Variations of natural 15N abundances in the tissues and digesta of domestic animals

The natural abundance of 15N (expressed as delta 15N per mil relative to air N2) in the tissues and the change of 15N abundance during the digestion processess in cattle, pig, and goat were investigated. The 15N abundances of cattle tissues differed by about 3.5% with high values in heart, urinary bladder and diaphragm. The ages of cattle did not affect on the 15N abundances of liver and kidney in cattle. The 15N abundances of urine were lower, and those of feces were a little higher than the values of diets in cattle and pigs. The delta 15N values of milk and blood were higher than the value of diets. Two peaks of 15N abundances at forestomach and caecum were observed during the digestion processes of diet in goats. The mechanisms of the variation of 15N abundances in animal bodies were briefly discussed.

The effects of feeding regimen and dietary sucrose supplementation on natural abundance of 15N in some components of ruminal fluid and plasma of sheep

An experiment was conducted to investigate the effects of changes in ruminal conditions arising from feeding and sucrose supplementation to the diet on the natural abundance of 15N (delta 15N value) of some biological components and of feces and urine in sheep. Four wethers fitted with ruminal fistulas were fed on alfalfa hay cubes with or without sucrose either 2 or 12 times daily. With twice-daily feeding, the delta 15N values of ruminal ammonia and plasma urea decreased after feeding, whereas only small changes were observed throughout the sampling period with 12 times daily feeding. With 12 times daily feeding with and without sucrose, the delta 15N values of ruminal ammonia were higher (P < .05) than those of the diet and plasma urea. The delta 15N values of ruminal bacteria were lower (P < .05) than those of ruminal ammonia but higher (P < .05) than those of the diet. The delta 15N values for feces were higher (P < .05) than those of the diet, and no differences (P > .25) were observed between the delta 15N values of urine and those of the diet. Dietary sucrose supplementation lowered (P < .05) the delta 15N values of ruminal ammonia but had no effect (P > .10) on values for ruminal bacteria and plasma urea. Nitrogen excretion in urine was decreased (P < .05) by sucrose supplementation to the diet, but the delta 15N value of urine showed no effect (P > .25) of sucrose addition.(ABSTRACT TRUNCATED AT 250 WORDS)

Salsolinol is present in the bovine posterior pituitary gland and stimulates the release of prolactin both in vivo and in vitro in ruminants

The aims of the present study were to determine whether salsolinol (SAL), a dopamine-related compound, is present in the bovine posterior pituitary (PP) gland, and to clarify the effect of SAL on the secretion of prolactin (PRL) in ruminants. SAL was detected in extract of bovine PP gland using high-pressure liquid chromatography with electrochemical detection (HPLC-EC). A single intravenous (i.v.) injection of SAL (5 and 10mg/kg body weight) significantly and dose-dependently stimulated the release of PRL in goats (P<0.05). Plasma PRL levels reached a peak 10min after the injection, then gradually returned to basal values in 60-80min. The PRL-releasing pattern was similar to that in response to sulpiride (a dopamine receptor antagonist). The intracerebroventricular (i.c.v.) injection of 1mg of SAL had no significant effect on the release of PRL in calves, however, 5mg significantly stimulated the release (P<0.05) with peak values reached 30-40min after the injection. Moreover, SAL significantly stimulated the release of PRL from cultured bovine anterior pituitary cells at doses of 10(-6) and 10(-5)M, compared to control cells (P<0.05). Taken together, our data clearly show that SAL is present in extract of the PP gland of ruminants, and has PRL-releasing activity both in vivo and in vitro. Therefore, this endogenous compound is a strong candidate for the factor having PRL-releasing activity that has been previously detected in extract of the bovine PP gland.

Twelve oxo-eicosatetraenoic acid induces fetal membrane release after delivery in cows

Fetal fibroblast cell culture from cotyledons of bovine placenta and animal experiments close to term were used to elucidate afterbirth release and factors missing in the signal transduction mechanism for retained fetal membranes (RFM) after delivery. In cell culture the addition of arachidonic acid (Ara) to the medium caused rapid release to free floating cell in the culture dish, accompanied by matrix metalloproteinase (MMP) activation, being consistent with previous in vivo observations, where a relation between MMP and fetal membrane release had been shown. Ara-induced cell floating was not inhibited by the addition of cyclooxygenase (COX) inhibitor, and not induced by the addition of PGF2α or PGE2 to replace Ara, while 12-lipoxygenase (12-LOX) metabolite of Ara, 12-oxo-eicosatetraenoic acid (12-oxoETE), strongly induced cell floating. In the animal experiments, 12-oxoETE injection to delivery-induced cows (n = 6) using prostaglandin (PG) and dexamethazone resulted in rapid release of fetal membranes. In cows with natural calf delivery, a 12-oxoETE peak (11.7-16.8 ng/ml) was observed in maternal blood plasma prior to release of fetal membranes. This investigation thus gives new indications for that the mediator for fetal membrane release is 12-oxoETE and not PG.

Effects of intracerebroventricular administration of neuromedin U or neuromedin S in steers

Although neuromedin U (NMU) and neuromedin S (NMS) are reported to modulate stress responses mainly through corticotropin-releasing hormone system in rodents, the in vivo effects of centrally administered NMU or NMS on stress regulation have not been fully elucidated in cattle. We examined adrenocorticotropic hormone levels, body temperature, and behavioral responses to intracerebroventricularly (ICV) administered rat NMU or rat NMS in steers. ICV NMU and NMS (0.2, 2, and 20 nmol/200 microl) evoked a dose-related increase in plasma cortisol concentrations (CORT). There was a significant time-treatment interaction for the time course of CORT (p<0.001). ICV NMU evoked a dose-related increase in rectal temperature (RT). There was a significant time-treatment interaction for the change in RT from pre-injection value (p<0.05). There was a significant difference among treatments in the percentage of time spent lying (Friedman's test, chi(2)=15.6, p<0.01) and in the total number of head shaking (Friedman's test, chi(2)=14.49, p<0.01). A high dose of NMS tended to shorten the duration of lying and increase the number of head shaking. These findings indicate that both central NMU and NMS might participate in controlling the hypothalamo-pituitary-adrenal axis, that central NMU might participate in controlling body temperature, and that central NMS is likely to be involved in behavioral activation in cattle.

[Studies on toxicity of clobetasone-17-butyrate (II)--chronic toxicity in rats (author's transl)]

Chronic toxicity of clobetasone-17-butyrate, an anti-inflammatory corticosteroid, was investigated in rats. Subcutaneous administration with the drug at dose of 0.003, 0.01 and 0.03 mg/kg/day for three and six months induced no significant changes in the rats. At 0.1 and 0.3 mg/kg/day, however, some dose-dependent symptoms such as suppression of body weight gain, emaciation, regressive changes in adrenals, lymphatic and hematopoietic tissues, decrease in circulating white blood cell and lymphocyte counts, which have been known as toxic effects of synthetic corticosteroids, were induced. The results indicates that the maximum no-toxic dose of clobetasone-17 butyrate was 0.03 mg/kg/day on this experimental condition. In the recovery test for two months no significant differences in the treated rats from controls were found, suggesting that the toxic effects were reversible in the animals treated at 0.3 mg/kg/day and lower than that.

[Studies on toxicity of clobetasone-17-butyrate (I)--acute toxicity in mice and rats and subacute toxicity in rats (author's transl)]

Acute and subacute toxicities of clobetasone-17-butyrate, a new anti-inflammatory corticosteroid, were studied in mice and rats. In the acute toxicity tests intraperitoneal LD50 values of the drug were estimated to be around 5 g/kg for both sexes of mice, 1.51 g/kg for male and 1.66 g/kg for female rats. Subcutaneous and oral administration induced no fatal cases at dose of 3.6 (mice, s.c.), 2.6 (rats, s.c.) and 6.0 g/kg (mice and rats, p.o.). As for the toxic signs in both mice and rats after the i.p. and s.c. administrations, emaciation was marked, and atrophy of thymus, spleen and adrenals were observed. No marked symptoms, however, were induced in animals administered orally. In the subacute toxicity tests male and female rats were subcutaneously administered with the drug at daily doses of 0.01, 0.03, 0.1, 1.0, 10 and 100 mg/kg for one month. Dose dependent symptoms such as suppression in body weight gain, emaciation, regressive changes in adrenal, lymphatic and hematopoietic tissues, decrease in circulating white blood cell and lymphocyte counts, and increase in total cholesterol level of serum were induced in the rats administered at 0.1 mg/kg/day and more than that, indicating that the maximum nontoxic dose in this experimental condition was 0.03 mg/kg/day. In recovery tests it was observed that the rats, which had been administered with the drug at 1.0 mg/kg/day for one month, were almost normal two months after the final administration.

Granular flow experiment using artificial gravity generator at International Space Station

Studying the gravity-dependent characteristics of regolith, fine-grained granular media covering extra-terrestrial bodies is essential for the reliable design and analysis of landers and rovers for space exploration. In this study, we propose an experimental approach to examine a granular flow under stable artificial gravity conditions for a long duration generated by a centrifuge at the International Space Station. We also perform a discrete element simulation of the granular flow in both artificial and natural gravity environments. The simulation results verify that the granular flows in artificial and natural gravity are consistent. Further, regression analysis of the experimental results reveals that the mass flow rate of granular flow quantitatively follows a well-known physics-based law with some deviations under low-gravity conditions, implying that the bulk density of the granular media decreases with gravity. This insight also indicates that the bulk density considered in simulation studies of space probes under low-gravity conditions needs to be tuned for their reliable design and analysis.

[Evaluation of the proximal stenosis of native coronary vessels after coronary artery bypass grafting]

This study was designed to evaluate proximal native coronary stenosis (PNCS) after coronary artery bypass grafting (CABG). In 36 patients undergoing postoperative coronary arteriography, the PNCS bypassed with internal thoracic artery (ITA), saphenous vein graft (SVG) and right gastroepiploic artery (RGEA) progressed in 9 of 23 vessels (39%), in 15 of 28 vessels (53%), in 4 of 11 vessels (36%), respectively. Stenosis of no grafted coronary vessels progressed in 3 of 26 vessels (11%). Twelve native coronary vessels (9: 99% and 3: 90% stenosis vessels) bypassed with grafts were obstructed. This study confirms that the PNCS progresses significantly by CABG just after the operation and that it tends to progress highly with SVG in comparison with arterial grafts such as ITA or RGEA. Because operative mortality for repeated CABG is approximately twice as high as that for primary CABG, it is important to decide whether early postoperative percutaneous transluminal angioplasty is needed or not, in considering of future graft failure and stenosis progression of the native coronary vessels by CABG.

[Prospective study of systemic inflammatory response syndrome after cardiac surgery as a effective indicator]

This prospective study was designed to elucidate the meaning of systemic inflammatory response syndrome (SIRS), the mechanisms that lead to the protraction of SIRS, and whether SIRS is potentially a simple and effective postoperative indicator or not in patients who are operated on with cardiopulmonary bypass (CPB). We studied the duration of SIRS in 90 patients. Our data showed that 83 (92%) of the 90 patients met 2 or more criteria for SIRS and that significant relationship between the protraction of SIRS and the duration of aortic clamping time, CPB time, operation time, and the risk of postoperative organ damage and complication. Those results suggest that SIRS after cardiac surgery with CPB can be regarded as right criteria and highly valuable indexes of preparatory state of organ dysfunction.

[Clinical evaluation of risk factors for respiratory failure after coronary artery bypass grafting with cardiopulmonary bypass]

The relationship between the duration of postoperative mechanical ventilation and pre-, intra- and just post-operative factors was studied in 48 patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. The patients were divided into 2 groups on the basis of the duration of mechanical ventilation: group A with less than 24 hours (n=35) and group B with more than 24 hours (n=13). Investigation of the perioperative parameters which significantly correlated with the duration of mechanical ventilation revealed that emergency case, cardiac dysfunction, high dose administration of cathecolamine, high left atrial pressure (LAP), low serum albmin, and renal dysfunction after transfer to intensive care unit (ICU) were found to be increased risks of postoperative respiratory failure.

[The effect of long-term physical training on asymptomatic patients with myocardial infarction]

To examine the long-term effect of intense physical training on exercise capacity of patients with myocardial infarction(MI), multiphasic treadmill stress test(MTST) with modified Bruce protocol was performed repeatedly in 10 patients with training(Ex) and in 6 without training(C). In C, heart rate(HR), systolic blood pressure(SBP), or pressure rate product (PRP: HR X SBP/10(-2)) at any stage of MTST was unchanged for 3 years after MI. In Ex, these indices were unchanged at rest, but at stage 4 of MTST decreased significantly as follows: HR 119 +/- 20.4 to 108.6 +/- 16.0/min(p less than 0.05), SBP 151.6 +/- 24.0 to 137.0 +/- 17.5 mmHg(p less than 0.05), PRP 181.9 +/- 49.5 to 153.3 +/- 29.7(p less than 0.05). These indices at maximal exercise increased significantly after one year of training. One year of training in asymptomatic patients with MI reduced of myocardial oxygen consumption index during exercise at given work rate and increased maximal exercise capacity. With continued training these beneficial effects can be maintained for additional 2 years.