F. DANIELLI 



Table I 



The distribution of injected substances in the water of eviscerated nephrectomized animals. The 

 figures are for the equilibrium volume of water in which the substances appear to be distributed, 

 expressed as percentages of body weight. It is assumed that at equilibrium the concentrations of 

 substances in all water into which they penetrate are the same as the concentrations in the blood. 



* Followed by slow steady increase, due to metabolism. 



linked with metabolism, for it is positive with some non-metabolized sugars and 

 negligible for some sugars which are metabolized. 



Results of similar significance to those of Levine et al. have also been obtained with 

 rat diaphragm (e.g. Haft, Mirsky and Perisutti, 1953) and heart (e.g. Bleehen and 

 Fisher, 1954). It has been shown that the insulin effect on glucose penetration may 

 be antagonized by other hormones, including anterior pituitary 'growth' hormone 

 and cortisone, and it is thought to be simulated by oestrogens (see, e.g. Ciba Founda- 

 tion Colloquia, VI). The relationships between the various hormones are far from 

 understood, for Ottaway (1951) has shown that 'growth' hormone, normally anta- 

 gonistic to insulin, under some circumstances has an insulin-like action. It is possible 

 that the anti-insulin action of 'growth' hormone involves displacement of insulin 

 from the plasma membrane by the hormone, and that the insulin-like action is due 

 to 'growth' hormone releasing active insulin by displacement from an inert tissue 

 complex (Ottaway, 1953). 



Another observation of great interest is that (Bleehen and Fisher, 1954) when a 

 rat heart, with coronary circulation, is perfused with an insulin-free medium, insulin 

 is removed from the heart at about the same speed as is the polysaccharide inulin. 



