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PubMed1976

Temperature and endocrine activity during sleep in man. Activation of cortisol and thyroid-stimulating hormone, inhibition of human growth hormone secretion by raised or decreased ambient and body temperatures.

1. Polygraphic night sleep recordings in eight healthy male volunteers with simultaneous measurement of rectal temperature, plasma growth hormone (HGH), cortisol, and TSH concentrations were performed during normal, raised, and lowered ambient and body temperature. 2. There was a statistically significant increase in plasma cortisol and TSH levels during cold nights with a smaller rise during high temperatures. 3. Growth hormone levels, measured as the mean highest plasma concentration in the first two NREM-REM sleep cycles, were slightly lower during hot and cold nights than corresponding baseline values. It is suggested that there may be an inverse relation between ACTH and HGH secretion by the anterior pituitary gland. 4. During the nights of high ambient temperature, decreased total duration of sleep and particularly low values of paradoxical sleep were observed. Night sleep in low ambient temperature with a significant decrease of body temperature is not different from baseline conditions. 5. The results suggest that a pronounced increase in stress hormone secretion may occur without changes in polygraphic EEG criteria.

Adult↗

PubMed1975

Genetic variation of body temperature of Coturnix coturnix in two ambient temperatures.

Coturnix quail were placed in an environmental chamber maintained at 21 degree C. and rectal temperatures taken. The birds were subjected to an abrupt change to 36 degree C. and the temperatures taken hourly for eight hours and at 25, 38 and 72 hours. Females had higher temperatures than males. When birds were moved to 36 degrees C. their temperatures rose rapidly and then dropped to a level higher than when birds were in the 21 degrees C. chamber. The genetic and total variation estimated from the analysis of variance method decreased under this sudden thermal stress condition. Birds kept in 36 degrees C. for three weeks were shifted to 21 degrees C. Their body temperature dropped sharply and then increased to a level lower than that obtained in the 36 degrees C. environment. The genetic variation was essentially zero when shifted to a lower temperature while the total variation increased.

Animals↗

PubMed1978

The temperature sensitive mutant 72c. II. Accumulation at high temperature of ppGpp and pppGpp in the presence of protein synthesis.

A heat sensitive mutant of E. coli has been analyzed. A shift to restrictive temperature leads to an accumulation of ppGpp and pppGpp in both the parental and the mutant strains (both are relA+). The pool of these compounds is shown to decrease with time after the temperature shift in the case of the parental strain, but remains at the same elevated level in the case of the mutant. The temperature shift of the mutant leads to an apparent reduction of stable RNA synthesis; this inhibition can be released by chloroamphenicol or tetracycline. Gross protein synthesis is more or less unaffected at restrictive temperature. In the parental strain little effect is seen on RNA and protein synthesis after the temperature shift. A relA derivative of the mutant does not show the same inhibition of RNA synthesis at high temperature. Sedimentation analysis suggests that mutant 70S ribosome are more stable, when exposed to a lowered Mg2+ concentration, than are 70S ribosomes from the parental strain. In addition, the relative amounts of the two forms of ribosomal protein S6, which can be obtained on DEAE chromatography (Held et al., 1973), are significantly changed in the mutant.

Bacterial Proteins↗

PubMed1977

Analogs of endoperoxide precursors of prostaglandins: failure to affect body temperature when injected into primary and secondary central temperature controls.

It is known that central administration of prostaglandins of the E series has marked effects on body temperature. The purpose in the present experiments was to learn whether stable analogs of the cyclic endoperoxide precursors of PGE2, PGF2alpha and PGD2, injected into the primary temperature control in the preoptic/anterior (PO/AH) hypothalamic region and into a presumed secondary control in the medulla oblongata, can produce rises in body temperature similar to those caused by PGE2. Injection of the analogs U-44069 and U-46619 (1.0 and 2.0 microng) into the PO/AH region of the rat, where both PGE2 and PGE1 caused hyperthermia, had no effect on Tre. Likewise, injections into the medulla oblongata, in the region where PGE2 and PGE1 caused hypothermia, were ineffective in altering body temperature. That neurons important to the control of body temperature are selectively sensitive to PGE2 and not to analogs of prostaglandin precursors suggests that local cyclic endoperoxides can influence body temperature only through bioconversion to prostaglandin.

Animals↗

PubMed1978

Temperature stress and immunity in mice: effects of environmental temperature on the antibody response to human immunoglobulin of mice, differing in age and strain.

Physiological responses at different ambient temperatures and temperature-dependent changes in immune responsiveness are polymorphic. At 4 degrees C, the antigen elimination from the bodies of SJL and C57Bl/6 mice is accelerated. In SJL, but not in C57Bl/mice, the half-life of antigen elimination decreased between the ages of 3 and 11 weeks. Parental mice and their F1 hybrids showed a fall in rectal temperature, which was greatest in young animals. Hypothermia was greater in C57Bl/6 than in SJL and F1 hybrids; in 3 week old C57Bl/6 it resulted in high mortality. The response to aggregated human immunoglobulin (HGG) was evaluated by (a) the number of animals with detectable antibody, (b) the minimal dose of antigen eliciting detectable antibody, and (c) the mean titre of haemagglutinating antibody. SJL mice were more responsive than C57Bl/6 mice. Low antibody formation in the secondary response was dominant, i.e. the amount of antibody produced by (SJL X C57Bl/6)F1 mice was the same as that produced by the parental C57Bl/6 strain. In a primary response, the quantity of antibody varied with the age of the immunized animal; 18 week old mice responded to lower minimal doses of antigen and produced more haemagglutinating antibody than 3 week old animals. After a second injection with HGG, SJL but not C57Bl/6 mice produced more antibody when kept at 14 degrees C rather than at 22 degrees C or 30 degrees C, and produced the lowest antibody titres when kept at 4 degrees C. The relation between ambient temperature and the response of the SJL mice was dominant over that of the C57Bl/6strain. Primary differed from secondary responsiveness in that neither strain produced significantly lower titres when ambient temperature fell to 4 degrees C; only 18 week old SJL mice responded with a marginal decrease in peak antibody production. The described polymorphism may affect both the individual capacity to cope with low temperatures and the evolutionary adaptation of a species to climatic extremes.

Age Factors↗

PubMed1979

Effect of blocking protein synthesis at nonpermissive temperatures on temperature-sensitive deoxyribonucleic acid mutants of Escherichia coli.

When protein synthesis was blocked in temperature-sensitive deoxyribonucleic acid synthesis mutants of Escherichia coli at nonpermissive temperatures, it reduced the amount of apparent subsequent chain elongation to approximately half that observed in the mutants either at nonpermissive temperatures alone or when protein synthesis was blocked at the permissive temperature. Blocking protein synthesis at the nonpermissive temperatures for periods of 40 min caused the loss of ability to reinitiate deoxyribonucleic acid synthesis at the permissive temperature.

Amino Acids↗

PubMed1977

[Fluctuation and distribution of animal room temperature and the temperature in cages (author's transl)].

The temperature of various positions in an occupied animal room (mice, rats) including inside of cages were measured using a 50 channels thermal data recorder (step time 0.5 sec, 5 min intermittent through 24 hr and continuous) in a summer day. Any short periodical fluctuation of room temperature had practically no influence on the inside temperature of plastic cages. Against small diurnal fluctuations, stable vertical gradients (about 1 degree C between tops and bottoms of racks) were observed among one hour averages of room air temperatures. Air temperature in the cage fluctuated in larger scale. (up to 3 degrees C) For controlling animal room temperature, each of short periodical fractuation, diurnal change and spasal distribution should be separately concerrned.

Animals↗

PubMed1976

Effects of temperature and wind on facial temperature, heart rate, and sensation.

Skin temperature measurements of the face have shown that the cheek cools faster than the nose and the nose faster than the forehead. The cooling effect of wind is maximum at wind speeds between 4.5 and 6.7 m/s. Cold winds produce significant bradycardia, which is, however, much more pronounced during the expiratory phase of respiration. A significant correlation was noted between cooling of face and the reflex bradycardia observed. Similarly, a very significant correlation was noted between drop in skin temperature and subjective evaluation of cold discomfort. Consequently, the drop in skin temperature, reflex bradycardia, and subjective evaluation are parameters which are directly affected by cold wind and can be used as adequate indicators of the degree of discomfort. When comparing the present results with the windchill index, it was found that in the zone described as "dangerously cold" the index fits well with the physiological measurements. In the zone described as "bitterly cold," the index by comparison with actual skin temperature measurements and subjective evaluation underestimates the cooling effects of combined temperature and wind by approximately 10 degrees C.

Adult↗

PubMed1976

Body temperature responses at different ambient temperatures following injections of prostaglandin E1 and noradrenaline into the brain.

Since prostaglandins of the E series have been implicated in the production of fever by pyrogens, we have applied them directly to the anterior-hypothalamic preoptic area of uunanesthetized rats at various ambient temperatures. In this paper we have determined accurately the region of the brain of the rat from which temperature responses can be produced by local injection. In addition we present evidence to suggest that the responses to local injections of PGE1 are relatively unaffected by environmental temperatures, whereas those in response to injections of noradrenaline are influenced by ambient temperature. These results are discussed in light of similar findings with respect to the response to pyrogens in that it is relatively unaltered by ambient temperature. This work lends further support to the hypothesis that pyrogens act in the hypothalamus by releasing prostaglandins.

Amygdala↗

PubMed1977

The effect of delta9-tetrahydrocannabinol on body temperature and brain amine concentrations in the rat at differnt ambient temperatures.

1. Rats were injected intravenously with 2 mg/kg (-)-trans-delta9-tetrahydrocannabinol (delta9-THC) at ambient temperatures of 4 degrees, 21 degrees, 31 degrees and 37 degrees C. 2. The general behavior exhibited by rats treated with delta9-THC was similar at all four ambient temperatures. 3. Body temperatures were recorded continuously before and after drug administration. At 4 degrees and 21 degrees C, delta9-THC caused hypothermia whereas no change in body temperature occurred at 31 degrees and 37 degrees C. 4. The concentrations in the whole brain of noradrenaline (NA), dopamine, 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were determined spectrophotofluorimetrically 1 h after drug administration. At 4 degrees C delta9-THC caused an increase of 5-HT, at 21 degrees C an increase of 5-HIAA, at 21 degrees C an increase of 5-HIAA AND A decrease of NA, and at 37 degrees C an increase of 5-HT and 5-HIAA. 5. At all ambient temperatures, delta9-THC increased the brain levels of 5-HT and/or 5-HIAA. A correlation between the delta9-THC-induced hypothermic response and the possible alteration of brain 5-HT metabolism cannot be excluded.

Animals↗

PubMed1979

Reflex control of skin blood flow by skin temperature: role of core temperature.

Two protocols were used to discover whether the reflex response in skin blood flow (SkBF) to rising skin temperature (Tsk) was dependent on the level of internal temperature. Part I. In five subjects, Tsk (controlled with water-perfused suits) was raised to 37 degrees C prior to, between 2 and 5 min, or between 10 and 17 min of exercise. The associated SkBF elevation per degree rise in Tsk averaged 0.20, 1.28, and 1.75 ml/100 ml . min, respectively. When Tsk was raised during the first 5 min of exercise, esophageal temperature (Tes) rose markedly (0.39 degrees C), but transiently fell if Tsk was raised after 10 min of exercise. Part II. In six subjects, different work loads were used to develop different levels of internal temperature. Tsk was elevated to 37 degrees C after 10--15 min at light (50--75 W) or moderate (100--150 W) work loads. At the heavier work load (and higher Tes), the rise in forearm SkBF per degree rise in Tsk averaged 2.33 +/- 0.38 (SE) times that observed at the light work load. These data strongly suggest that the reflex response of SkBF to rising Tsk is dependent on the level of internal temperature.

Adult↗

PubMed1977

Effect of temperature on arginine incorporation by ribosomeless extracts of cells transformed by a temperature-sensitive mutant of Rous sarcoma virus.

The effect of transformation of normal rat kidney cells by a temperature-sensitive mutant of the Prague strain of Rous sarcoma virus (ts LA 24 PR-A) on the post-translational addition of arginine to the NH2-terminus of preformed acceptor molecules has been studied. Cells maintained at the permissive (35 degrees C) temperature show a high arginine-incorporating activity in ribosome free extracts compared to that found in extracts of cells grown at the non-permissive (40 degrees C) temperature. Temperature shift experiments as well as studies with cells transformed by wild type Rous sarcoma virus suggest that the decreased activity in cells grown at 40 degrees C is not due to a high temperature per se. The lower arginine incorporation in the 40 degrees C cell extracts is partially due to a decrease in the activity of arginyl transferase which catalyses the transfer of arginine from arginyl tRNA to the acceptor protein. Polyacrylamide gel electrophoresis of the radioactive product shows that the acceptor molecules present in extracts of cells grown at 40 degrees C are larger and qualitatively different from those found in extracts of cells grown at 35 degrees C.

Acyltransferases↗

PubMed1977

Interaction between mutations of ribosomes and RNA polymerase: a pair of strA and rif mutants individually temperature-insensitive but temperature-sensitive in combination.

A temperature-sensitive lethal mutant of Escherichia coli has been constructed by combining two temperature-insensitive mutations: a rif180 mutation that modifies RNA polymerase (RNA nucleotidyltransferase; nucleosidetriphosphate:RNA nucleotidyltransferase, EC 2.7.7.6) and a strA24 mutation that modifies the ribosomal protein S12. The temperature sensitivity is a property of the combination of these two particular alleles; replacement of either of the alleles relieves the temperature sensitivity. An isogenic strain containing a different strA mutation (i.e., rif180 strA11) is not temperature sensitive. Evidently ribosomes modified by the particular strA24 polymerase altered by the rif180 mutation, which suggests that in vivo there may exist some interaction between structures of ribosomes and the RNA polymerase.

Bacterial Proteins↗

PubMed1977

Temperature-sensitive mutants of Streptococcus pneumoniae. I. Preparation and characterization in vitro of temperature-sensitive mutants of type I S. pneumoniae.

After exposure of type I Streptococcus pneumoniae to nitrosoguanidine, 13 temperature-sensitive (ts) mutants were selected that were restricted in capacity to form colonies on blood agar at 38 C. Whereas colony formation by the type I parent (ts+) was unaffected by a temperature of as high as 39 C, the ts mutants exhibited a spectrum of temperature sensitivity in which colony formation was inhibited significantly at 36 C, 37 C, 38 C, or 39 C. Growth of ts mutants at 38 C in broth was reduced or delayed relative to that of ts organisms under identical conditions. In general, there was a direct correlation between degree of temperature sensitivity and genetic stability. Mutants grown at a permissive temperature resembled the ts+ type I parent in colonial morphology and properties of alpha-hemolysis, bile solubility, optochin sensitivity, and antibiotic sensitivity. Moreover, in vitro studies indicated that the mutants retained capsules of immunochemically reactive type I capsular polysaccharide.

Bile↗

PubMed1977

Control of protein synthesis by a temperature-sensitive mutant of reovirus 3. I. Temperature-sensitive function of ts261-b mutant.

The ability of a temperature-sensitive (ts) mutant of reovirus, ts261-b, to synthesize virus-specific RNAs and proteins during infection at the nonpermissive temperature (37 degrees C) was investigated. The relative amounts of the mutant virus-specific single-stranded (ss) RNA's and double-stranded (ds) RNA's synthesized in cells at 37 degrees C were 20 to 25% as much as those synthesized in the wild-type virus-infected cells. The 10 segments of the mutant ds RNAs and the three size classes of the ss RNAs were synthesized in the usual proportions. The methylation of the mutant viral mRNA's (ss RNAs) was not blocked at 37 degrees C in infected cells. A striking temperature-sensitive restricted function of the ts261-b mutant was expressed in the synthesis of the viral proteins. This study, which uses an in vitro protein-synthesizing system reconstituted with an endogenous polysomal fraction and a postribosomal supernatant from reovirus-infected cells, has demonstrated that the endogenous polysomes obtained from ts261-b mutant-infected cells at 37 degrees C are not active in the synthesis of the viral polypeptides of known molecular weights, and the amounts of the mutant viral polypeptides synthesized in vitro by these polysomes are 5 to 9% of those synthesized by the corresponding fraction from wild-type-infected cells. The impaired protein-synthesizing capacity of the mutant virus-specific polysomes can be restored during maintenance of the infected cells at 30 degrees C after shift-down from 37 degrees C. The in vitro synthesis of viral polypeptides of known size by the active endogenous polysomes derived from cells infected at the permissive temperature is accelerated by the addition of the postribosomal supernatant obtained from cells infected at the permissive temperature. The postribosomal supernatant from mutant-infected cells at 37 degrees C did not have a stimulatory effect, but rather, it inhibited in vitro viral protein synthesis.

Cell-Free System↗

PubMed2025

Construction of cDNA library of Dalbergia odorifera induced by low temperature stress and screening of low temperature tolerant genes.

To systematically analyze the gene function of Dalbergia odorifera, the seedlings of D. odorifera were treated with low-temperature stress for 6 h. Total RNA was extracted from a mixture of seedling roots, stems, and leaves, and a low-temperature-induced D. odorifera yeast cDNA expression library was constructed. The library volume was 1.032 × 108 CFU, and the PCR (Polymerase Chain Reaction) identification of the library bacterial fluid showed that the amplification was around 1000 bp, with a single randomly distributed band, indicating that the library had been recombinantly inserted into the pYES2 vector. The GO (Gene Ontology) analysis showed that the library genes were mainly involved in metabolic and stress signaling pathways. The KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis showed that the genes were primarily related to energy and metabolic pathways. Twenty-one genes were screened or obtained at -20°C for low-temperature tolerance. In addition, the organ expression profiles of the candidate genes were analyzed based on RNA-seq data, and the expression profiles of the candidate genes under low-temperature stress were also examined. The construction of the yeast library provides genetic resources for the analysis of the mechanism of low-temperature tolerance of D. odorifera, which is important for comprehending and utilizing the genetic resources of D. odorifera.

Gene Library↗

PubMed1976

Decreases of local brain temperature due to convection (local brain blood flow) and increases of local brain temperature due to activity.

The influence of local brain blood flow upon variations of local brain temperature in chronical experiments was investigated in cats. It was found that changes of local brain temperature in chronic experiments are esclusively due to changes of local metabolic heat production as long as the temperature of brain inflowing blood remains constant. Decreases of temperature due to convection (increase of local blood flow) are smaller than increases of temperature due to activity.

Animals↗

PubMed1978

Cytogenetic studies of a simian virus 40 temperature-sensitive mutant-transformed Chinese hamster cell clone at the permissive and nonpermissive temperature.

A clone of Chinese hamster embryo cells transformed by tsA58, the temperature-sensitive mutant of simian virus 40, was analyzed for chromosome abnormalities at the permissive temperature (37 degrees C) and nonpermissive temperature (40.5 degrees C). Trypsin-Giemsa-banded metaphases were analyzed 1 week after the temperature shift. The metaphases from cells at both temperatures were pseudodiploid, with numerous chromosome changes primarily affecting chromosomes no. 1 and 2. Other chromosomes (no. 6, 11, and the X) were also frequently involved. A marker chromosome, LM, was present in 35% of the cells at 40.5 degrees C.

Animals↗