Effect of fat supplementation on the maintenance of gut integrity in elemental diet-fed rats.

AIMS: The aims of this study were to investigate the mechanism of atrophic change in ileal mucosa supplied with an elemental diet (ED) and to assess the value of supplemented fat emulsion in the prevention of atrophic change. MATERIALS AND METHODS: In experiment 1, 25 male Wistar rats with a body weight of 160-180 g were divided into 3 groups. The first group was fed regular rat chow (Control group, n=5). The second group was given ED containing 0.6% long-chain triglycerides (ED group, n=10). The third group was provided with fat-enriched ED (FED) containing 3.5% long-chain triglycerides (FED group, n=10). Each group received an isocaloric diet (300 kcal/kg/day). 4 weeks later, after euthanization, ileal samples were taken for light and electron microscopic examinations. The morphological changes of the intestinal mucosa and the crypt cell proliferation rate (CCPR) were determined. In experiment 2, to determine the site of fat absorption, 9 rats were fed ED for 1 week. After 24 h of food deprivation, all rats were given 2 ml of FED through a gastric tube. Then 1, 2, and 3 h(s) later, groups of 3 rats each were euthanized, and the total small intestine was obtained from each rat. The proximal and distal jejunum and distal ileum were stained with oil red O. RESULTS: In experiment 1, the samples had almost the same morphological appearance irrespective of the type of feeding. The CCPR was significantly diminished in the ED group compared with the Control group, while there was no statistical difference between the FED and Control groups. In experiment 2, the oil red O stain was positive in the proximal and distal jejunum, but was completely negative in the distal ileum. CONCLUSIONS: The introduction of ED does not soon result in an atrophic morphological change of the ileum but will decrease the CCPR. An additive fat emulsion which was rapidly absorbed by the distal jejunum could play a role in maintaining ileal mucosa integrity through some mechanism independent of absorption.

Theanine, gamma-glutamylethylamide, a unique amino acid in tea leaves, modulates neurotransmitter concentrations in the brain striatum interstitium in conscious rats.

Theanine (gamma-glutamylethylamide) is one of the major amino acid components in green tea and can pass through the blood-brain barrier. Recent studies suggest that theanine affects the mammalian central nervous system; however, the detailed mechanism remains unclear. In this study, we demonstrated the effect of theanine on neurotransmission in the brain striatum by in vivo brain microdialysis. Theanine injection into the rat brain striatum did not increase the concentration of excitatory neurotransmitters in the perfusate. On the other hand, theanine injection increased the concentration of glycine in the perfusate. Because it has been reported that theanine promotes dopamine release in the rat striatum, we investigated the glycine and dopamine concentrations in the perfusate. Co-injection of glycine receptor antagonist, strychnine, reduced theanine-induced changes in dopamine. Moreover, AMPA receptor antagonist, which regulates glycine and GABA release from glia cells, inhibited these effects of theanine and this result was in agreement with the known inhibitory effect of theanine at AMPA receptors.

Changes in calcium, PTH and 1,25(OH)2 vitamin D3 during tail-suspension in ovariectomized rats: effects of estrogen administration.

It is well known that estrogen deficiency results in osteoporosis in human and experimental animals. However, how its deficiency affects the development of disuse atrophy is not well understood. We thus investigated how estrogen deficiency caused by ovariectomy and estrogen supplements affect serum levels of calcium, parathyroid hormone (PTH), and 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) in tail-suspended rats. Five-week-old female Wistar rats were ovariectomized and divided into two groups. One group received an intramuscular injection of estradiol dipropionate once a week (OVX-E2 group), and the other received the vehicle alone (OVX group). After the third injection, the rats were subjected to tail-suspension in metabolic cages for 1, 3, 5 or 7 days. In the OVX group, urinary excretion of deoxypyridinoline (D-Pyr) tended to increase on day 1 after tail-suspension. In the OVX-E2 group, basal excretion was lower than that in the OVX group, and no increase was observed after the suspension. Serum concentrations of ionized calcium significantly increased on day 1 after the suspension in both groups. However, in the OVX-E2 group, the level tended to be higher than those in the OVX group from day 0 to day 3. Serum PTH tended to decrease on day 1 after suspension in the OVX group. In the OVX-E2 group, it did not change during the suspension, but the levels were higher than those in the OVX group during the experiment. Serum 1,25(OH)2D3 transiently and significantly increased on day 1 after suspension in both groups. However, in the OVX group, the level was significantly higher than that in the OVX-E2 group. These data indicate that estrogen treatment of ovariectomized rats modifies the changes in calcium metabolism induced by tail-suspension.

Technical advance: single pollen typing combined with laser-mediated manipulation.

We combined single pollen typing with laser-mediated manipulation. After drilling a hole in the wall of a pollen grain from a dioecious plant (Silene latifolia) with a UV-laser microbeam, the single pollen grain was recovered directly in the cap of a PCR tube, using a non-contact method called laser pressure catapulting. The entire genome of the single pollen grain was then amplified with improved primer-extension-preamplification PCR (I-PEP PCR). Nested PCR with sequence tagged site (STS)-specific primers was used to analyze several loci in the haploid genome. The single copy gene MROS1 was detected in most of the single pollen grains analyzed. Bgl10, which is localized on the Y chromosome, was detected in approximately half of the pollen grains. MROS3 is reported to be localized on the X chromosome. Using inverse PCR, we isolated two genomic clones of MROS3: MROS3A and MROS3B. The single pollen analysis using nested PCR showed that MROS3A and MROS3B are derived from different loci that are not located on the X chromosome. Single pollen typing not only reveals sex chromosome-linkage within the haploid genome, but can also discriminate between alleles and different loci. This method should also be useful for measuring recombination frequencies without genetic crossover analysis.

MROS1, a male stamen-specific gene in the dioecious campion Silene latifolia is expressed in mature pollen.

The MROS1 gene, one of the genes that are expressed specifically in male reproductive organs of a dioecious campion Silene latifolia, was predicted to encode only 36 amino acids but have an intron. In situ hybridization revealed that MROS1 mRNA was localized in mature pollen grains.

Effect of estrogen on the development of disuse atrophy of bone and muscle induced by tail-supension in rats.

Rat tail-suspension induces disuse atrophy of muscles and bones in hindlimbs. In the present investigation we studied how ovariectomy and estrogen substitution affect the development of the disuse atrophy induced by suspension. Five-week old female Wistar rats were ovariectomized and divided into two groups. One group received intramuscular injection of estradiol dipropionate once a week (OVX-E2 group), and the other received a vehicle injection (OVX group). After the third injection, each group was further divided into two groups, tail-suspended and non-suspended. After 7 days of tail-suspension, a significant decrease in the wet weight of femurs and their Ca and Pi content was observed in the OVX group. However, no significant change in those parameters was observed in the E2 group. In both E2 and OVX groups, a significant decrease in the wet weight of soleus and gastrocnemius muscles was demonstrated after the suspension. This demonstrated that estrogen administration to ovariectomized rats prevents the development of disuse bone atrophy but not that of muscle atrophy, suggesting that estrogen plays important roles in bone remodeling.

[Toxicity studies of paclitaxel. (II)--One-month intermittent intravenous toxicity in rats].

Paclitaxel, an antineoplastic agent, was intravenously given to Crj:CD (SD) rats of both sexes at 0 (saline), 0 (vehicle), 1.0 (low dose), 3.3 (intermediate dose) and 10.0 (high dose) mg/kg at five-day interval over one-month period (6 times in total) to investigate its repeated dose toxicity and the reversibility of toxic effects. The results obtained are summarized as follows: 1. Decreased activity with prone position was observed for high dose and vehicle groups, and alopecia was seen for many high dose rats. Body weight gain and food intake were suppressed for high and intermediate dose groups. No deaths occurred. 2. Red blood cell count, hemoglobin, hematocrit, white blood cell count, relative neutrophil count, platelet count and reticulocyte count were decreased for high dose groups. Red blood cells count was also decreased for intermediate dose groups. 3. Thymic atrophy, splenic hematopoiesis, bone marrow hypoplasia, testicular atrophy with suppression of spermatogenesis and tubular atrophy, and epididymal atrophy were observed for high dose rats. 4. Above-described changes excluding the findings on the testis and epididymis for high dose rats were shown to be generally reversible. Based on these results, the no-toxic effect dose of paclitaxel was estimated to be 1.0 mg/kg in rats under this study condition.

Potassium/energy and phosphorus/calcium ratios reflect the quality of nutrition.

A nutritional survey and questionnaire regarding dietary habits were administered to 649 men ranging in age from 35 to 64 years receiving a one-day health screening examination. First, comparisons of nutrient intake based on the nutrient rate of the Recommended Dietary Allowances for Japanese (RDA), and the total score on the questionnaire regarding dietary habits according to the RDA rates of total energy and calcium (Ca) were investigated. Then, the comparisons of intake of food groups, intake of nutrients and the total score on the questionnaire regarding dietary habits according to potassium/energy (K/E) ratio and phosphorus/calcium (P/Ca) ratio were determined. Last, differences between comparisons with the nutrient rates of RDA and comparisons with K/E ratio and P/Ca ratio were investigated. The following results were obtained: 1. Even in the group with RDA rates of total energy or Ca of > or = 90% and < or = 110% the RDA rates of some other nutrients were out-side the appropriate range. 2. In the group with high K/E ratios, as compared to the group with low ratios, the intake of potatoes, pulses, fruits, green/yellow vegetables, other vegetables, soy sauce, other beverages, fish/shellfish, and milk products showed high values, while cereals and fats/oils showed low values. For this reason, in the former group as compared to the latter, the intake and RDA total energy rate showed low values whereas the intake and RDA rates of nutrients such as Ca, Fe, and vitamin A were low. 3. In the group with high P/Ca ratios, as compared to the group with low ratios, the intake of beer and meats showed high values while that of pulses, green/yellow vegetables, and milk products showed low values. For this reason, in the former group as compared to the other groups, despite the fact that the intake and RDA total energy rate tended to be higher, the intake of nutrients such as Ca, P, K, and vitamin A showed lower values. 4. The RDA rates of all of the nutrients of group with a high K/E ratio and the group with a low P/Ca ratio generally showed largely appropriate values. 5. These results suggest that indices reflecting the balance of minerals such as the K/E and P/Ca ratios more objectively reflect the quality of nutrition than comparisons based on the RDA rates of total energy and specific-nutrient.

[Cefepime (BMY-28142 diHCl/L-arginine blend): one-month repeated dose subcutaneous toxicity study in rats].

In order to investigate the toxicity of cefepime (CFPM, BMY-28142 diHCl/L-arginine blend upon repeated subcutaneous dosing), the test article was administered to Crj:CD(SD) rats of both sexes at daily dose levels of 150 (low dose), 500 (intermediate dose) and 1,500 (high dose) mg/kg/day by subcutaneous route for 28 days. Two additional groups of rats were given either saline (negative control) or L-arginine (vehicle control). Doses were equally divided and administered twice each day with an interval of approximately 5 hours between the 2 doses of a same day. A half of rats in negative control and high dose groups were retained for examination during one-month recovery period. The results obtained are summarized as follows: 1. Upon general observations, it was found that drug-related changes were restricted to the injection sites. Depilation and scab-formation of the injection sites were noted in high dose rats of both sexes and intermediate dose females. No deaths occurred during the study. 2. Slightly depressed body weight gains were observed for high dose males during the latter part of the dosing period. 3. Slightly lower food consumptions were noted for intermediate and high dose males at Week 1. 4. Slightly higher water consumptions were generally detected for high dose rats during the dosing period. 5. Hematological examinations revealed that a slight decrease in the average value of relative lymphocyte counts and a slight increase in the average value of relative segmented neutrophil counts were evident for high dose males. These findings might be attributable to the inflammatory reactions at the injection sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Excitation of hypothalamic paraventricular neurons by stimulation of the raphe nuclei.

Extracellular recordings were made from 467 anti-dromically identified neurosecretory neurons and 148 non-neurosecretory neurons in the paraventricular nucleus of the hypothalamus of hemispherectomized cats under pentobarbital anesthesia. Stimulation of the dorsal, median, and pontine raphe nuclei excited 31%, 26%, and 12% of neurosecretory neurons tested, respectively, and inhibited 9%, 7%, and 8%. The excitatory responses in 13 of 14 neurons tested were blocked by either of two intravenously administered 5-HT2 antagonists, cyproheptadine or methysergide. The 5-HT1A antagonist, (-)pindolol, partially blocked the excitatory responses elicited by raphe stimulation in three of five neurons tested. The inhibitory responses to raphe stimulation were not affected by application of these antagonists. More non-neurosecretory neurons than neurosecretory neurons were excited in response to raphe stimulation and these excitatory responses were also blocked by these antagonists. We conclude that most electrically stimulated synaptic inputs from the midbrain raphe nuclei to the hypothalamic paraventricular nucleus are excitatory and are mainly mediated by 5-HT2 receptors.

Pressure profile of ophthalmic surgical procedures: an experimental study on the rabbit eye.

A balloon sensor was implanted in the posterior wall of the rabbit eye, and pressure fluctuation during several surgical procedures was monitored. Temporary IOP increase during digital massage sometimes reached near 100 mm Hg. Pressure increase during incision on the cornea was quite high, while corneal suturing, lens extraction, iridectomy, and open-sky vitrectomy induced minor fluctuating pressure on the posterior wall. Diathermy coagulation and scleral incision during simulated retinal detachment surgery increased IOP, exceeding 50 mm Hg and sometimes reaching 100 mm Hg.