Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

3':5'-Cyclic-AMP phosphodiesterase (PDE) (EC 3.1.4.17) activity was measured in interscapular brown adipose tissue (BAT) and in white epididymal adipose tissue of rats acclimated to constant or fluctuating cold. Experiments were carried out on isolated adipocytes or tissue homogenates. In brown or white adipose tissue or isolated adipocyte homogenates, two different apparent Km values were found according to the substrate (cAMP) concentration. The low Km was at about 10(-6) M and the high one at about 10(-4) M. The apparent V of the high Km enzyme was about 10-fold higher than the V of the low Km enzyme. Cold acclimation to constant or fluctuating cold did not modify appreciably the Km or V values. For low substrate concentrations (10(-6)-10(-8) M), the specific activity of PDE expressed per milligram of protein was decreased in BAT adipocytes of the two groups of cold-acclimated rats, compared to controls. Inversely, it was increased in total tissue homogenates. These variations were smaller in fluctuating cold than in constant cold-acclimate rats. They could, in part, induce the increases in lipolysis and in blood flow observed in the BAT of cold-acclimated rats.
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PMID:3':5'-Cyclic-AMP phosphodiesterase activities in white and brown adipose tissues of cold-acclimated rats. 17 98

1. The effects of cold acclimation (5 degrees C) on the lipid composition of plasma membrane and mitochondrial fractions from epididymal adipocytes of rats were studied. 2. The adipocyte plasma membrane fraction of the cold-acclimated rats had lower lipid, phospholipid and cholesterol to protein weight ratios, a lower cholesterol to sphingomyelin molar ratio, and a higher linoleic acid content in the phospholipids than controls. 3. The mitochondrial fraction of the cold-acclimated rat adipocyte had lower ratios of cholesterol to protein (weight), to phospholipid and to cardiolipin (molar), and less sphingomyelin content than did controls. 4. These data, discussed in terms of alterations in physical and biochemical properties, indicate cold-induced changes at the membrane level in rat epididymal adipocytes.
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PMID:The lipid composition of plasma membrane and mitochondrial fractions from epididymal adipocytes of cold-acclimated rats. 42 Aug 36

When fresh epididymal spermatozoa were cold shocked for 10 or 30 min, then warmed to 24 degrees C, sperm motility was normal, but cold shocking ejaculated or capacitated spermatozoa caused a significant decrease in the percentage of motile spermatozoa and, for capacitated spermatozoa, in the rate of motility. The acrosomes of motile fresh epididymal and ejaculated spermatozoa became crenulated after cold shock, and the percentage of spermatozoa with crenulated acrosomes increased with longer periods of cold shock and was higher when spermatozoa were cold shocked in serum than in saline. When epididymal spermatozoa were cold shocked after incubation for 4 h at 37 degrees C, the acrosomes on spermatozoa which had not undergone an acrosome reaction became swollen and elevated instead crenulated. Epididymal spermatozoa which were cold shocked and then incubated for 4 h at 37 degrees C exhibited acrosome reactions and activation of motility, but had reduced fertilizing capacity when tested in vitro. Spermatozoa incubated in serum and cold shocked were able to penetrate zone-free ova even though their tails had been bent through 180 degrees. It is suggested that cold shock decreases the fertilizing capacity of hamster spermatozoa by interfering with the ability of spermatozoa to bind to and/or penetrate the zone pellucida.
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PMID:Motility, acrosome morphology and fertilizing capacity of cold-shocked hamster spermatozoa. 42 98

Cold acclimatization induces morphological and compositional modifications of rat epididymal adipose tissue: a decrease in fat cell size, an increase of fat cell number per g of tissue, but no significant increase in total fat cell number in the tissue; finally, an increase in protein content and a decrease in triglyceride content.
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PMID:Cellularity and composition of epididymal adipose tissue from cold-acclimatized rats. 49 19

Calorigenic actions of noradrenaline and glucagon on isolated epididymal fat cells from warm-acclimated controls, cold-acclimated and heat-acclimated rats were measured by the use of a twin-type conduction microcalorimeter. Both noradrenaline and glucagon stimulated heat production in isolated adipocytes maximally in doses of 1 microgram/ml and 10 microgram/ml, respectively. Maximal responsiveness of adipocytes per unit cell to noradrenaline was not influenced by cold acclimation, while it was reduced by heat and acclimation. Maximal response in total epididymal fat cells to noradrenaline was increased in cold acclimation and not changed in heat acclimation at increased numbers of adipocytes in both cold-acclimated and heat-acclimated animals. Maximal response per unit cell as well as per total epididymal fat cells to glucagon was increased in cold acclimation and reduced in heat acclimation. The present results indicate that the modified responses of target adipocytes to noradrenaline and glucagon are involved in the development of temperature acclimation.
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PMID:Calorigenic effects of noradrenaline and glucagon on white adipocytes in cold- and heat-acclimated rats. 57 51

The purpose of the work was to establish the eventual "metabolic toxicity" of pesticide-contaminated diets in the Rat. The liver metabolic response to various stimuli was compared in dithiocarbamate-fed animals and in non-contaminated ones. 112 weanling male Wistar CF rats were fed, during 15 days, with a demi-synthetic control diet. They were then divided into 4 lots:--the control group C, which went on to receive the same diet,--the nabame group N, the diet of which was supplemented with 275 ppm of the dithiocarbamate;--the thirame groupe R, receiving the control diet + 600 ppm thirame;--the zineb groupe Z, given the control diet + 3 600 ppm Zineb. The animals were fed with these diets during 14 days, their dithiocarbamate intake thus averaging 1/20 th of the per os LD 50/rat/day. At the end of this 2-week period, each of the 4 groups was divided into 4 sub-groups, all the animals were fasted overnight, then sacrified:--after no other treatment (sub-groups T);--30 minutes after an i.p. injection of 2.6 g/kg glucose (G);--after having been forced to walk in a restraint wheel for 50 minutes/hr during the 18 hrs of the night fast (sub-groups W);--after a 90 minutes exposure in a cold room (F). The weights of the animals, of their liver, heart, kidneys, adrenals and epididymal pads were recorded. In their liver, the following compounds were determined: water, proteins, total lipids, triglycerides, long-chain acyl-CoA, non-esterified fatty acids, total cholesterol, glycogen, glucose, alpha-glycerophosphate. The thirame rats had a lower food intake than the others and the smallest body weight, but their relative liver and kidneys weights were the highest. The nabame animals did not differ from the control ones but the zineb rats had the lightest epididymal fat pads. The primary effects of the dithiocarbamate diets on liver metabolism were apparently not the same in the 3 groups compared to the control ones: nabame and thirame increased glycogen, thirame increased the lipid compounds: long-chain actyl-CoA and triglycerides, where as zineb feeding resulted in an increase of glucose concentration and in a decrease of triglycerides and total lipids. Muscular exercise, or cold exposure, had the following effects compared to those they had in the control group: a greater glucose utilization in the nabame and thirame rats, a smaller glycogen and glucose utilization, associated with an increase of alpha-glycerophosphate, in the zineb animals. These results were considered altogether with those obtained in a previous paper by the same authors, which concerned liver ketone bodies and adenine nucleotides changes after the same experimental conditions, and it was concluded that the 3 dithiocarbamates actually had a common effect on rat metabolism: they all impaired glucose utilization by the liver. Also, fat mobilization from peripheral depots was shown to occur in the 3 experimental groups, resulting in liver fatty acid oxidation in the nabame and zineb rats, and in liver steatosis for the thirame ones...
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PMID:[Short term effects of diets with high levels of dithiocarbamates on carbohydrate and lipid metabolism of rat liver]. 97 Aug 34

In an attempt to define pathogenesis of the previously described impaired triglyceride (TG) removal in uremia, the effects of the addition of normal and uremic plasma on the activity of lipoprotein lipase (LPL) from rat epididymal adipose tissue were examined. Six uremic patients on chronic dialysis and 13 normals were studied. Adding increments of normal and uremic plasma increased the LPL activity to maximal levels when 0.1 ml of plasma was added. Larger aliquots of uremic plasma produced marked inhibition of LPL activity. This inhibition was not observed with the normal plasma. When increasing amounts of uremic plasma were added to an incubation mixture already maximally activated by 0.1 ml of normal plasma, inhibition of LPL was again observed. This inhibition was still present in uremic plasma which had been dialysed against cold saline. The inhibitor was in the lipoprotein-free (d greater than 1.225) fraction of the plasma. The results indicate that uremic plasma has an LPL inhibitor which is probably a protein and may play a role in the pathogenesis of uremic hypertriglyceridemia.
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PMID:Inhibition of lipoprotein lipase by uremic plasma, a possible cause of hypertriglyceridemia. 118 98

The relationship between the antifertility effect of alpha-chlorohydrin and changes in composition of luminal plasma from the cauda epididymidis of rats and rabbits has been investigated. At each dose regimen studied, the fertilizing capacity of rats treated with alpha-chlorohydrin was reduced to zero. The levels of sodium, potassium, glycerylphosphorylcholine (GPC), acid phosphatase and alkaline phosphatase in epididymal plasma were not markedly affected by drug treatment. The most noticeable change was a considerable increase in the concentration of lactic dehydrogenase (LDH) at all dose levels and of glutamic-oxaloacetic transaminase (GOT) after 7 days of treatment with 8 and 16 mg/kg. The effect of cold shock on the composition of epididymal plasma showed that LDH and GOT are, at least in part, derived from spermatozoa. In contrast, alpha-chlorohydrin did not have an antifertility action in the rabbit, and the only notable change in the compositon of epididymal plasma was an increase in the level of GPC. These results provide evidence that, in the rat, alpha-chlorohydrin or a metabolite primarily exerts its antifertility effect by a direct action on the spermatozoa, whilst in the rabbit a barrier may exist to the entrance of the drug into the lumen of the epididymal duct.
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PMID:The effects of alpha-chlorohydrin on the composition of rat and rabbit epididymal plasma: a possible explanation of species difference. 119 43

Brown adipose tissue (BAT) is a major site of nonshivering thermogenesis (NST) during cold acclimation for most mammals. Repetitive nonthermal stress such as immobilization has been shown to enhance the capacity of NST as cold acclimation. In the present study, the effects of running training, another type of nonthermal stress, were investigated on in vitro thermogenesis and the cellularity of interscapular BAT in rats. The rats were subjected to treadmill running for 30 min daily at 30m/min under 8 degrees inclination for 4-5 weeks. In vitro thermogenesis was then measured in minced tissue blocks incubated in a Krebs-Ringer phosphate buffer containing glucose and albumin at 37 degrees C, using a Clark type oxygen electrode. The trained rats showed less body weight gain during the experiment. The weights of BAT and epididymal white adipose tissue were smaller in the trained rats. Noradrenaline- and glucagon-stimulated oxygen consumption were also significantly smaller in the trained rats. The tissue DNA level was greater in the trained rats, but the DNA content per tissue pad did not significantly differ. The results indicate that running training reduces BAT thermogenesis, possibly as an adaptation to conserve energy substrates for physical work.
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PMID:Effects of running training on in vitro brown adipose tissue thermogenesis in rats. 163 84

Ability to express uncoupling protein (UCP) and establish UCP-dependent thermogenesis was analyzed in anatomical areas of mice that are generally considered to be white adipose tissue: mesenterial, perimetral, epididymal, inguinal, and superficial layer of interscapular white adipose tissue. The mice were acclimatized for 1 week to 4 degrees C; the following week they were exposed to cold stress (1 h at -20 degrees C, 2-3 times daily). In such conditions in inguinal adipose tissue, slot-blot analysis detected significant amount of UCP mRNA and lipoprotein lipase mRNA. Immuno-electron-microscopic localization of UCP showed that developed mitochondria of cold-stressed inguinal adipocytes contained UCP in the same amount as uncoupled (UC)-mitochondria of brown adipocytes. Morphological and morphometrical analysis showed that such inguinal adipose tissue appeared as brown adipose tissue. Since in control mice, inguinal adipose tissue was UCP-negative and tissue appeared as white adipose tissue, the duration of this white-to-brown adipose tissue conversion was analyzed. Mice, cold stressed for 1 week, were rewarmed at 28 degrees C and their inguinal adipose tissue was analyzed in comparison with interscapular brown adipose tissue and epididymal white adipose tissue for another 37 days. During that time inguinal adipocytes ceased expressing UCP mRNA; UC-mitochondria in inguinal adipocytes were destroyed and replaced with common, C-mitochondria; and UCP was undetectable immunohistochemically. Adipocytes accumulated lipids, and the tissue morphologically once again resembled white adipose tissue. Described changes showed that besides typical brown and white adipose tissue in mice, there existed a third type of adipose tissue described as convertible adipose tissue.
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PMID:Convertible adipose tissue in mice. 174 9


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