SEARCH · PubMed Health

Results for “Dehydration”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

PubMed1999

Neuroendocrine effects of dehydration in mice lacking the angiotensin AT1a receptor.

Angiotensin (Ang) type 1a (AT1a) receptors are critical in the control of blood pressure and water balance. Experiments were performed to determine the influence of dehydration on brain Ang receptors and plasma vasopressin (VP) in mice lacking this receptor. Control or AT1a knockout (AT1aKO) male mice were give water ad libitum or deprived of water for 48 hours. Animals were anesthetized with halothane, blood samples were collected by heart puncture, and brains were processed for Ang-receptor autoradiography with 125I-sarthran (0.4 nmol/L). Dehydration produced an increase in AT1 receptors in the paraventricular nucleus (PVN) and anterior pituitary (AP) in control mice (PVN: 70+/-16 versus 146+/-10 fmol/mg protein; AP: 41+/-7 versus 86+/-15 fmol/mg protein). No changes were noted in the median preoptic nucleus. The majority of the brain receptors were of the AT1 subtype. There was little or no specific Ang binding in AT1aKO mice and no effect of dehydration. Plasma VP levels were elevated in the halothane-anesthetized animals (>200 pg/mL) with no significant effect of dehydration. A separate experiment was performed with decapitated mice anesthetized with pentobarbital. Dehydration increased plasma VP in control mice, from 3.3+/-0.6 to 13.3+/-4.7 pg/mL, whereas no change was noted in the AT1aKO mice, 5.1+/-0.3 versus 6.1+/-0.7 pg/mL (water versus dehydration). These results demonstrate a differential response to dehydration in mice lacking AT1a receptors. There was no evidence for AT1 receptors of any subtype in the brain regions examined and no effect of dehydration on VP secretion or brain Ang receptors.

Angiotensin II↗

PubMed1990

Effects of dehydration on gastric emptying and gastrointestinal distress while running.

Gastrointestinal distress is commonly reported by athletes after ingestion of a beverage. We speculate that ingestion may be occurring after dehydration has taken place. The high prevalence of GI disorders in marathon runners who have lost greater than or equal to 4% body weight supports this theory. To test this theory, the effects of dehydration, and dehydration in combination with endurance running, on gastric emptying (GE) and frequency of gastrointestinal (GI) complaints were tested in this experiment. A complete cross-over study was designed. Sixteen subjects ingested 8 ml.kg BW-1 of a 7% carbohydrate (296 mOsm.kg-1), solution after a euhydration or dehydration regime. Dehydration (4% BW loss) was produced by 60% maximal speed running at 30 degrees C or by intermittent sauna exposure at 100 degrees C. Euhydration experiments were conducted with a 2 h rest period with water administered at 20 and 40 min. Gastric drink volumes were measured every 10 min for 40 min. Emptying curves were compared using semi-log transformation of the percentage emptying data and simple linear regression. The slope of each line was used as a measure of average GE rate. Dehydration-exercise resulted in slower GE than in all other treatments (P less than 0.05). ANOVA revealed significant effects of dehydration (P less than 0.05) and exercise (P less than 0.05), these two effects being additive in delaying GE. GI complaints were reported by 37.5% of the subjects during dehydration-exercise experiments. No GI disturbance was reported in other tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1996

Atrial natriuretic peptide (ANP)-granules of auricular cardiocytes in dehydrated and rehydrated mice.

Atrial natriuretic peptide (ANP)-granules of auricular cardiocytes were examined by immunohistochemistry, transmission electron microscopy and ultrastructural morphometry in dehydrated and rehydrated mice. In addition, plasma ANP and tissue ANP mRNA levels were determined by radioimmunoassay and polymerase chain reaction, respectively. ANP immunoreactivity and the number of granules in the cardiocytes were increased with time in the dehydration group, while plasma ANP and tissue ANP mRNA levels were decreased on day 3 of dehydration. On day 3 of dehydration, the number of ANP-granules (153.2 +/- 8.3, mean +/- standard error) was significantly (p < 0.05) greater than in the control (125.8 +/- 6.7). IN the rehydration group, the immunoreactivity and number of ANP-granules were less than those in the group on day 3 of dehydration. The plasma ANP level during rehydration for 12 hr was slightly elevated in comparison with the group on day 3 of dehydration. The tissue ANP mRNA level after 12 hr of rehydration was lower than that on day 3 of dehydration. The diameter of ANP-granules was significantly (p < 0.01) smaller in all experimental groups than in the control. These findings suggest that synthesis and secretion of ANP are inhibited and ANP-granules are stored in auricular cardiocytes during dehydration.

Animals↗

PubMed2004

Unrecognized chronic dehydration in older adults: examining prevalence rate and risk factors.

Dehydration has serious consequences for older adults, including increased risk of illness or death. This retrospective review of medical records describes the prevalence, assessment, and risk factors for chronic dehydration in 185 older adults who visited an emergency department in June 2000. Results showed chronic dehydration was present in 89 (48%) patients. Physicians documented assessment for signs of dehydration in 23 (26%) of the dehydrated older adults, but no independent assessments for dehydration were recorded by nurses. These findings indicate many older adults may suffer from unrecognized dehydration, and nurses should be alert to the possibility that dehydration may be present in community-dwelling older adults as well as those who live in residential facilities.

Aged↗

PubMed1993

Hypertonic saline resuscitation detrimentally affects renal function and survival in dehydrated rats.

The purpose of our studies was to determine whether hypertonic (7.5%) saline (HTS) resuscitation is effective in the setting of dehydration. We compared the effects of HTS (5 cc/kg) to those of Ringer's lactate (RL; 45 cc/kg) on renal function, following resuscitation from hypovolemia in hydrated (free access to food/water) vs. dehydrated (food/water restricted) rats (300-350 g). Renal failure was produced by hemorrhage (15 cc/kg) plus renal artery occlusion (25 min) followed by fluid resuscitation. Dehydration was confirmed by hemoconcentration and weight loss (8-10%). Renal function was assessed at 24 hr using 14C-inulin clearance (Cin) measurements. In hydrated animals, the Cin of RL-treated rats (625 +/- 54 microliters/min/100 g; n = 12) was no different from the Cin in HTS-treated rats (517 +/- 48 microliters/min/100 g; n = 13). Among dehydrated rats, Cin in HTS-treated rats (n = 6) was significantly lower (P < or = 0.05) than in RL-treated rats (n = 5) (117 +/- 33 microliters/min/100 g vs. 542 +/- 84 microliters/min/100 g, respectively). Cin in dehydrated RL-treated rats was not significantly different from that in hydrated RL-treated rats. Furthermore, in dehydrated animals, nine of nine resuscitated with RL survived, compared to six of 13 resuscitated with HTS. All hydrated animals survived. In summary, renal failure was ameliorated by RL and worsened by HTS resuscitation in dehydrated rats. Furthermore, mortality was increased in dehydrated animals resuscitated with HTS compared to RL.

Animals↗

PubMed1994

Cloning of cDNAs for genes that are early-responsive to dehydration stress (ERDs) in Arabidopsis thaliana L.: identification of three ERDs as HSP cognate genes.

In Arabidopsis thaliana L., accumulation of abscisic acid (ABA) began to increase 2 h after plants had been subjected to dehydration stress and reached maximum levels after 10 h. Differential hybridization was used to isolate 26 Arabidopsis cDNAs with gene expression induced by a 1 h dehydration treatment. The cDNA clones were classified into 16 groups based on Southern blot hybridization, and named ERD (early-responsive to dehydration) clones. Partial sequencing of the cDNA clones revealed that three ERDs were identical to those of HSP cognates (Athsp70-1, Athsp81-2, and ubiquitin extension protein). Dehydration stress strongly induced the expression of genes for the three ERDs, while application of ABA, which is known to act as a signal transmitter in dehydration-stressed plants, did not significantly affect the ERD gene expression. This result suggests that these HSP cognates are preferentially responsive to dehydration stress in A. thaliana, and that signaling pathways for the expression of these genes under conditions of dehydration stress are not mainly mediated by ABA. We also discuss the possible functions of these three ERD gene products against dehydration stress.

Abscisic Acid↗

PubMed1986

Heterogeneity of the podocyte membrane in rat kidney as revealed by ethanol dehydration of unosmicated specimens.

The ultrastructure of the podocyte membrane was studied by means of transmission electron microscopy of unosmicated tissue samples after acetone or ethanol dehydration and subsequent embedding in a polyester resin. The podocyte membrane in glutaraldehyde (GA)-fixed, acetone-dehydrated samples consisted of a relatively thick, clear layer (about 6 nm) abutted by the dark staining cytoplasm and a dark surface layer. In GA-fixed, ethanol-dehydrated samples a striking intramembranous pattern was observed in the podocyte cell membrane. The luminal podocyte membrane was regularly perforated by gaps about 25 nm wide. In grazing sections these gaps appeared round and were separated by a honeycomb pattern of intact membrane. The abluminal membrane, in contrast, generally maintained its continuity. The clear layer of the podocyte membrane was thinner in ethanol-dehydrated samples than in acetone-dehydrated ones. In tissue samples fixed with GA supplemented by ruthenium red, ethanol dehydration was not associated with cell-membrane perforations. Based on these observations as well as on biochemical data from the literature we suggest that in GA-fixed, unosmicated, acetone-dehydrated samples the structural integrity of the podocyte membrane is well preserved, while ethanol dehydration extracts some specific material from regularly distributed domains in the podocyte cell membrane.

Animals↗

PubMed2006

Structure in dehydrated trehalose dihydrate--evaluation of the concept of partial crystallinity.

PURPOSE: (i) To use trehalose as a model compound to evaluate the concept of crystallinity in pharmaceuticals. (ii) To understand the structural nature of dehydrated trehalose dihydrate. MATERIALS AND METHODS: Trehalose dihydrate was dehydrated isothermally at several temperatures below 100 degrees C and the anhydrous product was characterized by XRD, DSC and water vapor sorption. RESULTS: XRD and DSC suggested that the dehydration product was a partially crystalline alpha-polymorphic form of anhydrous trehalose (T(alpha)). An increase in the temperature of dehydration resulted in a decrease in lattice order. In agreement with earlier findings, the ordered regions in the dehydrated lattice (T(alpha)) converted to the dihydrate at much lower RH values than amorphous trehalose. However, the lattice order in the dehydrated product dictated the RH at which this conversion was initiated--the higher the lattice order the lower this RH. The structural nature of these samples can be explained based on the one-state model of crystallinity. In dehydrated trehalose, there is a continuum in lattice order ranging from highly crystalline (T(alpha)) to a completely disordered (i.e., amorphous) state. CONCLUSION: The extent of lattice order in anhydrous trehalose T(alpha) was dictated by the kinetics of water removal from trehalose dihydrate. The partially crystalline nature of anhydrous trehalose produced by dehydration could be described on a continuous scale of lattice order based on the one-state model of crystallinity.

Adsorption↗

PubMed1985

The coincidental effects of dehydration and rehydration on plasma and cerebrospinal fluid angiotensin II levels in unrestrained steers.

Changes in plasma (pAII) and cerebrospinal fluid (csf AII) immunoreactive angiotensin II have been measured in 6 unrestrained steers during dehydration and rehydration. Prior to dehydration, plasma osmolarity (pOsm) was 301.3 +/- 0.62 mOsm/l (mean +/- S.E.M.) and on dehydration progressive elevation of pOsm developed so that after 4 days it was 338.5 +/- 3.00 mOsm/l (P less than 0.001). Packed cell volume was elevated during dehydration from 39.9 +/- 0.64% to 44.7 +/- 1.24% (P less than 0.001). Radioimmunoassay (RIA) of pAII indicated a similar pattern of progressive elevation during dehydration when after 4 days pAII had risen from 54.7 +/- 11.6 fM/ml to 177.6 +/- 18.4 fM/ml (P less than 0.001). RIA of csf AII, however, indicated no complementary pattern of change during dehydration, the only significant alteration from basal levels of 166.0 +/- 13.2 fM/ml occurred after 2 days when csf AII was reduced to 83.1 +/- 14.5 fM/ml (P less than 0.01). Antiserum specificity tests indicated that some of the csf AII could have been due to metabolites of AII, and high performance liquid chromatographic separation of angiotensin peptides in csf suggested that the major contributants were AII and AIII. These analogues which may have central neural effects were not consistently elevated during dehydration of cattle. It is concluded therefore, that the role of angiotensin in central neural mechanisms of fluid balance in dehydrated animals depends primarily on the systemic renin-angiotensin system and not an endogenous brain renin-angiotensin system.

Angiotensin II↗

PubMed2002

Production of conjugated linoleic acids through KOH-catalyzed dehydration of ricinoleic acid.

Production of conjugated linoleic acids (CLA) using castor oil as starting material involves conversion of ricinoleic acid to methyl 12-mesyloxy-octadec-9-enoate (MMOE) followed by dehydration. This process usually uses 1,8-diazabicyclo-(5.4.0)-undec-7-ene (DBU) as an expensive dehydrating reagent. The present study reports that potassium hydroxide (KOH) can serve as a dehydrating reagent in replacement of DBU. The results showed that conversion of MMOE to CLA catalyzed by KOH was an efficient reaction, with a 77% conversion efficiency at 80 degrees C. The CLA isomeric profile produced in KOH-catalyzed dehydration reaction was similar to that catalyzed by DBU. The CLA mixture produced in KOH-catalyzed dehydration of MMOE at 80 degrees C contained 72% 9c,11t-18:2 and 26% 9c,11c-18:2 while in that catalyzed by DBU, 9c,11t-18:2 and 9c,11c-18:2 accounted for 78 and 16%, respectively. It was found that the temperature of dehydration was an important factor in the determination of CLA isomer composition and yield of conversion. Elevating the temperature from 78 to 180 degrees C decreased not only the conversion efficiency but also production of total c,t-18:2 and c,c-18:2 isomers regardless of dehydration catalyzed by either DBU or KOH. It is concluded that KOH may replace DBU as a dehydrating reagent in conversion of MMOE to CLA when the reaction conditions are optimized.

Castor Oil↗

PubMed1993

The effects of dehydration and rehydration on some mechanical properties of human dentine.

This study was designed to investigate the effect of dehydration and rehydration on the brittleness and toughness of human dentine. Tensile and three-point bend tests were carried out on hydrated, dehydrated and rehydrated dentine bars, sectioned from sound extracted, human third molar teeth. The stress, strain and fracture energy (toughness) were calculated and the results were analysed using ANOVA and Duncan's multiple range test at p = 0.01. Stress at fracture did not differ significantly between hydrated, dehydrated or rehydrated dentine in bending or tensile tests. Strain at fracture and fracture energy were significantly greater for hydrated and rehydrated than for dehydrated dentine. In bending, the elastic energy (resilience) of dehydrated dentine was significantly greater than that of hydrated or rehydrated dentine, but dehydrated dentine showed no plastic energy (deformation) in contrast with the high values for hydrated and rehydrated dentine. Dehydration of human dentine resulted in decreased strain at fracture and demonstrated a brittle behaviour. The absence of plastic energy of deformation and the significantly reduced energy required to induce fracture were indicative of decreased toughness by dehydration. These changes were abolished after rehydration.

Body Water↗

PubMed1989

Neural systems for early independent ingestion: regional metabolic changes during ingestive responding and dehydration.

The ingestive behavior of young rodents, studied independently of the mother and suckling, provides a system for the developmental analysis of the neurobiology of feeding and drinking. In these experiments regional neural metabolic activity, as assessed by semiquantitative deoxyglucose (DG) autoradiography, was related to dehydration and ingestive behavior in 6-day-old rat pups. During simple ingestive responding, changes in relative DG uptake, representative of changes in neural metabolic activity, occurred primarily in hindbrain sensory and motor nuclei. Producing cellular dehydration resulted in activity changes primarily in the basal forebrain. When pups were dehydrated and allowed to ingest during the DG-uptake period, activity changes were seen in both the hindbrain and forebrain areas that responded to ingestion or dehydration alone as well as in regions that were not affected by either manipulation alone. These latter changes, which result from an interaction of behavioral and physiological stimuli, call attention to areas that may subserve motivational aspects of behavior. Extracellular dehydration was found to produce fewer and different forebrain responses in neural metabolic activity. During ingestion, the only effects of extracellular dehydration that overlapped with those of cellular dehydration appeared in circumventricular hypothalamic regions and brain stem motor nuclei. Thus, there appeared to be only a limited final common pathway for these two types of dehydration-induced drinking. Taken together, these findings in infant rats depict distributed neural systems subserving ingestion and responding to state change. They provide a starting point early in ontogeny for the developmental analysis of neural substrates of ingestive systems.

Animals↗

PubMed2002

Drying rate and dehydrin synthesis associated with abscisic acid-induced dehydration tolerance in Spathoglottis plicata orchidaceae protocorms.

Dehydration tolerance of in vitro orchid protocorms was investigated under controlled drying conditions and after abscisic acid (ABA) pretreatment. Protocorms were obtained by germinating seeds on Murashige and Skoog (MS) medium containing 10% (v/v) coconut water, 2% (w/v) sucrose and 0.8% (w/v) agar, and were dehydrated in relative humidities (RH) ranging from 7% to 93% at 25 degrees C. The critical water content of dehydration tolerance was determined, using the electrolyte leakage method. Drying rate affected the critical water content. Slow drying under high RH conditions achieved the greatest tolerance to dehydration. ABA pretreatment decreased the drying rate of protocorms, and increased dehydration tolerance. Improved tolerance to dehydration after ABA treatment was correlated with the effect of ABA on drying rate of protocorms. When critical water content of protocorms dried under different RH was plotted as a function of actual drying rate, no significant difference in tolerance to dehydration was observed between ABA-treated and control protocorms. ABA pretreatment and dehydration of orchid protocorms induced the synthesis of dehydrin, especially under the slow drying conditions. ABA pretreatment also promoted dry matter accumulation such as carbohydrates and soluble proteins and increased the concentration of K(+) and Na(+) ions in protocorms. The ABA-induced decrease in drying rate was correlated with lower osmotic potential, the enhanced maturity of protocorms and the accumulation of dehydrin in protocorms during pretreatment.

Abscisic Acid↗

PubMed1965

INFECTIVITY OF POLIOVIRUS AND ITS NUCLEIC ACID FOR DEHYDRATED HELA CELL MONOLAYERS.

Smull, Christine E. (The Geisinger Medical Center, Danville, Pa.), and E. H. Ludwig. Infectivity of poliovirus and its nucleic acid for dehydrated HeLa cell monolayers. J. Bacteriol. 89:52-57. 1965.-A study was made of the infectivity of poliovirus ribonucleic acid (RNA), applied in various diluents, and of poliovirus, on cell monolayers which were washed free from their nutrient medium and allowed to dehydrate for periods up to 3 days prior to inoculation. The plaque formation of poliovirus RNA, applied in isotonic diluent, was greatly increased when assayed on cell monolayers dehydrated for certain periods of time. Conditions are described for bringing about optimal plaque formation by this means, and evidence is presented which strongly indicates that dehydration of the cell is an important factor in the increase in plaque formation of the poliovirus RNA. The plaque formation of poliovirus RNA in certain hypertonic diluents and in a basic protein-containing diluent was also improved with the use of dehydrated cell monolayers, whereas the plaque formation of poliovirus varied very little when assayed on cell monolayers dehydrated for periods up to 2 days. Under certain conditions, the size of the plaques increased as the dehydration time of the cell monolayers was increased. This was true with plaques initiated either by poliovirus or the nucleic acid. Further investigation in these cases revealed that virus production at given times was considerably greater in the dehydrated than in the undried cell monolayers.

Ethanol↗

PubMed1981

Exercise-induced hemolysis in xerocytosis. Erythrocyte dehydration and shear sensitivity.

A patient with xerocytosis was found to have swimming-induced intravascular hemolysis and shortening of erythrocyte life-span. In a microviscometer, xerocytes were more susceptible than normal erythrocytes to hemolysis by shear stress. Fractionation of normal and abnormal cells on discontinuous Stractan density gradients revealed that increasingly dehydrated cells were increasingly more shear sensitive. This sensitivity was partially corrected by rehydrating xerocytic erythrocytes by means of the cation-ionophore nystatin in a high potassium buffer. Conversely, normal erythrocytes were rendered shear sensitive by dehydrating them with nystatin in a low potassium buffer. This effect of dehydration was entirely reversible if normal cells were dehydrated for less than 4 h but was only partially reversed after more prolonged dehydration. It is likely that dehydration of erythrocytes results in shear sensitivity primarily because of concentration of cell contents and reduced cellular deformability. With prolonged dehydration, secondary membrane changes may potentiate the primary effect. This increased shear sensitivity of dehydrated cells may explain atraumatic exercise-induced hemolysis in xerocytosis as cardiac output is shifted to vessels of exercising muscles with small diameters and high shear rates.

Adult↗

PubMed2005

Effect of tablet geometrical structure on the dehydration of creatine monohydrate tablets, and their pharmaceutical properties.

The effects of compression and pulverization on the dehydration kinetics and hardness of creatine monohydrate tablets were studied using a variety of kinetic equations and physical models. The dehydration behavior of unpulverized and pulverized tablets was investigated by using differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). The hardness of both unpulverized and pulverized monohydrate tablets was significantly decreased after dehydration. The relationship between the degree of dehydration and the tablet hardness of both unpulverized and pulverized monohydrate tablets formed a straight line. The results suggest that the reduction in tablet hardness is dependent on the dehydration of crystal water, and the values of the slopes indicate that the bonding energy of the unpulverized sample was stronger than that of the pulverized sample. The dehydration kinetics of the unpulverized and pulverized monohydrate tablets were evaluated by analyzing the fit of the isothermal DSC data using a variety of solid-state kinetic models. The dehydration of the unpulverized tablets at various levels of compression pressure followed the 3-dimensional growth of nuclei mechanism. In contrast, although the dehydration kinetics of pulverized monohydrate tablets compressed at 500 and 750 kg/cm2 followed the 3-dimensional diffusion mechanism, those compressed at 1000 kg/cm2 followed the 3-dimensional growth of nuclei mechanism. The PXRD analysis indicated that the diffraction intensity of the pulverized monohydrate powder was significantly lower than that of the unpulverized powder. The diffraction peaks of the (h00) planes and the micropore structure of the unpulverized monohydrate tablets were affected by pulverization and compression force, respectively.

Compressive Strength↗

PubMed1995

Regulatory responses of the coxal organs and the anal excretory system to dehydration and feeding in the spider Porrhothele antipodiana (Mygalomorpha: Dipluridae)

The roles of coxal and anal excretion in the regulation of haemolymph osmolality, [Na+] and [K+] were studied in the mygalomorph spider Porrhothele antipodiana (mass 0.71.0 g) under differing conditions of feeding and hydration state. Dehydration of starved spiders by removal of drinking water caused progressive mass loss at a rate of about 2.5 % of initial body mass per day and was associated with increases in the whole-body [Na+] and [K+] and in the osmolality, [Na+] and [K+] of the haemolymph. On provision of prey, feeding partially restored this mass loss but further elevated body and haemolymph ion concentrations. Dehydration reduced fluid excretion by the anal excretory system and the four coxal organs in both starved and feeding spiders. Starved hydrated spiders initially produced anal urine at 5 µl day-1 and this was progressively reduced to zero after 4 days of water deprivation. Spiders dehydrated to less than 12 % mass loss would nevertheless feed and this initiated a small post-prandial anal diuresis (<5 µl day-1 compared with >30 µl day-1 in fed hydrated spiders). Coxal fluid was produced by dehydrated spiders only during feeding and was delivered into the prey, the rate of production by single organs decreasing from about 19 µl h-1 g-1 body mass in hydrated spiders to about 4 µl h-1 g-1 body mass in spiders dehydrated to 11 % mass loss. There was an increase in urine [K+] and in the rate of anal K+ excretion associated with ad libitum feeding in dehydrated spiders. However, urine [Na+] and the rate of anal excretion of Na+ were not increased by feeding. This was associated with an increase in [K+] of the stercoral fluid above that observed in either fed or starved hydrated spiders, but no significant change in [Na+]. Conversely, [Na+] of the coxal fluid produced during feeding was increased by dehydration whereas [K+] was not. These observations are consistent with the previously postulated roles of the coxal organs (Na+) and anal system (K+) in the excretion of ions ingested with the prey. Full elimination of the prey ions was accomplished only after drinking water was resupplied, which initiated further anal and coxal diureses. Smaller anal and coxal diureses also occurred on rehydration of unfed spiders. The production of coxal fluid in the absence of prey is further evidence that the coxal organs have a true excretory function besides, presumably, assisting ingestion. During dehydration and feeding, P. antipodiana, unlike many insects, is unable simultaneously to conserve water and to eliminate ions by production of a highly concentrated excretory fluid. Both coxal fluid and anal urine were approximately iso-osmotic to the haemolymph and the urine was markedly hypo-ionic.

Journal Article↗

PubMed1998

Effect of blanching, dehydration method and temperature on the ascorbic acid, colour, sliminess and other constituents of okra fruit.

Freshly harvested okra fruits were blanched in boiling water (with or without 0.2% sodium metablsulphite salt) and the effect of this treatment, dehydration methods and temperature on certain characteristics of okra investigated. Blanching resulted in the slight decrease in carbohydrate, fat, ash, colour components, ascorbic acid and viscosity. Besides this initial loss, blanching in sulphite solution led to the retention of more of the colour components and ascorbic acid during dehydration. All dehydrated okra samples had higher contents of carbohydrate, fat and ash but lesser contents of protein and ascorbic acid than fresh okra. Fresh okra fruits, on the other hand, had higher content of the colour pigments and were more viscous than all dehydrated products. Samples blanched prior to dehydration retained more of the colour components but were less viscous than unblanched samples. Vacuum dehydrated samples retained more ascorbic acid, colour pigment and mucilage at each of the dehydration temperatures than those from a hot air oven. High dehydration temperatures had negative effect on the colour, ascorbic acid and viscosity of okra.

Ascorbic Acid↗