Organ Weight Ratios Research Articles

Influence of low tryptophan diet on survival and organ growth in mice

Greater survival and reduced growth were found to characterize mice on a tryptophan deficient diet as compared to fully fed control mice. The 50% survival point was reached by the tryptophan restricted group at 683 days, and by the control group at 616 days. Measurements of body weight, organ weight, and DNA level were made at 8, 12, 24, 36, 52 and 78 weeks of age. Both whole body weight and organ weight of liver, kidney, heart and spleen were about 30% lower in the tryptophan restricted group as compared to the controls, so that the ratio of organ weight to body weight remained at a constant value for both groups. There was no significant change in cell number as determined by DNA measurements, as a result of the tryptophan restriction.

Effect of vinyl chloride on testis in rats

A total of 300 male adult Wistar rats (180–220 g) were used. Animals were divided into four groups: control, vinyl chloride (VC) 10-, 100-, and 3000-ppm exposed groups. Seventy-five rats were used for each group. Inhalation exposure to VC was conducted 6 hr per day and 6 days per week. In the third, sixth, and twelfth month following exposure 8–30 rats of each group were killed. The others were under observation and sacrificed after 18 months. After exposure to VC, the organ and body weight ratio, such as the kidney, liver, spleen, and heart were increased, but those of the testis were decreased in the experimental groups in the sixth month. The differences between experimental groups and the control group were statistically significant ( P < 0.05 or P < 0.01). The weights of testis were decreased and damage of testicular seminiferous tubules were found in rats by histopathological examination. Incidence of damage of testicular seminiferous tubules in the control, 10-, 100-, and 3000-ppm groups were 18.9, 29.7, 36.5, and 56.0%, respectively. There was an obvious dose-response relation between the concentration of VC and the incidence of testis damage, with a correlation coefficient of 0.993 ( P < 0.01). Statistically, the incidence of damage of testicular seminiferous tubules in rats in the 3000-ppm group and in 100-ppm group were significantly higher than that of the control group, respectively ( P < 0.001 and P < 0.05).

Acute and subchronic toxicity of 2,4-dichlorophenol in CD-1 mice

The acute oral LD50 of 2,4-dichlorophenol (2,4-DCP) employing corn oil as vehicle was determined to be 1352 mg/kg for female and 1276 mg/kg for male CD-1 mice. CD-1 mice of both sexes were exposed to 2,4-DCP in drinking water containing 10% Emulphor for 90 days at concentrations of 0.2, 0.6, and 2.0 mg/ml providing theoretical daily doses of 50, 150, and 500 mg/kg. These concentrations resulted in mean daily doses of 50, 143, and 491 mg/kg for females and 40, 114, and 383 mg/kg for males. In both sexes, fluid consumption was lower in the vehicle control group (10% Emulphor) and in the 2,4-DCP treated groups than in the naive controls (deionized water). There were no biologically significant differences in body weight gain between females or males in the vehicle control and experimental groups. No differences were found in terminal organ weights or organ weight ratios in either sex. Hematological differences were observed in males only and included an increase in leukocytes (high dose) and an increase in polymorphonuclears (low dose). Clinical chemistry parameters were altered in females only and included a decrease in creatinine (low dose), an increase in BUN/creatinine ratio (mid dose), and an increase in ALP (high dose). In an assessment of the hepatic microsomal mixed function oxidase system, no significant differences were found in the components of the system, component activity, the kinetics of ethylmorphine N-demethylase, or the metabolism of testosterone. Administration of 2,4-DCP to CD-1 mice of both sexes for 90 days at mean doses of 40 to 491 mg/kg/day in drinking water did not elicit either consistent compound-related or dose-dependent significant toxicological effects.

Acute and Subchronic Toxicity of 2,4-Dichlorophenol in CD-1 Mice

Acute and Subchronic Toxicity of 2,4-Dichlorophenol in CD-I Mice. BORZELLECA, J. F., HAYES, J. R., CONDIE, L. W., AND EGLE, J. L. JR. (1985) Fundam. Appl. Toxicol. 5, 478–486. The acute oral LD50 of 2,4-dichlorophenol (2,4-DCP) employing corn oil as vehicle was determined to be 1352 mg/kg for female and 1276 mg/kg for male CD-I mice. CD-I mice of both sexes were exposed to 2,4-DCP in drinking water containing 10% Emulphor for 90 days at concentrations of 0.2, 0.6, and 2.0 mg/ml providing theoretical daily doses of 50, 150, and 500 mg/kg. These concentrations resulted in mean daily doses of 50, 143, and 491 mg/kg for females and 40, 114, and 383 mg/kg for males. In both sexes, fluid consumption was lower in the vehicle control group (10% Emulphor) and in the 2,4-DCP treated groups than in the naive controls (deionized water). There were no biologically significant differences in body weight gain between females or males in the vehicle control and experimental groups. No differences were found in terminal organ weights or organ weight ratios in either sex. Hematological differences were observed in males only and included an increase in leukocytes (high dose) and an increase in polymorphonuclears (low dose). Clinical chemistry parameters were altered in females only and included a decrease in creatinine (low dose), an increase in BUN/creatinine ratio (mid dose), and an increase in ALP (high dose). In an assessment of the hepatic microsomal mixed function oxidase system, no significant differences were found in the components of the system, component activity, the kinetics of ethylmorphine N-demethylase, or the metabolism of testosterone. Administration of 2,4-DCP to CD-I mice of both sexes for 90 days at mean doses of 40 to 491 mg/kg/day in drinking water did not elicit either consistent compound-related or dose-dependent significant toxicological effects

Effect of intermittent carbon monoxide inhalation on erythropoiesis and organ weights in rats.

Sprague-Dawley rats were exposed to 450 ppm carbon monoxide (CO) for 6 h per day, 5 days per week for 33 days. The effect of CO on reticulocyte count, hematocrit, hemoglobin concentration, body weight and selected organ weights was measured. Exposure to CO caused a three-fold increase in the youngest reticulocyte population, concomitant with an increase in the total reticulocyte count. Despite continued CO exposure, reticulocyte number and distribution returned to normal by day 9, suggesting that reticulocyte response of the organism to CO had changed. Both hematocrit and hemoglobin concentrations began to increase 16 days after CO exposure and remained at the increased level for the duration of the exposure period. There were no changes in kidney, liver and adrenal weights throughout the course of study. However, spleen weight was increased after 5 days of CO exposure. Left and right ventricular organ weight ratios increased equally at the same time during the study. These results indicate that the increase in the young reticulocyte population and the subsequent increase in total reticulocyte count are the earliest erythropoietic responses to intermittent CO exposure and that CO-induced polycythemia is associated with cardiac hypertrophy in rats.

Distribution and metabolism of iron in muscles of iron-deficient rats

Iron-deficiency anemia leads directly to both reduced hemoglobin levels and work performance in humans and experimental animals. In an attempt to observe a direct link between work performance and insufficient iron at the cellular level, we produced severe iron deficiency in female weanling Sprague-Dawley rats following five weeks on a low-iron diet. Deficient rats were compared with normal animals to observe major changes in hematological parameters, body weight, and growth of certain organs and tissues. The overall growth of iron-deficient animals was approximately 50% of normal. The ratio of organ weight: body weight increased in heart, liver, spleen, kidney, brain, and soleus muscle in response to iron deficiency. Further, mitochondria from heart and red muscle retained their iron more effectively under the stress of iron deficiency than mitochondria from liver and spleen.Metabolism of iron in normal and depleted tissue was measured using tracer amounts of(59)Fe administered orally. As expected, there was greater uptake of tracer iron by iron-deficient animals. The major organ of iron accumulation was the spleen, but significant amounts of isotope were also localized in heart and brain. In all muscle tissue examined the(59)Fe preferentially entered the mitochondria. Enhanced mitochondrial uptake of iron prior to any detectable change in the hemoglobin level in experimental animals may be indicative of nonhemoglobin related biochemical changes and/or decrements in work capacity.

Disproportionate growth of organs and body weight following glucocorticoid treatment of the rat fetus.

The effects of pharmacologic doses of dexamethasone, betamethasone, and cortisone given to pregnant rats on gestation days 12 and 13 were studied in mothers and fetuses on gestation day 21. Dexamethasone and betamethasone treatment resulted in a significant decrease in maternal and fetal weight gain, occurrence of cleft palate and omphalocele, and impaired growth of fetal heart, liver, adrenals, kidneys, and skeletal muscle. Cortisone produced fewer developmental defects and less impairment of growth of fetal weight and other organs. Corynebacterium kutscheri infections occurred in pregnant rats treated with dexamethasone but not in rats treated with betamethasone or cortisone. The analogues had widely different effects on organ growth and on the ratios of organ weight to body weight. The findings indicate that proportionate growth of fetal organs and body weight is disturbed by glucocorticoid treatment in rats.

Hyperplasic and hypertrophic growth in organs and tissues of the neonatal pig.

SUMMARY Five Yorkshire pigs, suckled by their dams, were slaughtered at each of six ages, 0, 10, 20, 30, 40 and 50 days. Total weights and tissue samples were taken of liver, heart, kidney, lung, brain and gastrocnemius muscle for determination of protein, DNA and RNA contents. Total DNA, an index of nucleus number, increased in all tissues throughout the 50 days but at a declining rate in brain and lung after 20 days; overall increase was greatest in muscle and least in brain. Ratio of protein to DNA, an index of cell size, increased throughout in all tissues with, again, the greatest increase occurring in muscle and the least in brain. An alternative index of cell size, the ratio of organ weight to its DNA content, showed less difference between tissues but a similar ranking. Ratio of RNA.-DNA, an index of cellular activity, changed relatively little in any tissue but tended to increase in liver and brain and decline in muscle. The tissue protein concentration increased appreciably in muscle and changed very little in brain and lung. (Key Words: Neonatal Pig, Growth, Hyperplasia, Hypertrophy, DNA, RNA.)

Comparison of accuracy in five measures of stress.

36 Sprague-Dawley rats were subjected to stress by immersion, erratic photoperiod and crowding for 28 days. Control and experimental animals were sacrificed and the thymus, spleen, adrenals, testis, and pituitary were removed and their weights were recorded as a ratio of organ weight to body weight. The pituitary was the most accurate measure of stress according to Z scores.

A comparative study of oxidative enzymatic potential of Sphermophilus lateralis and Spermophilus tereticaudus

1.1. Adult Spermophilus lateralis and Spermophilus tereticaudus were examined for possible differences in cellular metabolic potential as indicated by oxidative enzyme levels.2.2. The body weight of S. tereticaudus was 38% smaller than S. lateralis. The body to organ weight ratios of the two species were not significantly different except for the kidney which was higher in S. tereticaudus.3.3. The specific and total activity of succinoxidase in the heart, brown adipose tissue (BAT), muscle and kidney was greater (P ⩽ 0.05) in S. lateralis.4.4. The specific and total activity of glutamic acid oxidase was greater (P ⩽ 0.05) in kidney, muscle and liver of S. lateralis, but no differences were observed in BAT or heart.5.5. The total cytochrome oxidase activity of BAT was higher in S. lateralis; but there were no differences in the α-glycerophosphate dehydrogenase activity.6.6. These results indicate potential metabolic differences exist in two closely related but ecologically diversified scuirids.

Effect of Aflatoxin on Immunity in Turkeys. II. Reversal of Impaired Resistance to Bacterial Infection by Passive Transfer of Plasma

SUMMARY The manifestation of acquired resistance was impaired in turkey poults vaccinated against Pasteurella multocida infection while receiving a ration containing aflatoxin (0.25 to 0.5 ppm B1 activity). Passive transfer of plasma from immune birds or from normal birds supplemented acquired resistance to a point where the recipients survived challenge exposure; passive transfer of cells from immune birds did not supplement resistance. Ratios of organ weight to body weight and histopathologic appearance demonstrated thymal involution in recipients of aflatoxin.

Weight standards for organs from early human fetuses.

AbstractOne hundred and thirty‐six unfixed fetuses below 500 gm of body weight were examined and the brain, liver, lung, kidney, heart, adrenal, thymus, spleen, and thyroid were weighed. The ratios of organ weight to body weight could be divided into four general patterns: (1) constant; liver, heart, brain, and thyroid (2) increasing; thymus, adrenal, and spleen (3) initially increasing and then reaching a plateau; kidney, and (4) increasing and then decreasing; lung. Graphs of the mean and 95% confidence levels along with the formulas used for derivation are given for each organ on the basis of body weight.

Theoretical criteria for the use of relative organ weights and similar ratios in biology

1. I. Ratios of a type that may be exemplified by the so-called relative organ weight, i.e. the ratio of organ weight to body weight, are frequently used in biological and medical investigations for comparing two experimental groups. This is a practice which, if used indiscriminately, may lead to misleading results. 2. 2. The prerequisites for using such ratios are: (i) that the two quantities can be assumed positively and linearly related; (ii) that the regression line intersects the ordinate at the origin; and (iii) that the variance in y is proportional to x. The ratio is then constant and the equation of the regression line may be written y x = kx, where y x is mean organ weight and x is body weight, or other regressively related quantities. 3. 3. A difference that has been determined between two experimental groups in a ratio such as the so-called mean relative organ weight obviously lacks biological significance outside the range where the body weight weight variations in the two groups overlap. 4. 4. The same arguments apply to such quotients as the ratio of serum substances, e.g. cholesterol to serum phospholipids, the ratio of the function or volume of an organ to the body area, the ratio of the size of the nucleus to that of the cell, etc. 5. 5. Principles are stated for the analysis of differences between organ weights dependent on body weight.

Relationship between blood pressure and organ weight in the rat.

A relationship exists between systolic blood pressure and the organ to body weight ratios of heart, thyroid, adrenals, and kidneys. In the cases of heart, thyroid, and adrenals, the relationship is sigmoid in character, with the fast-rising portion of the curve beginning at a systolic blood pressure range of 150–159 mm Hg. Beginning at this same blood pressure range, kidney weight ratio increases linearly with increases in blood pressure. It is of interest that these changes occur at a blood pressure range which is generally considered to lie either at the high range of normotension or the low range of hypertension. The only organ weight ratio apparently unrelated to systolic blood pressure level is that of the testis. Some interrelationships among weight ratios of these organs were observed and are discussed.

Effect of potassium nitrate solutions on blood pressure of rats

Administration of KNO 3 solutions to rats as their sole drinking fluid was accompanied by an elevation of systolic blood pressure. The maximal elevation of blood pressure occurred when the rats were ingesting 0.3 M. KNO 3 solution, although even an isotonic solution elevated blood pressure to a modest degree. Treatment was accompanied by a gradual loss of body weight. Ratios of organ weight to body weight of kidneys, testis and adrenals were increased by treatment with KNO 3 while organ weight ratios of heart, seminal vesicles, prostate, thyroid and thymus were not affected. A similarity exists between the physiologic responses of rats treated with the same concentrations of NaCl and KNO 3.

Physiologic and anatomic effects of prophylthiouracil on normal and hypertensive rats.

The antithyroid drug propylthiouracil prevented or removed the hypertension associated with bilateral kidney encapsulation with latex envelopes. This effect did not appear to be the result of hypofunction of the adrenal glands. Propylthiouracil reduced growth rate in young rats and caused weight loss in adult rats. The latter effect appeared to be true tissue loss because water contents of heart, kidney, testes, liver, psoas, aorta and adrenal were unaffected. Administration of propylthiouracil for 7 to 19 weeks tended to reduce heart weight to body weight ratio as well as the ratio of kidney weight to body weight in both control and "encapsulated" rats. However, ratios of organ weight to body weight in the cases of thyroid, testes and eyes were larger than those of untreated control rats. In addition to its antihypertensive effect, propylthiouracil treatment of encapsulated rats also prevented the appearance of certain other manifestations of hypertension usually accompanying kidney encapsulation.