Regulation of synthesis of polyamines by progesterone, estradiol, and their receptors in uteri of cyclic ewes†

Progesterone (P4), estradiol (E2), and expression of their receptors (PGR and ESR1, respectively) by cells of the uterus regulate reproductive performance of mammals through effects on secretion and transport of nutrients into the uterine lumen. This study investigated the effect of changes in P4, E2, PGR, and ESR1 on expression of enzymes for the synthesis and secretion of polyamines. Suffolk ewes (n = 13) were synchronized to estrus (Day 0) and then, on either Day 1 (early metestrus), Day 9 (early diestrus), or Day 14 (late diestrus) of the estrous cycle, maternal blood samples were collected, and ewes were euthanized before obtaining uterine samples and uterine flushings. Endometrial expression of MAT2B and SMS mRNAs increased in late diestrus (P < 0.05). Expression of ODC1 and SMOX mRNAs decreased from early metestrus to early diestrus, and expression of ASL mRNA was lower in late diestrus than in early metestrus (P < 0.05). Immunoreactive PAOX, SAT1, and SMS proteins were localized to uterine luminal, superficial glandular, and glandular epithelia, stromal cells, myometrium, and blood vessels. Concentrations of spermidine and spermine in maternal plasma decreased from early metestrus to early diestrus and decreased further in late diestrus (P < 0.05). The abundances of spermidine and spermine in uterine flushings were less in late diestrus than early metestrus (P < 0.05). These results indicate that synthesis and secretion of polyamines are affected by P4 and E2, as well as the expression of PGR and ESR1 in the endometria of cyclic ewes.

Mesenteric Traction Syndrome or Gut in Distress

The mesenteric traction syndrome (MTS) remains, seventeen years after its first designation as a distinct pathologic entity, an aspect of surgical practice that has received limited attention. Apart from its symptomatology, there is mostly speculation about its exact causes and pathophysiologic mechanisms.

Even though full-blown MTS is rather rare, the advent of laparoscopic surgery has indicated that there are different stages of stress associated with open abdominal surgery. Some evidence points to the involvement of mast cell derived vasoactive mediators and suggests possible pharmacologic management.

Relationship between the niacin skin flush response and essential fatty acids in schizophrenia

The skin flush response to niacin is selectively mediated by the release of vasodilatory prostaglandins from the skin. The normal skin flush response to niacin is attenuated in many individuals with schizophrenia (SCZ). This finding suggests abnormal prostaglandin signaling in SCZ. Since prostaglandins are derived from arachidonic acid (AA), the finding of an abnormal skin flush response is consistent with biochemical data suggesting relative depletion of AA, and other essential fatty acids (EFAs), in a substantial portion of people with SCZ. This paper will describe the mechanism of the skin flush response to niacin, and will review evidence that the response to niacin is abnormal in SCZ, that this abnormality is not related to psychotropic medications, and that it may be a marker of the EFA deficiency which has been documented to be present in many patients with SCZ.

Psychoses and creativity: is the missing link a biological mechanism related to phospholipids turnover?

Recent evidence suggests that genetic and biochemical factors associated with psychoses may also provide an increased propensity to think creatively. The evolutionary theories linking brain growth and diet to the appearance of creative endeavors have been made recently, but they lack a direct link to research on the biological correlates of divergent and creative thought. Expanding upon Horrobin's theory that changes in brain size and in neural microconnectivity came about as a result of changes in dietary fat and phospholipid incorporation of highly unsaturated fatty acids, we propose a theory relating phospholipase A2 (PLA2) activity to the neuromodulatory effects of the noradrenergic system. This theory offers probable links between attention, divergent thinking, and arousal through a mechanism that emphasizes optimal individual functioning of the PLA2 and NE systems as they interact with structural and biochemical states of the brain. We hope that this theory will stimulate new research in the neural basis of creativity and its connection to psychoses.

The niacin skin flush abnormality in schizophrenia: a quantitative dose-response study

Niacin dilates cutaneous blood vessels, resulting in a pronounced skin flush in most people. The flush response to niacin is attenuated in schizophrenia, but the quantification and physiological mechanism of this abnormality have not been described in detail. It is not clear whether the mechanism involves changes in the pharmacological sensitivity to niacin, or whether there is a reduced ability of the vasculature to dilate adequately in subjects with schizophrenia. We address this question in the present study by characterizing the dose-response relationship between topically applied alpha-methylnicotinate (AMN) and cutaneous blood flow changes, which were quantified by laser Doppler flowmetry. The dose-response curve was shifted to the right in subjects with schizophrenia. The EC(50) value of AMN was significantly increased in the schizophrenia group (mean: 1.66 mM; 95% confidence interval: 1.04-2.65 mM) as compared to the control group (mean: 0.38 mM; 95% confidence interval: 0.263-0.547 mM). The blood flow responses to higher AMN doses were lower in the schizophrenics; however, there was no statistically significant difference in the extrapolated maximal blood flow response value (F(max)) between the two groups. The results suggest that the skin flush abnormality in schizophrenia primarily reflects reduced pharmacological sensitivity to niacin rather than an inadequate cutaneous vasodilatory response to the stimulus. Since vasodilatation in response to niacin requires the release of prostaglandins, the data from this study suggest that schizophrenia is associated with abnormalities in enzymes, receptors, or signal transduction mechanisms that affect the synthesis, release, or response to vasodilatory prostaglandins.

Histamine release in mesenteric traction syndrome during abdominal aortic aneurysm surgery: prophylaxis with H1 and H2 antihistamines

OBJECTIVE AND DESIGN

Mesenteric traction syndrome is described as sudden tachycardia, hypotension and flush. Among other etiological factors eventeration or mesenteric traction of the small intestine may cause histamine release from mesenteric mast cells. We hypothesized that mesenteric traction syndrome may be positively influenced by prophylactic antihistamine administration.

METHODS

Male patients (n = 17, ASA groups III-IV, 48-78 years old) were investigated in a randomised double blind study during elective abdominal aortic aneurysm (AAA) repair. Eight patients had pre-anaesthetic prophylaxis with dimetindene (H1-receptor antagonist) plus cimetidine (H2-receptor antagonist), 9 patients received placebo. Anaesthesia and invasive haemodynamic monitoring were standardised in all patients. Haemodynamic parameters, plasma histamine concentrations and clinical symptoms were determined 1 min after skin incision, as well as 5 and 20 min after mesenteric traction. Statistical analyses were performed using the Student's t-test, Chi2-test for incidences and Mann-Whitney-U-test for continuous data.

RESULTS

The incidence of histamine release was 55.5% (5/9) in the placebo group vs. 37.5% (3/8) in the antihistamine group (p > 0.05, Chi2-test). Plasma histamine levels (mean +/- SD) were higher in the placebo group than in the antihistamine group at 5 and 20 min after mesenteric traction but the difference did not reach statistical significance. Arrhythmias were significantly more frequent in the placebo group (6 times) than in the antihistamine group (none) (p = 0.005 Chi2-test). Systolic blood pressure was not statistically different between groups (e.g. 5 min after mesenteric traction, mean +/- SD; placebo 111 +/- 20 mm Hg vs. antihistamines 119 +/- 35 mm Hg). However, in the placebo group the haemodynamics only stabilised 5 min after mesenteric traction when anaesthetic gas concentration was repeatedly reduced and vasopressor/volume administration was increased (placebo-group = 20 times/antihistamine-group = 8 times, p = 0.001, t-test).

CONCLUSION

Prophylactic administration of antihistamines reduced the incidence of histamine release as well as the incidence of arrhythmias and the amount of stabilising measures during mesenteric traction. Prophylaxis with H1 and H2 antihistamines may be of perioperative benefit and should therefore be considered in AAA-surgery.

Sex difference in alcohol-related organ injury

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Nobuhiro Sato and Kai O. Lindros. The presentations were (1) Sex differences in ethanol pharmacokinetics, by E. Baraona; (2) Estrogen regulates the sensitivity to endotoxin in hepatic Kupffer cells, by K. Ikejima; (3) Sex difference in alcohol-related organ injury, by E. Mezey; (4) Aggravated ethanol-induced liver injury in female rats: Protection by the antiestrogen toremifene, by Harri A. Järveläinen; and (5) Alcohol metabolism in Asian subjects: Sex differences and flushing response, by V. A. Ramchandani.

[Biological actions of acetaldehyde]

Acetaldehyde (AcH), the first metabolite of ethanol (EtOH), is a chemically reactive and pharmacologically active compound. The author has been engaged in the study of AcH in cooperation with many researchers for three decades. We have found many biological actions of AcH which cause cardiovascular symptoms after drinking and also inhibited EtOH absorption via the canine and rat intestinal tract. This report covers the following five points. 1. The subjects were classified into a non-flushing group and a flushing group, according to the degree of facial flushing after drinking 200 ml of Sake (Japanese rice wire) at a rate of 100 ml per 5 min. Blood EtOH profile was much the same in both groups, yet peak blood AcH concentration in the flushing group was significantly higher than that in the non-flushing group. All subjects in the flushing group showed marked flushing and an increase in pulse rate after drinking, but these symptoms were not apparent in the non-flushing group. These results suggested that cardiovascular symptoms were caused by AcH itself. 2. Urinary excretions of both norepinephrine and epinephrine increased in the flushing cases after drinking Sake in comparison with those who drank the same volume of water. However, these catecholamines did not change in the non-flushing group. These results suggested that it is catecholamines released from the sympathetic nerve end or the adrenal medulla by AcH which caused an increase in pulse rate. 3. Bradykinin is released from high molecular kininogen by activated kallikrein and acts to dilate distal blood vessels and raise permeability in tissues. On the other hand, kallidin is released from low molecular kininogen by activated glandular kallikrein and its action is weaker than that of bradykinin. Blood low molecular kininogen levels in the flushing group decreased gradually after drinking and were mutually related to the blood AcH concentrations. But levels in the non-flushing group showed no difference before and after drinking. The decrease in low molecular kininogen levels indicates that kallidin released from glandular kallikrein exists in the glandular tissues such as the kidneys, sweat glands, saliva glands, etc. We hypothesize that kallikrein activated by AcH in the sweat glands produces kallidin which cause vessels around the glands to dilate, and flushing of the face and the whole body occurs due to escalation of the sphere of dilatation of blood vessels. 4. A isolated 30 cm length of the canine jejunum segment with intact vascular supply was performed. After pretreatment with cyanamide (CY), a potent inhibitor of aldehyde dehydrogenase, or pyrazole (PY), a potent inhibitor of alcohol dehydrogenase, a 17% EtOH solution (0.4 g/kg) was administered into the jejunum segment, and 150 min after the administration of EtOH, the fluid from the segment was collected to determine its volume and EtOH concentration. The CY-pretreatment group, in which an extremely high AcH concentration developed, in comparison with the control and PY-pretreatment groups, showed a gradual increase of portal blood EtOH, a 25% reduction in the amount of absorbed EtOH, and an 85% smaller absorption rate constant value (Ka value). These facts indicate that the presence of a high AcH concentration in the blood results in a reduction of EtOH absorption and retardation of EtOH reaching the systemic circulation. The rapid reduction of portal blood flow and lower EtOH level in the portal vein observed in the CY group, in comparison with the other groups, also indicate that the reduction of EtOH permeability through the absorption site to the blood is an important retarding factor induced by AcH. 5. After segmenting a 20 cm length of rat intestine, cannulae for EtOH perfusion were inserted into each end of the intestine segment. Perfusion of EtOH solution (4%) was performed for 30 min at steady rate, beginning 60 min after pretreatment with CY and/or PY. The blood EtOH and AcH concentrations in the f

Immunostaining for vasostatin I distinguishes between ileal and lung carcinoids

Although chromogranin A (CgA) is a recognized marker of neuroendocrine tumours, little is known about the distribution of the CgA-derived peptides, vasostatin (VST) I or II, in these tumours. Rabbit polyclonal antiserum was raised to a fragment of VST I and used to immunostain sections (5 microns) of wax-embedded tumour tissue. Immunoreactivity (IR) was detected using swine anti-rabbit fluorescein secondary antibody and sections were viewed by fluorescence microscopy. Of 24 tumours from patients with lung carcinoids, one was weakly positive, while 23 of 26 ileal carcinoid tumours were immunoreactive. Metastatic deposits from patients with ileal carcinoids also tended to be immunoreactive (9/10). The difference in IR between lung and ileal carcinoid primary tumours did not appear to be related to the metastatic potential, since appendiceal tumours, which seldom metastasize, also tended to be immunoreactive (4/6) for VST I. The strongest IR was recorded in two patients with flushing as a result of ileal carcinoids; five other 'flushers' with ileal carcinoids were also immunopositive for VST I-like IR. By contrast, patients with flushing as a result of lung carcinoids were immunonegative for VST. In conclusion, VST I-like IR may assist in the identification of a secondary deposit from an unknown primary site.

Changes in free and bound alcohol metabolites in the urine during ethanol oxidation

Free and bound ethanol, acetaldehyde, acetate, acetone and methanol in urine during alcohol oxidation were analyzed by means of a head space gas chromatography. Four healthy male volunteers drank beer for 20 min with 16 ml/kg for non-flushers (A, B) and 8 ml/kg for flushers (C, D). In the urine, the highest bound ethanol levels were between 0.5-1.1 mM for the non-flushers (NF) and 0.2-0.3 mM for the flushers (F). The urine free ethanol levels were 23-70 times as high as bound ethanol levels. The maximum free acetaldehyde in urine was 11-13 microM for the NF and 26-55 microM for the F. The urine bound acetaldehyde levels were 4-5 microM for the NF and 7-15 microM for the F. Urine acetaldehyde existed in free forms at 2.4-3.6 times as high concentrations as in bound forms during ethanol oxidation. The urine free acetate ranged between 0.3-2.0 mM. The bound acetate varied between 0.7-1.1 mM. The urine free methanol at 70-110 microM before the intake increased to 104-180 microM. The bound methanol reached to 78-126 microM from 48-97 microM before the intake. Ethanol levels in the urine were ethanol dose-dependent, whereas it was thought that free and bound acetaldehyde or acetate reflected individual metabolic abilities and not the amount of ethanol consumed.

Plasma substance-P in neuroendocrine tumors and idiopathic flushing: the value of pentagastrin stimulation tests and the effects of somatostatin analog

We examined the role of the potent vasoactive kinin substance-P (SP) in flushing derived from various causes. SP was measured in plasma after acetone/ether extraction using an antiserum directed at the carboxy-terminal 5-11 amino acid region of undecapeptide SP. The antiserum had less than 1% cross-reaction with the other neurokinins, neurokinin-A and neuropeptide-K, that derive from the beta-preprotachykinin gene and share carboxy-terminal residues. Basal and pentagastrin-stimulated SP levels were measured in 22 healthy controls, 11 patients with histologically proven carcinoid tumors, 8 patients with tumors other than carcinoid, and 7 patients with idiopathic flushing (IF). Basal SP levels were less than 10 pg/mL in normal subjects. All patients with midgut carcinoid tumors had SP levels greater than 25 pg/mL, as did 7 of 8 patients with noncarcinoid tumors and 5 of 7 patients with IF. Using 50 pg/mL as the cutoff point, the sensitivity was 63% for detection of a tumor, and 100% of nontumor patients were excluded. Pentagastrin administration uniformly induced flushing and caused a rise in SP levels greater than 150 pg/mL in 5 of 10 patients with carcinoid tumors, 3 of 8 with noncarcinoid tumors, and 0 of 7 with IF, i.e. a SP rise of more than 100 pg/mL suggests a tumor. Administration of somatostatin (150 micrograms) 0.5 h before the pentagastrin abolished flushing in all carcinoid patients and reduced SP levels, but not into the normal range. Long term treatment with SMS significantly reduced flushing and lowered SP levels, but did not restore these to normal. We conclude that 90% of patients with carcinoid/noncarcinoid tumor have raised COOH-terminal SP levels. A basal level above 50 pg/mL or a pentagastrin-stimulated rise of more than 100 pg/mL distinguishes carcinoid from IF. The dissociation between SP concentrations and flushing suggests that SP may not be the only kinin involved in the flushing associated with carcinoid tumors.

Distinguishing features of idiopathic flushing and carcinoid syndrome

We compared the clinical and biochemical profiles of 11 patients with idiopathic flushing (IF) with those of eight patients with carcinoid syndrome (CS). Patients with IF were more often women, had a longer duration of symptoms, and were younger. Palpitations, syncope, and hypotension occurred only in patients with IF, while wheezing and abdominal pain occurred only with CS; diarrhea occurred in both types of patients. Elevated blood serotonin levels were present primarily in CS. Increased levels of urine 5-hydroxyindoleacetic acid was specific for CS but unsufficiently sensitive to detect all cases. Abnormalities of gut and vasoactive peptides failed to distinguish the two conditions. Flushing in carcinoid patients responds uniformly to octreotide (Sandostatin), but only one third of the patients with IF are relieved of the symptom. Patients with IF have features that distinguish them from individuals with flushing from other causes, such as CS, postmenopausal state, chlorpropamide-alcohol flush, panic attacks, medullary thyroid carcinoma, and autonomic epilepsy. Familiarity with the clinical and biochemical features of IF should facilitate evaluation and identification of these patients.

Drug-alcohol flush reaction and breath acetaldehyde concentration: no interference with an infrared breath alcohol analyzer

Human volunteers were given a small dose of ethanol (0.25 g/kg body weight) after pretreatment with either calcium carbimide (50 mg) or a placebo according to a crossover design. Calcium carbimide, an inhibitor of aldehyde dehydrogenase, caused intense facial flushing and a pronounced rise in the concentration of acetaldehyde in breath. At 15-min intervals throughout the experiment, breath-ethanol concentrations were determined both by gas chromatography (GC) (specific method) and by infrared (IR) spectrometry with an Intoxilyzer model 4011 breath-alcohol analyzer. The results with these two independent methods of analysis were compared in experiments with and without calcium carbimide pretreatment. The regression equations relating breath-ethanol determinations by GC and IR methods in the two test situations were not significantly different. The elevated breath concentrations of acetaldehyde associated with a drug-alcohol flush reaction do not invalidate the use of infrared breath-alcohol devices for evidential purposes.