[Studies on the number of fat cells and connective tissue cells in white adipose tissue in chronic starvation and after refeeding. I. Investigations on aurothioglucose-obese NMRI-albino-mice(author's transl)].

UNLABELLED

Former investigations (Rakow et al., 1970, 1971 b) on epididymal fat pads of lean NMRI-Albino-mice during starvation and refeeding have shown that the number of fat cells (adipocytes) remained unchanged while the number of cells o connective tissue decreased during starvation and increased during the refeeding period. In the present paper the problem has been investigated whether these variations could be demonstrated also in NMRI-albino-mice obesified by administration of aurothioglucose.

MATERIAL AND METHODS

The investigations were performed with male NMRI-Albino-mice rendered obese by administration of aurothioglucose (800 mg per kg body weight). These animals were fed 2.5 g Altromin 1115 R daily for six weeks. After this they were fed Altromin 1115 R and additional oat flakes ad libitum for three (exp. groups HW3) and seven (exp. groups HW 7) days respectively. After this time the animals were sacrificed. The epididymal fat pads were removed and weighed. One of both pads of each animal was used for chemical investigations. After PCA-treatment (0.5 n, 90 degrees C. 15 min.) the DNA (Burton, 1956) and RNA (Ceriotti, 1955) was determined in the supernatant. After NaOH-treatment (0.5 n, 37 degrees C, 24 Hrs) the noncollagen protein content (Lowry et al., 1951) of the sediment was estimated. After HCl-treatment (25%, 110 degrees C, 20 hrs.) the collagen content (Stegemenn, 1958; modified by Rauskolb, 1967) was determined. The remaining fat pad was used for calculations of cell numbers in the fat cell and connective tissue cell compartment. For this reason fat cells were isolated according to Rodbell (1964). The fat cell diameters were determined microscopically and the average masses of the fat cells were estimated. From the wet weight of the fat pads and the average fat cell mass the number of fat cells was calculated. The remaining suspension of fat cells and cells of connective tissue was utilized for cell smears. These smears were stained with Schiff's reagent (Feulgen et al., 1924; Graumann, 1952). With an integrating microdensitometer (Deeley, 1955) the average relative DNA-content of single cell nuclei were measured and the ploidy patterns were estimated. From the whole DNA-content of the fat pads and the DNA-content of the fat cell population the number of cells of the connective tissue was calculated...