del esfuerzo, edad, sexo y patología subyacente conformando una suerte de retroalimentación biológica en este período
