Frank A. Hartman

Some Blood Constituents of the Normal Skate

IN PREPARATION for a study of the chemical changes produced by interrenalectomy in the skate we needed to know the values for normal animals. Smith (I929) has published normal values for electrolytes and urea in Raja laevis and R. diaphenes. At Woods Hole the most satisfactory animal for our purpose was the common skate, R. erinacea, because it was plentiful and it could be interrenalectomized without too much difficulty. Little or no data have been published on the electrolytes and urea in this species. Moreover, too little attention to the effect of inanition has been given. Kisch (1930) has shown that starvation causes a fall in blood urea, but he did not determine the electrolytes. We studied the range of variation in a large number of animals in both blood and perivisceral fluid. Then the effects of inanition and feeding were followed after it was found that plasma sodium rose with the fall in blood urea. Blood sugar and volumes per cent of erythrocytes were also determined.

LIPIDS IN THE LOCOMOTOR MUSCLES OF BIRDS

Fat content in locomotor muscles is an important source of energy, especially during sustained activity (George and Jyoti, 1957). The amount of such fat varies with different species, but whether this depends upon the use made of these muscles or other factors is uncertain. George and Naik (1960) reported values for the pectoralis major of birds ranging from 2.18 to 6.35 per cent in 18 species. Hoping to throw more light on this question, we have conducted the present investigation. A comparative study of the weights of the locomotor muscles gave us the opportunity to determine the fat or lipid content of the muscles in a large number of species of birds. Our study included muscles of the lower extremities as well as the pectoralis. We have determined muscle lipids in 104 species representing 42 families.

Vascular changes produced by adrenalin in vertebrates

The majority of physiologists still teach that adrenalin is essentially constrictor in its effect upon the blood vessels, ignoring the fact that doses which are probably physiological in their magnitude cause dilatation in a large proportion of vessels. These teachings are founded upon the older experiments in which massive doses of the hormone were used. Such amounts of adrenalin are probably never secreted by the adrenal glands (1, 2, 3). Although in the last few years it has been conclusively proven that small quantities of adrenalin cause vasodilatation and a fall in blood pressure as a result (4, 5, 6, 10) the fact is still ignored. This situation may be easily explained, for, among the common laboratory mammals some give evidence of vasodilatation while others consistently fail to do so. These animals which have been found to give positive proof of dilatation belong to the carnivores, while those that do not belong to the rodents. In face of the experimental facts it was as easy to believe the respo...

THE ACTION OF ADRENALIN ON THE KIDNEY

Many investigators have studied the action of adrenalin on the kidney, both in regard to circulatory changes and to urine flow, and have found that one or both may be modified by this substance. Inasmuch as Cow (1) has shown that there is direct communication between the adrenal medulla and certain parts of the kidney, it appears that adrenalin might have some important function in the control of the kidney. In the present instance we have made a study of the influence of adrenalin on the kidney volume, both from gangliar and peripheral action. Although it is possible that adrenalin may influence urinary secretion independent of vascular changes, yet we know that if vascular changes occur they will also modify kidney activity. It is assumed that volume changes are due to vascular changes.