Volume 5 | Issue 3 Article 3

1943 Radiant Energy L. A. Kanegis Iowa State College

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Recommended Citation Kanegis, L. A. (1943) "Radiant Energy," Iowa State University Veterinarian: Vol. 5 : Iss. 3 , Article 3. Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol5/iss3/3

This Article is brought to you for free and open access by the Journals at Iowa State University Digital Repository. It has been accepted for inclusion in Iowa State University Veterinarian by an authorized editor of Iowa State University Digital Repository. For more information, please contact [email protected]. Radiallt Energy

PhlSiolo~ic effects on the living organism

L. A. Kanegis, fall '43

T IS generally conceded that the study about an hour by an erythema due directly I of radiant energy as such is a matter to the ultra-violet rays. If the radiation involving the work of the physicist. It is be intense, or if absorbed over an ex­ to their credit that the various forms of tended period, blistering and even hemor­ radiant energy have been explored, meas­ rhage may result. The skin usually peels ured, and described. Of the new aids and pigmentation is evidenced. The long­ which physics has given workers in biol­ est wave length that is capable of produc­ ogy, probably the most important are the ing this type of erythema is approximately quantum theory of light, and the new 3150 Angstroms. implements, techniques of generating, manipulating and measuring radiations. Susceptibility Varies Radiant energy of desired wave lengths Susceptibility to sunburn varies with and frequencies is now at the command of groups and with individuals. Light skinned research workers in the field of biology individuals are more sensitive than those and physiology who are engaged in the of darker skins; the relative amount of study of the effects of radiant energy on cutaneous pigment being the important the living organism. factor. It is interesting to note that sea­ It is the purpose of this article to briefly sonal variation is a factor in individual present some of the work and results along susceptibility. March-April and October­ this line of investigation. November are sensitive maxima accord­ The radiant energy range in which we ing to Laurens1 • are here interested can be divided into The protection from these wave lengths three portions, the infra-red (12,000-8,000 in the dark skinned individual results from A *), the visible (8,000-4,000A), and the an increase in pigment formation and ultra-violet (4,000-2,000 A). The longer deposition, an increase in thickness in the waves of the spectrum such as radio waves skin, and an alteration of the cutaneous and the shorter waves, the X rays, gamma proteins, increasing their filtering proper­ rays and cosmic rays, will not be consid­ ties. ered, although there is evidence to prove The wave length of the rays determines that they all play a part in biologic pro­ the reaction produced. Wave lengths of cesses. from 3200 to 4800 Angstroms produce a Skin Reaction marked deep red erythema. The longer wave lengths, that is the longer ultra­ The skin reacts to radiations in a char­ violet and shorter visible rays, produce a acteristic manner, the blood supply and more intense tanning than do the shorter the metabolism being increased. The red­ ultra-violet rays. dening of the skin is a twofold process; The characteristic skin reaction is due the initial erythema is caused by the infra­ to the formation of substances in the skin red and long luminous rays. This hyper­ which induces vascular dilatation. If the emia soon disappears and is followed in intensity of the radiations be great enough, * One Angstrom = 0.1 millimicron. actual inflammation results. These sub-

Winter, 1943 109 stances are formed by the direct action of The ultra-violet radiations produce the radiant energy on the proteins present hyperemia of the superficial vessels, while in the skin, converting them to toxic prod­ the longer visible and the infra-red pro­ ucts probably of the histamine type. In duce the condition in the deeper vessels. many instances the presence of histamine Therefore to the histamine action must itself has been shown following irradia­ be added the direct action or influence of tion. Laurens1 and associates have shown heat energy itself, this being able to cause that carbon-arc irradiation definitely in­ vascular dilatation in itself. It is to be creases the histamine content of the blood. added, however, that Laurens found a It has been observed that natural sun­ definite positive correlation between low­ light hastens healing of wounds. This is ered blood pressure and histamine content accomplished by the whole spectrum and of the blood. The fact that the lowest promotes disinfection, proliferation of pressure resulted several days after ex­ granulation tissue, and an increase in blood posure may indicate that the slow absorp­ supply. It appears that certain substances tion of histamine was the retarding and liberated by the cells which are injured by vital factor. The effect on the heart rate the radiations effect an acceleration of was inconsistent. healing. It has been found that the metabolism Injury to Eye of body proteins is increased by moderate irradiation. An increased uric acid con­ The sensitive structures of the eye are tent of the blood indicates an increased especially susceptible to injury by strong purine metabolism. The concentration of radiations. Wave lengths of from about lipids may increase to 50 percent above 7600 to 3900 Angstroms penetrate to the its normal level. A very interesting ob­ retina and are perceived as light. Intense servation is the lowering of the blood white light injures the retina by heat co­ sugar due to an increase of glycogen for­ agulation, the heat energy being derived mation and storage. This action is identi­ from the absorption of long visible and cal with that of insulin. It has also been infra-red radiations. suggested that androgenic substances are It has been observed that the blood increased following ultra-violet irradia­ picture is improved following irradiation. tion. Repeated moderate irradiations are There is an increase in the number of ery­ believed to decrease the metabolic rate for throcytes, leucocytes, and blood platelets. as long as three to four weeks following A lower blood sugar level, higher calcium the last irradiation. Over-exposure, how­ concentration, and an increase in the pro­ ever, leads to deleterious effects, mani­ tein content of lymph have also been fested by such symptoms as restlessness, noted. anxiety, headache, and nausea. Laurens1 states that the influence of solar radiation on increased resistance to Vitamin D Increased disease is a matter of conjecture, and is An increase in the vitamin D content of still an unsettled problem. Blood pressure the body following ultra-violet irradiation is usually lowered by exposure to sun­ is well known. It is believed that radia­ light or an artificial source of radiant en­ tions between 2967 and 3131 Angstroms ergy. It has been recorded that in certain in particular are effective in activating cases of hypertension, the systolic pres­ provitamin D in the skin to vitamin D. sure has been lowered as much as 40 mm. Vitamin D is necessary for proper calcium of mercury. The explanation of this phe­ and phosphorus absorption from the in­ nomenon rests on the liberation of hista­ testines, and its subsequent metabolism mine in the skin which causes a dilatation in the body. Upon the proper calcium­ of the cutaneous blood vessels, thus re­ phosphorus level and concentration ratio ducing the general blood pressure. The depend normal bone formation and dilatation is by both direct and reflex growth, muscular tone and irritability, action. Increased capillary permeability formation of teeth, and proper lactation. is also a factor in this mechanism. (CO'ntinued CYn page 132)

110 The Veterinary Student Nelson, '40, W. L. Munson, '42, and Ed UAlJIANT ENERGY Hanna, '42, are all stationed in Iowa with headquarters at Ft. Des Moines. (Continued from page 110) It is held that the provitamin D of the skin Lt. Leslie J. Moore, '42, is stationed is 7-dehydrocholesterol. There have been at the New York Port of Embarkation some cases reported in which a hyper­ where he is doing food inspection work. vitaminosis D existed, characterized by decomposition of calcium salts in the va­ Change of Address rious tissues. Changes of address which have been reported are: Dr. Robert L. Alkire, '36, Undesirable Effects East Tenn. Packing Co., Knoxville, Tenn. Dr. Albert A. Peters, '34, 10 S. Main The effects discussed thus far have con­ St., Webb City, Mo. cerned mainly the beneficial manifesta­ Dr. C. W. Brown, '10, 322 W. Samano tions of radiant energy. There are, how­ St., Edinburg, Tex. ever, certain very undesirable effects Dr. W. E. Miller, '02, 441 Sixth St., which are produced when certain sub­ Ames, Iowa. stances combine with the radiations in Dr. Herbert A. Seidell ,'18, 3869 Dewey, such a manner as to produce unfavorable Omaha, Neb. conditions within the tissues. This phe­ Dr. Roland T. Coe, '37, 429 Hayward nomenon is referred to as photo-sensitiza­ Ave., Ames, Iowa. tion or photo-dynamic action. There are Dr. John R. Scott, '24, 3176 Rowland many dyes and pigments capable of sensi­ Ave., Kansas City, Kan. tizing cells to the deleterious effects of Dr. J. D. Cline, '10, 612 Polk Blvd., Des radiant energy. Certain plants are known Moines, Iowa. to contain such substances, and when these Dr. R. Steven Kufrin, '41, Winthrop, plants are consumed by animals, extensive Minn. skin inflammation, loss of hair or wool, and Dr. Leo M. Marshall, '19, 2039 Arizona, cutaneous necrosis often result after ex­ Butte, Mont. posure to sunlight. The action appears to Dr. M. J. Jones, '34, Milaca, Minn. be that of an unwarranted direct mole­ Dr. Leland C. Morely, '30, 622 W. cular oxidation in the cells which results Stuart, Clarinda, Iowa. in injury and death to the cells. The sen­ Dr. Lawrence Minsky, '37, 337-23rd St., sitizing substances have the ability when Merced, Calif. irradiated to absorb molecular oxygen Dr. L. L. Boxwell, '40, 315 State St., and transfer it directly to the cell. This Cedar Falls, Iowa. molecular oxidation under photo-chemi­ Dr. E. Paul Eder, '41, 7002 Plymouth cal influence is the actual cause of the Rd., Baltimore, Md. trouble, rather than the direct effect of the radiation on the cells. Under normal cell conditions this oxidation would not take place at body temperature. Physiologic I.V.M.A. oxidations are entirely independent of this Dr. P. V. Neuzil, '20, Blairstown, Iowa, phenomenon and occur as dehydrogena­ retiring president of the Iowa Veterinary tions rather than direct molecular oxida­ Medical Association, installed the offi­ tions in most cases. cers for the current year, 1943, at the Des The absorbing of a quantum of radia­ Moines meeting. The new officers are Dr. tion by the sensitizer is the initial process J. A. Barger, Des Moines, president; Dr. which sets the photodynamic action in V. B. Vanderloo, '21, Dubuque, vice-presi­ motion. It must be emphasized that the dent; and Dr. C. C. Franks, '11, re-elected photo-dynamic action proceeds only in secretary and treasurer. Dr. George A. the presence of molecular oxygen. It is Hawthorne, Clarinda, Iowa, was elected important that this injurious effect of president-elect for 1944. photo-dynamic action be distinguished

132 The Veterinary Student from the injurious effects of too intense ered by some to be the fundamental mech­ ultra-violet radiations. The former is de­ anism responsible for the various physio­ pendent on molecular oxygen, the latter logic effects of such radiations. The liber­ is not. ation of histamine or histamine-like sub­ It has been found that a malignant skin stances is a similar mechanism whereby ccndition could be induced in laboratory ultra-violet causes many complex changes. animals by exposure to light. Skin cancer in humans has been suggested following Other Ions irradiation. It is possible that a positive correlation exists between photo-sensitiza­ In addition to radiation, ions similar to tion and the production of malignancy. the alpha and beta particles from radium Some of the carcinogenic substances are are always darting through the air. These active photo-sensitizers. ions are fragments of atoms smashed by the impact of colliding high frequency Bacteria Killed quanta of radiant energy or with other ions. Practically all bacteria may be killed or According to Gray\ "It is known that rendered less virulent by ultra-violet ir­ when electrons of high velocity are ab­ radiation. The strict pathogens which sorbed in matter, the effect is to release have adapted themselves to living within a large number of secondary ions within the body of their hosts are most suscep­ a very small space. The impact of the tible. Those living free in nature, being speeding particle sets off a veritable ex­ more exposed to radiations, have devel­ plosion, smashing out parts of atoms, each oped degrees of resistance to them. Direct of which recoils at a high velocity to wreak solar radiation is a potent germicide for havoc wherever it strikes and in a frenzy almost all bacteria except some of the of chaotic movements causes destruction sulfur bacteria which utilize the sun's rays of the peculiar organization of proto­ in their metabolic processes. The maxi­ plasm." In irradiated tissues molecules are mum germicidal effect seems to be be­ ionized or activated. This leads to colloidal tween 2600 and 2700 Angstroms. It is be­ changes, increased viscosity, changes in lieved that the resistance of irradiated solubility and coagulation. bacteria to heat is much lowered. Bac­ terial toxins are likewise photo-labile, while antitoxins are relatively photo­ More Problems stable. In order to attenuate the virus of Some of the questions in the field of tobacco mosaic, wave lengths shorter than radiant energy have been answered but 3100 Angstroms are necessary. The resist­ there are still many problems to be solved, ance ratio of virus to bacteria is 200 to 1. especially regarding the mechanism of It has been shown that virus vaccines pre­ operation. Much work is being done by pared by attenuation with ultra-violet physicists and physiologists along this line irradiation possess greater immunological and slowly but resolutely the physical properties than those attenuated by heat. forces affecting life are being explored and unveiled. Sterilizing Air BIBLIOGRAPHY The possibility of sterilizing the air of 1. Laurens, H. 1942. The physiologic effects of radi­ hospital wards and operating rooms by ant enegry. Archives of Physical Therapy. means of radiations has been investigated. 23:153-170. In hospitals over 90 percent of wound in­ 2. The Faculty of Radiologists. 1942. Discussion on the constitutional effects of radiations with special fections are caused by staphylococci. In reference to volume-dose. British Journal of cases where ultra-violet light has been Radiology 15(172) :99-103. 3. Bodansky, M. Physiological Chemistry. John used, the incidence of post-operative WEey and Sons, Inc., New York. wound infection has decreased as much as 4. Runnells. R. A. Animal Pathology. Iowa State 85 percent. Denaturation of the protein College Press, Ames, Iowa. 5 Gray. G. W. 1934. Radiation and life. Harpers molecule by ultra-violet rays is consid- 169: 210-221.

Winter, 1943 133