Free amino acids in brain tissue and its subcellular structures in hyperthermia in rats

Free amino acids reserves in the brain tissue, nuclei and mitochondria were investigated in mongrel albino rats under conditions of hyperthermia (45 degrees C) of different duration--7,20 and 60 min. It was found that reserves of most free amino acids in the albino rat brain decreased under a short-term (7 min) hyperthermia and accumulated under more prolonged (20-60 min) one. The amount of amino acids in the brain mitochondria increased 7 min after the experiment start and decreased 20 min later, then (60 min later) the amount of most amino acids increased considerably. Opposite shifts were detected in the content of most amino acids in nuclei.     

Free amino acids in plasma and tissue of rats born to underfed dams.

Amino acids were determined in plasma, muscle, and liver tissues of adult male rats born of mothers on restricted or nonrestricted diets during pregnancy and lactation. The concentrations of plasma alanine, glutamic acid, glycine, proline, arginine, and valine were significantly lower in the progeny of restricted mothers as compared to non-restricted mothers. Similar changes were observed in liver tissues. The concentrations of free amino acids in muscle of the perinatally malnourished progeny, however, did not differ significantly from those of the controls. The differences determined in this study are of special significance in view of the fact that the animals studied had been maintained on an adequate diet since weaning. The demonstrated effect of the maternal diet on the plasma aminogram of the off-spring some months later must be considered when interpreting plasma aminograms in studies of malnourished children.     

Free amino acids in spider hemolymph

We examined the free amino acid composition of hemolymph from representatives of five spider families with an interest in knowing if the amino acid profile in the hemolymph of orb-web-building spiders reflects the high demands for small organic compounds in the sticky droplets of their webs. In nearly all analyses, on both orb and non-orb builders, glutamine was the most abundant free amino acid. Glycine, taurine, proline, histidine, and alanine also tended to be well-represented in orb and non-orb builders. While indications of taxon-specific differences in amino acid composition were observed, it was not apparent that two presumptive precursors (glutamine, taurine) of orb web sticky droplet compounds were uniquely enriched in araneids (orb builders). However, total amino acid concentrations were invariably highest in the araneids and especially so in overwintering juveniles, even as several of the essential amino acids declined during this winter diapause. Comparing the data from this study with those from earlier studies revealed a number of discrepancies. The possible origins of these differences are discussed.     

Free amino acids in some sponges

Most invertebrates, particularly those of marine origin, have relatively high concentrations of free amino acids which are considered an important constituent of their osmoregulatory mechanisms [1]. Very little information is available on the free amino acid distribution in Porifera [2,3]. Common amino acids in some sponges were recognised by paper chromatography by Inskip and Cassidy [4] and Ackermann et al. [5,6] included a few sponges in their survey of the occurence of nitrogen compounds in marine invertebrates. More recently Bergquist and Hartman [7] surveyed semiquantitatively the distribution of free amino acids in several sponges. In the present paper we report on the amino acid composition of 12 species of sponges belonging to the class Demospongiae as a part of a study on the metabolites of Porifera [8]. Fresh sponges were extracted with aqueous ethanol. The organic solvent was removed and the aqueous solution, after removal of the ether soluble compounds, was separated into cationic, anionic and neutral fractions by ion-exchange chromatography. The cation fraction was analysed for amino acids using an automatic amino acid analyser. The results, which are presented in Table 1, show that all species of sponges examined have a similar composition in common amino acids. Glycine almost always appears as the dominant protein amino acid, followed by high concentrations of alanine and glutamic acid, whereas relatively lower concentrations of basic amino acids are present. In Axinella cannabina, Chondrosia reniformis, Chondrilla nucula, Cliona viridis and Hymeniacidon sanguinea, glycine represents more than 77% of the total amino acids. The high percentage of free glycine (90.4%) in Chondrosia reniformis is noteworthy. The anionic and the neutral fractions were examined for sulfur-containing amino acids using PC. Taurine (Table 2) was detected in all the Porifera examined; this is in agreement with previous observations [5–7]. N-Methyltaurine was identified in some of the species examined, whereas neither N,N-dimethyltaurine nor N,N,N-trimethyltaurine were found.     

Free amino acids in calf embryos

In this work have been reported the research results tending to establish the free amino acidis concentration, existing in the calf embryos. The free embryonal amino acidis composition has been determined through an analysis effected with "Amino Acid Analyzer". Such studies, which conern the researches under execution in our Institute on the chemical composition of the calf embryos furnish the biochemical determination of a biological material, used in some Nations like a commercial product.     

Free amino acids from pollens

Pollens from Pinus canariensis, P. nigra, P. pinaster, P. pinea, Castanea sativa, Magnolia grandiflora, Olea sativa cv frantoio, cv itrana, cv pisciottana were examined for their free amino acid composition. A large amount of proline was found in all species; pollens of Olea also contain a large amount of serine.     

Free amino acids in the blood plasma of lampreys, frogs and rats

Free amino acids in the blood plasma of lampreys, frogs and rats were determined by HPLC. In spite of quantitative differences in the total pool of free amino acids, the specific content of physiologically important amino acids is quite similar in representatives of different classes of vertebrates, from cyclostomes to mammals.     

Increased brain P-glycoprotein in morphine tolerant rats

The objective of this study was to determine whether chronic morphine exposure increased P-glycoprotein in rat brain. Male Sprague-Dawley rats were treated with morphine, saline, or dexamethasone for 5 days. On day 6, antinociceptive effect was measured to evaluate the extent of functional tolerance to morphine. Brain P-glycoprotein was detected by Western blot analysis of whole brain homogenate. Morphine- and dexamethasone-treated rats exhibited decreased antinociceptive response when compared to saline-treated controls. Brain P-glycoprotein was approximately 2-fold higher in morphine-treated rats compared to saline controls based on Western blot analysis. Chronic morphine exposure appears to increase P-glycoprotein in rat brain. P-glycoprotein induction may enhance morphine efflux from the brain, thus reducing morphine's pharmacologic activity. Induction of P-glycoprotein may be one mechanism involved in the development of morphine tolerance.     

Free amino acids of maize seedlings

The free amino acids were determined in different parts of maize seedlings (seeds, roots and shoots), 0, 2, 4 and 6 days after sowing.