Developmental changes of Islet-activating protein-sensitive GTP-binding protein of rat white fat cell membranes

• Published in: Japanese Journal of Pharmacology 1989, Vol.49 (suppl), p.176-176
• Main Authors: Imaizumi, Taro, Watanabe, Yasuhiro, Keno, Yoshiaki, Kobatake, Takashi, Matsuzawa, Yuji, Tokunaga, Katsuto, Tarui, Seiichiro, Yoshida, Hiroshi
• Format: Article
• Language: English
• ISSN: 0021-5198; 1347-3506
• DOI: 10.1016/S0021-5198(19)56363-6

Age-related changes of islet-activating protein (IAP)-sensitive GTP-binding protein in membranes of rat epididymal fat cell were investigated. Young (6 weeks, about 190 g) and aged (20 weeks, about 490 g) SD male ratswere used. Rats were killed by decapitation. Epididymal fat pads from each age group were quickly removed and processed immediately for crude membrane preparation. Isolated fat cells were prepared according to the method of Kashiwagi. The area of absorbance of the bands of 39-41 K protein on autoradiography was measured by densitometry. The amounts of ADP-ribosylation of the protein by IAP was almost saturated for about 120 min at 25℃, and the amounts of ADP-ribosylation by IAP decreased to about 60% of the control in the older rats, while B max of [3H] rauwolscine increased remarkably from 19.8+4.9 (4) to 86.2+19.5 (4) fmol/mg of protein in the binding experiments using the fat cell membranes of young and old rats. Thus, developmental changes of these factors may modulate the modulation of anti-lipolytic factors with aging.