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)

During cold exposure, the expression of insulin-like growth factor I (IGF-I) mRNA in rat brown adipose tissue (BAT) increased significantly with the increase in the BAT weight. In addition, the blood plasma from cold-acclimated (CA) rats enhanced the proliferation of brown adipocyte precursor cells in primary culture and the expression of IGF-I mRNA in them compared to those from warm-acclimated rats. The cell proliferation was considerably inhibited by anti-growth hormone (GH) antibody. These results suggest that IGF-I produced by brown adipocytes may play a role in BAT enlargement during cold acclimation. It is probable that some factors (including GH) concerned with the proliferation of brown adipocyte precursor cells are involved in the blood plasma from CA rats.
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PMID:Is insulin-like growth factor I involved in brown adipose tissue enlargement? 801 57

We compared the influence of two cholecystokinin (CCK) antagonists, devazepide and L-365,260 [3R-(+)-(2,3-dihydro-1-methyl-2-oxo-5-phenyl-1H-1,4-benzodiazepine-3y l)-N'-(3-methyl-phenyl)urea], upon two distinct phenomena, behavioural and hormonal effects of caerulein (5 micrograms/kg s.c.), and unselective CCK agonist, in rats. Behavioural effects were assessed in the elevated plus-maze and open field tests. In separate experiments, effects on thyrotropin (TSH), prolactin (PRL) and growth hormone (GH) levels in serum of male rats were studied. Caerulein inhibited the exploratory behaviour in the plus-maze. Time spent in the open part, the number of line crossings and closed arm entries were significantly decreased, whereas the ratio of failed attempts/closed arm entries was increased. The anti-exploratory effect of caerulein was antagonized by the pretreatment with L-365,260 (10 micrograms/kg), a preferential antagonist at CCKB receptors, but was increased by devazepide (1-100 micrograms/kg), a preferential CCKA antagonist. L-365,260 (1-100 micrograms/kg) and devazepide (1-100 micrograms/kg) given alone did not change the behaviour of rats in the plus-maze test. Caerulein (5 micrograms/kg) itself did not modify the locomotor activity of rats in open field. However, the concomitant administration of caerulein with devazepide (1-10 micrograms/kg) reduced the frequency of line crossings and rearings. In the hormonal studies caerulein significantly decreased the cold-induced increase of TSH levels in serum. GH and PRL levels were not markedly affected by caerulein.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Opposite effects mediated by CCKA and CCKB receptors in behavioural and hormonal studies in rats. 806 61

Peptides are rapidly being developed as potential new therapeutic agents and the nasal route is being evaluated as a means of achieving systemic absorption. Current research in man is being directed at a number of polypeptides, including calcitonin, growth hormone releasing hormones (GHRH), insulin, gonadotropin hormone releasing hormones (GnRH) and vasopressin analogues. The underlying protective functions of the nose provide anatomical, temporal and enzymatic barriers to absorption of peptides. The nasal route is relatively unsuccessful when used for high molecular weight polypeptides. Penetration enhancers improve bioavailability but are poorly tolerated. Reproducibility of effect is highly variable, major contributing factors including the site of deposition and type of delivery system as well as changes in the mucous secretion and mucociliary clearance, compounded by the presence of allergy, hay fever and the common cold in treated subjects. The future potential for this route lies in development of effective and well tolerated formulations in highly accurate delivery systems for the chronic administration of peptides, enabling the replacement of impractical and invasive intravenous injections in patients on lifelong substitution treatment for various deficiency states.
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PMID:Review: clinical opportunities provided by the nasal administration of peptides. 806 48

The activities of malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G-6-PDH), two NADPH-generating lipogenic enzymes, were measured in brown adipose tissue (BAT) of rats undergoing various neurohormonal manipulations. Methimazole-induced hypothyroidism doubled the activity of these two enzymes but, surprisingly, triiodothyronine (T3) given to hypothyroid rats caused a time- and dose-dependent stimulation of up to three- to fourfold. Unilateral BAT denervation modestly reduced the activity of these enzymes (approximately 30%) and failed to prevent the stimulation induced by hypothyroidism, whereas growth hormone (GH) successfully blocked this effect of hypothyroidism. Insulin stimulated both enzymes regardless of the thyroid status but failed to abolish the inhibitory effect of GH. In intact rats, cold exposure caused a time-dependent increase in the activity of both ME and G-6-PDH, which reached 5.2- and 3-fold, respectively, after 96 h. This cold-induced stimulation was not observed in hypothyroid rats, but it was restored by physiological doses of thyroxine (800 ng.100 g body wt-1.24 h-1). Replacement with T3 (300 ng.100 g body wt-1.24 h-1), in contrast, did not have this effect. In hypothyroid rats with hemidenervation of BAT, norepinephrine (NE) modestly increased ME and G-6-PDH activities in the denervated side, with little or no effect in the intact side. Receptor-saturating doses of T3 (50 micrograms.100 g body wt-1.day-1 over 48 h) stimulated two- and threefold both enzymes in both sides, reducing or obliterating the effect of denervation. The data suggest a complex neurohormonal regulation of the activity of ME and G-6-PDH in BAT.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Hormonal regulation of malic enzyme and glucose-6-phosphate dehydrogenase in brown adipose tissue. 833 12

Membranes were prepared from tissues of the carp Ctenopharynogodon idellus including liver, kidney, intestine, adipose tissue, ovary, gill, heart, muscle and spleen. The carp liver and intestine membranes bound 125I-labeled bovine growth hormone and the binding could be displaced by cold bovine growth hormone. No changes in the ability to bind 125I-labeled bovine growth hormone occurred after treatment of the carp liver membrane with DNase, RNase, alpha-amylase and beta-glucosidase, suggesting that neither nucleic acids nor carbohydrates played an important part in the hepatic binding of growth hormone. Treatment of carp liver membranes with either chymotrypsin or trypsin produced a decrease in the growth hormone binding activity, indicating that the growth hormone receptor on carp liver membrane is a protein. Treatment of carp liver membranes with p-chloromercuribenzoate brought about a reduction in 125I-bGH binding. The inhibition could be reversed by dithioerythritol, suggesting the involvement of essential sulfhydryl group in bGH binding.
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PMID:Presence of growth hormone receptors in carp liver and intestine. 849 May 77

The central nervous system (CNS) may communicate with the immune system by direct innervation of lymphoid organs and/or by neurotransmitters and changes in neuroendocrine functioning and hormone release. The consequences of selective transient changes in circulating hormones on immune functioning in humans have not yet been studied. To address this problem, the authors evaluated the lymphoproliferative responses to optimal and suboptimal concentrations of phytohemagglutinin (PHA) and pokeweek mitogen (PWM) under selective enhancement of circulating growth hormone, prolactin, or norepinephrine. The authors failed to demonstrate any effect of elevated growth hormone levels after clonidine challenge on the lymphoproliferative response to mitogens. Similarly, the results did not show any effect of elevated prolactin concentrations induced by domperidone administration on the immune test. Exposure of volunteers to cold resulted in elevation of plasma norepinephrine levels without changes in growth hormone, epinephrine, or cortisol secretion. Cold exposure induced elevation of plasma norepinephrine and reduction of the lymphoproliferative response to the suboptimal dosage of PHA. The reduction was significant 180 and 240 min after exposure. These results are indicative of a relationship between norepinephrine and immunity.
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PMID:Central stimulation of hormone release and the proliferative response of lymphocytes in humans. 853 22

Nutritional factors, such as an excess or a deficiency of glucose, play an important role in neuroendocrine regulations. Hormonal and metabolic responses to hypoglycemia were examined in healthy non-obese volunteers under conditions of low ambient temperature. Hypoglycemia was induced by intravenous injection of insulin in two randomized trials performed at room temperature and at 4 degrees C. At room temperature, the typical neuroendocrine response to hypoglycemia was established. The increases of ACTH, beta-endorphin, growth hormone and cortisol in response to insulin hypoglycemia failed to be modified by low ambient temperature. Acute cold exposure significantly reduced epinephrine and totally inhibited prolactin response to insulin-induced hypoglycemia. In spite of significant changes in epinephrine response to hypoglycemia at low ambient temperature, no striking differences in plasma glucose levels compared to those measured at room temperature were observed. However, under conditions of low temperature the reestablishment of normoglycemia was delayed. No changes in free fatty acids were found under our experimental conditions. The presented data show that low ambient temperature exerts selective effects on some neuroendocrine and metabolic parameters.
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PMID:Low ambient temperature and neuroendocrine response to hypoglycemia in men. 865 53

At the time of birth, many rapid metabolic changes occur including the initiation of nonshivering thermogenesis and a rapid fall in growth hormone concentrations. To evaluate the interaction between these events 5 fetal sheep were studied at 135-144 days' gestation. The fetuses were first cooled 2.22 +/- 0.19 degrees C by circulating cold water through a coil placed around the fetal thorax and then ventilated with oxygen through an exteriorized tracheostomy tube to raise fetal arterial PO2 above 67.5 +/- 14.1 Torr. An hour later the beta adrenergic agonist isoproterenol was infused intravenously for 90 min. The fetuses were then separated from the placenta by occluding the umbilical cord. After 60 min the cooling and then the isoproterenol infusion were stopped and the responses monitored. Basal plasma free fatty acid (FFA 35 +/- 5 microEq L-1) and growth hormone (GH 141 +/- 12 ng mL-1) concentrations were not significantly altered by cooling alone, but oxygenation modestly increased plasma FFA to 237 +/- 55 microEq L-1 (P < 0.01) while GH concentrations fell to 58 +/- 27 ng mL-1 (P < 0.05). Isoproterenol administration did not significantly affect either FFA or GH concentrations. Occlusion of the umbilical cord caused a rapid nearly threefold increase in plasma FFA concentrations to 903 +/- 71 microEq L-1 (P < 0.01) and a fall in the same proportions in GH concentrations to 16 +/- 2 ng mL-1 (P < 0.005). Maximal fetal oxygen consumption was 24.2 +/- 4.4 mL kg-1 min-1. Cessation of cooling induced a significant fall in plasma FFA to 480 +/- 58 microEq L-1 (P < 0.01) and rise in GH concentrations to 46 +/- 5 ng mL-1 (P < 0.01). Following the withdrawal of isoproterenol, the fall in plasma FFA and rise in GH concentrations continued while the fetal oxygen uptake fell to 6.4 +/- 1.7 mliter kg-1 mL-1 (P < 0.01). During the study the variation in plasma GH was inversely correlated with changes in FFA concentrations (R = 0.77, P < 0.001). This study confirms that the major factors initiating nonshivering thermogenesis at birth are: sympathetic stimulation from cutaneous cooling, which was not significantly enhanced by isoproterenol; adequate oxygenation; and removal of placental inhibitor(s). The findings are in agreement with a causal relationship between the initiation of nonshivering thermogenesis and consequent rise in FFA concentrations and the rapid fall in circulating GH concentrations after birth in the lamb, independent of beta adrenergic stimulation.
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PMID:Relationship between the fall in growth hormone secretion at birth and the onset of nonshivering thermogenesis is independent of beta adrenergic stimulation. 884 94

Rats were made tolerant to morphine by a 5-day regimen with increasing doses. The time course of changes in serum anterior pituitary hormone levels, brain endo- and exopeptidase activity, levels of brain biogenic amines and body weight were studied during abrupt morphine withdrawal. Cold stimulated secretion of thyrotropin and the secretion of growth hormone were both decreased whereas that of prolactin was increased. In the hypothalamus both prolyl endopeptidase and dipeptidyl peptidase IV activities were concomitantly increased. The hypothalamic 5 hydroxyindole acetic acid levels were also increased. Changes in hormone secretion, peptidase activity and monoamine turnover had returned to baseline levels by 92 hr. Our results indicate that morphine withdrawal and the associated stress produce alterations in anterior pituitary thyrotropin and growth hormone secretion. Concomitant increases in hypothalamic prolyl endopeptidase and dipeptidyl peptidase activities may contribute to these changes.
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PMID:Morphine withdrawal alters anterior pituitary hormone secretion, brain endopeptidase activity and brain monoamine metabolism in the rat. 888 44

The association of therapeutic agents with biomaterials has been achieved through various techniques, such as coating of the ceramic block surface or drug incorporation into ceramics. The dynamic compaction method recently was developed to consolidate drug-loaded calcium phosphate powder without a sintering step. In the present work, human recombinant growth hormone was loaded on biphasic calcium phosphate powder and consolidated by a specific process of cold sintering (dynamic compaction). Analyses of the biocompatibility of compacted pellets (mouse L929 fibroblastic cell culture) and the bioactivity of the drugs released by them (growth hormone bioassay) were performed. This report demonstrates the biocompatibility of the compacts prepared by dynamic compaction. L929 cell proliferation was maintained and the capacity to secrete fibronectin was conserved in the presence of compacted materials. Comparison of released growth hormone integrity, revealed by radioimmunoassay and eluted stain bioassay, has shown that the biological activity of growth hormone was totally preserved after dynamic compaction. However, 35% of loaded growth hormone was not released in our experimental conditions, probably because of the inaccessibility of growth hormone within the granulated compacts. Dynamic compaction shows good potential for the production of biomaterials capable of releasing therapeutic agents in situ.
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PMID:Association of human growth hormone and calcium phosphate by dynamic compaction: in vitro biocompatibility and bioactivity. 926 88


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