oxytocin and Shock--Septic

Septic shock is a major cause of death following trauma and a persistent problem in surgical patients. It is a challenge to the critical care medicine specialist and carries an unacceptably high mortality rate, despite adequate antibiotic and vasopressor therapy. The prevalent hypothesis regarding its mechanism is that the syndrome is caused by an excessive defensive and inflammatory response. During the acute phase some signalling mechanisms are activated, particularly hormone release, which function to restore the host homeostasis that has been disturbed by the infection. Since the neuroendocrine and immune systems are functionally related, so the exposure to antigens induces a synchronized response, which allows the organism to successfully endure immunology changes. An important characteristic of this communication includes the appearance of proteins released into the circulation by activated immune cells. These proteins, called cytokines can enter the circulation and reach neuroendocrine organs, where they act either themselves or through the release of intermediates such as prostaglandin, catecholamines and nitric oxide. The synthesis of nitric oxide may be induced in brain as a consequence of infection and may alter the function of the hypothalamic-pituitary axis. In this review we discuss the physiologic roles of the nitric oxide in central nervous system controlling the regulation of vasopressin and oxytocin during the pathophysiology of sepsis.

Topics: Animals; Female; Humans; Male; Nitric Oxide; Oxytocin; Shock, Septic; Vasopressins

Neuropeptides are an extremely conserved arm of neurobiology. Despite their effects as neurohormones and neurotransmitters, a multitude of other effects have been described, putting in evidence their importance as regulators of immune responses, such as chemotaxis, oxidative burst, pro-inflammatory signaling, and many others. The effects of neuropeptides in the pathophysiology of sepsis, however, remain poorly investigated. A prospective cohort study to investigate the effects of neuropeptides in sepsis was carried out. Here, we describe that neuropeptides are downregulated during septic shock. We propose that it may be a protective mechanism of the host to avoid further inflammatory injury.

Topics: alpha-MSH; Cohort Studies; Down-Regulation; Humans; Hydrocortisone; Inflammation; Melatonin; Neuropeptides; Neurotensin; Oxytocin; Prospective Studies; Shock, Septic; Substance P

Septic shock is a serious condition with a consequent drop in blood pressure and inadequate tissue perfusion. Small-volume resuscitation with hypertonic saline (HS) has been proposed to restore physiological haemodynamics during haemorrhagic and endotoxic shock. In the present study, we sought to determine the effects produced by an HS infusion in rats subjected to caecal ligation and perforation (CLP). Male Wistar rats were randomly grouped and submitted to either CLP or sham surgery. Either HS (7.5% NaCl, 4 ml kg(-1) i.v.) or isotonic saline (IS; 0.9% NaCl, 4 ml kg(-1) i.v.) was administered 6 h after CLP. Recordings of mean arterial pressure and heart rate were made during this protocol. Moreover, measurements of electrolyte, vasopressin and oxytocin secretion were analysed after either the HS or the IS treatment. Six hours after CLP, we observed a characteristic decrease in mean arterial pressure that occurs after CLP. The HS infusion in these rats produced a transient elevation of the plasma sodium concentration and osmolality and increased plasma vasopressin and oxytocin levels. Moreover, the HS infusion could restore the mean arterial pressure after CLP, which was completely blunted by the previous injection of the vasopressin but not the oxytocin antagonist. The present study demonstrated that rats subjected to CLP and an infusion of hypertonic saline respond with secretion of neurohypophyseal hormones and a transient increase in blood pressure mediated by the V(1) receptor.

Topics: Animals; Antidiuretic Hormone Receptor Antagonists; Arterial Pressure; Disease Models, Animal; Fluid Therapy; Heart Rate; Homeostasis; Hormone Antagonists; Infusions, Intravenous; Male; Osmolar Concentration; Oxytocin; Pituitary Gland, Posterior; Rats; Rats, Wistar; Receptors, Oxytocin; Receptors, Vasopressin; Saline Solution, Hypertonic; Shock, Septic; Sodium; Time Factors; Vasopressins; Water-Electrolyte Balance

This study examined whether electrolytic ablation of the periventricular anteroventral third ventricle (AV3V) region would affect the hypothalamic activation and the increase of hypophysial hormone secretion induced by systemic injection of lipopolysaccharide (LPS) in rats. LPS significantly increased the number of cells showing Fos immunoreactivity in the paraventricular (PVN) and supraoptic (SON) nuclei of the hypothalamus (P<0.05) and also increased plasma levels of vasopressin, oxytocin, adrenocorticotropin and corticosterone (P<0.05). AV3V lesion significantly reduced LPS-induced Fos immunoreactivity (P<0.05) and vasopressin and oxytocin secretion (P<0.05). Elevations in adrenocorticotropin but not in plasma corticosterone after LPS were affected by prior AV3V lesions. These findings demonstrate that LPS-induced Fos expression in the PVN and SON, and hypophysial hormone secretion is dependent on the integrity of the AV3V region.

Topics: Adrenocorticotropic Hormone; Animals; Cardiovascular Physiological Phenomena; Disease Models, Animal; Hypothalamo-Hypophyseal System; Hypothalamus; Inflammation Mediators; Lipopolysaccharides; Male; Neurons; Oxytocin; Paraventricular Hypothalamic Nucleus; Pituitary Hormones; Proto-Oncogene Proteins c-fos; Rats; Rats, Wistar; Shock, Septic; Stress, Physiological; Supraoptic Nucleus; Third Ventricle; Vasopressins; Water-Electrolyte Balance

Topics: Abortion, Induced; Adult; Anaphylaxis; Bronchial Spasm; Critical Care; Female; Humans; Laryngeal Diseases; Oxytocin; Pregnancy; Shock, Septic

We analyzed the clinical course and investigated possible pathophysiologic mechanisms of amniotic fluid embolism.. We carried out a retrospective review of medical records. Forty-six charts were analyzed for 121 separate clinical variables.. Amniotic fluid embolism occurred during labor in 70% of the women, after vaginal delivery in 11%, and during cesarean section after delivery of the infant in 19%. No correlation was seen with prolonged labor or oxytocin use. A significant relation was seen between amniotic fluid embolism and male fetal sex. Forty-one percent of patients gave a history of allergy or atopy. Maternal mortality was 61%, with neurologically intact survival seen in 15% of women. Of fetuses in utero at the time of the event, only 39% survived. Clinical and hemodynamic manifestations were similar to those manifest in anaphylaxis and septic shock.. Intact maternal or fetal survival with amniotic fluid embolism is rare. The striking similarities between clinical and hemodynamic findings in amniotic fluid embolism and both anaphylaxis and septic shock suggest a common pathophysiologic mechanism for all these conditions. Thus the term amniotic fluid embolism appears to be a misnomer.

Topics: Adolescent; Adult; Anaphylaxis; Chi-Square Distribution; Embolism, Amniotic Fluid; Female; Fetal Death; Fetus; Heart Rate, Fetal; Humans; Hypersensitivity; Male; Obstetric Labor Complications; Oxytocin; Pregnancy; Prognosis; Puerperal Disorders; Registries; Retrospective Studies; Sex Factors; Shock, Septic; Survival Rate; United States

Topics: Abortion, Criminal; Abortion, Septic; Anti-Bacterial Agents; Castration; Drug Resistance, Microbial; Female; Heparin; Humans; Hysterectomy; Oxytocin; Pregnancy; Prognosis; Shock, Septic

Topics: Abortion, Septic; Adrenal Cortex Hormones; Anti-Bacterial Agents; Blood Transfusion; Electrolytes; Female; Genital Diseases, Female; Humans; Hyperbaric Oxygenation; Hysterectomy; Oxytocin; Pregnancy; Pregnancy Complications, Infectious; Shock, Septic

Topics: Abortion, Septic; Acute Kidney Injury; Anti-Bacterial Agents; Corticosterone; Female; Humans; Hysterectomy; Oxytocin; Pregnancy; Shock, Septic; Uterine Cervical Neoplasms; Vaginal Smears; Vasoconstrictor Agents; Vasodilator Agents

Topics: Abortion, Criminal; Abortion, Spontaneous; Abortion, Therapeutic; Acute Kidney Injury; Adult; Anti-Bacterial Agents; Contraception; Female; Humans; Hysterectomy; Infusions, Parenteral; Oxytocin; Physician-Patient Relations; Pregnancy; Shock, Septic; Sterilization, Reproductive

Topics: Abortion, Septic; Chloramphenicol; Female; Humans; Hydrocortisone; Metaraminol; Norepinephrine; Oxygen Inhalation Therapy; Oxytocin; Penicillins; Phenylephrine; Pregnancy; Sepsis; Shock; Shock, Septic; Streptomycin; Water-Electrolyte Balance