Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Cell renewal in hibernators undergoes seasonal rhythm independent of the hibernation state. 2. We propose that seasonal depression of cell renewal in tissues of hibernators is caused by seasonal involution of thymus in these animals. 3. The latter is known to be involved in the control of cell proliferation. 4. The state of hibernation per se has also an effect on cellular proliferation. 5. It induces the block of cells in the permitotic phase. It is suggested that the blockage of cells in renewing tissues of hibernators under natural deep hypothermia throughout a period of torpidity represents the adaptive reaction of the organism.
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PMID:Comparative analysis of cell replacement in hibernators. 134 19

N-(2,2-Diphenylethyl)adenosine (DPEA) has been identified as a potential antipsychotic agent acting via stimulation of adenosine receptors. The projected human therapeutic dose, based on animal studies, is 2-3 mg/kg. DPEA has been tested for potential toxicity in mice, rats, dogs and monkeys. Following single oral doses, median lethal dose values were approximately 10-fold greater in rats than in mice, although similar clinical signs including reduced activity, prostration, and necrosis of the tail were seen in both species. DPEA was well tolerated at daily doses up to 40 mg/kg in rats for 2 weeks. A no observed effect level (NOEL) was not identified in the dog or monkey studies. Reduced activity, dacryorrhea, ptosis, hypothermia, necrosis of the tail, and death occurred in rats given 120 and 160 mg/kg. Pathologic changes consisted of pancreatitis, gastric erosion/ulceration, lymphocyte depletion of the thymus, and pulmonary congestion and hemorrhage at 80 mg/kg or greater. In dogs, sporadic emesis was noted at 12.5 mg/kg and greater, and significant pathologic changes consisted of coronary arteritis associated with myocardial lesions and lymphocyte depletion at 25 and 50 mg/kg, pancreatic acinar necrosis at 50 mg/kg, and renal tubular degeneration at 12.5 mg/kg and greater. Emesis and depression were noted at 25 and 50 mg/kg in monkeys. Renal tubular dilatation and degeneration at 25 and 50 mg/kg were noted in the monkeys. These studies demonstrated that DPEA produced a range of adverse effects in common laboratory animal species.
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PMID:Preclinical toxicity studies of an adenosine agonist, N-(2,2-diphenylethyl) adenosine. 187 77

The experiments have been performed on 60 white female rats with body mass 180-200 g. Under ether anesthesia the animals are cooled up to +18 degrees C of the rectal temperature, and then warmed up to +37 degrees C. Using certain morphometrical methods at staining paraffin slices with toluidine++ blue, tissue basophils (TB) in the dermis++, hypoderma, lymph nodes, thymus and spleen are studied. In response to cooling degranulation increases, some part of TB in all the organs is destroyed, this results in decreasing amount of the cells (except the thymus, where TB amount increases). The greatest pronounced decrease of TB amount occurs in the lymph node. The restorative reaction during the post-hypothermic period depends on the initial lesion. There are no TB in the spleen. In different organs TB demonstrate various sensitivity to hypothermia, that is evidently connected with their microenvironment and initial state at the moment of the experiment, as well as with various role of the organs investigated in the defensive-adaptive reactions of the organism.
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PMID:[Changes in tissue basophils of skin and lymphoid organs in total, deep hypothermia]. 277 86

Morphine, an alkaloid known for its potent analgetic action, also affects a variety of immunologic functions. In the experiments reported here, the time course for the effect of 75-mg morphine pellet implants on spleen and thymus size and cellularity and in vitro proliferative responses of lymphocytes from male C3H/HeN mice is described. T lymphocyte proliferation in response to concanavalin A (Con A) was not significantly affected at 6 or 24 hr after morphine pellet implantation but was reduced at 48 and 72 hr. B lymphocyte proliferation in response to lipopolysaccharide was more sensitive to morphinization, as the response was reduced at the 24, 48 and 72 hr intervals after implantation of the morphine pellet. No differences in Con A- or lipopolysaccharide-induced proliferation were observed 96 hr after pellet implantation. Interestingly, a slight elevation of Con A-induced proliferation was observed 120 hr after morphine pellet implantation. By contrast with Con A proliferative data, lipopolysaccharide-induced proliferation of lymphocytes from morphine-treated mice was not different from placebo-pelleted mice at 120 hr. A marked atrophy of the spleen and thymus accompanied the reduced splenocyte proliferative responses of morphine-treated mice and was greatest at the 48 to 72 hr postimplantation interval. The attenuation of mitogen-induced proliferative responses and atrophy of immune organs was accompanied by hypothermia and a marked tolerance to the antinociceptive effect of morphine in morphine-pelleted mice at all of the time points that were monitored.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Morphine pellet-induced immunomodulation in mice: temporal relationships. 338 46

1 Three injections of cannabis extract (500 mg/kg s.c. given over 3 or 5 days) diminished thymus gland weight but not the weights of spleen or liver in weanling female and adult male mice kept at room temperature.2 Both cannabis extract (500 mg/kg s.c.) and Delta(1)-tetrahydrocannabinol (Delta(1)-THC; 10 and 20 mg/kg i.p.) elevated corticosterone levels in mouse plasma.3 A pretreatment that consisted of three daily subcutaneous injections of 500 mg/kg of cannabis extract and that was shown to produce tolerance to the ;cataleptic' effect of Delta(1)-THC (2 mg/kg i.v.) in mice, also produced tolerance to the effect of Delta(1)-THC (10 mg/kg i.p.) on corticosterone levels in mouse plasma. However, this pretreatment did not reduce the rise in plasma corticosterone concentration produced by immobilization.4 Tolerance to the effect of Delta(1)-THC (10 mg/kg i.p.) on corticosterone levels in mouse plasma was also produced by the pretreatment of mice with a single injection of Delta(1)-THC (10 mg/kg s.c.). Three daily injections of Delta(1)-THC (10 or 30 mg/kg s.c.) also produced tolerance.5 In a thermoneutral environment (30-32 degrees C) in which cannabis extract does not produce hypothermia, the drug no longer reduced thymus gland weight. However the effect of cannabis extract and of Delta(1)-THC on corticosterone plasma levels was the same at room temperature as at 30-32 degrees C. Tolerance to the latter effect of Delta(1)-THC was also produced equally readily under the two conditions.6 It is concluded that pretreatment with cannabis extract or Delta(1)-THC can produce tolerance to the effect of Delta(1)-THC on corticosterone levels in mouse plasma and does so without impairing the effect of immobilization stress on corticosterone release. In addition, both the rise in corticosterone plasma levels produced by cannabis or Delta(1)-THC and the development of tolerance to this effect can still take place in the absence of hypothermia.
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PMID:Tolerance to the effect of delta1-tetrahydrocannabinol on corticosterone levels in mouse plasma produced by repeated administration of cannabis extract or delta1-tetrahydrocannabinol. 445 52

Substantial evidence suggests that stress can alter the general toxicological properties of the substituted amphetamines (AMPs) as well as their psychostimulant properties. Research concerning the interactions between stress and the neurotoxicity associated with the AMPs is, however, limited. Our previous work demonstrated that a variety of AMPs, including d-METH, d-MDA, d-MDMA but not d-FEN are able to damage dopaminergic elements of the striatum as shown by decreases in dopamine and tyrosine hydroxylase. The neurotoxic capabilities of these AMPs appear linked to their hyperpyrexic actions as diverse manipulations able to block AMP-induced hyperthermia are also neuroprotective. Surprising, since stress usually potentiates the actions of the AMPs, it is our finding that restraint, a commonly used stressor, is protective against the injurious actions of all neurotoxic AMPs evaluated to date. In the mouse restraint acts to elevate blood levels of corticosterone (CORT) by activating the hypothalamic-pituitary-adrenal (HPA) axis as well as inducing a profound hypothermia. The role CORT may play in the neuroprotective actions of restraint, if any, is unknown. Here, data is presented showing the impact of several HPA axis manipulations, including restraint, supplementation with CORT in the drinking water and removal of CORT by adrenalectomy (ADX) on the striatal dopaminergic neurotoxicity of d-AMP. As strain is known to be a powerful determinant of the actions of stress an essential element of these experiments was the evaluation of both an inbred, C57BL/6J and outbred, CD-1, mouse strain. Exposure to d-AMP caused hyperthermia and substantial striatal dopaminergic neurotoxicity in both strains suggesting that an elevation in body temperature is as important a component of the neurotoxicity of d-AMP, as it is of the other neurotoxic AMPs. Restraint was equally effective in both strains and completely blocked the hyperthermia and striatal neurotoxicity induced by d-AMP. CORT supplementation, evaluated in only the C57BL/6J mouse at dosages not capable of involuting either the thymus or the spleen, did not alter d-AMP-induced neurotoxicity. Although the immune system organs of the two strains responded differentially to the removal of CORT, ADX provided equivalent partial protection against the loss of dopaminergic elements in striatum for both strains. Adrenal status clearly affects d-AMP neurotoxicity but the interaction is complex. Future work should examine the roles of the cortical and medullary components of the adrenal gland in the neuroprotective actions of ADX. A precise assessment of the role of circulating CORT In the neurotoxicity of the AMPs will require additional work in which a wider range of CORT dosages, including those capable of involuting thymus and spleen, are evaluated.
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PMID:Neurotoxicity of d-amphetamine in the C57BL/6J and CD-1 mouse. Interactions with stress and the adrenal system. 895 30

NS-21, (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate, is a new drug for the treatment of urinary frequency and incontinence. To evaluate acute toxicities of its related compounds including the optical isomers of NS-21 ((S)NS-21 and (R)NS-21), the active metabolite of NS-21 ((R/S)RCC-36), the optical isomers of (R/S)RCC-36 ((S)RCC-36 and (R)RCC-36), the hydrolysis products of NS-21 (RCC-32 and RCC-38) and the bi-product of NS-21 (RCC-66), single-dose intraperitoneal toxicity studies were conducted in ddY mice. The LD50 values of these compounds in male and female mice were as follows: 199 and 184 mg/kg for (S)NS-21, 261 and 240 mg/kg for (R)NS-21, 74 and 100-150 mg/kg for (R/S)RCC-36, 93 mg/kg for (S)RCC-36 in both sexes, 83 and 104 mg/kg for (R)RCC-36, higher than 510 mg/kg for RCC-32 in both sexes, 340-510 mg/kg for RCC-38 in both sexes, and 1000-2000 mg/kg for RCC-66 in both sexes, respectively. The clinical signs included decreased spontaneous locomotor activity, prone or lateral position, ataxic gait, clonic convulsion, hypopnea, hypothermia, pale skin, mydriasis, abdominal distention and unkempt fur for (S)NS-21, (R)NS-21, (R/S)RCC-36, (S)RCC-36 and (R)RCC-36, decreased spontaneous locomotor activity, prone position, ataxic gait, clonic convulsion, tail elevation and hypopnea for RCC-32 and RCC-38, and decreased spontaneous locomotor activity and unkempt fur for RCC-66. Body weight was decreased or its gain was suppressed for every compound examined. Pathological examination of the dead mice showed atrophy of the thymus and spleen, intestinal distention with the retention of dark red contents, white spots or white materials in the abdominal fatty tissue for (S)NS-21, (R)NS-21, (R/S)RCC-36, (S)RCC-36, (R)RCC-36 and RCC-66, but no treatment related change for RCC-32 and RCC-38. Adhesion between the abdominal organs was observed in survivors treated with (S)NS-21, (R)NS-21, (S)RCC-36, (R)RCC-36, RCC-32 and RCC-66.
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PMID:[Intraperitoneal single-dose toxicity studies of active metabolite, optical isomers, hydrolysis products and bi-product of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate(NS-21), a novel drug for urinary frequency and incontinence, in mice]. 917 Jun 1

In order to investigate the recovery from activity-stress ulcers by ad lib-feeding and/or cessation of running, male Wistar rats were exposed to the activity-stress paradigm, and the rats that revealed hypothermia (their rectal temperature fell below 36 degrees C) were sacrificed either immediately or after several 24 h periods of healing. Rats that were sacrificed immediately after the appearance of hypothermia and those that were exposed to restricted feeding plus cessation of running revealed severe activity-stress ulcers, whereas few ulcers were observed in rats given ad lib-feeding and those that were given ad lib-feeding plus cessation of running. Although no significant differences in relative weights of spleen and thymus were obtained among the different recovery conditions, the relative weights of the adrenal glands were highest in the restricted feeding plus cessation of running group, whereas, the other animals exposed to the activity-stress paradigm showed no differences. These results indicate that activity-stress ulcers recover under conditions of ad lib-feeding within 24 h, but they are not influenced by cessation of running. These data also suggest that organ weights are not affected by any manipulations employed in the present study.
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PMID:Recovery from activity-stress ulcer by ad lib feeding in rats. 940 20

The functional activity of the synthetic apparatus (parameter alpha) in blood lymphocytes, bone marrow hemopoietic cells, and thymus cells, as well as the total number of blood and bone marrow cells in rats after y-irradiation at a dose of 8 Gy in the conditions of normothermia and hypothermia (16-18 degrees C) with hypoxia-hypercapnia were investigated after 2 h and on days 1 and 4. The recovery processes in blood in both groups of rats after acute X-irradiation at a dose of 7 Gy for 36 days were analyzed too. Under hypothermia, on days 1-4 after acute gamma-irradiation, a decrease in the synthetic activity in remaining cells and devastation in the hemopoietic system were pronounced to a lesser degree. After X-irradiation, the restoration of synthetic activity in blood lymphocytes was shown to begin earlier and to finish faster in "hypothermic" rats as compared with the animals irradiated in the state of normothermia. The survival of "hypothermic" rats was 100% as compared with 30% in "normothermic" animals. Thus, the data show that hypothermia exerts a radioprotective effect on the cells of the immune and hemopoietic systems, thus enhancing the resistance of the organism to radiation.
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PMID:[The radioprotective effect of hypothermia on the immune and hematopoietic systems in mammals]. 1854 76

Antioxidants specifically addressed to mitochondria have been studied to determine if they can decelerate senescence of organisms. For this purpose, a project has been established with participation of several research groups from Russia and some other countries. This paper summarizes the first results of the project. A new type of compounds (SkQs) comprising plastoquinone (an antioxidant moiety), a penetrating cation, and a decane or pentane linker has been synthesized. Using planar bilayer phospholipid membrane (BLM), we selected SkQ derivatives with the highest permeability, namely plastoquinonyl-decyl-triphenylphosphonium (SkQ1), plastoquinonyl-decyl-rhodamine 19 (SkQR1), and methylplastoquinonyldecyltriphenylphosphonium (SkQ3). Anti- and prooxidant properties of these substances and also of ubiquinonyl-decyl-triphenylphosphonium (MitoQ) were tested in aqueous solution, detergent micelles, liposomes, BLM, isolated mitochondria, and cell cultures. In mitochondria, micromolar cationic quinone derivatives were found to be prooxidants, but at lower (sub-micromolar) concentrations they displayed antioxidant activity that decreases in the series SkQ1=SkQR1>SkQ3>MitoQ. SkQ1 was reduced by mitochondrial respiratory chain, i.e. it is a rechargeable antioxidant. Nanomolar SkQ1 specifically prevented oxidation of mitochondrial cardiolipin. In cell cultures, SkQR1, a fluorescent SkQ derivative, stained only one type of organelles, namely mitochondria. Extremely low concentrations of SkQ1 or SkQR1 arrested H(2)O(2)-induced apoptosis in human fibroblasts and HeLa cells. Higher concentrations of SkQ are required to block necrosis initiated by reactive oxygen species (ROS). In the fungus Podospora anserina, the crustacean Ceriodaphnia affinis, Drosophila, and mice, SkQ1 prolonged lifespan, being especially effective at early and middle stages of aging. In mammals, the effect of SkQs on aging was accompanied by inhibition of development of such age-related diseases and traits as cataract, retinopathy, glaucoma, balding, canities, osteoporosis, involution of the thymus, hypothermia, torpor, peroxidation of lipids and proteins, etc. SkQ1 manifested a strong therapeutic action on some already pronounced retinopathies, in particular, congenital retinal dysplasia. With drops containing 250 nM SkQ1, vision was restored to 67 of 89 animals (dogs, cats, and horses) that became blind because of a retinopathy. Instillation of SkQ1-containing drops prevented the loss of sight in rabbits with experimental uveitis and restored vision to animals that had already become blind. A favorable effect of the same drops was also achieved in experimental glaucoma in rabbits. Moreover, the SkQ1 pretreatment of rats significantly decreased the H(2)O(2) or ischemia-induced arrhythmia of the isolated heart. SkQs strongly reduced the damaged area in myocardial infarction or stroke and prevented the death of animals from kidney ischemia. In p53(-/-) mice, 5 nmol/kgxday SkQ1 decreased the ROS level in the spleen and inhibited appearance of lymphomas to the same degree as million-fold higher concentration of conventional antioxidant NAC. Thus, SkQs look promising as potential tools for treatment of senescence and age-related diseases.
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PMID:An attempt to prevent senescence: a mitochondrial approach. 1915 10


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