Dilatation of colon induced in rats by β-aminopropionitrile feeding

EXPERIMENTAL

Dilatation

AND

MOLECULAR

of Colon

6, l-10

PATHOLOGY

Induced

(1967)

in Rats

by P-Aminopropionitrile

Feeding’ JOSEPH J. LALICH AND HAMISH TURNERS Department

of Pathology,

IJniversity

of Wisconsin

Received

July

Medical

School

Madison,

Wisconsin

14, 1965

Some degree of skeletal deformit’y is regularly produced in weanling rats by feeding either Lathyrus odoratus seeds (Geiger et al., 1933; Lewis et al., 194s; Dasler, 1954) or its toxin p-aminopropionitrile (Wawzonek et al., 1955; Dasler, 1957; Doerr et al., 1960). On the other hand, aortic rupture (Ponseti and Baird, 1952; Pyorala et al., 1956; Menzies and Mills, 1957), herniabion (Geiger et aZ., 1933; Lalich, 1956), or hind limb paralysis (Lewis et al., 194s; Lee et al., 1956; Hartmann and Lalich, 1961) develop inconsistently after the feeding of lathyrogenic agents. For example neither Geiger et al. (1933) nor Lewis et al. (1948) observed aortic rupture when 1s % casein was fed with 50% L. odoratus seeds. Ponset’i and Baird (1952) produced skelet,al deformities and aortic rupture for the first time either by excluding casein or feeding less than 10 % of this protein with I, odoratus seeds. These workers, however, did not appreciate the importance of dietary protein in the production of angiorrhexis in rats. It was possible to produce aortic rupture in a significant number of rats fed 50 % L odoratus seeds only when the casein concentration was reduced to 10% (Bachhuber and Lalich, 1954). Undoubtedly another factor of prime import,ance in the production of tissue alteration is the concentration of p-aminopropionitrile (BAPN) in the diet,. Unfortunately, the concentration of this toxic amine varies considerably in different batches of L odoratus seeds (Garbut,t and Strong, 1957). Before proper evaluations of BAPN toxicity can be made, its concentrat,ion in the diet must be known. There is evidence to suggest that besides the concent,rations of BAPN and prot’ein in t’he diet’ the tissue response is further complicated by other variables such as age of the animals (Dasler, 1957; Gilman and Hat#horn, 1959) and t’he duration of the feeding period (Dasler, 1954; Aschkenasy, 1960). The object of the present investigat’ion was to evaluate the effect of several proteins on tissue response when the di-BAPN fumarate concent’ration in the diet was constant’. In addition t’o t’he tissue changes previously described, colonic dilatation was frequently observed in rats fed BAPN and cottonseed meal. These observations therefore lend furt’her support to t’he hypothesis that dietary protein does exert an appreciable influence on BAPN toxicity in weanling rats. MATERIALS AND RIETHODS Weanling male Sprague-Dawley rats were used. Five diets containing di-BAPNfumarate were tested for their modifying effect on the tissue response. In each in1 This investigation was supported Grants, Public Health Services. 2 Department of Pathology, Teviot. * Copyright

@ 1967 by Academic

Press Inc.

by grant Place,

(AM-0644492) Edinbrtrgh 1

from

8, Scotland.

the Division

of Research

2

JOSEPH

J.

LALICH

AND

HAMISH

TURNER

stance two grams of di-BAPN-fumarate per kilogram of diet was fed to the test rats. The nutrients employed in the different diets are shown in Table I. The diets were mixed by hand and kept at 4°C between feedings. Rats in groups of three were housed in an open-bottle mesh cage and fed ad lib&m for periods up to 51 days. Autopsies were made at the end of the experimental period on all animals that were killed or died. The presence and severity of bony malformation, herniation, hindlimb paralysis, aortic alterations and the condition of the colon were recorded. A numerical approximation of the composite skeletal deformity in each group of rats was estimated as follows: sternal, vertebral column, and femoral malformations were expressed numerically; i.e., normal bone = 0, while deformities were assigned the following values; minimal = 1, moderate = 2, and severe = 3. The mean for any group of rats was obtained by dividing the sum representing the deformities by the number of bones examined (Merkow and Lalich, 1960). As shown in Tables II and III, normal bones have a value of 0.0, whereas, moderate deformity in the three skeletal specimens examined is expressed numerically by 2.0. Tissue for microscopic examination were collected only from the control and test rats fed cottonseed and fishmeal diets. Tissues from control rats fed these two diets were examined to exclude microscopic alterations which could be attributed solely to cottonseed or fishmeal in that diet. RESULTS Response of rats fed various types of protein and BAPN are recorded in Table II. When male Sprague-Dawley rats are fed 12.5 % casein the weight gain is not comTABLE COMPOSITION

OF DIETS

FED

WITH

I

BAPN-FUMARATE

IN DIFFERENT

ASSAYS

1

2

3

4

5

Crude Casein Cottonseed meala

125.0

250.0

-

-

Fish meal (Menhaden) Commercial dietb Cerelose Wesson salt Corn oil Chlorine chloride” Dry vitamin mixtured Fat soluble vitamin”

-

-

-

500.0 -

500.0 -

777.0 40.0 50.0 3.0 2.1 1.0

562.0 40.0 50.0 3.0 2.1 1.0

Assay

No.

-

-

998.0

-

-

-

422.0 20.0 50.0 3.0 2.1 1.0

-

392.0 40.0 50.0 3.0 2.1 1.0

a Cottonseed Meal Buckeye Cotton Oil Division, Cincinnati, Ohio. Cottonseed meal was sifted through B 18 mesh wire to remove coarse hulls. A supplement of 5 gm of dl-methionine and 5 gm of Z-lysine was added to each kilogram of cottonseed meal diet. b Rockland-Rat diet, Monmouth, Illinois. c The casein-choline mixture consisted of 40 gm vitamin free casein and 20 gm choline chloride. d Dry vitamin mixture contained (mg/kg) thiamine HCl 2.5; riboflavin, 3.0; pyridoxine HCl 2.5; calcium pantothenate, 20.0; nicotinic acid 10.0; inositol 10.0; menadione 10.0; folic acid 2.0; biotin 0.5; dl-methionine, l,OOO.O; and I-cystine l,OOO.O. e The fat soluble vitamins were (per kilogram of diet) : Vitamin A acetate, 6000 IU; vitamin D 60 IU; alpha tocopherol, 100 mg.

DILATION

OF

COLON

INDUCED

IN

3

RATS

parable to that seen in controls fed 25 % casein. (Compare lines 1 and 3 of Table II). Six males fed 0.2 % di-BAPN-fumarate in 12.5 % casein had a significant suppression in weight gain and one died of angiorrhexis on the day 44, at which time this assay was terminated (Table II, line 2). The skeletal deformity in this group is minimal. Feeding 25% casein to three male rats produced an excellent weight gain. Feeding 0.2%) di-BAPN-fumarate in 25% casein suppressed the growth of eight male test rats considerably. Because the rats did not die of angiorrhexis their mean survival time equalled that of the controls (Table II, line 4). Again the skeletal deformity was minimal. Feeding a ground commercial diet to 12 males produced good growth (Table II, line 5). In 16 test rats fed 0.2 % di-BAPN-fumarate in a commercial diet, the tissue injury was more extensive than that encountered in test rats fed casein. Since 15 of 16 rats died of aortic rupture, there was reduction in mean survival from 47 to 32 days (Table II, line 6). Again suppression of weight gain is evident. A numerical estimate of skeletal deformity was somewhat greater than in the casein assays. For the first time 2 of 16 rats also developed hind-limb paralysis. While such rats may retain some motion in their hind-limbs, they were not able to stand or walk. Control rats which were fed a 50 % fishmeal diet grew well. When BAPN was added to the fishmeal diet the tissue response was comparable to that of test rats fed a casein diet. In 26 male control rats fed cottonseed meal, growth was not comparable to that following the ingestion of a commercial diet or 25 % casein. Slower growth in cottonseed meal fed control rats is attributed to the poor quality of this protein despite supplements of dl-methionine and I-lysine. When 0.2 di-BAPN-fumarate was fed in 50 % cottonseed meal in addition to tissue changes which were previously observed, colonic atony was encountered in a significant number of rats (Table II, line 10). Rats with colonic dilatation invariably developed diarrhea prior to death. Seventeen of 33 rats developed dilatation of the colon which was filled either with a pasty TABLE TISSUE

CHANGES

OBSERVED

II IN DIFFERENT

ASSAYS

Gross Diet

“;;,z’ rats

BAPNa gmikg

sEzf:al (days)

Wt. gain (gmiday)

N?merical es~~~‘~f

Aortic ;;F;

alterations Paralysis iiris

seen Colonic di:;;-

Hernia

deformity Casein 12.5 Casein 12.5 Casein 25.0 Casein 25.0 Commercial Commercial Fishmeal Fishmeal Cottonseed Cottonseed

7 6 3 8 12 16 3 6 26 33

0 Purchased from b Fecal peritonitis

0 2 0 2 0 2 0 2 0 2

44 44 42 42 47 32 51 42 50 30

3.9 2.3 5.4 2.9 5.1 3.3 4.7 3.4 3.6 2.4

0.0 1.1 0.0 0.9 0.0 1.3 0.0 0.8 0.0 1.4

0 1 0 0 0 15 0 2 0 21

Abbott Laboratories, North Chicago, Illinois. developed in 8 of 17 rats with a dilated colon.

0 0 0 0 0 2 0 0 0 3

0 0 0 0 0 0 0 0 0 17b

0 0 0 0 0 0 0 0 0 12

4

JOSEPH

J.

LALICH

AND

HAMISH

TURNER

or hard feces. Colonic dilatation could not be attributed to differences in feeding habits of the test rats fed cottonseed meal. The fecal retention and subsequent colonic dilatation led to peritonitis in 8 of 17 rats. Hind-limb paralysis was observed in three of these test rats. Herniation was also frequent in the cottonseed meal-fed test rats. Hernial sacculations of 2.0-5.0 cm. occurred either in the right or left costovertebral angle in 10 of 33 rats. Some of these hernias were so massive that most of the small intestines escaped into the sacculation. Hypertrophy of smooth muscle was seen only in one rat which developed a scrotal herniation. The skeletal deformity was comparable to that encountered in test rats fed a commercial diet and survival time was reduced from 50 to 30 days. Examination of the controls discloses that the assays varied from 42 to 51 days. Despite the shorter duration of the casein assays rats fed BAPN in casein survived 10 days or longer than those fed the lathyrogen in a commercial or cottonseed meal diet. Mean survival time in rats fed BAPN in casein or a commercial diet depended solely on the occurrence of aortic rupture. In rats fed BAPN in cottonseed meal, 21 died of aortic rupture while eight succumbed to the effects of peritonitis. The response of the rats fed di-BAPN-fumarate and a supplement in different diets can be observed in Table III. Test rats fed BAPN in casein, commercial diet, or cottonseed meal, which were shown in Table II, are included in Table III so that comparisons can be made with the assays to which supplements were added. When TABLE INFLUENCE

OF SUPPLEMENTS

ON Ram

FED

2.0 GM

III DI-BAPN-FUMARATE

IN DIFFERENT

Aortic rupture

Diet

Paralysis hind limb

DIETS ~!$~~~ iion

Hernia

deformity Casein Casein

25 25

Ba 5

Casein

25

5

Commercial

16” 7

Commercial

3

Commercial

3

Cottonseed Cottonseed

33a 6

Cottonseed

3

Cottonseed

6

Cottonseed

3

Cottonseed

3

Cottonseed

4

Cottonseed

5

0 l-arginine 25 g m Z-bistidine 25 g m 0 Z-bistidine 30 g m thyronine* 409 he3 thyronine 800 I.@ 0 I-bistidine 30 g m d-histidine 25 g m I-glutamic 30 g m l-arginine 30 g m glycine 12.5 g m thyronioe 499 Pi3 Z-cyst&x 10 g m

a Groups of rats shown in Table II. b Triiodothyronine was fed in the diet.

42 42

2.9 4.1

0.9 1.1

0 0

0 0

0 0

38

4.0

1.2

1

0

0

32 31

3.3 3.5

1.3 1.1

15 7

33

3.5

0.8

3

33

3.2

1.1

2

30 45

2.4 2.4

1.4 0.7

21 3

33

2.2

1.3

3

40

2.1

1.8

3

1

24

3.6

0.8

3

0

36

1.6

1.2

2

1

35

2.2

0.8

3

40

1.9

1.2

2

0 -

2 1 -

0 0

-

-

1

-

-

3

li

-

12 -

-

-

1

1

-

-

-

-

-

-

1

DILATION

OF

COLON

INDUCED

IN

RATS

3

Z-arginine was fed in either 25% casein or 50% cottonseed meal diets the test rat’s gained more weight t’han when this amino acid was omitted. l-Histidine supplementation in casein improved the weight. However, when added to a commercial or cottonseed meal at 30 gm/kg it did not do so. Keither I-arginine nor l-histidine supplementation appeared to influence the incidence of aort’ic rupture. The skeletal abnormalities were most pronounced in cot’tonseed meal test’ rats fed supplements of I-glutamic acid. Triiodothyronine at two concentrations in a commercial and cottonseed meal diet’s did not counteract the toxic effects of BAPN. In contrast to observations made after I-arginine supplements of l-glutamic acid, Z-histidine, Icysteine, and glycine when added to the cottonseed meal did not appear to exert any beneficial effect on growth. Survival times in rats fed l-histidine, I-glutamic acid, and I-cysteine in cottonseed meal however, were increased from 30 to 45 days. There is also a suggestion that these amino acid supplements may have reduced the incidence of herniation and colonic dilatation in BAPN-fed rats receiving cottonseed meal. Future feeding will resolve whether t,he beneficial effect on survival time and colonic dilatation is real or fortuitous when supplements of amino acids are added to cottonseed meal. Perforations developed in the aortic arch in 6S test rats. Sudden massive hemo-

in cottonseed meal for 36 days when death occurred FIG. 1. Rat 126 was fed BAPN perforation on the aorta. Note the hemopericardium and hemorrhage int.0 the thymus. dilated colon, filled with feces, extends from the pelvic region and touches the liver.

from The

JOSEPH

J.

LALICH

AND

HAMISH

TURNER

Rat 133 developed dilatation of the colon and fecal accumulation FIQ. 2. tion of BAPN in cottonseed meal for 29 days. Superficial mucosal ulceration cosal inflammation were seen in the colon. Hematoxylin and eosin stain.

after the con, sumpand acu .te si ubmuX 80.

Rat 198 died from the effects of a fecal peritonitis after being fed BA PN in clottonFIG. 3. seed for 33 days. The markedly dilated colon is filled with feces and extends horn roni ally into a left abdominal hernia. The vessels are congested and the serosal surface is cover *ed with L flecks of fecal material.

DILATION

OF

COLON

INDUCED

IN

RATS

‘I

thorax was the cause of death in these animals. Only one rat in this study died after perforation of the abdominal aorta. Arterial perforations occurred anytime after the third week; however, they were most frequent during the fourth and fifth weeks. It was not possible to anticipate on the basis of inspection, food consumption or weight gain which rats would develop angiorrhexis. Some degree of aneurysmal dilatation and obvious fibrosis of the aortic arch could be seen in about one-third of the rats which survived longer than 35 days. Microscopic

examination

Inspection of control rats fed cottonseed meal or fishmeal revealed no microscopic changes in tissues which could be attributed to the feeding of these two proteins. Inspection of the colons from 21 control rats fed cottonseed meal revealed nothing unusual, all structures appearing normal. Sections of colon from 23 test rats fed cottonseed meal and BAPN were examined. In 12 instances the colon was normal while in 11 wit’h dilatation of the colon a complicating hemorrhagic purulent peritonitis was observed in eight instances (Fig. 3). In six test rats which died from angiorrhexis or peritonitis, autolysis was so extensive that the dilated colons were not subjected to microscopic examination. Peritonitis was attributed to fecal impaction in seven instances and to a scrotal herniation in one rat. Despite the presence of some

FIG. 4. Rat 103 the consumption of an area of mucosal acute inflammation

developed aortic rupture and colonic atony with fecal accumulation after BAPN in cottonseed meal for 32 days. This section of colon was adjacent to ulceration. Whereas the overlying mucosal layer appears normal, a zone of can be seen in the submucosa. Hematoxylin and eosin stain. X 80.

S

JOSEPH

J.

LALICH

AND

HAMISH

TURNER

autolysis in the colons which were examined, it was possible t,o observe ulceration of the mucosa in two rats and submucosal inflammation in four animals (Figs. 2 and 4). Significant thinning of the muscular wall was encountered nine times while muscular hypertrophy was observed only on one occasion. Microscopic inspection, however, did not reveal any cause for the fecal inspissation and dilatation of the colon. The alterations which were encountered in the aortas and the bones of these test rats were similar to those previously recorded in rats fed BAPN. il/licroscopic deviations from normal in the skeleton and aorta were omitted from this study for this reason. DISCUSSION Colonic dilatation and frequent herniation occurred for the first time when a mixture of cottonseed meal and BAPN was fed to the rats. The colonic dysfunction cannot be attributed solely to the presence of di-BAPN-fumarate because dilated colons were not observed when this lathyrogen was added to casein, fishmeal, or commercial diets. It is believed that colonic dilatation and fecal accumulation are caused by the combined effects of cottonseed meal and BAPN It has not been demonstrated whether the colonic dysfunction is secondary to fecal impaction, smooth muscle atony, a disturbance in nervous activity or an accelerated resorption of colonic fluid. In agreement with the observations of Ambrose and Robbins (1951) the feeding of gossypol free cottonseed meal did not produce any discernable microscopic tissue alterations in the control rats. The amino acid supplements in cottonseed meal and BAPN fed rats however, appeared to alleviate the tendency to develop either colonic dilatation or herniation. Growth response of control rats fed various diets is roughly proportional to the protein quality and its concentration in the diets. Rats fed 12.5% casein or 50% cottonseed meal did not grow as well presumably due to a limitation of essential amino acids in these two diets. Whenever di-BAPN-fumarate was added to the diet, test rats gained less weight than their controls despite adequate concentrations of protein. This suggests that BAPN somehow diminishes the nutritive value of the protein in an unknown manner. Some degree of skeletal deformity was always observed in test rats, irrespective of the diet fed. The casein mixture, however, was able to protect against the occurrence of aortic rupture more effectively than the other proteins. This is in agreement with the previous observations (Dasler, 1954; Menzies and Mills, 1957; Bachhuber and Lalich, 1954). There is no suggestion from this study why casein is able to delay or inhibit the development of aortic rupture which is commonly caused by the ingestion of BAPN. It has been suggested that lathyrogenic agents may suppress the thyroid activity because hormonal supplementation in experimental lathyrism is believed to be beneficial (Khogali, 1961; Pyorala et al., 1959 and Selye, 1957). We were not able to observe any protective effect after the addition of triiodothyronine at different concentrations to several diets. Lee et al. (1956) after observing the beneficial influence of protein supplementation in BAPN-fed rats suggested that the lathyrogen somehow suppresses the utilization of amino acids. Juva et al. (1961) observed that the ratio of food consumption to weight gain was less in BAPN-fed rats. McCrary and Orbison (1960) reported that BAPN-fed rats retained less nitrogen than their pair-fed controls. The results from

DILATION

OF

COLON

INDUCED

IN

RATS

9

this study lend support to the hypothesis that the proteins exert a significant influence on the tissue changes which can be produced by BAPN ingestion. That the proteins may be exerting a moderating influence on tissue response in BAPN-fed rats is also fortified by the observation that several amino acid supplements are capable of partially inhibiting the toxic effects of BAPN ingestion. The wide spectrum of tissue changes which have been documented in experimental lathyrion becomes understandable when one assumes that the tissue response is a function of the concentration of lathyrogen and amino acids in any given diet. SUMMARY Diets containing different sources of protein were fed to weanling Sprague-Dawley control rats for periods up to 51 days. Test rats were fed 2.0 gm of di-BAPN-fumarate per kilogram of diet in each instance. Variations in tissue response which were observed in the different assays are attributed to the proteins present in the diets. Diarrhea, colonic dilatation, and fecal accumulation only developed in rats fed cottonseed meal and BAPN. Herniation in the costovertebral angle was also encountered in rats fed cottonseed meal and BAPN. None of the rats fed BAPN in casein, fishmeal, or a commercial diet developed either colonic dilatation or herniation. The production of fecal accumulation in the colon and herniation is attributed to the combined influence of cottonseed meal and BAPN feeding. Microscopic inspection of the dilated colons did not reveal any significant tissue alterat,ions which would explain the colonic dysfunction. REFERENCES AMBROSE, A. M., and ROBBINS, D. J. (1951). Studies on the chronic oral toxicity of cottonseed meal and cottonseed pigment glands. J. Nutr. 43, 357-370. ASCHKENASY, A. (1960). Protection par la caseine alimentaire contra les lesions ossouses du lathyrisme chew le rat male. Protection reduite chez le rat femelle et le rat male contre’. Sot Biol. 154, 556-560. BACHHUBER, T. E., and LALICH, J. J. (1954). Production of dissecting aneurysms in rats fed Lathyrus odoratus. science 120, 712-713. The effect of high levels of dietary fat on BetaBARNETT, B. D. and MORGAN C. L. (1959). aminopropionitrile induced internal hemorrhage in chicks. Poultry Sci. 38, 589-593. DASLER, W. (1954). Partial protection against odoratism (sweet pea Lathyrism) by diets high in gelatin or casein. Proc. Sot. Exptl. Biol. Med. 85, 485488. DASLER, W. (1956). Protective action of glutamine, cysteine and other substance against experimental lathyrism in the rat. Proc. Sot. Exptl. Biol. Med. 91, 554-557. (1957). Experimental lathyrism. Chicago Med. School Quart. 18, l-10. DASLER, W. DOERR, W. ROSSNER, A. J., and SCHREIL, W. (1960). Experimentelle mesenchymschaden durch Lathyrus odoratus. Lagenbecks Arch. Klin. Chir. 294,42&449. GARBUTT, J. T., and STRONG, F. M. (1957). Calorimetric determination of Beta-aminopropionitrile in mature legume seeds. Agr. Food Chem. 5, 367-370. GEIGER, B. J., STEENBOCK, H. and PARSONS, H. T. (1933). Lathyrism in the rat. J. Nutr. 6, 427442. GILLMAN, T., and HATHORN, M. (1959). Post-natal vascular growth and remodelling in the pathogenesis of arterial lesions. Allg. Pathol. Bacterial. 22, 6187. HARTMANN, H. A., and LALICH, J. J. Paralysis and cord injury in rats fed B-amino(1961). propionitrile. Federation Proc. 20, 4358 JUVA, K. TUOMINER, T., MIKKONEN, L., and KULONE, E. (1961). Effect of proteins, fat carbohydrate and some enzyme inhibitors on symptoms of experimental lathyrisms. Acta Pa&l. Microbial. Stand. 51, 250-258. KHOGALI, A. (1961). Quantitative studies on the suppression of the skeletal lesion of baminopropionitrile by L- and n-triiodothyronine. J. Physiol. (London) 158, 29-36P.

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J.

LALICH

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HAMISH

TURNER

J. J. (1956). Production of aortic rupture in rats fed purified diets and b-aminopropionitrile. Arch. Pathol. 61, 52&524. LEE, J. G., DUPUY, H. P., and ROLFS, H. E. (1956). Dietary protein and the development of rat lathyrism. J. Nutr. 58, 433442. LEWIS, H. B., FAJANS, R. S., ESTERER, M. B., SHEN, C. W., and OLIPHANT, M. (1946). The nutritive value of some legumes. Lsthyrism in the rat. The sweet pea (Lathyrus odoratus), Lathyrus sativus, Lathyrus cicera and some other species of Lathyrus. J. Nutr. 36, 537-559. MCCRARY, C., and ORBISON, J. L. (1960). Nitrogen balance in lathyritic rats. Federation Proc. 19, A-145. MENZIES, D. W., and MILLS, K. W. (1957). The aortic and skeIetai lesions of Lathyrism in rats on a diet of sweet pea. J. Pathol. Bacterial. 73, 223-237. MEREOW, L. P., and LALICH, J. J. (1960). Influence of diet on the incidence of angiorrhexis in B-aminopropionitrile fed rats. Arch. Pathol. 70, 752-756. PONSETI, I. V., and BAIRD, W. A. (1952). Scoliosis and dissecting aneurysm of the aorta in rats fed with Lathyrus odoratus seeds. Amer. J. Pathol. 28, 1059-1077. PETERSEN, W. R. (1962). Osteolathyrism in mice and its modification by strain, age and diet. Exptl. Med. Surg. 20, 267-271. PYORALA, K., SEPPALA, T., and PUNS-, S. (1956). Aorten-und knochen-veranderungen beim rattenfotus verrusacht durch futterung von Lathyrussamen an muttertiere. Acta Pathol. Microbial. &and. 38, 27K%4. PYORALA, K., SEPPALA, T., PUNSAR, S. (1959). Effect of corticoids, adrenocorticotrophic hormone, thyroxine, and thyrotrophic hormone on aortic lesions in experimental lathyrism. Acta Pathol. Microbial. &and. 45, 3748. SELYE, H. (1957). Uber die humorale Beeinflussung des experimentellen Lathyrismus. Arch. Exptl. Pathol. Pharmakol. 230, 155160. WAIBEL, P. E., and POMEROY, B. S. (1959). Effect of diet on the development of B-aminopropionitrile-induced vascular hemorrhage in turkeys. J. Nutr. 67, 275-288. WAWZONEK, S., PONSETI, I. V., SHEPARD, R. S., and WIEDENMANN, L. G. (1955). Epiphyseal plate lesions, degenerative arthritis and dissecting aneurysm of the aorta produced by aminonitriles. Science 121, 63-65. LALIcH,