Akie Yonekubo

Simplified preparation of a refined milk formula comparable to rat's milk : Influence of the formula on development of the gut and brain in artificially reared rat pups

BACKGROUND Milk formulas for artificially reared (AR) rat pups are mostly based on complex cows milk products, prepared by laborious and time-consuming processes. The aim of this study was to develop a simplified procedure for preparing a refined formula and to examine its influences on gut and brain development. METHODS The formula comprised a combination of purified cows casein and whey proteins, five kinds of edible oil, minerals, and vitamins. Detailed analyses showed that the composition of macro- and micro-nutrients, osmolarity, and pH of the new formula closely resembled those of rats milk. Rat pups, each with an intragastric cannula implanted at age 5 days, were artificially reared for the following 10-15 days. RESULTS The body weight gain of AR pups matched that of mother-reared (MR) pups. Histoplanimetrical analyses showed that the small intestine in AR pups was more developed in relation to area of a transverse section, number and length of villi, and thickness of tunica muscularis than that of MR pups. Fat components in the formula influenced the fatty acid composition and the cholesterol-to-phospholipid ratio in the small intestinal microvillus membrane (MVM) of AR pups, but not the MVM fluidity. Brain weight was not significantly different between the two groups at age 15-20 days. CONCLUSION This formula is useful for artificial rearing of rats and for identifying dietary components contributing to metabolic adaptation during the suckling period.

Effects of dietary nucleotides on serum antibody and splenic cytokine production in mice

Abstract We examined the effects of dietary nucleotides on the immune response balance in two subtypes of T helper cells, type 1 (Th1) and type 2 (Th2) cells. In experiment 1, BALB/c mice were maintained on a nucleotide-free diet (NT(−) diet) or the NT(−) diet supplemented with dietary nucleotides (NT(+) diet) from 4 weeks prior to mating and throughout the experiments. The second generations of these mice (F1) were maintained on the same diet as the respective dams. Male F1-generation mice were used to determine the serum immunoglobulin levels. The serum IgE levels were significantly decreased in mice fed the NT(+) diet ( p p

Effects of Dietary Safflower Oil or Soybean Oil on the Milk Composition of the Maternal Rat, and Tissue Fatty Acid Composition and Learning Ability of Postnatal Rats

This study was done to identify the effects of dietary safflower oil or soybean oil on the milk composition of maternal rats and the tissue fatty acid composition in postnatal rats. Different types of dietary fats affected the fatty acid pattern in the dams milk. They affected tissue weight, lipid content, and phospholipid fatty acid compositions in the liver and brain of young rats, showing a large amount of docosahexaenoic acid in soybean oil-fed rats, and a large amount of docosapentaenoic acid in safflower oil-fed rats. The learning ability of the soybean oil-fed rats, evaluated by a swimming test, was significantly superior to that of the safflower oil-fed rats. The presence of large amounts of docosahexaenoic acid in the tissue phospholipid of soybean oil-fed neonatal rats without an alteration of their arachidonic acid levels may contribute to the enhancement of learning ability in rats.

Reactivity of Secretory IgA Antibodies in Breast Milk from 107 Japanese Mothers to 20 Environmental Antigens

The secretory IgA (sIgA) antibody response to 20 environmental antigens, including microorganisms, toxins, food, and inhaled allergens, was evaluated in the breast milk from 107 Japanese mothers 1–10 days after delivery. Specific sIgA antibody responses were detected in most milk samples against almost all of the antigens tested, although there was a wide variation in the specific sIgA antibody profiles of each individual’s milk. With regard to twelve bacterial antigens, highly specific sIgA antibody responses were detected against Escherichia coli, Yersiniaenterocolitica, and Pseudomonasaeruginosa. With regard to eight nonbacterial antigens, highly specific sIgA antibody responses were detected against rotavirus, cholera, and pertussis toxins. Similar sIgA antibody profiles were obtained when the 107 milk specimens were divided into colostrum (milk 1–5 days after delivery, n = 36) and transitional milk (milk 6–10 days after delivery, n = 71). This study provides information on the possible protective role of human milk sIgA antibodies and will serve as a baseline for future studies.

Effect of several dietary iron compounds on iron bioavailability.

貧血ラットに各種鉄剤を含む回復食を投与し, 7日目のHb, Ht値および14日目の血清鉄, 総鉄結合能, 臓器鉄を測定することにより貧血回復の度合を評価して, 鉄剤の種類や形態の違いが生体利用性に及ぼす影響を検討した。得られた結果は以下のとおりである。1) 使用した鉄剤のなかでは, 硫酸第一鉄とオルトリン酸第二鉄の生体利用性が最もよく, コロイド性ピロリン酸第二鉄もそれらとほぼ同等の生体利用性を示した。2) 粉末ピロリン酸第二鉄はその乾燥条件によって生体利用性に違いがみられた。しかし, いずれの場合も, そのままの状態で粉末飼料に配合すると生体利用性は硫酸第一鉄に比べて劣っていた。3) 粉末ピロリン酸第二鉄は, あらかじめデキストリン, あるいはデキストリンおよびビタミンCの両者と反応させることにより生体利用性が大きく改善された。これは, 飼料中に加えた鉄が生体に利用されやすい状態に変化したことによるものと考えられた。

Studies on the Properties of Cow's Milk Lipid VII. Fatty Acid Composition and the Proportions of each Fatty Acid in the β-position of Triglyceride

全国6地域12地区の1年間の牛乳脂質試料144点につき,トリグリセリドのβ位脂肪酸組成を測定し,主要脂肪酸のβ位への結合比率を算出した.β位の脂肪酸で最も量の多い成分はC16:0で平均32.4%,次いでC18:1の平均20.9%,C14:0の平均15.5%であった.C4:0,C6:0はほとんど検出されなかった.C14:0,C16:0は冬季に多く,C18:0,C18:1,C18:2は逆に夏季に多かった.これらの季節変化は北海道地域で特に顕著で,最大値,最小値はそれぞれC14:0では18.2%,13.7%,C16:0は42.6%,27.5%,C18:0は8.4%,4.7%,C18:1は25.1%,13.4%,C18:2は2.9%,1.5%であった.北海道,東日本,西日本I地域に比較して,西日本II,大都市近郊,大都市専業地域ではC18酸が多く,C16以下の脂肪酸が少なかった.この傾向は東京地区で特に顕著であった.主な脂肪酸のうちβ位への結合比率の最も高いのはC14:0で平均56.1%であり,C12:0,C16:0がこれに次ぎ,それぞれ平均48.6%,42.8%であった.C18:0とC18:1のβ位結合比はそれぞれ平均23.2%,27.3%と低かったが,同じC18酸でありながらC18:2のそれは41.9%と高かった.これらの季節変化は北海道地域で特に顕著で,C10:0,C12:0,C16:1,C18:0,C18:1,C18:2は夏季にβ位への結合比率が上昇し(夏季の平均値はそれぞれ38.8%,51.3%,46.1%,24.1%,28.4%,43.0%,冬季のそれはそれぞれ34.0%,44.6%,41.3%,19.2%,23.0%),C16:0のβへの結合比率は冬季に上昇した(夏季,冬季の平均値はそれぞれ43.1%,46.2%).地域別には西日本II,大都市近郊,大都市専業地域でC16:0,C18酸のβ位結合比が高かった.