A TRACE OF COPPER

Evening Post, Issue 2, 2 July 1932, Page 13

A TRACE OF COPPER

. ; ■ .; .- —; ♦ NECESSARY TO THE BODY CHEMICAL INVESTIGATION

Chemical research in which white rats played an important part was the subject of an address entitled ♦' The Eole of Copper in Animal to the Wellington B ranch of the New Zealand Institute of Chemistry recently. The speaker wag Dr. I. J. Cunningham, of the Agricultural Department, who carried out. this work, atthe Bowett Institute, near. Aberdeen.. lii discussing -tha nutrition of animals, the speaker: referred to the fact that in addition to. the.elements generally recognised as essential to the construction of the body and the regulating of its functions, many others occur hi minute' amounts, though as yet the reason for their presence is often unknown. Evidence is accumulating, however, to show that the presence of these ."trace," elements'in. ani* mal tissues is a physiological necessity, such as the. well-known relation between.iodine and the thyroid gland. The particular part played by copper was investigated in the research with which the paper, dealt.

Dealing first witi the source of supply to tho animal,' DrY Cunningham stated that both the soil and. river water contained copper, while- in all plant materials there is a small though varying. amount,, which-, .assure a natural and regular supply to all animals subsisting on unmodified vegetable foods. Copper is found-in both ■marine and land typesl'ln land animals the most noticeable feature is that in all species every part examined contains copper, though the distribution is not uniform, tho liver being richest in the element. Though the individual organs do not contain a definite proportion of copper, the order of copper content is substantially the same in any one animal. It appears, also, that copper and also'iron aie stored progressively in the foetal liver and reach a maximum at - the'< time of birth of the animal and then fall during ■earlyyouth. The- explanation seems to be that the store provides the newly-boi-n animal with its . requirements for growth during the suckling period when the only food-—milk—is deficient both in copper and iron. : .Therefore, since both herbivorous and carnivorous animals are always assured of a supply of copper in their foods, while it is found distributed in a fairly regular manner throughout, the various .organs of the body, it would seem that' Nature has been too careful in her work for the copper to be merely a useless factor. ■■•:■■ ■■.. .' • .>..:. :

■ Iron is considered • important ■in animal metabolism, as. it enters into the constitution- of. the haemoglobin of the .blood. W^rk on the rat has shown that anaemia:"due to lack of iron could, be cured' by feeding of purified iron salts, provided that small .quantities 'of copper were also sup..plied. ' Experiments showed that the function of the copper is to convert inorganic iron stored in the liver into organic iron. Since copper feeding simultaneously effuses an increase in the haemoglobin content of' the blood of the animal, the organic iron formed must be similar to that in. haemoglobin. The main function of copper, therefore,1 .is connected •witfi iron utilisation. The importance of this need not be stressed, as the grave effects of iron deficiency both in humans arid animals is familiar to all. Though most of the. work discussed was carried: put on rats; it nas been demonstrated' that copper is es,sential to the chicken, the pig, and the ox, and in. humans' beneficial results ;have\followed its use. Therefore, concluded ' the- speaker, 'copper-providing articles should not bo neglected: in oar dietary, and though sheep- liver is richest in the element, cocoa; mushrooms, oj-sters, nuts,"' and. green vegetables arc very good suppliers.

Dr. Cunningham also mentioned the reputed toSic .effect 'of' copper, and stated that'it is generally agreed that acute ipoi'soriing by- copper is 'extremely rare, ■vyhile, though there 13 no absolute agreement regarding chronic poisoning, it has been shown that large amounts of copper, have not adversely affected the growth rate of young rats, nor the maintenance' of .weight of adult rats.

Many questions were asked by the large audionce present,'" and Dr. Cunningham was congratulated on the interesting nature and method of presentation of his address.