Female Cialis

By I. Diego. Life University.

A full-length cDNA was described and encoded a spinal cord CRF neurons may represent preganglionic neu- putative 40-amino acid peptide that was related to CRF rons that modulate sympathetic outflow buy discount female cialis 10 mg on-line. The human form was subsequently identified using a cDNA probe encoding the peptide region of rat urocortin Distribution of CRF in Peripheral Tissues and screening a human genomic library (21) purchase female cialis 20 mg with amex. The resulting putative peptide demonstrated 88% identity to rat at the In addition to its CNS distribution,CRF has been localized nucleotide level and 95% identity at the amino acid level in a variety of peripheral tissues (14). In both species,urocortin is a 40-amino acid active fibers are present in the intermediate lobe of the pitui- residue single-chain polypeptide; the two forms differ by tary; these fibers originate in the hypothalamus. A physio- only two amino acids at positions 2 (Asn to Asp) and 4 logic role has been proposed for CRF in regulating pro- (Ser to Pro) (21). In addition to the homology between the opiomelanocortin (POMC)-derived peptide secretion from species,the deduced amino acid sequence of rat and human the intermediate pituitary. CRF has also been localized in urocortin exhibits sequence identity with urotensin I (63%) the adrenal medulla of a variety of species and is increased and human CRF (45%) (20). Consistent with the other following stimulation of the splanchnic nerve stimulation CRF-related peptides,urocortin is also amidated at its car- and hemorrhagic stress. CRF-like immunoreactivity and boxy terminal,again suggesting the importance of amida- CRF mRNA have been detected in lymphocytes,where they tion to this family of peptides (Fig. Other tis- sues in which CRF has been localized include the testis (Leydig cells and advanced germ cells),pancreas,stomach, Anatomic Distribution of Urocortin and small intestine. Although CRF is not detected in the circulation under normal circumstances,very high levels The distribution of urocortin in rat tissues was elucidated have been measured in the plasma of pregnant women; the first by examining the cellular localization of urotensin-like source of CRF in pregnancy appears to be the placenta. The highest areas of correlation and overlapping localization were the Edinger-Westphal nucleus and the lateral superior olive UROCORTIN: A NOVEL MAMMALIAN (20). In addition,cellular staining was observed in the exter- CRF-RELATED PEPTIDE nal plexiform layer of the rat olfactory bulb and lateral hypo- thalamus. Interestingly,terminal projection fields in the lat- Urocortin is the newest member of the CRF peptide family eral septum also demonstrated distinct localization where and has been demonstrated to possess many of the intrinsic CRF2receptors have been uniquely localized (see the follow- properties of CRF itself as well as some unique properties ing). Although the localization of urocortin appears to be of its own. Originally,the nonmammalian CRF-related ana- in very discrete brain regions,these regions demonstrate logues urotensin I (teleost fish) (15) and sauvagine (frog) no CRF mRNA,suggesting that urocortin subserves some (16) were thought to subserve the functions of CRF in the unique functionality within the CRF system. As described respective species; however,the discovery of peptides even in the following,its affinity and functional activity at the 94 Neuropsychopharmacology: The Fifth Generation of Progress CRF2 receptor subtype suggest that this may be one endoge- tors for calcitonin,vasoactive intestinal peptide,parathyroid nous ligand for this subtype. In addition,the known members of this neuropeptide receptor In Vitro and In Vivo Pharmacologic family also belong to the superfamily of G-protein coupled Effects receptors; thus far,all have been shown to stimulate adenyl- Urocortin binds with high affinity to all the known effectors ate cyclase in response to their respective agonist activation. This profile makes urocortin unique in the technique and characterized as a 415-amino acid protein CRF system because endogenous r/hCRF has been shown with potential N-linked glycosylation sites,protein kinase to have relatively low affinity for the CRF2 receptor subtypes C phosphorylation sites in the first and second intracellular and oCRF,which also has lower affinity for the CRF2 sub- loops and in the C-terminal tail,as well as casein kinase type,also has very low affinity at the CRF-binding protein. II and protein kinase A phosphorylation sites in the third Urocortin binds to cells stably transfected with the CRF1, intracellular loop (2). Independently,this receptor subtype CRF2 ,or CRF2 receptors with affinities in the 100 to was also identified in mouse (22) and rat (23,24). In all 500 pM range and has 100 pM affinity for the CRF-BP three species,CRF1 receptor mRNAs encode proteins of (20). In in vitro studies,urocortin stimulates cAMP accu- 415 amino acids,which are 98% identical to one another. The effects on coupled receptors and confirm the glycosylation profiles de- the CRF1 receptor subtype are comparable to the effects of termined by chemical affinity cross-linking studies (25). In CRF itself; however,the activities observed at both CRF2 those studies,although the molecular weights of the proteins receptor isoforms are approximately tenfold more potent labeled from brain or pituitary appeared different when la- beled with [125I]oCRF,the deglycosylation and peptide than CRF itself (20,21). Furthermore, as has been shown for CRF,the presence of CRF-BP can decrease the ability mapping studies suggested that the protein itself was identi- of urocortin to stimulate ACTH release in vitro. Moreover, cal and that the differences were owing to posttranslational specific CRF-BP inhibitors such as r/hCRF(9-33) can re- modification (25). Indeed,the molecular weight predicted store the ability of urocortin to stimulate ACTH,further from the deglycosylated forms of the CRF1 receptor was confirming the functional activity of urocortin at the CRF- virtually identical to that obtained from the cloned amino BP (21). These data taken together established the In unanesthetized freely moving rats,urocortin adminis- fact that the CRF1 receptor subtype is the dominant form tered IV was fivefold more potent than CRF in increasing in both the brain and pituitary. Similarly,urocortin reduced mean arte- CRF2 Receptors rial pressure more potently and for a longer period of time than CRF or urotensin I (20). Thus,although capable of Following the cloning of the CRF1 subtype,two forms of interacting with the CRF1 receptor with equivalent potency a second family member were discovered in the rat and and activity,the anatomic distribution,localization,and termed CRF2 and CRF2. The rat CRF2 receptor (19) potency at the CRF2 subtypes support the notion that uro- is a 411-amino acid protein with approximately 71% iden- cortin is likely one endogenous ligand for this receptor sub- tity to the CRF1 receptor. Clearly,further study is required to determine the cloned from both rat (19) and mouse (24,26), and is a 431- specific role that this novel endogenous peptide plays in the amino acid protein that differs from the CRF2 subtype in regulation of the CRF system. The geno- mic structure and corresponding cDNA of the human CRF RECEPTORS CRF2 receptor subtype was cloned and characterized. The cDNA sequence in the protein-coding region had 94% Cloningof CRF Receptor Subtypes identity with the previously reported rat CRF2 receptor Molecular cloning studies have enabled the elucidation of (27).

In spite of the high levels of brain discount 10mg female cialis fast delivery,mRNA is localized to the amygdaloid complex with CRF in the maternal plasma order 10mg female cialis overnight delivery,there is no evidence of mark- a distinct lack of immunostained cells in the medial nucleus. A plausible explanation for this paradoxic the brainstem particularly in the auditory,vestibular,and situation could be the presence of a binding protein in the trigeminal systems,raphe nuclei of the midbrain and pons, plasma of pregnant women that could specifically inhibit and reticular formation (50). In addition,high expression the biological actions of CRF (44,45). This hypothesis was levels of binding protein mRNA are seen in the anterior validated by the isolation of a CRF-binding protein (CRF- pituitary,predominantly restricted to the corticotrope cells. BP) from human plasma and its subsequent cloning and Expression of this protein in the corticotropes strongly sug- expression (see the following). Norepinephrine has been the interactions of CRF with its receptor,which is also reported to have both stimulatory and inhibitory effects on known to reside on corticotropes; however,the detailed role CRF release that may be a consequence of the dose adminis- of the binding protein in regulating pituitary–adrenal func- tered as well as the receptor subtype involved. Similarly,opioids have been re- ported to either inhibit or stimulate CRF release depending Regulation of Pituitary Hormone on the nature of the opioid tested,dose utilized,and recep- Secretion tor specificity ( versus ) involved. Drugs acting at CRF is the major physiologic regulator of the basal and GABA–benzodiazepine–chloride ionophore complex are stress-induced release of ACTH, -endorphin,and other potent inhibitors of CRF secretion. The extent and time course of changes POMC-derived peptides in anterior pituitary cells in culture in CRF in the paraventricular nucleus and median eminence and in vivo; these actions of CRF can be antagonized by of the hypothalamus following application of stress are the CRF receptor antagonist -helical ovine CRF(9-41) or highly dependent on the nature of the stressor as well as by immunoneutralization with an anti-CRF antibody. The effects of stress to increase eral other lines of evidence support a critical role for endoge- the release and synthesis of CRF are mediated by many of nous CRF in regulating ACTH secretion. For example,in- neurotransmitter systems described in the preceding. Administration of CRF anti- back regulation the hypothalamic–pituitary–adrenocortical sera or the CRF receptor antagonist results in attenuation of axis,are potent inhibitors of CRF release. Conversely,the stress- or adrenalectomy-induced ACTH secretion further absence of glucocorticoids following adrenalectomy results substantiating a role for CRF in regulating ACTH secretion in marked elevations in the synthesis and release of CRF. In addition to effects in the The actions of glucocorticoids to inhibit CRF release are anterior pituitary,CRF also has been reported to stimulate mediated directly at the level of the paraventricular nucleus POMC-derived peptide secretion from the intermediate of the hypothalamus as well as indirectly through actions lobe of the pituitary gland. Central administration of CRF inhibits the secretion of luteinizing hormone (LH) and growth hormone without Modulation of Pituitary CRF Receptors any major effects on follicle-stimulating hormone,thyroid Stress (29,32,33,53) or adrenalectomy (29,32,33) result in stimulating hormone,or prolactin secretion (3,4). The ef- hypersecretion of CRF and a consequent down-regulation fects of CRF to inhibit LH secretion appear to be mediated of receptors in the anterior pituitary. The adrenalectomy- at the hypothalamic level through effects of CRF to inhibit induced decreases in anterior pituitary receptors can be pre- gonadotropin releasing hormone secretion. CRF-induced vented by glucocorticoid replacement with corticosterone inhibition of LH secretion may also involve endogenous or dexamethasone (29,32,33). In addition, chronic adminis- opioids since the effects are attenuated by administration tration of corticosterone has been reported to cause dose- of naloxone or antiserum to -endorphin (3,4). An age-related decline in anterior pitui- Regulation of Hypothalamic CRF Release tary CRF receptors has also been reported (54). In contrast, lesions of the paraventricular nucleus that result in dramatic Plotsky and associates (52) and Owens and Nemeroff (4) reductions in hypothalamic CRF secretion have been re- provide a comprehensive review of the neurotransmitter reg- ported to increase the density of pituitary CRF receptors ulation of hypothalamic CRF release. Thus,CRF receptors in the anterior pituitary appear strate stimulatory effects of cholinergic and serotonergic to be reciprocally regulated by hypothalamic CRF release. The muscarinic and/or nicotinic cholinergic receptor subtypes involved in the stimulatory effects of acetylcholine on CRF secretion remain to be pre- CRF REGULATION OF CNS ACTIVITY cisely elucidated. The effects of serotonin to stimulate CRF Electrophysiologic Effects of CRF release appear to be mediated by a variety of receptor sub- types,including 5-HT2,5-HT1A,and 5-HT1C receptors. CRF stimulates the electrical activity of neurons in various The effects of catecholamines and opioids on hypothalamic brain regions that contain CRF and CRF receptors,includ- Chapter 7: Corticotropin-Releasing Factor 101 ing locus ceruleus (55),hippocampus (56),cerebral cortex, Gastrointestinal Effects of CRF and hypothalamus as well as in lumbar spinal cord motor Studies examining the gastrointestinal effects of CRF have neurons (3,4). In contrast, CRF has inhibitory actions in determined that CRF modulates gastrointestinal activity by the lateral septum,thalamus,and hypothalamic PVN (3, acting at central and possibly peripheral sites,and that these 4). The electrophysiologic effects of CRF on spontaneous effects are qualitatively similar to those observed following and sensory-evoked activity of locus ceruleus neurons are exposure to various stressors. Furthermore,dysfunc- and fecal excretion in a dose-dependent manner when ad- tion of this nucleus has been implicated in the pathophysiol- ministered centrally or systemically to dogs or rats. Centrally administered CRF equipotent in inhibiting gastric emptying in both species increases the spontaneous discharge rate of the locus ceru- following both central and peripheral routes of administra- leus in both anesthetized and unanesthetized rats,while de- tion. The central effects of CRF on gastric acid secretion creasing evoked activity in the nucleus (55). Thus,the over- do not appear to result from leakage of the peptide into all effect of CRF in the locus ceruleus is to decrease the peripheral blood because measurable quantities of CRF are signal to noise ratio between evoked and spontaneous dis- not present in the circulation following injection of CRF charge rates. Furthermore,an intrave- The effects of CRF on EEG activity have been reviewed nous injection of anti-CRF serum completely abolishes the in detail (3,4,57). CRF causes a generalized increase in EEG peripheral but not the central effect of CRF on gastric acid activity associated with increased vigilance and decreased secretion. These data strongly implicate CRF in the mecha- sleep time. Higher doses of the peptide, on the other hand,cause seizure activity that is indistin- guishable from seizures produced by electrical kindling of Behavioral Effects of CRF the amygdala,further confirming the role of CRF in brain activation. The behavioral effects of CRF in the CNS have been re- viewed extensively (3,4,61).

Role of arachidonoylethanolamine in blood pressure regulation in volume-resistant patients on peritoneal dialysis buy female cialis 10 mg on-line. Bai Q purchase female cialis 10 mg without a prescription, Zhang J, Zhang AH, Cheng LT, He L, Fan MH, et al. Roles of human urotensin II in volume resistance hypertension in peritoneal dialysis patients. Castellano S, Palomares I, Moissl U, Chamney P, Carretero D, Crespo A, et al. Risk identification in haemodialysis patients by appropriate body composition assessment. Chen HS, Lee KC, Cheng CT, Hou CC, Liou HH, Lin CJ, Lim PS. Application of Bioimpedance Spectroscopy in Asian Dialysis Patients (ABISAD): serial follow-up and dry weight evaluation. Davies SJ, Engel B, Chan C, Tan BK, Yu ZZ, Asghar R, et al. Breath analysis and the measurement of total body water using isotope dilution – applications in the dialysis clinic. Dekker MJ, Marcelli D, Canaud B, Konings CJ, Leunissen KM, Levin NW, et al. Unraveling the relationship between mortality, hyponatremia, inflammation and malnutrition in hemodialysis patients: results from the international MONDO initiative. Di Gioia MC, Gallar Ruiz P, Cobo G, Garcia Lopez F, Agud Aparicio JL, Oliet A, et al. Body composition changes in hemodialysis patients: implications for prognosis. Impact of hydration and nutrition status on the Watson formula in peritoneal dialysis patients. Hassan MO, Duarte R, Dix-Peek T, Vachiat A, Dickens C, Grinter S, et al. Volume overload and its risk factors in South African chronic kidney disease patients: an appraisal of bioimpedance spectroscopy and inferior vena cava measurements. Fluid volume expansion and depletion in hemodialysis patients lack association with clinical parameters. Characteristics and clinical outcomes of hyponatraemia in peritoneal dialysis patients. Kaysen GA, Larive B, Painter P, Craig A, Lindsay RM, Rocco MV, et al. Baseline physical performance, health, and functioning of participants in the Frequent Hemodialysis Network (FHN) trial. Kwan BCH, Szeto CC, Chow KM, Law MC, Cheng MS, Leung CB, et al. Bioimpedance spectroscopy for the detection of fluid overload in Chinese peritoneal dialysis patients. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals 105 provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK. APPENDIX 6 Lu Q, Cheng LT, Wang T, Wan J, Liao LL, Zeng J, et al. Visceral fat, arterial stiffness, and endothelial function in peritoneal dialysis patients. Marcelli D, Usvyat LA, Kotanko P, Bayh I, Canaud B, Etter M, et al. Body composition and survival in dialysis patients: results from an international cohort study. Marcelli D, Brand K, Ponce P, Milkowski A, Marelli C, Ok E, et al. Longitudinal changes in body composition in patients after initiation of hemodialysis therapy: results from an international cohort. Mathew S, Abraham G, Vijayan M, Thandavan T, Mathew M, Veerappan I, et al. Body composition monitoring and nutrition in maintenance hemodialysis and CAPD patients – a multicenter longitudinal study. Passauer J, Petrov H, Schleser A, Leicht J, Pucalka K. Evaluation of clinical dry weight assessment in haemodialysis patients using bioimpedance spectroscopy: a cross-sectional study. Can bioimpedance measurements of lean and fat tissue mass replace subjective global assessments in peritoneal dialysis patients? Pérez-García R, Palomares I, Merello JI, Ramos R, Maduell F, Molina M, et al. Hyponatraemia, mortality and haemodialysis: an unexplained association.

There are sex differences in the incidence or clinical course of many diseases associated with anorexia as well as in the anorectic response to many immune-system mediators order 10mg female cialis with mastercard, such as IL-1 and -TNF female cialis 10 mg sale. Some of these sex differences appear to be related to estrogenic function. Crohn disease, an inflammatory bowel disease in which anorexia is an early sign (53), is one such. Anorexia caused by Gram-negative bacterial infection is also estradiol-sensitive. The effect of estradiol to increase the anorexia produced in rats by intraperitoneal administra- tion of bacterial lipopolysaccharide is expressed by a decrease in meal frequency without a change in meal size (56), indi- cating that this effect of estrogen is separate from the effects on meal size. Furthermore, endogenous CCK does not appear to contribute to Our understanding of the controls of eating in rodents has the tonic inhibitory effect of estradiol on meal size because deva- been transformed in the past 5 years. Although the relation- zepide did not increase meal size during diestrus. Data are mean ship of eating to nutritional and energetic homeostasis con- meal sizes per 3-hour quartile of the nocturnal phase. More attention to behavioral analysis not an artifact of the cyclic differences in meal size. It has meal size after devazepide larger than after vehicle, P. Re- revealed the operation of a cpg as the final common path produced from Eckel LA, Geary N. The satiating effect of cholecystokinin and The recognition that the size of a meal is under positive bombesin-like peptides. Satiation: from gut to and negative feedback controls has been exploited. Inhibition of food strated to be involved in these feedbacks. The afferent nerves intake in response to intestinal lipid is mediated by cholecystoki- that carry the peripheral information generated along the nin in humans. Cholecystokinin decreases sucrose intake in preabsorptive surface of the gut from the tip of the tongue chronic decerebrate rats. In: Bray of these peripheral mechanisms are activated in every meal, GA, Ryan DH, eds. Baton Rouge, all controls of eating not related to the food being ingested LA: Louisiana State University Press, 1999:227–245. Identification of rat brainstem multisynaptic a new theory of the controls of eating that is more biological, connections to the oral motor nuclei using pseudorabies virus. In: Adelman G, Smith The widely distributed processing of information rele- BH, eds. Systemic factors in the control of food tance and complexity of eating in omnivores such as rodents intake. Patterns of body pressing questions for rodents as well as humans. The ability temperature during feeding in rats under varying ambient tem- peratures. Recognition of this fact increasingly affects re- of food intake after 2-deoxy-D-glucose and nicotinic acid injec- search on eating. The paradigm shift that the study of eating has under- 16. Analysis of the microstructure of the rhythmic tongue movements of rats ingesting maltose and sucrose gone, that is, from viewing eating as serving only nutrient solutions. A model for the control of ingestion, 20 years later. Progress in psychobiology and ioral neuroscience (1), makes the basic science more useful physiologic psychology. Caudal brainstem participates in the distrib- uted neural control of feeding. Using the similarity in eating behavior, gastroin- of behavioral neurobiology. In: Shils ME, Olson JA, Shike as a bridge, the transfer of new information from the labora- M, et al, eds. Baltimore: tory to the clinic should accelerate markedly in the next 5 Williams & Wilkins, 1999:631–644. A direct measure of satiety disturbance in patients with bulimia nervosa.

Female Cialis
9 of 10 - Review by I. Diego
Votes: 219 votes
Total customer reviews: 219