Physiologie der Zellen, Gewebe und Organe. 327 



837) Markwalder, J. and Starling, E. H., A note on some Factors which 

 determine the blood-flow trough the coronary circulation. In: Journ. 

 of Physiol., Bd. XL VII, S. 275, l!)13. 



The coronary circulation is intiniately dependent on the arterial pressure. 

 Hence in excised heart a normal arterial pressure must be kept u]) if the heart 

 muscle is to be properly supplied with blood. When the peripheral resistance 

 is high, the coronary flow niay form a large proportion of the total ventricular 

 Output, Adrenalin causes dilatation of the coronary vessels. Increased COg ten- 

 sion and still more potently, the non-volatile metabolites produced by heart 

 muscle cause dilatation of the coronary vessels. In asphyxia the circulation 

 through the coronary System is at a maximum just before the heart falls alto- 

 gether. Min es. 



828) Cruickshaiik, E. W. H. and Patterson, S. W., The sugar consump- 

 tion in the surviving normal and diabetic heart. In: Journ. of Physiol., 

 Bd. XL VII, S. 381, 1913. 



Non-utilisation of sugar in the perfused diabetic heart is not a constant 

 phonemenon: when present it is connected with the greater störe of glycogen 

 in the hearts of diabetic animals. The results are, however, in harmony with the 

 view that sugar is attached rather less readily in the diabetic heart. The heart 

 uses its own störe of glycogen, under experimental conditions, in preference to 

 the sugar supplied in the circulating blood. Mines. 



829) Csithcart, E. P. and Clark, G. H., The influence of carbon dioxide on 

 the heart in varying degrees of anaesthesia. In: Journ. of Physiol, Bd. XL VII, 

 S. 393, 1913. 



The effects of Inhalation of COg on the heart beat of the rabbit are much greater 

 when the animal is lightly anaesthetised than when it is deeply anaesthetised with 

 ether. Mines. 



830) Clark, A. J., The action of Ions and lipoids upon the Frog's 

 heart. In: Journ of Physiol, Bd. XLVII, S. 66—106, 1913. 



An excised heart after perfusion with Ringer 's Solution for several hours 

 passes into a "hypodynamic" State in which force of contraction and rate of con- 

 duction from auricle to ventricle are impaired. In this condition the heart is more 

 affected by alterations in ionic content of the perfusion fluid than is the fresh 

 heart. The force of contraction is greatly improved by increasing the relative 

 concentration of Ca but not much improved by increased alkalinity. Probably 

 the hypodynamic heart has partly lost the power of combining with Ca. 



The hydrogen ion concentration limits for activity of the isolated frogs 

 heart are about 10 ~ ® ' '^ and 10 ~ ^ ^. A slight increase in COg present in perfusion 

 fluid produces a beneficial effect on the heart not to be explained by the change 

 in hydrogen ion concentration. 



Amino-acids, glycogen and to some extent sugars benefit the hypodynamic 

 heart. The soaps of fatty acids higher than caproic acid revive the hypodynamic 

 heart most strikingly. Their action depends on the presence of Ca with which 

 they form insoluble Compounds. 



Serum has a very beneficial effect; so has an alcoholic extract of serum. 

 The effect is due to lipoids: proteins are without action. The perfused heart loses 

 lipoids: this may be the cause of the hypodynamic condition. It is suggested that 

 Ca forms Compounds with lipoid substances at the surfaces of certain cells in 

 the heart and that the presence of this Compound at the surface is requisite 



