scholarly journals Inhibition of degradation of insulin by ophthalamic acid and by a bovine pancreatic proteinase inhibitor

1979 ◽  
Vol 182 (1) ◽  
pp. 249-251 ◽  
Author(s):  
R E Offord ◽  
J Philippe ◽  
J G Davis ◽  
P A Halban ◽  
M Berger

We have previously observed that, on subcutaneous administration, a significant proportion of insulin is degraded at the site of injection. The present paper reports that the degradative activity of slices of rat adipose tissue can be inhibited in vitro by ophthalmic acid, a natural analogue of glutathione, and by bovine pancreatic proteinase inhibitor, whereas it is increased by the addition of reduced glutathione.

1959 ◽  
Vol 234 (12) ◽  
pp. 3111-3114 ◽  
Author(s):  
Albert I. Winegrad ◽  
Walter N. Shaw ◽  
Francis D.W. Lukens ◽  
William C. Stadie

2004 ◽  
Vol 33 (1) ◽  
pp. 11-19 ◽  
Author(s):  
RY Li ◽  
HD Song ◽  
WJ Shi ◽  
SM Hu ◽  
YS Yang ◽  
...  

In addition to serving as a fat depot, adipose tissue is also considered as an important endocrine organ that synthesizes and secretes a number of factors. Leptin is an adipocyte-derived hormone that plays a vital role in energy balance. Expression of leptin is regulated by dietary status and hormones. In the present study, we report that galanin, an orexigenic peptide, inhibits leptin expression and secretion in rat adipose tissue and in 3T3-L1 adipocytes. Treatment with galanin (25 micro g/animal) induced approximately 46% down-regulation of leptin secretion at 15 min, followed by 40, 37 and 47% decreases in leptin secretion at 1, 2 and 4 h respectively. Although Northern blot analysis of adipose tissue from the same animals showed that leptin mRNA expression in adipose tissue was unaffected by galanin treatment for 2 h, galanin treatment for 4 h led to decline of leptin mRNA expression in a dose-dependent manner. Meanwhile, treating the rats with galanin had no effect on leptin mRNA expression in the hypothalamus. The inhibitory action of the galanin on leptin mRNA and protein levels was also observed in vitro. When incubated with 10 nM galanin for 48 h, leptin mRNA expression and protein secretion also decreased in 3T3-L1 adipocytes. On the other hand, galanin was found not only to express in rat adipose tissue, but also to increase about 8-fold after fasting. Based on these data, we speculate that increased galanin expression in rat adipose tissue after fasting may be involved in reducing leptin expression and secretion in fasting rats.


FEBS Letters ◽  
1974 ◽  
Vol 49 (1) ◽  
pp. 65-69 ◽  
Author(s):  
P. Zumstein ◽  
J. Zapf ◽  
E.R. Froesch

1964 ◽  
Vol 207 (6) ◽  
pp. 1215-1220 ◽  
Author(s):  
Alisa Gutman ◽  
Eleazar Shafrir

Rat adipose tissue from different body sites was shown to contain uridine diphosphoglucose (UDPG)-transglucosylase activity, which on the basis of protein content was comparable to or higher than that reported for muscle or liver. In epididymal adipose tissue, the activity of UDPG-glycogen transglucosylase and phosphorylase, as well as the content of glycogen per wet weight, decreased with increasing age of the animals in parallel with the decrease of tissue protein content. On prolonged fast the activity of UDPG-glycogen transglucosylase and phosphorylase per milligram protein dropped by 25–50% of the control value. On refeeding, the extent of changes was variable but, in general, at 24 hr control or higher levels of activity were reached and at 48 hr the activities were elevated. The ratio of glucose 6-phosphate independent activity of UDPG-glycogen transglucosylase to total activity was not affected by fasting and refeeding or by the administration of glucose with insulin. In adrenalectomized rats, with high adipose tissue glycogen, no change in UDPG-glycogen transglucosylase was found, whereas the levels of phosphorylase were elevated. Epinephrine in vivo and in vitro did not affect the activity of UDPG-glycogen transglucosylase of adipose tissue.


1960 ◽  
Vol 198 (3) ◽  
pp. 640-644 ◽  
Author(s):  
Rodney D. Orth ◽  
William D. Odell ◽  
Robert H. Williams

The effects of various hormones on the metabolism of acetate-i-C14 by rat adipose tissue in vitro were investigated. Using an albumin-containing medium, it was found that ACTH, growth hormone, epinephrine and glucagon each caused increased oxygen consumption, a decreased incorporation of acetate into tissue lipid, and an increase in the amount of newly synthesized lipid attached to albumin. The basic mechanism involved in the production of such qualitatively similar effects by each of the hormones studied are unknown.


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