Increase In Tissue Weight Research Articles

Beneficial effects of chromium on glucose and lipid variables in control and somatotropin-treated pigs are associated with increased tissue chromium and altered tissue copper, iron, and zinc.

Chromium (Cr) and somatotropin have been shown to increase lean body mass in pigs but by independent mechanisms. Somatotropin and Cr also affect blood glucose, lipids, and tissue trace metal concentrations. Twenty-four castrated male pigs were divided into four groups: 1) control basal diet; 2) basal diet + 300 micrograms of Cr/kg of diet as Cr picolinate; 3) basal diet + pituitary porcine somatotropin (ppST; 100 micrograms/kg live weight injected daily); and 4) basal diet + Cr + ppST. Pigs were fed the diets from 30 to 60 kg body weight and then killed. Supplemental Cr led to increased total Cr in kidney (1.1 vs 2.3 micrograms) and liver (5.9 vs 8.8 micrograms) but not in the heart independent of ppST treatment. Chromium concentrations in longissimus muscle were less than 1.5 ng/g in all samples, and any increases due to supplemental Cr were not detected. Somatotropin treatment led to decreased hepatic Cr, Cu, Fe, and Zn concentrations and increased total renal Cu, Fe, and Zn. These data demonstrate that supplemental Cr causes increased tissue Cr in the liver and kidney but not in the heart or muscle in control and somatotropin treated pigs. Somatotropin treatment caused decreased kidney and liver Cr concentrations that were offset by increased tissue weights. Somatotropin effects on tissue Cr, Cu, Zn, and Fe were variable and difficult to evaluate due in part to growth hormone-induced changes in organ weights.

The effect of C5a and U46619 on the isolated, perfused human placental lobule: Development of a method for the online estimation of tissue fluid accumulation

A method for the automatic and simultaneous determination of perfusion pressure and fluid accumulation in the isolated, perfused human placental lobule is described. We demonstrated that the inflammatory mediator, C5a, a C5a agonist analogue peptide, and the thromboxane mimetic U46619 caused increased fetal perfusion pressure and increased tissue weight when administered via the fetal arterial circulation. Occlusion of the fetal venous effluent tubing caused significantly greater increases in tissue weight than the pharmacological agents. Detectable increases in tissue weight occurred within 47 ± 3 sec ( n = 21) following pressure increases caused by the pharmacological agents. In each case, the increase in tissue weight was accompanied by an increased permeability of the materno-fetal barrier, shown by the transfer of Evans blue albumin from the fetal circulation to the maternal compartment.

Juvenile growth of the South China Sea whelk Hemifusus tuba (Gmelin) (Prosobranchia: Melongenidae) and the importance of sibling cannibalism in estimates of consumption

As an adult, Hemifusus tuba (Gmelin) is a predator of bivalves. Egg capsules are laid in spring and hatch 2 to 3 months later. Hatchlings emerge at a mean length of ≈ 4.4 mm and commence feeding. This study examines growth in hatchlings from birth for 12 wk. Up to Wk 7 post-hatching, growth in total weight is principally of the shell. A large shell, the juveniles primary defence, probably enhances survival by reducing predation. Significant increases in tissue weight, to fill the shell, only begin after Wk 4. This is preceded at Wk 3 by dramatically elevated feeding rates upon bivalve prey. At this time the juveniles consume > 40% of their wet tissue weightday −1. Subsequently, consumption rates fall to adult levels of ≈ 4%. Of a mean of 1500 eggs laid in each capsule, only a mean of 8.8 emerge as juveniles. In the capsule they feed on “nurse” eggs and cannibalize siblings. Post-hatching mortality is high (≈ 14%) but declines to 0 by Wk 10. Estimates of the potential value of such dying or killed hatchlings to the consumption of surviving siblings, in relation to the bivalve diet, show that they are insignificant (<2.0% · day −1). It is concluded that cannibalism is only a feature of pre-hatched H. tuba. Post-hatching cannibalism may enhance the survival of an individual, but can play little roˆle in species survival, especially in the natural environment where hatchlings are likely to disperse randomly.

Blood flow responses to small bowel resection.

The objective of this study was to determine whether the gastrointestinal blood flow response to small bowel resection is related to the compensatory hyperplasia resulting from resection. In one group of rats, a laparotomy was performed and 80% of the small bowel resected, reanastomosing proximal jejunum with distal ileum. In the second group (controls), a transection followed by reanastomosis was performed either in the jejunum or ileum. One, two, three, or five days later, the animals were anesthetized, and blood flows to the stomach, jejunum, ileum, cecum, colon, and pancreas were measured using the radioactive microsphere technique. Samples of these tissues were obtained for determination of thymidine incorporation and DNA content. Growth, as evidenced by increases in tissue weight, DNA content, and rate of DNA synthesis, occurred in all tissues. Blood flow was elevated in the pancreas and in bowel segments (ileum and cecum) distal to the site of resection. Gastric, jejunal and colonic blood flows were not affected by bowel resection, in spite of similar trophic changes. Paired-value analyses did not reveal any correlation between blood flow and rate of DNA synthesis. The results of these studies suggest that humoral, rather than metabolic, factors are responsible for the gastrointestinal and pancreatic hyperemia that occurs after small bowel resection.

Effect of Age, Weaning and Diet on Digestive Enzyme Levels in the Piglet

Thirty-seven pigs were used to evaluate the effects of age and weaning on the level of protease in the gastric mucosa and trypsin, chymotrypsin, amylase and lipase in the pancreas. There was a positive allometry of the pancreas and gastric mucosa associated with age and with weaning to a solid diet. Increases with age in total activity of chymotrypsin, trypsin, amylase and gastric proteases were due to increases in both tissue weight and enzyme activity per gram of tissue. A general depression in pancreatic enzymatic activities, but not in gastric proteolytic activity, was found during the first week following weaning. Forty pigs were used in a second trial to evaluate the effects of age and weaning diet on the same digestive enzymes. Total activity of all enzymes assayed increased with time postweaning. Increases in total activity of lipase and chymotrypsin were due primarily to increased pancreatic weight postweaning. Amylase, trypsin and gastric protease increases were due both to increased tissue weight and increased activity per gram of tissue. There were no effects of diet on the weight of gastric mucosa or the level of activity of the gastric proteases. Pigs fed a diet containing 20% whey had larger pancreases (P less than .10) at slaughter and a greater, but nonsignificant, mean activity per gram of pancreas for all pancreatic enzymes. It appears that the pig has sufficient pancreatic and gastric enzyme activity so that performance should not be limited, with the possible exception of the period shortly after weaning. However diet digestibility and subsequent pig performance may be more directly related to the extent of release of these enzymes into the intestine and the conditions that exist therein.

Levels of neural vasoactive intestinal polypeptide in rat uterus are markedly changed in association with pregnancy as shown by immunocytochemistry and radioimmunoassay.

Immunocytochemical studies have shown that the rat uterus is well innervated by nerve fibers containing vasoactive intestinal polypeptide (VIP). The fibers were associated with both vascular and nonvascular smooth muscle cells, and they were somewhat more numerous in the cervix compared to the uterine horns. This was confirmed in radioimmunologic determinations. Pregnancy induced a marked, almost 50% reduction in the total content of VIP in the uterine horns, which was associated with an almost complete disappearance of immunocytochemically visible nerve fibers in this part of the uterus. The innervation normalized within 25 days following delivery. Less marked changes occurred in the VIP innervation of the cervical region, where the concentration of the peptide was reduced mainly as a result of the increased tissue weight during pregnancy.

Regulation of submaxillary gland muscarinic receptors during heat acclimation

Binding properties of submaxillary gland muscarinic receptors and agonist-induced saliva secretion were studied in rats subjected to heat acclimation. The maximal binding capacity for the muscarinic antagonist N-[ 3 H]methyl-4- piperidyl benzilate was increased from control value of 0.21 to 0.40 pmol/mg protein within 1–2 days of heat acclimation. The increase in the number of muscarinic recetors per gland (100%) was by far higher than the increase in tissue weight (20%), indicating higher density of receptors in the acinar cells of the treated rats. High levels of receptors coincided with the appearance of high-affinity binding sites for muscarinic agonists (oxotremorine, pilocarpine and carbamylcholine), and with reduced tissue sensitivity to pilocarpine. After 4–8 weeks of heat acclimation, the number of receptors as well as tissue response to pilocarpine returned to control levels. These results suggest a functional correlation between the transient upregulation muscarinic receptors in the submaxillary gland and the physiological activity in salivary secretion, and indicate that the high-affinity muscarinic receptors may attenuate saliva secretion during the initial phase of heat acclimation.

Hypertrophic effect of unavailable carbohydrate on cecum and colon in rats.

The effects of unavailable carbohydrate on the cecum and colon were investigated in rats raised on diets containing 20% of glucomannan or cellulose for 8 weeks. Glucomannan ingestion caused the increase of cecum and colon weights, and the effect was greater in the cecum than in the colon. However, on ingestion of cellulose, a remarkable increase in tissue weight was observed in the colon rather than in the cecum. Measurement of DNA, RNA and protein in cecal and colonic mucosa demonstrated that the cecal enlargement caused by glucomannan was dependent on the increases in both number and size of mucosal cells, and that the cecal and colonic enlargements caused by cellulose and the colonic enlargement caused by glucomannan resulted from an increase in the number of mucosal cells; i.e., hyperplasia. (Na + K)ATPase activity of the cecal and colonic mucosa in the cellulose and glucomannan groups was significantly higher than that in the control group. Thus, (Na + K)ATPase activity was increased proportionally to the intensity of the process of tissue enlargement.

Oestrogen metabolism in the endometrium, corpus luteum and ovarian residual tissue of the rabbit.

Reproductive tissues (uterine endometrium, corpus luteum and ovarian residual tissues) from pregnant and pseudopregnant rabbits were incubated with equimolar concentrations of [3H]oestrone and [3H]oestrone sulphate (0.375 pmol) to monitor the changes in oestrogen metabolism during the early stages of pregnancy (days 0, and 3-8 post coitum) and to investigate the embyonic effect upon maternal oestrogen metabolism. Oestradiol-17 beta was the major metabolite formed from oestrone and sulphoconjugation occurred in all tissues studied. Oestrone sulphate was converted primarily to oestradiol-17 beta-3-monosulphate. Endometrial 17 beta-oxidoreductase significantly decreased and sulphotransferase increased in activity during the preimplantation period, but no differences were noted between gravid and non-gravid horns in unilaterally pregnant animals, nor between pregnant or pseudopregnant animals. Significant decreases occurred in 17 beta-oxidoreductase and sulphotransferase activity in luteal tissue, but these were more than offset by increases in tissue weight. No differences in the activities in luteal tissues were detected between pregnant or pseudopregnant animals, nor between ovarian tissue adjacent to gravid or non-gravid uterine horns. The results show that significant changes occur in oestrogen metabolism in the rabbit endometrium and corpus luteum within 8 days after ovulation, and that these changes result from maternal factors expressed systemically rather than by the effects of the developing conceptus expressed locally.

Effects of gestation and lactation on rat gastric fundus.

This study evaluated the effects of gestation and lactation on stomach growth in rats. Constant increases were observed in gastric fundus weight during pregnancy and lactation, with a maximum obtained after 3 weeks of lactation. This increase in tissue weight was not associated with hyperplasia of the gastric fundus as in no instance did total DNA contents from mated females differ significantly from those of the unmated controls. Mild hypertrophy, as evidenced by significant increases in cellular mass and RNA and protein concentrations, was observed during late lactation. Gastrin might be responsible for these modest changes in the gastric fundus.

Steroid delta 4-5 alpha-reductase and 3 alpha-hydroxysteroid dehydrogenase in the rat epididymis during development.

delta 4-5 alpha-Reductase activity is apparently regulated by a testicular factor(s) secreted directly into the epididymis, whereas 3 alpha-hydroxysteroid dehydrogenase activity, in this tissue, appears to reflect circulating androgen levels. To test whether the factor(s) regulating delta 4-5 alpha-reductase activity is directly associated with spermatozoa, a developmental study was undertaken to temporally correlate various parameters of the male reproductive tract with enzymatic activities. delta 4-5 alpha-Reductase activity is first detectable at 21 days of age. Activity increases until day 77, after which time enzymatic activity decreases by more than 60%, reaching steady adult values at 105 days. 3 alpha-Hydroxysteroid dehydrogenase activity is detectable as early as 7 days. Levels of this enzyme increase until day 63, after which time constant adult values are maintained until at least 1 yr. Spermatids and/or spermatozoa are first seen in the testes at 42 days, and plateau levels are reached by day 77. Spermatozoa are first seen in the epididymis at 49 days and reach maximal values by 91 days; no significant change occurs thereafter (until 365 days). Increases in seminal vesicle and ventral prostate weights are of a sigmoidal type, paralleling increases in plasma androgens, with the greatest rate of rise between days 35--63. This sigmoidal type of increase in tissue weights and plasma androgens is similar to that seen for epididymal 3 alpha-hydroxysteroid dehydrogenase but markedly different from that found for delta 4-5 alpha-reductase. The importance of delta 4-5 alpha-reductase and 3 alpha-hydroxysteroid dehydrogenase activities in the epididymis before the entry of spermatozoa and the decline in delta 4-5 alpha-reductase activity with age is discussed.

Characterization of mouse mammary tissue estrogen receptors under conditions of differing hormonal backgrounds

The receptor-like nature of previously-observed specific 4S estrogen binding in adult virgin female mouse mammary tissue cytosol has been further substantiated. The binding component does not arise from a plasma protein contaminant, nor is it an α-fetoprotein-type binder as evidenced by lack of affinity for diethylstilbestrol. The 4S protein binds 17β-estradiol with very high affinity (KA = 3 × 1010M−1), transforms to a 5.5 S form which translocates to nuclear binding sites under appropriate in vitro conditions. In vivo cytosol-nuclear binding distribution results are analogous to other estrogen receptor systems. During pregnancy, the 4S receptor is gradually replaced by an 8S form. This 8S complex does not represent a concentration-dependent aggregation of 4S subunits, as does the 8S receptor encountered in aged mice. The change in receptor concentration throughout pregnancy and lactation reflects the overall increase in tissue weight, and no major changes occur in specific binding activity, expressed on the basis of DNA content, cytosol protein concentration or unit weight of tissue. A single injection of 0.2 mg of prolactin to an adult virgin mouse results in an acute stimulation of receptor number, and a shift in molecular form from 4S to 8S. The effect is more pronounced if 3 successive daily injections of prolactin are administered, and thyroidectomy enhances the sensitivity of the receptor system to prolactin stimulation. Although the equilibrium binding constants are similar for the 4S and 8S complexes, analysis of the kinetics of formation and dissociation revealed that the 8S complex forms less readily, but has a half-life equal to 3 times that of the 4S complex. The differences in the amount, molecular nature and reactivity of the mammary tissue estrogen receptors, and the influence of specific hormonal elements on these parameters, set the stage for analysis of cellular response and responsiveness under diverse physiological and pathological conditions.

Lipid Accumulation and Cell Multiplication in Adipose Bodies in White Leghorn and Broiler-Type Chicks

Reduction of nutrient intake from hatching until six weeks of age by dietary dilution decreased growth rate and lipid accumulation in the retroperitoneal adipose depot. In White Leghorn chicks fed the undiluted diet adipocyte size remained relatively constant during the six-week period and was approximately half that in broiler-type chicks. With the diluted diets, adipocytes decreased in size to a minimum at 4–5 weeks of age and then increased. The breed difference in adipocyte size was generally maintained with restricted nutrient intake.The response of adipose tissue to withholding feed for up to five days after hatching was studied. At hatching the lateral thoracic body was a major fat depot and, in the 24-hour-old broiler and White Leghorn chicks, contained 215 and 177 mg. of lipid, respectively. In chicks not given feed the amounts of lipid declined to 14 and 13 mg. by the fifth day. White Leghorn chicks withstood the starvation period after hatching better than the broiler chicks and had 6% mortality as contrasted with 27% in the broilers. Four-week old chicks of both breeds had deposited less retroperitoneal lipid when feed had been withheld for five days after hatching.Broiler-type chicks fed ad libitum to 21 days of age showed an increase in the weight of the retroperitoneal adipose body which was due mainly to hyperplasia but with some increase in cell size. The lateral thoracic subcutaneous fat body showed no growth until approximately 12 days in birds fed ad libitum. In birds fasted for three-days after hatching, adipocytes in this site, which had lost lipid during the starvation period, were repleted after feeding. Cell multiplication in the retroperitoneal adipose body, as estimated by 3H-thymidine-uptake and dilution, was retarded immediately following fasting either post-hatching or at 10 days of age. The three-day old fasted chicks showed, nevertheless, considerable cell multiplication in this depot as soon as they were fed. In 13-day old chicks no appreciable cell multiplication occurred in the retroperitoneal depot immediately after refeeding and it was apparent that the increase in tissue weight following refeeding was due to refilling of existing adipocytes.

Binding of glucocorticoids in fetal tissues

Glucocorticoids enhance the activity of a number of enzyme systems in fetal tissues. In the rabbit fetal lung [ 3H]-dexamethasone binds to cytosol and nuclear receptors with a high degree of specificity which is not competed for by other hormones or metabolites. The cytosol [ 3H]-dexamethasone-receptor complex sediments at 4 s in sucrose density gradients in the presence of 0.6 M KCl and at approximately 7–8 s in the absence of salt, whereas the nuclear complex sediments at approximately 4–5 s in the presence or absence of 0.4 M KCl. At 37°C the saturation of nuclear binding sites is reached with 5 × 10 −8−1 × 10 −7 M [ 3H]-cortisol or with 1 × 10 −8 M [ 3H]-dexamethasone. There is an increase in the uptake of [ 3H]-cortisol by lung nuclei (c.p.m./mg DNA) with advancing gestation, beginning on day 20 and reaching a maximum on day 28–30. A lower uptake is observed in lung nuclei of the newborn, the one-month-old and the adult rabbit. The maximum uptake of [ 3H]-cortisol by fetal lung nuclei correlates well with the concentration of surface-active phospholipids extracted from lungs of rabbit fetuses. [ 3H]-Dexamethasone binds to macromolecules in the cytosol and nuclei of fetal rabbit small intestine. The binding is specific for steroids with glucocorticoid potency. There is a parallelism between the increase in the total number of glucocorticoid binding sites in the cytosol and nuclei and the increase in tissue weight up to term. The concentration of binding sites (pmol/mg protein or DNA) is maximum at day 25 to 26 of gestation, followed by a decrease to adult levels within a few days of birth. Alkaline phosphatase activity is first detectable on day 25 of gestation and increases rapidly thereafter. There seems to be a temporal relationship between the development of the fetal rabbit small intestine and the level of glucocorticoid receptors in the cytosol and nuclei.

Development of perirenal adipose tissue in the neonatal lamb: effects of dietary safflower oil.

Perirenal adipose tissue development was investigated in lambs from birth until 17 days of age. Changes in the morphology, the lipid, protein, RNA and DNA content, the adipocyte number and size, and the rate of protein, RNA and DNA synthesis of the perirenal fat-pads are reported. During the first 9 days after birth the tissue lost the morphological characteristics of brown adipose tissue and acquired those of white adipose tissue. As there was no change in either the number of adipocytes or the DNA content of the fat-pads between birth and 9 days of age it is concluded that there was a differentiation of brown into white adipocytes. Over 80% of the increase in tissue weight between birth and 17 days of age was due to lipid deposition. Administration of safflower oil to the lambs had no apparent effect on the change from brown to white fat, but it markedly reduced the rate of lipid deposition between days 9 and 17 post partum.

Effect of depletion of vitamin A, followed by supplementation with retinyl acetate or retinoic acid, on regeneration of rat liver.

After partial hepatectomy the net increase in tissue weight and in RNA, DNA and proteins in the regenerating liver was markedly less in vitamin A-deleted or retinoic acid-supplemented male rats, compared with the corresponding normal control or retinyl acetate-supplemented ones.

Postembryonic growth of the optic lobe of Octopus vulgaris, Lam.

AbstractThe pattern of growth of the optic lobe of Octopus vulgaris has been investigated from 0.1 to 6.0 gms body weight by measuring the weight of the lobe and the number of nuclei present in the tissue homogenate. In the normal habitat, the rate of increase in nulcear number relative to increase in body weight is 1.32 up to 1.5–1.8 gms, but undergoes a three‐fold decrease above this size. On the other hand, the rate of increase in tissue weight remains essetially constant throughout the same period of development, with the exception of the interval between 1.0 g and 1.5 gms during which it rises markedly. Nuclear density increases steadily up to approximately 1.2 gms and approaches a constant value above this size.In octopuses reared in transparent containers or under an opaque cover the rates of increment in number of nuclei and in tissue weight are generally lower than normal between 0.2 g and 1.5 gms. In both experimental conditions the wave of acceleration in the rate of increase of tissue weight occurring between 1.0 g and 1.5 gms in normal animals appears earlier particularly in octopuses reared under an opaque cover. At body weights larger than 1.5–2.0 gms the rates of increment in number of nuclei and tissue weight become higher than normal in octopuses reared in transparent boxes, but change in the opposite direction when rearing takes place in opaque containers. In the former condition, the nuclear density of newly added tissue starts decreasing earlier than normal but reaches a higher level at body weights above 2 gms, while in octopuses reared under an opaque cover the decrease occurs at approximately normal timing but attains lower values at higher body weights.

Seasonal changes in biochemical composition of the bivalve Abra alba from the Clyde Sea Area

Seasonal changes in the tissue weight and biochemical composition of the bivalve Lima hians (Gmelin) from a station in the Skelmorlie Bank, Clyde Sea Area, were studied during 1969–1971. The composition of an animal of standard size was calculated for each sampling date to give information on seasonal changes independent of shell growth. Increases in tissue weight took place between April and July as the gonad developed and reserves were built up. Between July and March tissue weight fell, at first rapidly as a result of spawning in the population, and later more slowly as reserves were utilized. Differentiation of the gonad began during the winter, at the expense of stored reserves, but was greatly accelerated during the spring due to increased food from the plankton. The lipid and nitrogen content of a standard animal rose to a pre-spawning maximum in July and then fell. Carbohydrate content also rose during this period, but continued to rise to reach maximum values in September. Carbohydrate and nitrogen both declined during the winter, but there was little indication of any net utilization of lipid during the winter months. The tissues of the ripe female contained more lipid than the male, and the tissues of the ripe male contained more nitrogen than those of the female. The total calorific content of the tissues of the male was greater than that of the female.

The maturation of 5-hydroxytryptophan decar☐ylase in regions of the mouse brain

5-Hydroxytryptophan decar☐ylase (5-HTPD) activity has been measured in 4 subdivisions of the mouse brain during various stages of postnatal maturation. Each region demonstrated a different pattern of maturation. During the first few days post-partum increases in enzyme activity are slower than increases in tissue weight for all regions studied. However, by the end of the first week all regions are undergoing rapid increases in enzyme activity. Maturation of the enzyme proceeds in a caudal rostral direction, with cerebellum and medulla-pons reaching adult-like status by 2 weeks, mesencephalon-diencephalon by 4 weeks and cerebral hemispheres sometime after 6 weeks. Comparisons of these enzyme data to previously reported data for 5-hydroxytryptamine (5-HT) maturation, measured upon a similar basis, indicate that the enzyme (5-HTPD) and its product (5-HT) mature differently in all regions.

Unilateral visual deprivation and avian optic lobe development

The total decussation of avian optic tracts offers a system in which biochemical correlates of visual deprivation in one tract can be compared with the opposite tract as a normal control. The short term effect of unilateral eye removal in new hatched chicks was to prevent the normal increases in tissue weight and to modify the level of acetylcholinesterase activity in the contralateral optic lobe.