Suppressive effects of milk-derived lactoferrin on psychological stress in adult rats

Lactoferrin (LF) is known as an iron-binding glycoprotein. It has been shown that bovine LF (bLF) is transported into cerebrospinal fluid via blood although its physiological effects in the central nervous system (CNS) are still unclear. In this study, a suppressive effect of bLF on psychological distress was investigated in adult rats. Intraperitoneal injection of bLF (100 mg/kg) reduced stressful behaviors in a conditioned fear-induced freezing test and an elevated plus-maze test. Interestingly, the suppressive effect of bLF was enhanced by pretreatment with electric foot-shock (FS). This suppressive effect of bLF in the elevated plus-maze test was reversed by pretreatment with naloxone, an opioid receptor antagonist, at a dose of 1 mg/kg (ip). N(omega)-nitro-l-arginine methyl ester (l-NAME), a nitric oxide synthase (NOS) inhibitor, also blocked the suppressive effect of bLF and foot-shock. In addition, combined application of a low dose of bLF (30 mg/kg, ip) and l-arginine (30 and 100 mg/kg, ip) showed significant potentiated effects on psychological stress. These results suggest that bLF has suppressive effects on psychological distress, especially under the condition of moderate stress. Furthermore, it is suggested that bLF possibly activates an endogenous opioidergic system via nitric oxide synthase activation.     

A trial of a smoking rate survey using the coming-of-age ceremony for evaluating action plans to prevent tobacco use in the young

PURPOSE: To assess a smoking rate survey using the coming-of-age ceremony to examine the practicality for estimating the under twenties' smoking rate as a baseline and a long term assessment index for action plans to prevent smoking in the young. METHODS: We undertook the survey at village A (with a population of about 6,500) and town B (with about 12,000 residents) in Niigata Prefecture. Village A started a comprehensive anti-smoking policy featuring cooperation between schools and the community. Subjects were twenty-year young adults (69 in village A and 118 in town B) who attended rural coming-of-age ceremonies in 2002. The self-rated questionnaire included smoking habits, age of first smoking experience, and age of becoming a regular smoker (only in village A). RESULTS: Smoking rates were 68.0% for men and 48.6% for women in village A. Of these, approximately 90% smoked daily and more than 70% became regular smokers before the age of 20. Smoking rates in town B were similar. The results were about 20% higher than found by a smoking rate survey performed at high schools. CONCLUSION: Smoking rate surveys at coming-of-age ceremonies offer a practical and easy approach to estimate under twenties' smoking rate and assess the effects of smoking prevention strategies among the young.     

Identification of 33 polymorphisms in the adipocyte-derived leucine aminopeptidase (ALAP) gene and possible association with hypertension

Adipocyte-derived leucine aminopeptidase (ALAP) inactivates angiotensin II and/or generates bradykinin in the kidney, suggesting a possible role for ALAP in the regulation of blood pressure. We considered the hypothesis that genomic variants of the ALAP gene are associated with hypertension or individual variations in blood pressure. We screened for mutations in the ALAP gene in 48 unrelated Japanese individuals and identified 33 polymorphisms including 15 novel polymorphisms. We then performed a two-stage analysis. In the first stage, the eight missense polymorphisms were evaluated for associations with blood pressure in 96 apparently healthy individuals. In the second stage, only the most promising polymorphisms were evaluated for association with essential hypertension in 143 hypertensive and 348 normotensive subjects. Among the eight missense polymorphisms, the Ile276Met and Lys528Arg polymorphisms showed significant association with blood pressure. Subsequent analysis confirmed association between the Lys528Arg polymorphism and essential hypertension. The estimated odds ratio for essential hypertension was 2.3 for presence of the Arg allele at codon 528, in comparison with presence of the Lys/Lys genotype (P = 0.004). These findings support involvement of ALAP in the regulation of blood pressure.     

Increased plasma concentrations of the mature form of adrenomedullin during cardiac surgery and hepatosplanchnic hypoperfusion

Adrenomedullin is a potent vasodilatory peptide. Plasma adrenomedullin (AM) concentrations increase during and after cardiopulmonary bypass (CPB). However, the cause of this increase and its site of production have not been identified. We investigated the role of the hepatosplanchnic and cerebral circulations in the increase of plasma AM and investigated whether tissue hypoxygenation is a cause of the AM increase seen during CPB. We measured plasma total AM (AM-T) and the biologically active form of AM, mature AM (AM-m), in seven patients undergoing CPB. Both plasma AM-T and AM-m concentrations increased significantly 60 min after weaning from CPB. At this time point, arterial AM-T and AM-m concentrations were 18-fold and 10-fold larger, respectively, than baseline values measured after the induction of anesthesia. The plasma AM-m concentration and the ratio of AM-m/AM-T in blood from the hepatic vein were significantly larger than those from the radial artery or jugular bulb. The AM-m/AM-T ratio decreased during CPB, suggesting that production of the intermediate form of AM, AM-glycine, is more than that of AM-m. The oxygen tension of the hepatic venous blood (PhvO2) was significantly less during CPB. Plasma AM-m concentrations sampled from the hepatic vein showed a significant negative correlation with PhvO2 at 10 min (r = 0.824; P < 0.02) and 60 min (r = 0.828; P < 0.02) after the onset of CPB. These data suggest that the hepatosplanchnic circulation is an important source of AM-m during CPB. Furthermore, hypoxygenation of the hepatosplanchnic region may be an important cause of this AM-m increase.     

Sudden increase in bispectral index during propofol anesthesia in three patients

We report 3 patients who developed a sudden unpredicted increase in bispectral index (BIS) value during propofol and fentanyl anesthesia. The patients were induced with propofol 2-mg.kg-1 and fentanyl 2-micrograms.kg-1 and muscle relaxation was obtained by vecuronium 0.12-mg.kg-1. During induction of anesthesia, BIS value went down to below 50 in all three cases, and anesthesia was maintained by continuous infusion of propofol at a rate of 5 mg.kg-1.hr-1 and intermittent administration of fentanyl. Forty to sixty min after starting the operation, BIS value increased suddenly (up to 80) and the body movement of the patients was observed. The serum concentration of propofol was approximately 2.5 micrograms.ml-1. All patients were successfully treated with increasing the infusion rate of propofol and additional administration of fentanyl. No clear recall or explicit memory during operation was observed after anesthesia, but, anesthesiologists might have to pay more attention to unpredictable changes of anesthetic depth during propofol anesthesia using target controlled infusion.     

Pharmacological studies on Y-8894. (VII). Effects on transient cerebral ischemia-induced amnesia in rats

The effects of Y-8894 on experimental amnesia in rats induced by transient cerebral ischemia (600 sec) according to the method of Pulsinelli and Brierley were studied using the one trial passive avoidance response and the pole climbing discrete avoidance response. All drugs were administered to the rats immediately after recirculation. The following results were obtained: 1) In the one trial passive avoidance response test, Y-8894 (2.5, 5 and 10 mg/kg, i.p.) improved significantly the decreased latency induced by the ischemia, and it was most effective at 5 mg/kg. Calcium-hopantenate (100, 250 and 500 mg/kg, i.p.) and dihydroergotoxine (5 and 10 mg/kg, i.p.) tended to increase the latency. On the other hand, physostigmine (0.025, 0.05 and 0.1 mg/kg, i.p.), a cholinesterase inhibitor, increased the latency significantly, and it was most effective at 0.05 mg/kg. 2) The pole climbing discrete avoidance response was significantly decreased by the ischemia compared with the sham operated group, and Y-8894 (5 mg/kg, i.p.) tended to improve this decreased avoidance response. 3) Y-8894 (5 mg/kg, i.p.) facilitated recovery from the changes in glycolytic metabolism, and inhibited the accumulation of choline due to the dysfunction of the neuronal membranes induced by the ischemia. These results show that Y-8894 has beneficial effects on experimental amnesia induced by transient cerebral ischemia.     

Pharmacological studies on Y-8894 (VI). The effect on monoamine uptake and turnover in mouse brain

The effect of Y-8894 (+/-) 2-[[o-(2-thenyl)phenoxy]methyl] morpholine maleate, which has been shown to improve experimentally induced learning and memory deficits, on cerebral monoamine uptake and turnover was studied in the mouse. The following results were obtained: 1) It inhibited in vitro norepinephrine (NE) uptake to the mouse cerebral synaptosomal fractions about 800 and 1250 times more potently than it did those of dopamine (DA) and serotonin (5-HT), respectively. 2) It dose-dependently inhibited in vivo NE uptake, but not DA or 5-HT uptake. 3) It reduced the accumulation of the NE metabolite, 3-methoxy-4-hydroxyphenylglycol (MHPG), increased that of the 5-HT metabolite, 5-hydroxyindoleacetic acid (5-HIAA), and had no effect on that of the DA metabolite, homovanillic acid (HVA). These effects were compared with those of imipramine, calcium hopantenate (Ca-hopantenate) and dihydroergotoxine. Y-8894 appeared to act by stimulating the noradrenergic receptor, and it acts to a lesser extent by blocking the serotonergic receptor in the brain.