The effect of ad libitum oral-administration of (-)catechin solution on ischemia-reperfusion-induced cell death of hippocampal CA1 in the gerbil was histologically examined. When (-)catechin solution instead of drinking water was orally administered ad libitum for 2 weeks, dose-dependent protection against neuronal death following by transient ischemia and reperfusion was observed. To evaluate the involvement of reduction of reactive-oxygen-species (ROIs) by the antioxidant activity of (-)catechin in this protection, the superoxide scavenging activity of the brain in catechin-treated gerbils was measured by ESR and spin-trapping using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). The superoxide scavenging activities of the brains obtained from catechin-treated gerbils were significantly higher than those of catechin-untreated animals. From these results, it was suggested that orally administered (-)catechin was absorbed, passed through the blood-brain barrier and that delayed neuronal death of hippocampal CA1 after ischemia-reperfusion was prevented due to its antioxidant activities.

Recently, the second mammalian chitinase, designated acidic mammalian chitinase (AMCase), has been identified in human, mouse, and cow. In contrast to the earlier identified macrophage-derived chitinase (chitotriosidase), this chitinase is richly expressed in the gastrointestinal (GI) tract, suggesting its role in digestion of chitin-containing foods as well as defense against chitin-coated microorganisms and parasites. This in situ hybridization study first revealed cellular localization of the gut-type chitinase in the mouse and chicken. In adult mice, the parotid gland, von Ebner's gland, and gastric chief cells, all of which are exocrine cells of the serous type, expressed the gut chitinase mRNA. In the chicken, oxyntico-peptic cells in glandular stomach (proventriculus) and hepatocytes expressed the chitinase mRNA. Because cattle produce the gut chitinase (chitin-binding protein b04) only in the liver, the gut chitinases in mammals and birds have three major sources of production, i.e., the salivary gland, stomach, and liver. During ontogenetic development, the expression level in the parotid gland and stomach of mice increased to the adult level before weaning, whereas in the stomach of chickens intense signals were detectable in embryos from incubation day 7.

ABSTRACT. Urinary excretion of N-acetyl-β-D-glucosaminidase (NAG) was examined in healthy dogs and dogs with urinary diseases, and its clinical usefulness as an indicator of urinary diseases was discussed. Twenty-eight healthy dogs and 20 dogs with urinary diseases were used. Urinary NAG activity was measured using p-nitrophenyl N-acetyl-β-D-glucosaminide as substrate, and expressed as units per gram of urinary creatinine (NAG index). Urinary NAG index in urine of healthy dogs was 3.2 ± 2.4 U/g, and NAG index in the dogs with chronic renal failure or lower urinary tract infection accompanied by pyelonephritis was higher than that in healthy dogs. However, the dogs with lower urinary tract infection without pyelonephritis showed normal values of NAG index. Some dogs with diabetic mellitus showed elevated values of NAG index when control of blood sugar was not successful. Increase of NAG index was observed in some dogs with pyometra before increases of BUN and serum creatinine concentration. Therefore, NAG index in urine seems to be a good indicator for urinary diseases in dogs. KEY WORDS: canine, N-acetyl-β-D-glucosaminidase (NAG), urinary disease, urine.J. Vet. Med. Sci. 64(4): 361-365, 2002 N-Acetyl-β-D-glucosaminidase (NAG; EC 3.2.1.30) is a lysosomal enzyme found predominantly in the proximal renal tubular cells. Urinary NAG activity has been reported to increase under conditions of renal pathologic damage in both humans [2,6,[8][9][10]20] and other animals [1,4,15]. Urinary NAG activity also has been proposed as a sensitive marker of the progression of renal diseases [2,6,8,9] and the rejection of renal allografts [13,21]. Its activity increases prior to abnormal changes of other renal function test results [8]. The usefulness of urinary NAG activity values in dogs with drug-induced proximal tubular damage has been reported [4]. We reported the usefulness of measurements of urinary NAG activity in cattle [14,15]. However, there is little information available about the measurement of urinary NAG activity in clinical cases of canine renal diseases.In the present study, to clarify the usefulness of measurements of urinary NAG activity, we evaluated urinary levels of NAG in healthy dogs and dogs with urinary diseases. MATERIALS AND METHODS Animals:Twenty-eight healthy dogs (18 males and 10 females, 1-8 years old) and 20 dogs with urinary diseases (10 males and 10 females, 1-17 years old ) were studied. The clinical conditions of the dogs with urinary disease are shown in Table 1, and included chronic renal failure (7 cases), lower urinary tract infection accompanied by pyelonephritis (2 cases), lower urinary tract infection without pyelonephritis (4 cases), diabetes mellitus (3 cases) and pyometra (4 cases). All of these dogs were sexually intact. Clinical diagnoses in diseased dogs were decided based on physical examinations, urinalysis, CBC, serum biochemistry, ultrasonography and radiography (plain and excretory urography).Urine preparation: Untimed, freely caught urine samples were collected from the do...

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