Erythrocytes possess a Cl-dependent, Na-independent K transport system cotransporting K and Cl in a 1:1 stoichiometry that is membrane potential independent. This K-Cl cotransporter is stimulated by cell swelling, acidification, Mg depletion, and thiol modification. Cell shrinkage, elevation of cellular divalent ions, thiol alkylation, phosphatase inhibitors, and derivatives of certain loop diuretics and stilbenes are inhibitory. Thus regulation of K-Cl cotransport at the membrane and cytoplasmic levels is highly complex. Basal K-Cl cotransport decreases with cellular maturation, whereas its modes of stimulation and inhibition are variable between species. The physiological inactivation appears to be prevented in low-K animal erythrocytes. In certain human hemoglobinopathies, K-Cl cotransport may be the cause of cellular dehydration and volume decrease. K-Cl cotransport occurs also in nonerythroid cells, such as in epithelial and liver cells of other species. At the threshold of molecular characterization, this comprehensive review places our present understanding of the mechanisms modulating K-Cl cotransport physiologically and pathophysiologically into kinetic and thermodynamic perspectives.
The serum levels of C-reactive protein (CRP) produced as an inflammatory response in dogs with various disorders and surgical traumas were measured by enzyme-linked immunoabsorbent assay and slide reversed passive latex agglutination test (RPLA). The CRP levels were greatly increased 1-2 days after surgery in most of the dogs (n = 29) subjected to surgery. These levels had markedly decreased by the time the sutures were removed. In dogs with various disorders (n = 58), the serum CRP levels at first diagnosis were high in infectious diseases. In dogs from which paired serum samples were examined, the serum CRP usually showed a decrease with improvement in the condition (n = 11) or a terminal increase (n = 4) but, conversely, some showed an increase with improvement in the condition (n = 3).
ABSTRACT. Collagen synthesis was evaluated by measuring prolyl hydroxylase (PHL) activity induced within rat granulation tissue by a polyester non-woven fabric (NWF, 1 × 1 cm, 0.6 mm in thickness) impregnated with a chitin or chitosan suspension ranging in concentration from 0.1 to 10 mg/ml. In addition, PHL activity induced in rat granulation tissue by a NWF impregnated with a phosphate buffer solution was examined as a control. The PHL activity in each group remained low until 4 days post-implantation (Day 4). However, in the 10 mg chitin group, the PHL activity increased rapidly without scatter of the data at Day 7 and remained at a plateau until Day 14. In other groups, PHL activity increased linearly until Day 14. The data varied widely at Day 7. Compared to chitosan, chitin at the higher concentration was found to induce stable collagen synthesis in the early wound healing process. KEY WORDS: chitin, chitosan, prolyl hydroxylase.J. Vet. Med. Sci. 66(12): 1595-1598, 2004 Chitin and chitosan have been widely studied in both engineering and medicine. In the field of medicine, the effects of chitin and chitosan on wound healing have been the focus of great attention since Prudden et al. published a paper in 1970 stating that these agents accelerate wound healing [15]. Numerous reports describe the stimulatory effects of chitin and chitosan on tissue reactions involved in wound healing [1,[3][4][5][7][8][9][10][11][12][13]. Their most notable property is their propensity to induce abundant granulation tissue formation with angiogenesis. Previous reports indicated that chitin and chitosan induced fine collagen fibers histologically [3,11]. Moreover, chitin was found to enhance synthesis of types I, III, and IV collagen [4]. However, these reports indicate only the properties of the collagen synthesized. To understand more about wound healing acceleration by chitin and chitosan, it is important to clarify the quantity of collagen synthesized as well as its properties. In this paper, we evaluated the degree to which chitin and chitosan stimulate collagen synthesis by measuring prolyl hydroxylase activity, an activity necessary for collagen synthesis in rats [18].Thirty Wistar rats (adult females, weighing 270-300 g) were used in this study. The animals were purchased from Hamaguti Laboratory Co., Ltd. (Kobe, Japan). Chitin and chitosan were supplied by Sunfive Co., Ltd. (Tottori, Japan). Molecular weights and rates of deacetylation were determined using the viscoanetric method [19] and infra-red spectroscopic method [17], respectively. The data obtained for chitin and chitosan yielded molecular weights of 300 and 80 kD, and deacetylation rates of <10 and >80%, respectively. Chitin and chitosan having a mean particle size of 3.5 µm were sterilized separately using ethylene oxide gas and suspended in phosphate buffered solution (PBS, pH 7.2) at a concentration of 10 mg/ml. According to our measurements in a previous investigation [5], the optimum doses of chitin and chitosan in granulation tissue formation in rats w...
ABSTRACT. The phenotype of high K (HK) red blood cells, which is an autosomal recessive, was found in dog groups from 10 of 13 breeds or populations in Japan. The incidence of HK was 26 to 38% in the San'in-Shiba, Shinshu-Shiba and Akita breeds, and the gene frequencies of HK ranged from 0.513 to 0.612. The highest incidence (42%) was found in the Jindo breed from Korea, and the gene frequency was 0.652. Two other groups from Korea also possessed this HK variation. However, although HK cells were not found in dogs from Taiwan, Indonesia, Mongolia and Sakhalin, Russia, the HK phenotype is clearly distributed now throughout Japan and Korea. -KEY WORDS: canine, potassium, red blood cell.
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