On the Action of Hormones Which Accelerate the Rate of Oxygen Consumption and Fatty Acid Release in Rat Adipose Tissue in Vitro

Heat production in the new‐born rabbit and the fat content of the brown adipose tissue.

“…For example, these animals were probably hypoglyeaemic (D. Hull, H. J. Shelley and M. Young, unpublished). Apart from its effect on the central nervous system, hypoglycaemia might impair the ability of brown adipose tissue to produce heat by limiting the re-esterification of triglyceride (Ball & Jungas, 1961). Blood-sugar estimations were not made in the present experiments but occasional unfed animals on day 2 had convulsions which were relieved by the administration of glucose.…”

“…Heat is produced in the adipose tissue cell by the hydrolysis and subsequent re-synthesis of triglyceride in a process that involves oxidation (Ball & Jungas, 1961). The availability of fat for hydrolysis will depend on the total surface area which the fat vacuoles present to the lipolytic enzymes.…”

Calorigenic Effect of Norepinephrine Correlated with Plasma Free Fatty Acid Turnover and Oxidation*

“…A minimal figure can be calculated by assuming no dilution, and as shown in Table III (40). The increment in oxygen consumption may partly reflect the energy used for the breakdown and resynthesis of triglycerides within the adipose tissue, as proposed by Ball and Jungas (41), and the energy required for re-esterification of FFA mobilized and then taken up again in the liver and other tissues.…”

Studies on Lipolysis in Human Adipose Cells *

“…We first tested the extract on isolated fat cells of the rat to determine whether it contained any substances that might interfere with lipolysis. As shown in Table VIII, the powder markedly increased the production of glycerol and fatty acids from adipose cells of the rat, but when the same pituitary extract and cortisol (1 jig per ml) were added to the incubation medium with human adipose cells, no effect on lipolysis was seen (Table VIII) stimulated by epinephrine; this probably represents activation of the esterification pathway by the fatty acids liberated during lipolysis (17). The effect of epinephrine on lipolysis was observed in both Krebs-Ringer phosphate and bicarbonate buffers in the presence and absence of glucose (Tables V and VI).…”