Search results for "Vitamin A Deficiency"

Vitamin A-Wachstums- und Leberspeichertest bei Ratten, mit gleichzeitiger Prüfung eines wasser- und fettlöslichen Präparates

1960

1. Wir fuhrten den Vitamin A-Wachstumstest mit dem wasserloslichen Palmitinsaureester und dem fettloslichen Vitamin A-Acetat durch. Die Tagesdosis betrug 1,5 bzw. 2,5 IE/Tier. Jede der 4 Gruppen bestand aus 30 Mannchen. Das Ergebnis wurde nach dem t-Test vonStudent ausgewertet. 2. Unter den Bedingungen unseres Experimentes erhoht der wasserlosliche Palmitinsaureester das Wachstum gegenuber dem fettloslichen A-Acetat signifikant. Die Differenz ist bei der geringen Dosis von 1,5 IE am grosten. Der Einflus des Futterverzehrs auf das Wachstum wird diskutiert. 3. Beim Leberspeichertest arbeiteten wir wieder mit 4 Rattengruppen zu je 30 Tieren. Verwendet wurden die gleichen Praparate wie beim Wac…

An ex vivo model of the rat trachea to study the effect of inhalable toxic compounds

1996

Different cell culture and organ systems are used to evaluate the physiological responses of the airways to the effects of carcinogenic [e.g., benzo(a)pyrene] and anticarcinogenic (e.g., retinoids) compounds on cellular growth and differentiation. However, in contrast to in vivo conditions dissociated epithelial cells or tracheal ring cultures are covered with medium. Therefore, we developed an ex vivo perfusion model enabling evaluation of morphology and metabolism of different compounds under near-physiological conditions. The trachea was surrounded with culture medium and perfused with air by means of a small animal respirator. To test the viability of the system under various experiment…

Uptake and Metabolism of ?-Carotene Isomers in Rats

1993

Vitamin A deficiency is associated with disease severity in patients with liver cirrhosis

2020

Vitamin A deficiency alters rat lung alveolar basement membrane: reversibility by retinoic acid.

2010

Vitamin A is essential for lung development and pulmonary cell differentiation and its deficiency results in alterations of lung structure and function. Basement membranes (BMs) are also involved in those processes, and retinoic acid, the main biologically active form of vitamin A, influences the expression of extracellular matrix macromolecules. Therefore, we have analyzed the ultrastructure and collagen content of lung alveolar BM in growing rats deficient in vitamin A and the recovering effect of all-trans retinoic acid. Male weanling pups were fed a retinol-adequate or -deficient diet until they were 60 days old. A group of vitamin A-deficient pups were recovered by daily intraperitonea…

Vitamin A deficiency alters the structure and collagen IV composition of rat renal basement membranes.

2005

Retinoids can modulate the expression of extracellular matrix (ECM) proteins with variable results depending on other contributing factors. Because changes in these proteins may alter the composition and impair the function of specialized ECM structures such as basement membranes (BMs), we studied the effects of vitamin A deficiency on renal BMs during the growing period. Newborn male rats were fed a vitamin A-deficient (VAD) diet for 50 d. The ultrastructure of renal BMs was analyzed by electron microscopy. Total collagen IV, the different alpha(IV) chains, matrix degrading metalloproteinases (MMP), and tissue inhibitors of metalloproteinases (TIMP) were quantified by immunocytochemistry a…

Vitamin A deficiency increases noise susceptibility in guinea pigs.

1990

The effect of vitamin A deficiency in guinea pigs on noise-induced temporary threshold shift (TTS) was evaluated after short (15 min) acoustic overstimulation with a moderate (90 dB) broad-band white noise. Some guinea pigs were fed ad libitum a purified diet deficient in vitamin A (VAD group) until biochemical signs of deficiency occurred. A second, control group (VA group) received the same diet as well as 100 IU vitamin A daily by pharyngeal tube. Cochlear potentials were recorded by special computerized equipment using implanted electrodes. Before acoustic stimulation, a baseline value was determined with a test stimulus [90 dBA (A-filter according to usual DIN instructions)] correspond…

Crystalloid lysozyme inclusions in Paneth cells of vitamin A-deficient rats.

1990

The effect of vitamin A-deficiency on jejunal Paneth cells in rats was investigated. Crystalloid particles were observed in secretion granules of Paneth cells from 6 out of 8 rats with vitamin A-deficiency. The particles were similar to those found in Paneth cells under other experimental conditions. Using an immuno-electron-microscopic technique we demonstrated a clear lysozyme immunoreactivity of these particles. In 2 vitamin A-deficient rats tubular structures have been detected in addition to the crystalloid particles. Crystalloid particles or tubular structures were not detectable in a control group of 8 vitamin A-supplemented rats. The morphological alterations of Paneth cells may be …

Vitamin A in parenteral nutrition: uptake and distribution of retinyl esters after intravenous application.

1989

Short-term parenteral application of vitamin A was examined in rats. Retinyl margarinate, which is chemically similar to physiological retinyl esters, was used in vitamin A-depleted rats to study uptake, distribution, and storage of retinyl esters in tissues. Vitamin A-depleted and Vitamin A-sufficient rats were infused with a micellar suspension of retinyl margarinate for 7 h and then killed at different times. Retinyl margarinate was directly taken up by all tissues examined. It appears that infusion of retinyl esters in micellar form provides a direct way to supply vitamin A to peripheral, vitamin A-dependent tissues. Therefore, a short-term infusion of retinyl esters with an emulsifier …

Effects of vitamin A deficiency on mitochondrial function in rat liver and heart.

2000

The aim of this study was to investigate comparative effects of vitamin A deficiency on respiratory activity and structural integrity in liver and heart mitochondria. Male rats were fed a liquid control diet (control rats) or a liquid vitamin A-deficient diet (vitamin A-deficient rats) for 50 days. One group of vitamin-A deficient rats was refed a control diet for 15 days (vitamin A-recovered rats). To assess the respiratory function of mitochondria the contents of coenzyme Q (ubiquinone, CoQ), cytochrome c and the activities of the whole electron transport chain and of each of its respiratory complexes were evaluated. Chronic vitamin A deficiency promoted a significant increase in the endo…