The physiological effects of partially purified estrogenic extracts from forage plants of widespread economic importance have been studied, using the laboratory mouse and rat as experimental animals. The main purpose of these studies was to compare physiological activities of estrogenic substances from plants with those of a well known synthetic estrogen, diethylstilbestrol (D.E.S.). The latter, like many of the "natural" animal estrogens, is well known to influence the fundamental processes of animal production namely, reproduction, lactation, and growth. The estrogenic treatments were administered orally, either mixed with the diet, or by means of a rubber catheter. Dosage levels were in most cases designed with the grazing animal in mind, so as to allow some opportunity for tentative extrapolations of the results to farm animals which are the chief consumers of estrogen-like substances in forage plants. Red clover estrogenic extracts were used mainly, although some effects of subterranean clover, and birdsfoot trefoil are discussed. Non estrogenic timothy grass extracts were used to help control the experimental conditions. No effect of red clover "estrogens" on Maternal Performance of lactating mice as determined by the total weights of their litters at 12 days was detected. Performances calculated on the basis of 17th day total litter weights appeared to be adversely affected although not to the same extent as a similar level of D.E.S. The high estrogenic content of the diet is believed responsible for this result. Red clover "estrogens" induced increased testes weights, decreased seminal vesicle weights and lowered fertility in intact male mice. Remarkable recovery to normal, of these organs took place within eight days after cessation of estrogenic treatment. Some differences both in genital organ weights, and fertility data between males weaned from normally fed dams and those weaned from dams receiving estrogenic materials throughout the lactation period were observed. Per cent fertility data from females were essentially similar. The effects of red clover "estrogens" on uterine weight and histology, in intact, ovariectomized, hypophysectomized, and hypophysectomized-ovariectomized rats were studied. The absence of the hypophysis, and, or, the ovary does not interfere with the rate or degree of uterine response. The histology of uteri from "estrogen" treated animals is discussed in relation to fertilization, and implantation i.e. fertility. Method of administration of red clover "estrogens" influences the physiological effectiveness of a given dose. When mixed with feed their effect is more marked in terms of uterine response than when the same quantity is administered orally by means of a catheter, in two equal portions, twice daily. Once daily catheterization is even less effective. These results are discussed in relation to quantitative comparisons between injected or implanted doses of "natural" animal estrogens and D.E.S., and the quantities of estrogenic materials likely to be consumed by a grazing animal. Finally, red clover estrogenic extract from 8.4. gm. of dry ground forage increased thyroid uptake of radioactive sodium iodide (I¹³¹ ) in ovariectomized rats with a mean weight of 110 gm. Scintillation count data were confirmed by histological examination of carefully prepared thyroid sections. The likely endocrinological interpretation of this observation is discussed. / Land and Food Systems, Faculty of / Graduate

Isoidide dinitrate (IIDN), a new nitrate ester, an isomer of isosorbide dinitrate (ISDN) and isomannide dinitrate (IMDN), has been studied on the isolated rabbit intestine and on the anesthetized rat blood pressure. Potency was observed as was tachyphylaxis and the effect of certain blocking agents. On the isolated rabbit intestine similar results were obtained when nitroglycerin was substituted for IIDN. In both preparations IIDN was more potent than ISDN or IMDN and ISDN more potent than IMDN. The potency dependence on configuration suggests a possible action on specific receptor sites. A type of tachyphylaxis to IIDN which was prominent in the isolated rabbit intestine was almost absent in the anesthetized rat blood pressure. This is probably due to metabolism of the drug in the intact animal and further suggests an action on receptors. In these preparations the nitrate action was not blocked by: the beta adrenergic blocking agents DCI or nethalide, the alpha adrenergic blocking agent dibenzyline, or a combination of an alpha and a beta blocking agent. Drugs that are selectively blocked by these agents were used as controls to indicate the presence of the desired blocking action. Neither the primary bretylium-like action nor the secondary reserpine-like action of guanethidine blocked the effect of IIDN on the isolated rabbit intestine. Depletion of catechol amines by pretreating the animals with reserpine did not alter the response of either preparation to the nitrate esters. The antihistamine diphenhydramine did not block the vasodepressor action of IIDN on the anesthetized rat blood pressure. It was concluded that although IIDN probably does not exert its effect through combination with adrenergic or histaminergic receptors, it possibly acts on receptors which are specific for the nitrite or nitrate group. / Medicine, Faculty of / Anesthesiology, Pharmacology and Therapeutics, Department of / Graduate

The alpha-glyceryl ethers (AGE) are widely distributed in nature, occurring in many marine organisms, land animals, plants, and humans. A series of preliminary experiments was begun to determine whether these compounds possessed possible pharmacological actions against inflammation. Anti-inflammatory tests utilized both the granuloma pouch and cotton pellet granulation methods. Possible glucocorticoid activity was checked by measuring liver glycogen deposition. The effects of AGE on growth and weight of the animals was also noted. Neither selachyl dihemisuccinate sodium (selachyl DHSS) nor selachyl alcohol decreased the exudate formation in the granuloma pouch experiments, although excellent results were obtained with hydrocortisone. The high dose of the AGE was the equivalent of ten milligrams; low doses were three hundred and six hundred micrograms. Routes of administration used were oral, intraperitoneal, and subcutaneous. In the cotton pellet granuloma test, some indication of anti-inflammatory activity was obtained, in accordance with previous results in this and other laboratories. Selachyl DHSS decreased granulation tissue formation by only 11.7% in growing rats, which is not significant; however, in mature rats, there was a decrease of 29.5%. The dosage used in this series was 30 milligrams per kilogram daily by the subcutaneous route, A definite and comparatively large increase in liver glycogen deposition was observed in rats allowed to eat freely, when given selachyl DHSS subcutaneously. These glycogen values were decreased radically by a paired feeding study in which the treated rats were allowed to eat only the same amount of food as their paired control animal. Thus food intake appears to be one of the factors responsible for the increased glycogen storage. The AGE appear to affect growth only by the Intraperitoneal route of administration. In this case, the growth of rats was retarded by 29.6%. It was also noted that these animals ate somewhat less food than the controls, although this did not appear to be an important enough difference to account for the lack of weight gain. Throughout these experiments one of the most notable observations was a lack of uniformity of the results. Factors which appeared to cause a variability in the outcome of tests included the age of the animals, length of time of preoperative housing in new quarters, route of administration, and dosage. A non-linear relationship between dose and effect appears probable. / Medicine, Faculty of / Anesthesiology, Pharmacology and Therapeutics, Department of / Graduate

Caffeine has been shown to induce a transient hypertensive state in Wistar rats. The height to which the blood pressure rises in this caffeine-induced hypertension, and the duration of this hypertensive state was found to be dependent on the concentration of caffeine administered. Caffeine exposed to negatively ionized air was shown to undergo a loss in its pressor activity. This loss in pressor activity was found to be greater when the caffeine was exposed in solution than when it was exposed in the crystalline state. Once the blood pressures of Wistar rats were elevated with injections of caffeine and had again returned to normal levels there were no further rises in blood pressures with the administration of an equal number of injections of this drug. / Science, Faculty of / Botany, Department of / Zoology, Department of / Graduate

Extracellular action potentials and isometric contractile tension have been recorded simultaneously in vitro from uterine longitudinal smooth muscle of the pregnant cat, pregnant rabbit, estrogen-treated rabbit, and estrogen-treated rat. Action potentials were recorded from the surface of the muscle strips with glass electrodes having a large tip diameter. Tension was recorded with an RCA transducer. Spontaneous contractions are associated with a series of action potentials. During relaxation no electrical activity is observed. Electrical and mechanical activities were first recorded in Kreb's Ringer medium and then in sodium-poor media (replacement of sodium chloride with choline chloride or sucrose). Sufficient reduction in the external sodium concentration resulted in increased amplitude (peak to peak) of the biphasic action potential spikes. The duration of the peak to peak deflection and the maximum rate of potential, change remained unchanged. However, decrease in the external sodium concentration reduced the frequency of the action potentials, considerably in the cat, and less so in the rabbit and rat. The external sodium concentration was reduced in stepwise ; fashion to ½, ¼ , ⅛ its initial value. Each successive decrease in the external sodium concentration was accompanied by a prompt initial contraction, followed by very slow relaxation and subsequent resumption of spontaneous contractions accompanied by action potentials. With cat uteri reduction of the sodium concentration of the medium to a level of 15-20 mEq/1 resulted in a greatly prolonged contraction with eventual relaxation when tissues failed to contract. This paralysis was associated with cessation of action potentials. The electrical responses of uteri of the other two species (rabbit and rat) during exposure to sodium-poor media were similar to those observed with the cat uterus. However, the mechanical activity of rat and rabbit uteri in sodium poor media was different from that of the cat uterus. Decrease in the external sodium concentration below 25-30 mEq/1 usually resulted in prolonged contractions, and finally to complete failure of the tissue to relax (even after 2-2½ hours). Outbursts of action potentials at irregular intervals were seen in the initial stages of this persistent contraction but eventually action potentials also disappeared. It was difficult to reconcile these facts with the "Sodium Hypothesis". A selective inward flow of sodium ions probably cannot account for the initiation of action potentials in uterine smooth muscle since considerable reduction of the external sodium concentration (down to 15-20 mEq/1 in cat and 25-30 mEq/1 in the other two species) did not affect the characteristics of the action potentials in the expected manner. However, further reduction in sodium did result in electrical and mechanical inactivity. The view that an outward flow of intracellular anions might be responsible for depolarization (14) receives further support from the present studies. In addition to many differences from other types of excitable tissue (nerve, cardiac and skeletal muscle), uterine smooth muscle also shows considerable intra- and inter-species variation. / Medicine, Faculty of / Anesthesiology, Pharmacology and Therapeutics, Department of / Graduate

This report contains an analysis of the factors responsible for the 1949-50 winter injury to cherry, peach and apricot trees in the Okanagan Valley of British Columbia, Canada. Included in the report are sections dealing with the history of winter injury, various theories of the causes of winter injury, and a description of the many forms of injury. The non-climatic and climatic factors affecting the intensity of injury are discussed in detail. Recommendations for minimizing the susceptibility of trees to winter injury under Okanagan Valley conditions are included, together with recommendations for the care of trees after injury has occurred. Reports on the relative hardiness of specific stone-fruits are presented in some detail. The report is liberally supplied with tables indicating the extent of crop damage and tree damage in each district of the Okanagan Valley. These tables are based on observations made in over two thousand orchards. The statistical analyses are based on detailed observations carried out in over four hundred orchards. The published literature dealing with winter injury has been freely consulted, and reference is made to many of the important papers dealing with the winter injury complex. A complete bibliography is included. / Land and Food Systems, Faculty of / Graduate

The behaviour reactions and the mechanisms involved in the injury and death of goldfish (Carassius auratus) exposed to chill temperatures have been investigated. Upon direct transfer to colder water goldfish exhibit an initial shock reaction followed by a primary chill-coma reaction with the latter reaction sometimes being followed, after apparently normal recovery, by a secondary chill-coma that ends in death. The first two reactions are believed to result from the effect of an excessive thermal stimulation of the cells of the central nervous system whereas the death that follows the secondary chill-coma is attributed to a disruption of the osmotic regulatory system. Within the range of size compared (three to ten centimeters and one to twelve grams), the tolerance to chilling temperatures of goldfish of the same or nearly the same age increases as the size of the fish increases. Statistical analysis of this relation shows a significant positive correlation between the survival times and the weight of the fish over their length as well as a significant negative correlation between the survival times and the surface area of fish over their weight. Several factors are thought to be involved in this effect of size of fish on tolerance to chill temperatures, viz., the insulation and surface area of fish relative to body mass in relation to the rate of heat loss and therefore to the body temperature; the gill surface area of fish relative to body mass in relation to the rate of abnormal osmotic passage of water subsequent to a disruption of the osmotic regulatory system. / Science, Faculty of / Zoology, Department of / Graduate

Cold injury of both the dry and the moist types are of the utmost importance in military operations, and are likely to assume even greater importance in the event of polar warfare. The modern literature on frostbite began with Napoleon's retreat from Moscow in 1812 when his surgeon, Baron Larrey recorded the disastrous event in his memoirs. Since then it has been the various wars of the western world that has provided the main stimulus for investigation into the cold problem. The experimental investigation has effected little positive benefit by way of management of an acute cold injury, but it has served to break down many time honoured doctrines, especially the theory that slow thawing of a frozen limb provided the best treatment. The significance of the various events that occur in the tissues during a freezing reaction are not agreed on by all workers, but the course of the reaction and especially the danger of the secondary effects during thawing are well known. The present investigation concerned an attempt to observe microscopically the vascular changes in the rat mesoappendix according to a technique of Zweifach. A cold point apparatus described by Hass and Taylor was utilized for exact freezing of a capillary bed. The influence of ten selected drugs on the reactions of the vascular bed after freezing was tested alternately with control rats. Procaine, priscoline, benadryl, etamon, hydergine, apresoline, chlor-tripolon, rutin, ascorbic acid, and histamine were tested. The criteria for a drug effect included delay in onset of vascular stasis, lessening the rate and extent of the stasis, and resumption of circulation in static vessels. No significant difference was observed between the treated and the control animals. In an effort to confirm this impression grossly, the hind legs of rats were frozen in a carbon dioxide and ether mixture at -20°C. for twenty seconds. The changes observed grossly following thawing were described numerically and the arbitrary concept of an Injury Index was utilized which could be expressed graphically on a day by day basis. Of the same ten drugs tested, procaine, priscoline, benadryl, etarnon, hydergine, and ascorbic acid were found to have no significant effect. Chlor-Tripolon and histamine were found to have an adverse effect, and apresoline, and especially rutin, were found to have a probably significant beneficial effect. The value of rapid thawing in water at 42°C. was consistently confirmed throughout all gross experiments. / Medicine, Faculty of / Graduate

The welfare of mankind is intimately bound up with the welfare of soils and plants as all of man's food comes, in the, first instance, from plants. Much research has been done to increase yields but little is known of the nutrient values of plants. Since little is known about potassium's effect on the nutrient value of plants, and because carrots have a high Vitamin A precursor content and radishes have a higher Vitamin C content, the author decided to determine what level of potash fertilization should be applied for optimum nutrient value in carrots and radishes. His decisions were, that while the addition of potash to land containing sufficient readily available potassium appears to tend to reduce yields, it does increase the mineral content of the produce. It also increases the total sugar up to a point after which it inhibits the carbohydrate formation. The author also found that additional potassium has no effect on the nitrogen content and, while it has no significant effect on the Vitamin A content it does have a very definite upward trend to produce more with the increases of potassium applied. The addition of potash increases the trend to produce more Vitamin C to the extent that high and very high levels of potassium applications become significant. The author found that correlation exists between the application of potassium and the protective nutrient value in plants. / Land and Food Systems, Faculty of / Graduate

An attempt has been made to follow some of the metabolic changes occuring during acclimation of goldfish (Carassius auratus) to temperature. The goldfish were acclimated to certain temperatures and then reacclimated to different temperatures. The change in the unsaturation of their body fats was found using Wij's iodine value determinations. The fats of goldfish fully acclimated to different temperatures show different iodine values. In general the fats are more saturated at higher temperatures. Changes in the amount of unsaturation during the acclimation process have been followed. It has been found upon increase in temperature there is a decrease in the amount of unsaturation. / Science, Faculty of / Zoology, Department of / Graduate