The role of glucagon in weight loss-mediated metabolic improvement: a systematic review and meta-analysis.

Aims This meta-analysis aimed to investigate the role of glucagon suppression in regulating glucose homeostasis following diet or bariatric surgery. Methods A comprehensive search of intervention and observational studies was conducted in Medline, Scopus, Web of Science, PubMed and Embase. Random effects model meta-analysis was performed. Primary outcomes were (i) body weight change, (ii) fasting glucagon, (iii) fasting glucose and (iv) fasting insulin concentrations. Results Twenty articles reporting data from 29 interventions were eligible for analysis. Bariatric surgery caused greater weight loss than diet (bariatric -29.7 kg [CI:-36.8, -22.6]; diet -5.8 kg [CI: -8.4, -3.3]; P < 0.00001), an effect that remained significant after adjusting for study duration (P < 0.05). Mean fasting glucagon decreased in parallel with weight loss (-11.8 ng/L [CI: -15.9, -7.8]; P < 0.00001) with no difference between bariatric and diet intervention. Both fasting glucose, and insulin decreased following weight loss (both P < 0.00001; glucose -1.7 mmol/L [CI: -2.0, -1.3]; insulin -50.6 pmol/L [CI: -66.5, -34.7] with greater decrease in fasting insulin between bariatric versus diet (P = 0.01). Conclusions Synergistic suppression of fasting glucagon and insulin resistance may act together to restore normoglycaemia following weight loss. Whether suppression of plasma glucagon may contribute to increased hunger after weight loss and gradual weight regain is not yet known.

The use of alpha 2 agonists during idiopathic scoliosis repair : a narrative review of the literature.

Alpha 2 agonists are appreciated drugs designed for the peri-operative period, because of their anxiolytic, sedative and analgesic properties. However, they are usually avoided during scoliosis surgery, a longlasting major procedure involving healthy patients, because of their potential effects on Somatosensory and Motorevoked potentials. The absence ofrecommendations suggests that their effects on evoked potentials are still unclear. Thus, we tried in this narrative review to identify the literature representative of the effects of clonidine and dexmedetomidine on evoked potentials, on human beings, published between 1988 and 2015 in English or French, using GOOGLE SCHOLAR and PUBMED. Paucity of literature prevented any conclusion about Clonidine's effects on evoked potentials, but no data suggested a noxious effect of Clonidine on evoked potentials, used in oral premedication (300 µg) or during the procedure (2 to 5 µg/kg). If literature was more extensive for dexmedetomidine, studies were still controversial. Although the majority of the studies did not find statistically significant differences concerning the effects of this drug on evoked potentials (loading dose of 0.3 to 1 µg/ kg followed by continuous infusion of 0.3 to 0.8 µg/kg/h), 2 case reports and 2 studies described substantial decreases. However, dexmedetomidine's shorter duration of action allowed a quick return to basal situation within an hour. In conclusion, more studies are needed in order to evaluate the effects of alpha 2 agonists on evoked potentials and to assess the safety of their use in this setting.

Mirizzi syndrome associated with hepatic artery pseudoaneurysm: a case report.

INTRODUCTION: This is the first case report of Mirizzi syndrome associated with hepatic artery pseudoaneurysm. CASE PRESENTATION: A 54-year-old man presented with painful obstructive jaundice and weight loss. Computed tomography showed a hilar mass in the liver. Following an episode of haemobilia, angiography demonstrated a pseudoaneurysm of a branch of the right hepatic artery that was embolised. At surgery, a gallstone causing Mirizzi type II syndrome was found to be responsible for the biliary obstruction and a necrotic inflammatory mass and haematoma were found to be extending into the liver. The mass was debrided and drained, the obstructing stones removed and the bile duct drained with a t-tube. The patient made a full recovery. CONCLUSION: This case highlights another situation where there may be difficulty in differentiating Mirizzi syndrome from biliary tract cancer.

Embolisation of cancer: what is the evidence?

Embolisation has become an accepted modality of cancer treatment in patients with a variety of clinical scenarios. It is commonly used in clinical practice in the treatment of hepatocellular carcinoma, hepatic metastases from colorectal cancer and neuroendocrine tumours, and renal cell carcinoma. This review summarizes the current evidence for the efficacy of embolotherapy in these clinical settings, together with the associated complications.

Identification of Lps2 as a key transducer of MyD88-independent TIR signalling.

In humans, ten Toll-like receptor (TLR) paralogues sense molecular components of microbes, initiating the production of cytokine mediators that create the inflammatory response. Using N-ethyl-N-nitrosourea, we induced a germline mutation called Lps2, which abolishes cytokine responses to double-stranded RNA and severely impairs responses to the endotoxin lipopolysaccharide (LPS), indicating that TLR3 and TLR4 might share a specific, proximal transducer. Here we identify the Lps2 mutation: a distal frameshift error in a Toll/interleukin-1 receptor/resistance (TIR) adaptor protein known as Trif or Ticam-1. Trif(Lps2) homozygotes are markedly resistant to the toxic effects of LPS, and are hypersusceptible to mouse cytomegalovirus, failing to produce type I interferons when infected. Compound homozygosity for mutations at Trif and MyD88 (a cytoplasmic TIR-domain-containing adaptor protein) loci ablates all responses to LPS, indicating that only two signalling pathways emanate from the LPS receptor. However, a Trif-independent cell population is detectable when Trif(Lps2) mutant macrophages are stimulated with LPS. This reveals that an alternative MyD88-dependent 'adaptor X' pathway is present in some, but not all, macrophages, and implies afferent immune specialization.

Indomethacin blocks pre-partum nest building behaviour in the pig (Sus scrofa): effects on plasma prostaglandin F metabolite, oxytocin, cortisol and progesterone.

In the pig, nest building occurs in the day preceding parturition (gestation=114--116 days). Nest building behaviour can be induced in pregnant, pseudopregnant and cyclic female pigs following injection of prostaglandin F2alpha. Here we investigated behaviour and endocrine changes after the administration of indomethacin, which inhibits cyclo-oxygenase enzymes and thus prostaglandin synthesis. In experiment 1, pregnant primiparous pigs (gilts) were blood sampled through jugular vein catheters every 20 min from 1000 h on day 113 of pregnancy and behaviour was recorded until birth. Two hours after pre-partum nest building began, animals received 4 mg/kg indomethacin (n=7) or control vehicle (n=8) intramuscularly. Indomethacin-treated animals showed less nest building than controls between 1 and 5 h after injection (P<0.05), during which time they were mostly inactive and lay down for longer than controls. From 5 h before birth until birth there was no significant treatment difference in nest building behaviour. There was a tendency for the start of birth to be delayed in indomethacin-treated animals. Plasma 13,14-dihydro-15-keto-prostaglandin F2 alpha (a major metabolite of prostaglandin F2 alpha) rose during pre-injection nest building and then fell following indomethacin treatment, but was not significantly different between groups when behaviour differed. Plasma oxytocin, cortisol and progesterone were not significantly affected by treatment. In experiment 2, indomethacin-treated non-pregnant gilts (n=7) did not show any changes in activity or posture compared with vehicle-treated controls (n=6) between 90 and 150 min after treatment. These results suggested that indomethacin treatment reversibly and specifically inhibits porcine pre-partum nest building by a mechanism that may involve endogenous prostaglandin F2 alpha synthesis inhibition but is independent of circulating oxytocin, cortisol and progesterone concentrations.

Undisclosed port-wine stain--anesthetic implications and psychosocial considerations: a case report.

Port-wine stains (nevus flammeus, port-wine nevus) are congenital vascular lesions that have psychological and physiological implications for patient care. The location and size of these lesions can lead to complications related to anesthetic management. Facial lesions have the most profound psychological effect on the patient with respect to behavior alterations and reluctance to disclose the lesion's presence. Covering makeup has become increasingly effective not only in concealing the lesion, but also in being nearly undetectable during routine examination. Issues such as agent choice, surgical position, frequency of positioning evaluation, and choice of intravenous fluid should be considered when caring for a patient with a port-wine stain. In this case study the authors describe the anesthesia implications and outcome in a patient who refused to disclose her port-wine lesion in the preoperative interview and who ignored preoperative instructions to remove all makeup before presenting for surgery.

The role of the coronoid process in elbow stability. A biomechanical analysis of axial loading.

BACKGROUND: The current treatment of coronoid process fractures of the ulna is based on the classification system of Regan and Morrey. We found no biomechanical studies that specifically addressed the role of the coronoid process in elbow stability. In the present investigation, the elbows of cadavera were tested before and after fracture of the coronoid process to assess the stabilizing contribution of the coronoid process under axial loading. METHODS: Six fresh-frozen cadaveric elbows were tested mechanically. All soft tissue surrounding the elbow, including the skin, was left intact. An axial load compressing the elbow joint was applied along the shaft of the forearm in the sagittal plane. A displacement of fifteen millimeters per minute was applied until a load of 100 newtons was attained. Each elbow was tested in 15, 30, 45, 60, 75, 90, 105, and 120 degrees of flexion. Next, less than 25 percent, 25 to 50 percent, or more than 50 percent of the coronoid process was fractured with an osteotome under radiographic guidance, and the testing was repeated. Each elbow served as its own control, and one elbow was used for two tests; therefore, a total of seven situations were investigated. The difference in displacements between the intact and osteotomized elbows was measured. RESULTS: There was no significant difference, at any flexion position, in posterior axial displacement between the intact elbows and the elbows in which 50 percent or less of the coronoid process was fractured (type I and type II) (p = 0.43). There were significant differences, across all flexion positions, in posterior axial displacement between the intact elbows and the elbows in which more than 50 percent of the coronoid process was fractured (type III) (p = 0.006). Specimens with a type-III fracture also showed a significant increase in displacement compared with specimens with a type-I or type-II fracture (p = 0.012). Specifically, from 60 to 105 degrees of flexion, a significant increase in posterior translation of up to 2.4 millimeters was found (p<0.05). CONCLUSIONS: In response to axial load, elbows with a fracture involving more than 50 percent of the coronoid process displace more readily than elbows with a fracture involving 50 percent or less of the coronoid process, especially when the elbow is flexed 60 degrees and beyond.

Release of oxytocin and prostaglandin f(2alpha) around teasing, natural service and associated events in the mare.

Mating has been shown in many species to provoke the release of oxytocin (OT). In our study, various stimuli were applied to mares to study release of OT and prostaglandin F(2alpha) (PGF(2alpha)) associated with mating. Blood samples were collected from mares around the time of teasing both in oestrus and dioestrus and at mating. For comparison, blood samples were also collected at the time of manual manipulation of the genital tract and after intrauterine infusion of 500 ml phosphate buffered saline (PBS). Additional samples were collected 16 to 18 h after mating. Mating caused a significant increase in OT in all mares and teasing caused a significant OT response in 6 of 10 oestrous and 3 of 5 dioestrous mares. However, mating and teasing had no significant effect on concentrations of 15-keto-13,14-dihydro-PGF(2alpha) (PGFM). Manual manipulation of the clitoris, vagina and cervix caused significant OT release in all mares and intrauterine infusion of 500 ml PBS caused significant OT release in three of the five mares. However, only one mare had a significant PGF(2alpha) response during manual manipulation and only one responded positively to intrauterine infusion of 500 ml PBS. We concluded that events around mating, including stimulation of the genital tract and uterine distension, often caused an increase in circulating concentrations of OT but only rarely in PGFM.

Anterior cruciate ligament reconstruction in adolescents with open physes.

The purpose of this study was to evaluate anterior cruciate ligament reconstructions performed in adolescents with open physes and a skeletal age of at least 14 years. At one center, from 1992 to 1996, 19 adolescents (ages, 11 to 15 years) with open physes and a skeletal age of at least 14 years underwent arthroscopic anterior cruciate ligament reconstruction using an Achilles tendon allograft placed through drill holes across the open physes in both the distal femur and proximal tibia. Fifteen patients returned for reevaluation at an average of 25 months postoperatively (range, 12 to 60 months); the remaining four patients were interviewed by telephone. There were no significant leg-length discrepancies or angular deformities as determined by scanograms and anteroposterior and lateral radiographs of the femur and tibia. The mean Lysholm knee score was 97 (range, 94 to 100) and the mean KT-1000 arthrometer side-to-side difference at 20 pounds of anterior force was 1.7 mm (range, 0.0 to 3.0). All patients were satisfied with the results of surgery, and 16 of 19 patients returned to the same sport they were participating in before the injury. This study demonstrates that anterior cruciate ligament reconstruction using an Achilles tendon allograft is a viable treatment option for skeletally immature patients with a skeletal age of 14 years who have sustained midsubstance tears of the anterior cruciate ligament.

The timing of parturition in the pig is altered by intravenous naloxone.

This experiment tested the hypothesis that opioid antagonists could influence the timing of the onset and progress of parturition in the pig. Primiparous pigs (gilts) received a jugular catheter on Days 104 to 106 of pregnancy. At 1400 h on Day 112 the gilts received 10 mg PGF2alpha, i.m. to induce parturition. At 1000 h on Day 113 (i.e., 20 h later) gilts received either saline (n=6), 1 mg/kg, i.v. naltrexone (n=4) or 1 mg/kg, i.v. naloxone (n=5). Blood samples were taken daily from Days 108 to 116. On Day 113, blood samples were taken hourly from 0500 to 0900 h and then every 30 min until 2400 h, or until the birth of the last piglet (BLP) (whichever was sooner) and assayed for progesterone, oxytocin (OT), cortisol and PRL. Additional blood samples for OT and cortisol assay were taken every minute from 0930 to 1100 h on Day 113 and for 30 min during parturition. Naloxone, but not naltrexone, delayed the onset of parturition relative to saline controls (by 14 h 21 min; P<0.05). Duration of parturition and rate of births were not significantly affected by treatment. Mean plasma OT increased in the 4 h following naloxone but not saline treatment, during which time OT plasma pulse amplitude was reduced in naloxone and naltrexone-treated animals relative to saline treated controls. The PRL secretion rose following treatment in saline treated animals, consistent with approaching parturition, but failed to rise in opioid antagonist treated animals. Progesterone concentrations remained elevated in naloxone-treated animals for longer than in the other groups. These data suggest that a rapid change in overall effect of parenteral administration of naloxone to parturient pigs occurs from delaying its onset when administered as in these experiments, to facilitating its progress when given during parturition (earlier experiments). The delay of onset of parturition may be mediated by interference with hypothalamic control of OT or PRL release.

Decision making, beliefs, and attitudes toward hysterectomy: a focus group study with medically underserved women in Texas.

Variations in hysterectomy rates have been associated with assorted physician and patient characteristics, and the disproportionate rate of hysterectomies in African American women has been attributed to a higher prevalence of leiomyomas. The role of women's beliefs and attitudes toward hysterectomy and participation in decision making for medical treatment has not been explored as a source of variance. The purposes of this qualitative study were to explore these constructs in a triethnic sample of women to understand beliefs, attitudes, and decision-making preferences among underserved women; to facilitate development of a quantitative survey; and to inform development of interventions to assist women with such medical decisions. Twenty-three focus groups were conducted with 148 women from community sites and public health clinics. Thirteen self-identified lesbians participated in three groups. Analysis of audiotaped transcripts yielded four main themes: perceived outcomes of hysterectomy, perceived views of men/partners, opinions about healthcare providers, decision-making process. Across groups, the women expressed similar expectations from hysterectomy, differing only in the degree to which dimensions were emphasized. The women thought men perceived women with hysterectomy as less desirable for reasons unrelated to childbearing. Attitudes toward physicians were negative except among Hispanic women. All women expressed a strong desire to be involved in elective treatment decisions and would discuss their choice with important others. Implications for intervention development include enhancing women's skills and confidence to evaluate treatment options and to interact with physicians around treatment choices and creation of portable educational components for important others.

Implementation of a pharmacy-based immunization program in a supermarket chain.

OBJECTIVE: To describe procedures for implementing a pharmacy-based immunization program in a supermarket chain. SETTING: Supermarket chain pharmacy. PRACTICE DESCRIPTION: Ukrop's is a local supermarket chain with 27 stores in the greater area of Richmond, Fredericksburg, and Williamsburg, Virginia, 19 of which have pharmacies. Ukrop's offers enhanced patient care services including immunizations, diabetes, asthma, hypertension, hyperlipidemia monitoring, and smoking cessation. All pharmacies offer adult immunizations and host periodic diabetes, hypertension, and hyperlipidemia screening events. PRACTICE INNOVATION: Adult immunization program. INTERVENTIONS: Each pharmacy offered influenza and pneumococcal vaccinations on a walk-up basis during pharmacy hours and during clinics held at least 3 days per week. Immunizations were also offered periodically at off-site locations. Distribution of letters and chart stickers to patients' physicians, and even partnership with a physician to establish the immunization protocol, helped increase awareness of the pharmacy immunization services. This service involved a core group of immunizing pharmacists who developed a policies and procedures manual, distributed the vaccine, and handled additional staffing requirements. MAIN OUTCOME MEASURES: Number of adult influenza and pneumococcal vaccinations administered by pharmacists. RESULTS: Between September and December 1998, Ukrop's pharmacists administered 5,137 influenza vaccinations and 613 pneumococcal vaccinations. Between September 1999 and January 2000, Ukrop's pharmacists administered 18,000 influenza vaccinations and 1,200 pneumococcal vaccinations. CONCLUSION: In addition to immunizing thousands of people in its first year, the program served as a successful marketing tool to increase awareness of enhanced pharmacy services in the community and among local physicians. Administration of vaccines increased pharmacists involvement with and enthusiasm for enhanced patient care services and generated a revenue stream for the pharmacies.

Role of anagrelide in the treatment of thrombocytosis.

OBJECTIVE: To review the role of anagrelide in the management of essential thrombocythemia. DATA SOURCES: A MEDLINE search (January 1966-August 1998) was performed using the key terms anagrelide, thrombocytosis, and essential thrombocythemia. In addition, the package insert, product monograph, and patient information pamphlets were reviewed. DATA SYNTHESIS: Recently, there has been a trend toward the use of anagrelide in the management of thrombocythemia. Anagrelide lacks leukemogenic and mutagenic potential and possesses a more favorable adverse effect profile compared with other therapeutic agents. At recommended doses, anagrelide induces thrombocytopenia in thrombocythemic patients with a concomitant reduction in the incidence of disease-related symptoms. CONCLUSIONS: Although the treatment of choice for thrombocythemia is still an area of debate, anagrelide has distinct advantages over alternative therapies. Anagrelide represents an important therapeutic option in the treatment of patients with thrombocythemia.

Intravenous lysine vasopressin lowers body temperature in normal and febrile pigs.

Vasopressin has been implicated as a centrally acting endogenous antipyretic. However, in several species, including the pig, plasma vasopressin concentrations increase during the early stages of fever. This experiment investigated the effects of intravenous lysine vasopressin on core temperature in normal and febrile swine. Lysine vasopressin (20 microg/pig) stimulated cortisol release and induced a 60-min hypothermic episode in normal animals, although a 10-fold lower dose was without effect. The peptide also delayed the pyretic response to bacterial endotoxin (20 microg intravenously). It is speculated that the hypothermic action of circulating vasopressin may involve nitric oxide.

Effects of oestrogen supplementation and space restriction on PGF2alpha-induced nest-building in pseudopregnant gilts.

This study examined the role of oestrogen supplementation on PGF2alpha-induced nest-building in pseudopregnant gilts. Oestradiol valerate (5 mg/day) injections were given on Days 11-15 of the oestrous cycle to induce pseudopregnancy. A further series of injections of either oestradiol valerate (5 mg/day) or vehicle were given on days 44-46 of pseudopregnancy to reflect more closely the hormone profile seen in pregnancy. Nest-building was induced by a single intramuscular injection of 15 mg of PGF2alpha (Lutalyse) on Day 47 of pseudopregnancy. The gilts were housed in pens (2.8 x 1.7 m) containing straw in experiment 1 or chronically confined in crates (0.6 x 1.7 m) that did not contain straw on days 44-48 of pseudopregnancy for experiment 2. Oestrogen supplemented gilts had significantly higher concentrations of circulating 17beta-oestradiol on day 47 of pseudopregnancy but there were no significant differences between treatments for circulating levels of prolactin, progesterone, cortisol or oxytocin, or for any behavioural measure in either experiment. These results indicate that there is no direct effect of supplementing already pseudopregnant gilts with oestradiol valerate on PGF2alpha-induced nest-building. The results also show that the pre-partum environment has a pronounced effect on nest-building behaviours and that non-pregnant pigs might be a useful model for pre-partum nest-building in this species.

Does prolactin mediate induced nest-building behaviour in pseudopregnant gilts treated with PGF2alpha?

Nest-building behaviour occurs 6-24 h before parturition in pigs (gestation=116 days). Pseudopregnancy in pigs (induced with oestradiol valerate injections) lasts 50-80 days. We have shown that prostaglandin F2alpha (PG) administration on day 47 of pseudopregnancy induces nest-building and changes to plasma prolactin, oxytocin, cortisol and progesterone similar to those seen before normal parturition. Peripheral prolactin has been proposed as a modulator of nest-building. This study assessed nest-building behaviour in prolactin-deprived gilts. Jugular vein catheters were inserted on day 39 of pseudopregnancy and blood samples collected daily from days 40-48. Animals were injected im with either 40 mg bromocriptine in 2 ml 70% ethanol (n=8) or vehicle (n=7) at 17.00 h on day 46 and 09.00 h on day 47 of pseudopregnancy. PG (15 mg Lutalyse: Upjohn) was injected im at 11.00 h on day 47. Blood and behavioural samples were taken from 90 min before PG to 6 h post-PG. Plasma prolactin increased in control but not bromocriptine treated animals following PG (P<0.05). Elevations in oxytocin, cortisol and progesterone (P<0.05) above pre-PG concentrations were also seen, but of these only progesterone showed between group differences [greater (P<0.05) in control gilts on both days 47 and 48]. PG significantly (P<0.05) increased both the rate and proportion of total time spent performing straw/floor-directed behaviours not including foraging (an index of nesting behaviour) in both treatment groups with no significant differences between groups. There were also no significant differences between groups in time spent performing pen fixture directed activities before or after PG. Bromocriptine suppressed the rise in prolactin concentrations after PG without suppressing nest-building behaviour. We conclude that peripheral prolactin is not an essential component of the nest-building complex in pigs.

Prostaglandin F2alpha-induced nest-building in pseudopregnant pigs. II. Space restriction stress does not influence secretion of oxytocin, prolactin, oestradiol or progesterone.

We have previously shown that prostaglandin F2alpha (PG) is capable of inducing nest-building behaviour in pseudopregnant gilts and established a protocol. This experiment examined which reproductive endocrine systems might mediate these behavioural responses, in the presence or absence of a space restriction stress. Pseudopregnancy was induced with 5 mg/day i.m. (intramuscular) injections of oestradiol valerate (OV) on Days 11-15 of the oestrous cycle, jugular vein catheters were placed on Day 39 of pseudopregnancy, and blood samples were collected daily from Day 40 to Day 48. On Day 42, gilts were either space restricted to farrowing crates 1.6 x 0.6 m (C: n = 11) or left in pens 2.8 x 1.74 m (P: n = 11). On Day 47, blood samples were collected from all animals every 15 min from 90 min prior to a single i.m. injection of 15 mg of prostaglandin F2alpha (PG: Lutalyse, Upjohn, Crowley, West Sussex) to 120 min post-PG and then hourly for 4 h and assayed for oxytocin, prolactin, progesterone, and oestradiol. Results showed that mean daily concentrations of prolactin and progesterone were significantly lower (p < 0.05 respectively) in C than P gilts from Day 42 to Day 46 of pseudopregnancy. There were no significant differences in mean daily concentrations of oxytocin and oestradiol between C and P gilts during this time. For both groups, oxytocin, prolactin, and progesterone concentrations increased significantly (p < 0.05) post-PG when compared to their respective pre-PG values. However, for both groups, oestradiol concentrations were unaffected by PG injection. The prostaglandin-induced increases in oxytocin, prolactin, and progesterone concentrations did not differ between groups. We conclude that coincident changes in oestradiol secretion does not influence nesting behaviour and that space restriction stress associated with nest-building does not influence secretion of oxytocin, prolactin, oestradiol, or progesterone.

Interrelated adrenocortical and neurohypophysial responses associated with fever in endotoxin-treated pigs.

Low intravenous doses of endotoxin [lipopolysaccharide (LPS), 0.7 microgram/kg] induce monophasic fever, increase anterior and posterior pituitary hormone release, and enhance hypothalamic c-Fos expression in pigs, all of which can be prevented by indomethacin (Ind). The present study shows that the synthetic corticosteroid dexamethasone (Dex, 5 mg/kg) has a similar action to Ind and, when given alone, lowers core temperature. In addition, the corticosteroid synthesis inhibitor metyrapone (Met, 3.3 mg/kg, every one-half hour) reduces LPS fever and amplifies the effect of LPS on vasopressin, but not on oxytocin, release. The similar actions of Dex and Ind suggest that phospholipase A2 pathways controlling prostaglandin synthesis mediate the responses of prepubertal pigs to immunological challenge with LPS. The increased vasopressin release induced when animals receiving Met are also given LPS supports findings in other nonrodent species indicating an inverse relationship between cortisol and vasopressin. The attenuation of LPS fever by Met is suggestive of an endogenous antipyretic mechanism associated with enhanced neurohypophysial vasopressin secretion.

Changes in content of mRNA encoding oxytocin in the pig uterus during the oestrous cycle, pregnancy, at parturition and in lactational anoestrus.

The aim of this study was to show that the pig uterus synthesizes oxytocin. Uteri were obtained from 2-7 pigs at regular intervals during the oestrous cycle, throughout pregnancy, at parturition and in lactational anoestrus. Localization of mRNA encoding oxytocin was by in situ hybridization and oxytocin concentrations were measured by radioimmunoassay. As reproductive status changed, mRNA encoding oxytocin varied significantly (P < 0.05). Uterine tissue type was a significant factor in determining synthesis of mRNA encoding oxytocin (P < 0.001). In luminal epithelia, concentrations of mRNA encoding oxytocin were greater at oestrus than during day 14 of the luteal phase (P < 0.01) or at any stage of pregnancy (P < 0.05), with concentrations minimal at parturition. This trend was also exhibited in uterine circular muscle. In longitudinal muscle, concentrations of mRNA encoding oxytocin were lower during late pregnancy than at oestrus (P < 0.05) or during the luteal phase (P < 0.05). Concentrations were minimal at parturition. The oxytocin content in endometrial and myometrial tissue was positively correlated across reproductive status (P < 0.02, r = 0.402, n = 35). These data are the first indication that the uterine endometrium and musculature of the pig express mRNA encoding oxytocin. The luminal epithelium of animals at oestrus was particularly rich in mRNA encoding oxytocin, whilst late pregnant and parturient animals did not show a rise in mRNA encoding oxytocin. Local uterine synthesis of oxytocin may therefore be more important in control of the oestrous cycle than in pregnancy or at parturition in pigs.