Adipose tissue-derived stem cells upon decellularized ovine small intestine submucosa for tissue regeneration: An optimization and comparison method

The extracellular matrix of different mammalian tissues is commonly used as scaffolds in the field of tissue engineering. One of these tissues, which has frequently been studied due to its structural and biological features, is the small intestine submucosal membrane. These research are mainly done on the porcine small intestine. However, a report has recently been published about a scaffold produced from the submucosal layer of the ovine small intestine. In the present study, ovine small intestine submucosal (OSIS) was decellularized in a modified manner and its histological, morphological, and biomechanical properties were studied. Decellularization was performed in two phases: physical and chemical. In this method, a chloroform-methanol mixture, enzymatic digestion, and a constant dose of sodium dodecyl sulfate (SDS) was used in the least agitation time and its histological property and biocompatibility were evaluated in the presence of adipose tissue-derived stem cells (ADSCs); furthermore, ADSCs were isolated with a simple method (modified physical washing non-enzymatic isolation). The results were showed that the use of OSIS could be effective and operative. Mechanical properties, histological structure and shape, and glycosaminoglycan content were preserved. In the SDS-treated group, more than 90% of the native cells of tissue were deleted, and also in this group, no toxicity was observed and cell proliferation was supported, compared to the untreated group. Therefore, our results indicate that ADSCs seeded on OSIS scaffold could be used as a new approach in regenerative medicine as hybrid or hydrogel application.     

Radioprotective effect of drug combinations on the small intestine

The study of the radioprotective effect of complexes containing small amounts of cystamine or gammaphos mixed with mexamine, gutimine and ethyrone on mouse small intestine showed high efficiency of the drugs as determined by cellularity and DNA-synthesizing activity of intestinal epithelium. This is connected with the influence of the complex mexamine + gutimine + ethyrone on the pharmacodynamics and pharmacokinetics of cystamine and gammaphos.     

Nucleotide diversity on the ovine Y chromosome

To investigate the impact of male-mediated introgression during the evolution of sheep breeds, a sequencing approach was used to identify single nucleotide polymorphisms (SNPs) from the male-specific region of the ovine Y chromosome (MSY). A total of 4380 bp, which comprised nine fragments from five MSY genes was sequenced within a panel of 14 males from seven breeds. Sequence alignment identified a single segregating site, an A/G SNP located approximately 1685 bp upstream of the ovine SRY gene. The resulting estimation of nucleotide diversity (piY = 0.90 +/- 0.50 x 10(-4)) falls towards the lower end of estimates from other species. This was compared with the nucleotide diversity estimated from the autosomal component of the genome. Sequence analysis of 2933 bp amplified from eight autosomal genes revealed a nucleotide diversity (piA = 2.15 +/- 0.27 x 10(-3)) higher than previously reported for sheep. Following adjustment for the contrasting influence of effective population size and a male biased mutation rate, comparison revealed that approximately 10% of the expected nucleotide diversity is present on the ovine Y chromosome.     

Galanin: an inhibitory neural peptide of the canine small intestine

Galanin injected intraarterially during phasic activity of the canine small intestine in vivo produced inhibition. Fifty percent inhibition occurred at 1.5 +/- 0.5 X 10(-10) mols lasting for 0.7 min. The inhibitory response was not decreased by treatment with atropine, hexamethonium, yohimbine or naloxone, suggesting that muscarinic, nicotinic, alpha 2 adrenergic or opiate receptors were not being stimulated. Since tetrodotoxin blockade of nerves did not reduce the response and galanin at 10(-10) mols was able to eliminate the smooth muscle response to intraarterial acetylcholine, we suggest that galanin acts to inhibit smooth muscle directly. Galanin 10(-9) M added to the muscle bath also inhibited phasic activity of the canine ileum circular muscle in vitro in the presence of tetrodotoxin. These results suggest that the neural peptide galanin may be a non-adrenergic, non-cholinergic, non-opioid neurotransmitter in the canine small intestine.     

The effect of acute ischemia on the small intestine of the dog

There were carried out macroscopic and microscopic observations of dog's small intestine after putting a clamp on the artery only or on the artery and the upper mesenteric vein. Examinations were performed after 1 and 2 h of ischemia and in different periods after restitution of circulation. By means of histologic and histochemical methods it was found out that no later than after 1 h of ischemia there occur pathologic, irreversible changes in the wall of the small intestine.     

Lymphodynamic effect on the condition of iscnemia--reperfusion of the dog small intestine

Ischemia (30 min)--reperfusion (60 min) of the dog small intestine created by occlusion of the cranial mesenteric artery decreased formation and lymph flow, changed the blood and lymph viscosity and coadulation which had been induced by damaging effect of hypoxia.     

The effect of age on the rhythmic contractions of the rat small intestine

In vivo and in vitro rates of intestinal rhythmic contractions were measured in the same rats varying in age from very young to the senescent. Two rat strains, three small intestine locations, and six ages were compared. Contraction rates determined in vivo and in vitro were similar. Rhythmic contractions at all ages were fasted in the duodenum, slower in the jejunum, and slowest in the ileum. Contractions at 10 days of age were significantly slower than at all other ages; otherwise no systematic age-associated difference in contractions was demonstrated in either strain. Several factors were suggested as possibly influencing the developmental aspects of contraction rate and, therefore, their potential involvement in the early post natal period was suggested. It appears that old age does not influence the rate at which rhythmic contractions occur in the small intestine of the rat, and very possibly, these results are applicable to other species including humans.     

Novel polymorphisms in ovine prion protein gene

The aim of this study was to identify the PRNP polymorphisms outside the standard codons 136, 154 and 171 in 1110 sheep with no clinical sign of scrapie from all 18 Turkish native sheep breeds and compare our results with published data on ovine PRNP polymorphism from other regions of the world. Among the 22 amino acid polymorphisms and three silent mutations, 10 were novel for ovine PRNP: p.Gly94Gly, p.Leu128Ile, p.Met132Leu, p.Ser135Arg, p.Met137Val, p.Asn146Lys, p.Arg159Arg, p.Tyr160Asn, p.Gln163His and p.Thr193Ser. These data reveal that sheep breeds close to the historic center of small ruminant domestication have remained highly diverse in the prion gene locus, with distinctive genetic similarities to both Asian and European sheep breeds.     

Influence of season and sex on the inhibitory effect of ovine follicular fluid on plasma gonadotrophins in gonadectomized sheep

The inhibitory effects of follicular fluid on FSH secretion were similar in gonadectomized male and female sheep, and in the anoestrous and breeding seasons. Significant suppression of LH was variable and was observed only at the highest dose of follicular fluid when suppression rarely exceeded 50% of pretreatment values. Basal plasma FSH and LH concentrations were higher in castrated males than in ovariectomized females in both seasons. Plasma FSH concentrations in gonadectomized males and females and LH concentrations in the males were lower in the anoestrous than the breeding season. Therefore, in the absence of the gonads, sex and photoperiod can influence hypothalamic control of basal pituitary gonadotrophin secretion in males and females, whereas the feedback effect of non-steroidal factors in follicular fluid (inhibin) on FSH secretion is not influenced by photoperiod or sex.     

Cellular features of the extra-embryonic endoderm during elongation in the ovine conceptus

The extraembryonic endoderm of the elongating ovine conceptus was analyzed by scanning and transmission electron microscopy and by whole mount actin staining and immunofluorescence. Morphological and functional differences between the visceral endoderm (VE), the founding cell layer, and the parietal endoderm (PE) are presented. During the elongation process, the PE differentiated to fusiform multinucleated cells aligned parallel to the elongation axis of the conceptus, whereas the VE cells retained the aspect of typical epithelial cells. The multinucleated PE cells however, expressed cellular and nuclear markers typical of endodermal and polarized epithelial cells. The proteins of the extracellular matrix, laminin, and fibronectin, were specifically expressed in the PE. The presence of pairs of nuclei linked by mid-bodies positively stained with tubulin antibodies, indicated that the syncytial differentiation of the PE was due to karyokinesis which was not followed by cytokinesis rather than by cell fusion.     

Lysine transport across the small intestine. Stimulating and inhibitory effects of neutral amino acids

Summary The ordinary aliphatic, neutral amino acids and phenylalanine have been examined for cis-inhibition of influx of alanine (J _mc ^ala ) and lysine (J _mc ^lys ) and trans-stimulation ofJ _mc ^lys across the brush border membrane of rat small intestines: and their effects on the unidirectional mucosa-to-serosa flux (J _ms ^lys ) across the short circuited intestine have been studied. The effects of alanine, -amino-n-butyric acid, leucine, and methionine on the steady-state epithelial uptake of lysine [Lys] _c have also been measured. In addition the trans-effects of alanine and leucine have been examined for sodium-dependence, and alanine was tested as trans-stimulator of influx of galactose across the brush border membrane (J _mc ^gal ).All the neutral amino acids were found to be competitive cis-inhibitors ofJ _mc ^lys , and all, except isoleucine, were trans-stimulators ofJ _mc ^lys . The magnitude of the trans-effect was unrelated to the efficiency of the amino acid as cis-inhibitor. As illustrated by alanine, the trans-effects are probably completely sodium-dependent. Alanine was also effective as trans-stimulator ofJ _mc ^gal . With respect to effects on [Lys] _c andJ _ms ^lys the neutral amino acids fall into two groups: One which reduces [Lys] _c and stimulatesJ _ms ^lys , and one which increases [Lys] _c and relatively inhibitsJ _ms ^lys . These effects are not correlated with the affinities of the neutral amino acids for the two carriers involved.It is proposed that the trans-effects onJ _mc ^lys are induced by an electrogenic, sodium-coupled efflux of the neutral amino acid across the brush border membrane, that the stimulation ofJ _ms ^lys is brought about by a selective stimulation (of unknown nature) of efflux of lysine across the basolateral membrane (J _cs ^lys ), assisted by competitive inhibition of lysine efflux across the brush border membrane (J _cm ^lys ), and that the amino acids which do not stimulateJ _cm ^lys increase [Lys] _c by competitively inhibitingJ _cs ^lys andJ _cm ^lys .The inhibitory effect of the neutral amino acids onJ _mc ^lys support the view that the carrier of basic amino acids serves as a second carrier of these amino acids.