Cardioprotective efficacy of dinitrosyl iron complex with L-cysteine in rats in vivo

The effect of dinitrosyl iron complex (DNIC) with L-cysteine on the hemodynamic indices and the size of myocardial infarction, which was induced by 40-min regional ischemia and subsequent 60-min reperfusion, have been studied in rats in vivo. Intravenous bolus injection of DNIC (3.1 μmol/kg body weight in 0.5 ml saline) was performed before regional ischemia; the control group was administered the same volume of saline. DNIC administration significantly decreased the mean blood pressure throughout the experiment. DNIC reduced the duration of cardiac arrhythmias to 170 ± 10 s as against 445 ± 30 s in control. The myocardial infraction size significantly decreased in the DNIC group compared to control (38.0 ± 1.4 and 48.0 ± 3.9% of the area at risk, respectively; p < 0.05). A combination of the vasodilatory effect of DNIC with the reduction of the damaging effect of cardiac ischemia and reperfusion encourage the development of hypotensive and antiischemic drugs on this class of NO donors.     

Doses of prostaglandin F2α effective for induction of parturition in goats

Twelve mixed breed does were injected with different doses of prostaglandin F₂α (PGF₂α) or saline on day 144 of gestation. Four each received single intramuscular injections of 5.0 or 2.5 mg PGF_2α, or 1.0 ml saline (controls). Systemic progesterone (P₄) concentrations were determined daily from day 144 until the day of kidding. Does receiving 5.0 mg PGF₂α, 2.5 mg PGF₂α, or saline kidded within mean (± SD) hours and range (hours) of 35 ± 8.6 and 28–48, 43 ± 11.8 and 29–57, and 111 ± 79.1 and 41–200, respectively. Mean (± SD) concentrations of P₄ (ng/ml) on the day of injection and on day 1 postinjection were 5.2 ± 2.6 and 0.7 ± 0.9, 5.3 ± 2.2 and 1.1 ± 1.0, and 6.4 ± 3.9 and 4.1 ± 2.6 for does receiving 5.0 mg PGF₂α, 2.5 mg PGF₂α, or saline, respectively. It was concluded that 5.0 mg and 2.5 mg PGF₂α effectively shortened the interval from injection to parturition, but that this interval was not as predictable as that previously reported with 20 mg PGF₂α.     

The life cycle of Haemaphysalis qinghaiensis (Acari: Ixodidae) ticks under laboratory conditions

The developmental stages in the life cycle of Haemaphysalis qinghaiensis were investigated under laboratory conditions. The larval, nymphal and adult ticks were fed on sheep at 25–27 °C, 50 % relative humidity (RH) and exposed to daylight. All free-living stages were maintained in an incubator (28 °C with 90 % RH and a 12-h photoperiod). The whole life cycle of H. qinghaiensis was completed in an average of 176 days (range 118–247 days). The average developmental periods were 34.44 days for egg incubation; 5.83, 4.20 and 33.70 days for larval pre-feeding, feeding and pre-molting; and 3.88, 5.30 and 46.50 days for nymphal pre-feeding, feeding and pre-molting. The average times for pre-feeding, feeding, pre-oviposition and oviposition of female adult ticks were 2.60, 11.40, 8.50, and 19.35 days, respectively. The results confirmed the positive correlation between the weight of the engorged female and the egg mass laid (r = 0.557, P < 0.05). The reproductive efficiency index and reproductive fitness index in females were 5.49 and 4.98, respectively. Engorged nymphs moulting to females (4.53 ± 0.16 mg) were significantly heavier (P < 0.001) than those moulting to males (3.45 ± 0.19 mg). The overall sex ratio of the adult ticks was 1:1.1 (M:F).     

<Emphasis Type="Italic">HMG1A</Emphasis> and <Emphasis Type="Italic">PPARG</Emphasis> are differently expressed in the liver of fat and lean broilers

The expression of nine functional candidates for QT abdominal fat weight and relative abdominal fat content was investigated by real-time polymerase chain reaction (PCR) in the liver, adipose tissue, colon, muscle, pituitary gland and brain of broilers. The high mobility group AT-hook 1 (HMG1A) gene was up-regulated in liver with a ratio of means of 2.90 (P?≤?0.01) in the «fatty» group (relative abdominal fat content 3.5?±?0.18%, abdominal fat weight 35.4?±?6.09 g) relative to the «lean» group (relative abdominal fat content 1.9?±?0.56%, abdominal fat weight 19.2?±?5.06 g). Expression of this gene was highly correlated with the relative abdominal fat content (0.70, P?≤?0.01) and abdominal fat weight (0.70, P?≤?0.01). The peroxisome proliferator-activated receptor gamma (PPARG) gene was also up-regulated in the liver with a ratio of means of 3.34 (P?≤?0.01) in the «fatty» group relative to the «lean» group. Correlation of its expression was significant with both the relative abdominal fat content (0.55, P?≤?0.05) and the abdominal fat weight (0.57, P?≤?0.01). These data suggest that the HMG1A and PPARG genes were candidate genes for abdominal fat deposition in chickens. Searching of rSNPs in regulatory regions of the HMG1A and PPARG genes could provide a tool for gene-assisted selection.     

Field and laboratory studies in a Neotropical population of the spinose ear tick, Otobius megnini

Abstract One ear of each of five cows on a property close to Dean Funes, province of Córdoba, Argentina, was inspected monthly from December 2004 to November 2006 to determine the presence of Otobius megnini (Dugès) and to ascertain its seasonality. Ticks were collected to study the biological parameters of larvae, nymphs and adult ticks. Groups of nymphs were also maintained at three different photoperiods at 25 °C. The abundance of immature stages was greatest during January–April and August–October in the first and second years of the study, respectively. No larvae successfully moulted. Nymphs weighing < 17 mg also failed to moult, but 89% of heavier nymphs moulted into adults. Nymphs moulting to males weighed less (49.5 ± 16.09 mg) than nymphs moulting to females (98.1 ± 34.08 mg). The pre‐moult period was similar for nymphs moulting to either sex and significantly longer (P < 0.01) for female nymphs maintained at 25 °C compared with nymphs kept at 27 °C. No effect of photoperiod on the pre‐moult periods of nymphs was detected. Female ticks produced a mean of 7.0 ± 1.94 egg batches after a preoviposition period of 16.4 ± 8.41 days for the first batch. The mean oviposition period was 61 ± 20.8 days and the duration of oviposition for each batch varied from 1 to 6 days. The mean number of eggs per batch was 93.1 ± 87.53. The minimum incubation period for the first egg batch was 13.6 ± 2.77 days. The total number of eggs laid by each female was 651.6 ± 288.90. Parthenogenesis was not observed. The reproductive efficiency index (REI) (number of eggs laid/weight of female in mg) was 5.5 ± 1.26. Pearson’s correlations showed a significant direct relationship between the weight of the female and number of eggs laid (P < 0.01) and REI (P < 0.05). Several of the biological values presented above for the tick population from the Neotropical zoogeographic region showed marked differences to equivalent values for O. megnini populations from the U.S.A. (Nearctic) and India (Oriental). Nevertheless, the only two sequences of 16S rDNA deposited in GenBank from ticks originating in Argentina and allegedly in the U.S.A. indicate that they are conspecific (99.8% agreement). We tentatively consider the biological differences among populations of this tick species to represent adaptations for survival at different conditions.     

The persistence of blood-flow oscillations in the rat kidney

The nonlinear dynamics of renal blood-flow oscillations in rats were studied in baseline conditions and a perturbed state. An intramuscular injection of aspirin in 0.9% saline (0.5 mg per 100 g body weight) served as the perturbation factor. Capillary blood flow in the right kidney was measured by laser Doppler flowmetry. The persistence of the time series was estimated by the Hurst method. The time series were shown to persist in the baseline conditions (Hurst index H = 0.817 ± 0.041). The statistical parameters of the perturbed state significantly differed from those that were observed at the baseline. However, the perturbed series remained persistent. The Hurst index for the series was H = 0.677 ± 0.057. The decrease in the index relative to the baseline was insignificant.     

Attenuation of oxidative damage-associated cognitive decline by Withania somnifera in rat model of streptozotocin-induced cognitive impairment

Oxidative stress is a critical contributing factor to age-related neurodegenerative disorders. Therefore, the inhibition of oxidative damage, responsible for chronic detrimental neurodegeneration, is an important strategy for neuroprotective therapy. Withania somnifera (WS) extract has been reported to have potent antioxidant and free radical quenching properties in various disease conditions. The present study evaluated the hypothesis that WS extract would reduce oxidative stress-associated neurodegeneration after intracerebroventricular injection of streptozotocin (ICV-STZ) in rats. To test this hypothesis, male Wistar rats were pretreated with WS extract at doses of 100, 200, and 300 mg/kg body weight once daily for 3 weeks. On day 22nd, the rats were infused bilaterally with ICV-STZ injection (3 mg/kg body weight) in normal saline while sham group received only saline. Two weeks after the lesioning, STZ-infused rats showed cognitive impairment in the Morris water maze test. The rats were sacrificed after 3 weeks of the lesioning for the estimation of the contents of lipid peroxidation, reduced glutathione, and activities of glutathione reductase, glutathione peroxidase, and catalase. Pretreatment with WS extract attenuated behavioral, biochemical, and histological alterations significantly in dose-dependent manner in the hippocampus and cerebral cortex of ICV-STZ-infused rats. These results suggest that WS affords a beneficial effect on cognitive deficit by ameliorating oxidative damage induced by streptozotocin in a model of cognitive impairment.     

Ovarian activity in synchronized mares following administration of follicle stimulating hormone

Twelve non-pregnant, non-lactating, light horse type mares of unknown breeding were randomly assigned to two treatment groups with six replicates per group. Mares were administered PGF_2α (10 mg, IM) on days 0 and 14, and HCG (3000 IU, IM) on days 6 and 20. Group A received FSH (5 units, IM) twice daily (06.00 and 18.00 h) on days 15 through 10. Group B received saline twice daily (06.00 and 18.00 h) on days 15 through 19. Ovaries were recovered at necropsy on day 30 (10 days post-ovulation). Ovaries were weighed, CL number and weight determined, follicles counted and measured, and volume of follicular fluid quantified.Mean ovarian weight (g) and number of CL per mare, respectively, were: Group A, 148.1 ± 62.3, 0.83 ± 0.31; Group B, 91.3 ± 16.8, 0.83 ± 0.81. Mean number of follicles > 10 mm and total volume (ml) of follicular fluid per mare, respectively, were: Group A, 2.25 ± 0.71, 38.7 ± 26.3; Group B, 2.25 ± 0.73, 14.7 ± 4.9. There was no difference (P > 0.05) in mean ovarian weight, CL number, CL weight, follicular fluid volume, number of follicles, or size of follicles between treatment groups. These results show no significant effect on ovarian activity in mares following administration of exogenous FSH.     

Is there an opiate receptor in the snail Megalobulimus sanctipauli? Action of morphine and naloxone

The effects of morphine sulfate (10, 15 and 20 mg/kg) or saline control (5 mg/kg) on the latency of the anterior body-lifting response to heat (avoidance response) were determined in four groups of snails Megalobulimus sanctipauli (n = 6) individually placed on a metal plate mounted on the surface of a water bath at 52 ± 1°C. The effects of pre-treatment with naloxone hydrochloride (5 mg/kg) or saline (2.5 ml/kg) control on the responses to morphine (15 mg/kg) were determined in two different groups of animals (n = 6). Administration of morphine resulted in an increase in the avoidance behavior latency with maximum effects occuring at 15 mg/kg, 10–15 min after injection. The effects of morphine disappeared within 90–120 min. Saline treatment had no detectable effects on the latency of the response to an aversive stimulus. Naloxone significantly blocked (P < 0.05, Student paired t-test) the increase in avoidance behavior latency. The present results indicate that: 1. morphine has an antinociceptive effect on the response of Megalobulimus sanctipauli to an aversive thermal stimulus; and 2. the morphine-induced “analgesia” may be caused by the stimulation of μ opiate receptors.     

Analgesic Effects of β-Phenylethylamine and Various Methylated Derivatives in Mice

Administration of β-phenylethylamine (PEA), the simplest endogenous neuroamine, and various methylated PEA derivatives including α-methyl PEA (amphetamine, AMP) elicits analgesia in mice. Five or 20 min after intraperitoneal PEA injection of as little as 6 mg/kg resulted in an increased latency response time (from 2.4 ± 0.4 to 8.5 ± 2.3 or 7.0 ± 3.0 s, respectively) to the thermal stimulus (hot-plate test), which reached statistical significance at the 15 mg/kg (20 min; 13.1 ± 0.4 s) or 25 mg/kg dose (5 min; 15.3 ± 4.1 s). This PEA effect, was dose-dependent (albeit non-linear: 6, 12, 15, 25, 50 and 100 mg/kg), reached the cut-off time of 45 s at the upper PEA dose (5 min), and it was consistently enhanced by pretreatment with the monoamine oxidase inhibitor pargyline (P). Methylated PEA derivatives (15 and 100 mg/kg dose) produced various degrees of analgesia (in decreasing order p-Me PEA > PEA > N,N-diMe PEA > N-Me PEA) which, likewise to PEA itself, were consistently increased by P and declined over time (mice tested 5, 20 and 60 min after amine injection); small but statistically significant o- and β-Me PEA antinociceptive effects (5 min) were observed only at the higher dose (in the presence of P for β-Me PEA). A small analgesic effect was observed after the administration of AMP (5 or 10 mg/kg) which failed, even after P, to reach statistically significance. Independent of the amine and concentration tested, individual compound’s antinociceptive properties were reliably increased by P (exception of AMP), decreased by reserpine (R) or haloperidol (H), and remained essentially unchanged after naloxone (N) administration suggesting the involvement of catecholamines, but not opioid peptides, in their observed analgesic effects. Injection of P + N produced results similar to those seen after P alone. Under the experimental conditions described neither P, R, H or N had any effects by themselves. These findings suggest additional understanding of the mechanism of action responsible for the analgesic effects of these amines would be of interest, leading further to controlled studies on their alleged usefulness as weight reducing agents and sport performance enhancers.     

Développement endoparasitaire et croissance pondérale larvaire du parasitoïdeLixophaga diatraeae [Dip.: Tachinidae] dans un hôte de substitution:Galleria mellonella [Lep.: Pyralidae]

Résumé L'étude du développement endoparasitaire deLixophaga diatraeae (Towns.) dans un h?te de substitutionGalleria mellonella L. a été effectuée par dissections d'h?tes hébergeant des parasito?des d'age connu. Les résultats mentionnés sont obtenus avec en movenge 2.6 parasito?des par h?te. Les élevages ont lieu à 22.5±0.5°C et 85±5 % H.R. avec une photophase de 12 h pourL. diatraeae et à 28±1°C à l'obscurité pourG. mellonella. La croissance pondérale larvaire suit une loi exponentielle et correspond à un temps de doublement du poids de 0,65 j pour les stades 1 et 2 et environ 0,8 j pour le stade 3. Le développement larvaire complet requiert 7,5 j en moyenne. Les stades 1,2 et 3 durent en moyenne respectivement 2,9, 2,5 et 2,1 j. La mue larvaire L₁–L₂ intervient vers 0,23 mg et la mue L₂–L₃ vers 3,2 mg. La larve nouvelle née pèse 12,3 μg et la croissance larvaire représente un facteur multiplicatif maximum d'environ 2 500 fois. Le poids moyen des pupes obtenues est de 14,2 mg.

---

Summary Endoparasitic development ofLixophaga diatraeae (Towns.) reared in a substitution hostGalleria mellonella L. was studied by dissections of hosts containing known aged parasitoids. The exposed results are obtained with an average of 2,6 parasitoids per host. Rearing ofL. diatraeae was performed at 22.5±0.5°C and 85±5% R.H. with 12 light hours and rearing ofG. mellonella at 28±1°C in darkness. The larval weight growth is exponential and exhibits a doubling time of 0.65 day for the 1st and 2nd stages and around 0.8 d. for the 3rd stage. Mean complete larval development time is 7.5 days. The 1, 2 and 3 stages last respectively 2.9, 2.5 and 2.1 days. Larval moulting 1–2 happens around 0.23 mg and moulting 2–3 around 3.2 mg. New hatched larva weights 12.3 μg and during larval growth multiplicates its weight by about 2,500. The mean pupal weight is 14.2 mg.

---

---

Nous remercionsColette Ogier pour sa collaboration technique,P. Laviolette etG. Bonnot pour leur lecture critique du manuscrit.     

Cardioprotective properties of natural medicine in isoproterenol induced myocardial damage in the male Albino rats

The main aim of this study is to investigate cardioprotective properties of natural medicine inmyocardial damage induced male Albino rats. The aqueous extractof Allium sativumwas used for the determination of phenolic compounds and flavonoids. The amount of phenol (1.39 ± 0.37 GAE/g dry weight) and flavonoids (49.1 ± 2.79 QE/g dry weight) were high in aqueous extract. A. sativumextract and showed 68.39 ± 3.6% DPPHscavenging activity. Isoproterenol was used to induce myocardial injury in Albino rats in vivo by subcutaneous injection (100 mg/kg body weight). To achieve this, experimental animals were categorized into six groups (n = 4), namely, positive, negative control, only isoproterenol administered groups, and garlic extract administered group at 100–300 mg extract/kg body weight. Oxidative stress marker and cardiac markers were assayed to analyze the cardioprotective properties of garlic extract. At 300 mg/kg doseof garlic extract, rat was recovered from various altered factors such as, aspartate aminotransferase, alkaline transminase and alkaline phosphatase. The rats treated with 300 mggarlic extract/kg body weight decreased the level of asparate aminotransferase (126 ± 6.4 IU/L) than other lower doses (100 mg extract/kg and 200 mg extract/kg). Alkaline transaminase level of rat serum level was 81 ± 4.34 IU/L. In the isoproterenol treated rats elevated level was observed (152 ± 4.42 IU/L enzyme activity). Pre-treatment of Albino rat with A. sativum extract reduced cardiac damage. Isoproterenol exposed animal showed 207.6 ± 1.2 mg/dL triglyceride and the garlic administered rat (300 mgextract/kg) reduced LDL-cholesterol level (61.3 ± 1.3 mg/dL) significantly (p < 0.05). Creatinine kinase -MB level was 269.5 ± 12.5 IU/L in the control animal and stress induced animal showed elevated level (572.3 ± 19.4 IU/L). Garlic treated experimental animal (300 µg/kg bw) decreased CK-MB level. To conclude, the aqueous extract of A. sativumshowed cardio protective properties against myocardial injury.     

The influence of heart disease on characteristics, quality of life, use of health resources, and costs of COPD in primary care settings

Background

Ectonucleotidase dependent adenosine generation has been implicated in preconditioning related cardioprotection against ischemia-reperfusion injury, and treatment with a soluble ectonucleotidase has been shown to reduce myocardial infarct size (IS) when applied prior to induction of ischemia. However, ectonucleotidase treatment according to a clinically applicable protocol, with administration only after induction of ischemia, has not previously been evaluated. We therefore investigated if treatment with the ectonucleotidase apyrase, according to a clinically applicable protocol, would reduce IS and microvascular obstruction (MO) in a large animal model.

Methods

A percutaneous coronary intervention balloon was inflated in the left anterior descending artery for 40 min, in 16 anesthetized pigs (40-50 kg). The pigs were randomized to 40 min of 1 ml/min intracoronary infusion of apyrase (10 U/ml, n = 8) or saline (0.9 mg/ml, n = 8), twenty minutes after balloon inflation. Area at risk (AAR) was evaluated by ex vivo SPECT. IS and MO were evaluated by ex vivo MRI.

Results

No differences were observed between the apyrase group and saline group with respect to IS/AAR (75.7 ± 4.2% vs 69.4 ± 5.0%, p = NS) or MO (10.7 ± 4.8% vs 11.4 ± 4.8%, p = NS), but apyrase prolonged the post-ischemic reactive hyperemia.

Conclusion

Apyrase treatment according to a clinically applicable protocol, with administration of apyrase after induction of ischemia, does not reduce myocardial infarct size or microvascular obstruction.     

Prolactin secretion in cattle as affected by haloperidol and α-Methyl-p-Tyrosine

Prolactin (PRL) secretion in response to i.v. injection of different doses of α-Methyl-p-Tyrosine (αMT) and haloperidol (HAL) was studied in one cow and three bulls. HAL was tested at doses of 0.033, 0.1, and 0.33 mg/kg body weight (BW), and αMT was tested at doses of 0.1, 1.0, 10, and 30 mg/kg BW. Blood was collected via an indwelling catheter into the external jugular vein, and plasma PRL was analysed by radioimmunoassay. Dose-related increases in plasma PRL concentrations were observed after administration of both αMT and HAL. Peak PRL concentrations after injection of HAL at a low, medium, and high dose were 22, 45, and 70 ng/ml, respectively. Peak PRL concentrations after injection of increasing doses of αMT were 3.0, 10, 40 and 70 ng/ml. HAL (0.1 mg/kg BW) and αMT (10 mg/kg BW) were administered intravenously to four heifers during summer and winter. Response to both drugs, as measured by changes in PRL secretion, was greater in summer than winter. Peak plasma PRL levels after HAL injection were 327 ± 58 ng/ml in June and 149 ± 27 ng/ml in January, whereas peak levels after αMT were 166±29 and 60±9 ng/ml, respectively. Basal PRL secretion was also greater in summer than winter. The results of this study demonstrate that PRL in peripheral plasma of cattle is increased in response to administration of antidopaminergic drugs and that this increase is greater during the summer than the winter.     

Visceral and Subcutaneous Adipose Tissue Diacylglycerol Acyltransferase Activity in Humans

Diacylglycerol acyltransferase (DGAT) could be a rate limiting step in triglyceride (TG) synthesis as it is the final step in this pathway. As such, between depot differences in DGAT activity could influence regional fat storage. DGAT activity and in vitro rates of direct free fatty acid (FFA) storage were measured in abdominal subcutaneous and omental adipose tissue samples from 12 nonobese (BMI <30 kg/m²) and 23 obese men and women (BMI >30 kg/m²) undergoing elective surgery. DGAT activity was greater in omental than in abdominal subcutaneous adipose tissue from nonobese patients (2.0 ± 0.9 vs. 0.9 ± 0.3 pmol/min/mg lipid, respectively, P = 0.003), but not from obese patients (1.4 ± 0.6 vs. 1.7 ± 0.7 pmol/min/mg lipid, respectively, P = 0.10). DGAT activity per unit adipose weight was negatively correlated with adipocyte size (P < 0.01) and positively correlated with direct FFA storage in omental (P < 0.001) but not in abdominal subcutaneous fat. Tissue DGAT activity varies as a function of adipocyte size, but this relationship differs between visceral and abdominal subcutaneous fat in obese and nonobese humans. Our results are consistent with the hypothesis that interindividual variations in DGAT activity may be an important regulatory step in visceral adipose tissue FFA uptake/storage.     

A glucocorticoid receptor agonist improves post-weaning growth performance in segregated early-weaned pigs

While beneficial for sow reproductive efficiency and biosecurity, segregated early weaning (SEW) leads to a systemic immune response that adversely affects the digestive physiology and post-weaning growth of pigs. Two experiments were conducted to evaluate the effects of a glucocorticoid receptor agonist (GA) on growth performance, measures of immune function and intestinal integrity of SEW pigs. In both experiments, pigs were fed corn-soybean meal-based starter diets. In the first experiment, 48 pigs (initial BW 4.8 ± 0.7 kg) were weaned at 21 ± 1 days and randomly assigned to three GA treatment groups: 0, 0.2 and 0.6 mg GA/kg of BW injected intramuscularly. Treatments were administered one day before weaning. Pigs in the 0 mg GA group received sterile saline in place of GA. Body weight was measured daily from one day before to 7 days post-weaning, and then weekly until 28 days post-weaning. Piglets treated with 0.2 mg GA had a higher BW than piglets in other treatment groups during the 28-day course of the study (P <0.02). To further explore the mechanisms behind this result, a second experiment was performed in which a total of 18 gilts (BW 5.6 ± 0.85 kg) were randomly assigned into three treatment groups: suckling plus saline (UWS), weaned treated with GA (WGA; 0.2 mg GA/kg BW) and weaned plus saline (CON). Treatments were administered one day before and 3 days post-weaning. The WGA and CON groups were weaned at 23 ± 2 days, while the UWS group remained with sow for the duration of the study. Body weight was measured daily and blood plasma was collected at 0, 1, 4 and 5 days post-weaning. All gilts were euthanized 5 days after weaning and jejunum samples were collected for mucosal scrapings, histomorphological analysis and gene expression analysis. Plasma levels of interleukin-1β (IL-1β) and haptoglobin were lower in WGA pigs compared with CON (P <0.02), while plasma total antioxidant capacity was higher in WGA pigs compared with both CON and UWS groups (P <0.01). Relative to CON, GA downregulated IL-18 gene expression in the jejunum, as assessed by both tissue homogenate and mucosal scrapings, but it upregulated claudin-IV gene expression only in the tissue homogenate (P <0.01). These results suggest that GA treatment improves the growth performance of SEW pigs in part by mitigating the negative effects of systemic inflammation. However, the effect of GA on barrier integrity requires further investigation.     

Diminution de la capacité de surfusion au cours de l'embryogenèse et du développement larvaire chez un coléoptère

Potential cold resistance of non-diapause eggs and first instar larvae of Osmoderma eremita (Coleoptera, Cetoniidae, Trichiinae) during embryogenesis and post-embryonic growth was assessed by measuring individual supercooling points (SCP): sterile eggs had a mean SCP of −24.3 ± 2.0 °C; fertilized newly laid eggs a mean SCP of −23.4 ± 3.2 °C and eggs about to hatch a mean SCP of −9.2 ± 2.9 °C. Water absorption by fertilized eggs is a necessary requirement for the development of the embryo and results in an increase in weight and water content: fertilized newly laid eggs had a mean fresh weight of 10.687 ± 1.072 mg and a mean water content (expressed as a percentage of the dry weight) of 79.5 ± 10.83%; eggs about to hatch had a mean fresh weight of 19.127 ± 3.183 mg and a mean water content of 250.10 ± 74.15%. The ex-ovo larvae, hatched 30 days after oviposition, had a mean SCP of −10.1 ± 3.6 °C (no significant difference with eggs about to hatch) and had gained in weight (24.845 ± 3.911 mg) and in water content (499.72 ± 55.49%). Feeding 1st instar larvae had a decreased supercooling ability (mean SCP = −5.7 ± 0.4 °C) whereas their mean fresh weight (99.858 ± 53.091 mg) and mean water content (665.83 ± 82.74%) increased. The eggs and larvae of O. eremita are freezing intolerant. Before overwintering, all larvae switch to being freezing tolerant and can survive ice formation in their tissues and body fluids, whereas their mean SCP stays at around −5 °C. However, recent experiments in the winter of 1996 have shown that frozen larva mortality does occur at temperatures lower than about −12 °C.     

Short-term inhibition of prolactin secretion by naloxone treatment in the pregnant gilt

The involvement of endogenous opioids in modulation of prolactin (PRL) secretion during pregnancy in the pig was studied. Twenty-four crossbred pregnant gilts (150 ± 10 kg) were cannulated via the cephalic vein 24–48 h before treatment with 1 mg kg⁻¹ body weight of naloxone (NAL) or 3 ml of saline (CONT) i.v. at Day 40 (NAL, n = 6; CONT, n = 6) or Day 70 (NAL, n = 6; CONT, n = 6) of pregnancy. Blood plasma was collected at 15 min intervals from 1 h before to 3 h after treatment with NAL or saline. At Day 40 of pregnancy, administration of NAL caused a decrease in mean plasma PRL concentrations at 60 min, 120 min and 180 min post-treatment (NAL, 19.1 ± 1.3 ng ml⁻¹, P < 0.05; 15.8 ± 0.6 ng ml⁻¹, P < 0.001; 14.6 ± 0.7 ng ml⁻¹, P < 0.001, respectively) when compared with the CONT group (22.9 ± 0.7 ng ml⁻¹, 21.6 ± 0.6 ng ml⁻¹ and 22.4 ± 0.5 ng ml⁻¹, respectively). Mean plasma estradiol concentration was higher (P < 0.01) in the NAL group during the second and third hour post-treatment than in the CONT group. At Day 70 of pregnancy, infusion of NAL also decreased (P < 0.001) plasma PRL concentrations at 60 min, 120 min and 180 min after treatment (20.1 ± 1.6 ng ml⁻¹, 16.2 ± 1.5 ng ml⁻¹ and 14.8 ± 0.4 ng ml⁻¹, respectively) compared with the CONT group (33.4 ± 1.7 ng ml⁻¹, 34.1 ± 1.3 ng ml⁻¹ and 29.1 ± 0.9 ng ml⁻¹, respectively). Estradiol concentrations were not different (P > 0.05) between groups in this stage of gestation. Mean concentrations of progesterone were similar during the pre- and post-treatment periods in both stages of pregnancy.These data would suggest a possible role of the opioids in modulation of PRL secretion at these stages of pregnancy in the pig.     

Effects of deep seawater medium on growth and amino acid profile of a sterile Ulva pertusa Kjellman (Ulvaceae, Chlorophyta)

The potential use of deep seawater (DSW) for the cultivation of macroalgae was evaluated by analysis of the growth rate of thalli (by surface area), photosynthetic pigment content, and total free amino acid content of sterile Ulva pertusa cultured in the control medium (one-fifth strength Provasoli’s enriched seawater (PES) medium), surface seawater (SSW) medium and also seawater medium collected from 400 m depth (400-DSW) and 1,200 m depth (1,200-DSW). The growth rate of the sterile U. pertusa grown in 400-DSW and 1,200-DSW was similar to that of thalli cultured in the one-fifth strength PES medium that had previously been shown to be the optimum concentration for the cultivation of Ulva. Photosynthetic pigment content in the control medium, 400-DSW- and 1,200-DSW-cultured thalli was 1.7–2.0 times higher than that of the SSW-cultured thalli. The total free amino acids content of the control medium and SSW-cultivated thalli was 264?±?64 and 120?±?39 mg per 100 g dry weight, whereas the 400-DSW- and 1,200-DSW-cultivated thalli had significantly more amino acids (342?±?69–327?±?64 mg per 100 g dry weight). The results of this study indicate that DSW has a high potential for cultivation of edible macroalgae without any supply of extra nutrient until it grows to harvest size.     

Skeletal growth in the echinoderm Asterias rubens L. (Asteroidea,Echinodermata) estimated by 45Ca-labelling

The skeletal dry weight of the 4.4 ± 0.2 cm size class of Asterias rubens L. from Kiel Bay in the western Baltic is 0.34 ± 0.08 g. The sum of calcium and magnesium carbonates in the skeleton amounts to 94.0 ± 1.3% while the individual concentrations are 86.9 ± 1.3% CaCO₃ and 7.1 ± 0.7% MgCO₃. The MgCO₃ is 4% lower than expected for a magnesium calcite precipitated under Baltic temperature conditions (8°C). Strontium was not determined but strontium carbonate is known to be in the region of 0.4%. The remainder is organic matter and this gives rise to 2.9 ± 1.3% organic carbon.Animals studied were at the ‘waiting stage’ and their actual growth was minimal. Uptake of ⁴⁵Ca in the skeleton consists of a fast step followed by a slow step. The fast step is attributed to saturation of exchangeable skeletal pools while the slow step is due to net deposition of CaCO₃. Skeletal growth at the waiting stage calculated from the second rate constant was found to be 0.76 μg CaCO₃j-mg skeleton^?1 · day^?1 or 0.09% · day^?1 compared with 9.3 μg CaCO₃ · mg skeleton^t1&#x0304; · day^?1 or 1.1% · day^?1 at log phase. The isotope method is considered superior to size-frequency analysis in that it is capable of detecting differences in growth rate in individuals of the same size class and thus provides an insight into asteroid population structure.