Lysosomal enzymuria in protein energy malnutrition

Effect of starvation and refeeding on biochemical and immunological status of Balb/c mice: an experimental model of malnutrition

CONTEXT

Although new methods for the induction of malnutrition disorders in laboratory animals have been developed, the bulk of the models described in the literature are essentially based on dietary restriction/starvation principle. In this context, little data are available about the metabolic and the immune system parameters of Balb/c mice under starvation/refeeding.

OBJECTIVE

This study examined the effects of starvation and refeeding on the biochemical and immunological status of undernourished Balb/c mice.

METHODS

Female Balb/c mice, weighing 20 g, were starved for 3 days and then refed with commercial pelleted diet for 8 days. The variables considered were as follows: body weight; serum protein and amino acid concentrations; liver protein content, and cholinesterase and arginase activities; jejunal protein and DNA contents as well as oligosaccharidase levels; hematological parameters (bone marrow and peripheral blood cellularity); peritoneal macrophage activation; and humoral and cell-mediated immune functions.

RESULTS

Profound alterations in both biochemical and immunological conditions appeared after the starvation period. Refeeding resulted in the normalization of serum albumin levels, the intestinal DNA content and the gut-mucosal associated enzymatic activities, the blood lymphocyte counts, and the number of peritoneal macrophages. The markers of liver metabolic function (cholinesterase and arginase activities), and those of bone marrow hemopoiesis and the adaptive immune response (T-dependent antibody titres and delayed-type hypersensitivity response) remained altered after refeeding compared with control mice.

CONCLUSION

These findings suggest that fasted mice can be used as an animal model of acute starvation that might prove useful in evaluating the effectiveness of nutritional and immunopharmacological interventions.

Differential gene expression in the kidney of sickle cell transgenic mice: upregulated genes

The S+S-Antilles transgenic mouse used in this study has renal defects similar to those seen in sickle cell anemia patients: congested glomeruli, medullary fibrosis, renal enlargement, vasoocclusion, and a urine concentrating defect. We used gene expression microarrays to identify genes highly up-regulated in the kidneys of these mice and validated their expression by real-time PCR. Kidney hypoxia, as demonstrated by the presence of deoxyhemoglobin, was detected by blood oxygen dependent magnetic resonance imaging (BOLD-MRI). Some of the up-regulated genes included cytochrome P450 4a14, glutathione-S-transferase alpha-1, mitochondrial hydroxymethylglutaryl CoA synthase, cytokine inducible SH-2 containing protein, retinol dehydrogenase type III, arginase II, glycolate oxidase, Na/K ATPase, renin-1, and alkaline phosphatase 2. An increase in enzyme activity was also demonstrated for one of the up-regulated genes (arginase II). These genes can be integrated into several different pathophysiological processes: a hypoxia cascade, a replacement cascade, or an ameliorating cascade, one or all of which may explain the phenotype of this disease. We conclude that microarray technology is a powerful tool to identify genes involved in renal disease in sickle cell anemia and that the identification of various metabolic pathways may open new avenues for therapeutic interventions.

Changes in urination/defecation, auditory startle response, and startle-induced ultrasonic vocalizations in rats undergoing morphine withdrawal: similarities and differences between acute and chronic dependence

In drug-free subjects, a single dose of morphine followed by an opioid antagonist a few hours later results in signs of a withdrawal syndrome, suggesting a state of physical dependence. Increased urination/defecation, altered startle, and ultrasonic vocalizations (USV) are some signs of the withdrawal syndrome in rats chronically dependent on morphine. We investigated whether naltrexone stimulates urination/defecation and alters startle and USV in male rats that were pretreated with only a single dose of morphine and compared these indices to the ones of chronic dependence. Separate groups of rats were pretreated with either a single dose (10 mg/kg) or with a continuous s.c. infusion of morphine via an osmotic pump. Naltrexone (0.01-1.0 mg/kg) was administered 2 to 6 h after the single dose of morphine and on days 7 to 11 of the infusion. Immediately after the naltrexone injection subjects were placed in sound-attenuating boxes to record startle and USV and to collect urine/feces. Subjects chronically exposed to morphine also were tested during spontaneous withdrawal 3 to 24 h after pump removal. Naltrexone increased urination/defecation in subjects pretreated with morphine either chronically or acutely; it increased startle and USV in acutely dependent rats but decreased them in chronically dependent rats. In the latter group, changes in the four variables during spontaneous withdrawal were qualitatively similar to those during precipitated withdrawal but smaller in magnitude. Differences in withdrawal signs between acute and chronic dependence suggest that the neural substrates that mediate those particular components of the withdrawal syndrome are affected differently in the two states of dependence.

Determination of urinary and serum beta-glucuronidase and alkaline phosphatase in various renal disease and kidney rejection transplanted patients

Beta-glucuronidase (beta-Glu) and alkaline phosphatase (ALP) were evaluated in serum and urine in 50 subjects classified into five equal groups. Group I was control healthy subjects, while groups II, III, IV, and V were patients with nephritic syndrome, pyelonephritis, kidney rejection, and end-stage renal disease, respectively. Urinary beta-Glu was significantly elevated in all four groups; while serum enzyme showed no change. On the other hand, serum ALP showed a significant elevation in all abnormal groups. Accordingly, urinary beta-Glu and serum ALP could be used as diagnostic markers for various renal diseases.