Death in the sauna-vitality markers for heat exposure.

In sauna-associated deaths, the vitality of heat exposure is of great importance. Two case reports address this. First, we present the case of a 77-year-old man who was found dead in the sauna of his family home. When found, the sauna door was closed, and the sauna indicated a temperature of 78 °C. The body had already begun to decay and was partially mummified when it was found. In the other case, a 73-year-old woman was found dead in the sauna by her husband. In this case, the sauna door was also closed. The sauna was still in operation at a temperature of approximately 70 °C. Epidermal detachments were found. In both autopsies and their follow-up examinations, there were no indications of a cause of death competing with heat shock. The expression of heat shock proteins in kidneys and lungs and the expression of aquaporin 3 in skin were investigated to detect pre-mortal temperature influences.

[Investigating effect of Faeces Bombycis on intestinal microflora in rats with syndrome of damp retention in middle-jiao by high-throughput sequencing].

The aim of this paper was to investigate the effect of Faeces Bombycis(FB) on the intestinal microflora in rats with syndrome of damp retention in middle-jiao, and to explore its mechanism in regulating intestinal microflora from the perspective of microorganisms contained in FB. The contents of antidiuretic hormone(ADH) and C-reactive protein(CRP) in serum and aquaporin 3(AQP3) in jejunum were determined by enzyme-linked immunosorbent assay(ELISA). Illumina Miseq platform was used for high-throughput sequencing of the rat feces and FB. The ELISA results showed that as compared with the normal control group, the contents of ADH and CRP in the model group were significantly increased(P<0.05), and the content of AQP3 was significantly decreased(P<0.05). After drug administration, the ADH, CRP and AQP3 contents were recovered. Sequencing of rat feces showed that the ACE, Chao1 and Shannon indexes of the intestinal microflora were the lowest in the model group. As compared with the normal control group, the levels from phylum to genus were all significantly changed in model group, and Proteobacteria, Acinetobacter, Anaerobacter, Pseudomonas, and Parabacteroides levels were significantly increased(P<0.05), while Marvinbryantia level was significantly decreased(P<0.05). As compared with the model group, Proteobacteria was significantly decreased in the FB low and high dose groups(P<0.05), and Acinetobacter, Anaerobacter, Pseudomonas, Parabacteroides levels were significantly decreased in the low, medium and high dose groups(P<0.05), while Lachnoanaerobaculum, Intestinimonas and Marvinbryantia were increased significantly in the high dose group(P<0.05). Sequencing analysis of FB showed that the relative abundance of Leclercia, Pantoea, Brachybacterium, Shimwellia, Hartmannibacter, Klebsiella, Serratia, Aurantimonas, Paenibacillus and Bacillus was high in the FB, but they were basically not present or little in the rat feces. In conclusion, FB may play a role in the treatment of "syndrome of damp retention in middle-jiao" by balancing the intestinal microflora, and this effect may be related to the metabolites of microorganisms in the FB.

Rhubarb tannins extract inhibits the expression of aquaporins 2 and 3 in magnesium sulphate-induced diarrhoea model.

Tannins, a group of major active components of Chinese rhubarb and widely distributed in nature, have a significant antidiarrhoeal activity. Aquaporins (AQPs) 2 and 3 play important roles in regulating water transfer during diarrhoea. The present study aims to determine the effect of the total tannins extract of rhubarb on aquaporins (AQPs) 2 and 3 in diarrhoea mice and HT-29 cells both induced by magnesium sulphate (MgSO4). Our results showed that rhubarb tannins extract (RTE) significantly decreased the faecal water content in colon and evaluation index of defecation of diarrhoea mice. Interestingly, RTE could markedly reduce the mRNA and protein expression levels of AQPs 2 and 3 in apical and lateral mucosal epithelial cells in the colons of diarrhoea mice and HT-29 cells both induced by MgSO4 in a dose-dependent manner. Furthermore, RTE suppressed the production of cyclic monophosphate- (cAMP-) dependent protein kinase A catalytic subunits α (PKA C-α) and phosphorylated cAMP response element-binding protein (p-CREB, Ser133) in MgSO4-induced HT-29 cells. Our data showed for the first time that RTE inhibit AQPs 2 and 3 expression in vivo and in vitro via downregulating PKA/p-CREB signal pathway, which accounts for the antidiarrhoeal effect of RTE.

Expression of aquaporin proteins in vagina of diabetes mellitus rats.

INTRODUCTION: Aquaporins (AQPs) are membrane proteins that facilitate water movement across biological membranes. Vaginal lubrication may be mediated by blood flow and other potential mechanisms related to transudation of fluid. The most common female sexual dysfunction in diabetes is inadequate vaginal lubrication. AIM: To investigate the expression of AQP1-3 in vaginal tissue of diabetes mellitus rats. METHODS: Female Sprague-Dawley rats (N = 20) were randomly divided into group A (12-week-old nondiabetic control, N = 5), group B (16-week-old nondiabetes control, N = 5), group C (12-week-old diabetes mellitus rats, N = 5), and group D (16-week-old diabetes mellitus rats, N = 5). Vaginal fluid was measured by fluid weight absorbed by cotton swabs after pelvic nerve electrostimulation and anterior vaginal tissue was dissected for determining the expression of AQP1-3 by immunohistochemical study and Western blot. MAIN OUTCOME MEASURES: The expression of AQP1-3 was determined in the vagina of diabetes mellitus rats by Western blot. RESULTS: There are no significant differences in serum estradiol concentrations of rats among these groups (P > 0.05). Vaginal fluid was significantly lower in group C (2.7 ± 0.67 mg) and group D (2.5 ± 1.03 mg) than in group A (5.74 ± 1.23 mg) and group B (5.5 ± 1.08 mg) (P < 0.05), respectively. The protein expressions of AQP1-3 were significantly lower in group C (43.40 ± 4.83, 60.60 ± 12.80, and 59.60 ± 6.95) and group D (20.81 ± 2.86, 47.80 ± 11.43, and 54.20 ± 5.26) than in group A (116.62 ± 3.21, 110.81 ± 8.044, and 108.80 ± 4.97) and group B (122.12 ± 14.54, 111.21 ± 15.07, and 106.40 ± 4.16) (P < 0.05), respectively. CONCLUSIONS: Decreased vaginal fluid in diabetes mellitus rats after electrostimulation may be partly due to estrogen-independent decreases of AQP1-3 in vaginal tissue.

COX-2 disruption leads to increased central vasopressin stores and impaired urine concentrating ability in mice.

It was hypothesized that cyclooxygenase-2 (COX-2) activity promotes urine concentrating ability through stimulation of vasopressin (AVP) release after water deprivation (WD). COX-2-deficient (COX-2(-/-), C57BL/6) and wild-type (WT) mice were water deprived for 24 h, and water balance, central AVP mRNA and peptide level, AVP plasma concentration, and AVP-regulated renal transport protein abundances were measured. In male COX-2(-/-), basal urine output and water intake were elevated while urine osmolality was decreased compared with WT. Water deprivation resulted in lower urine osmolality, higher plasma osmolality in COX-2(-/-) mice irrespective of gender. Hypothalamic AVP mRNA level increased and was unchanged between COX-2(-/-) and WT after WD. AVP peptide content was higher in COX-2(-/-) compared with WT. At baseline, plasma AVP concentration was elevated in conscious chronically catheterized COX-2(-/-) mice, but after WD plasma AVP was unchanged between COX-2(-/-) and WT mice (43 ± 11 vs. 70 ± 16 pg/ml). Renal V2 receptor abundance was downregulated in COX-2(-/-) mice. Medullary interstitial osmolality increased and did not differ between COX-2(-/-) and WT after WD. Aquaporin-2 (AQP2; cortex-outer medulla), AQP3 (all regions), and UT-A1 (inner medulla) protein abundances were elevated in COX-2(-/-) at baseline and further increased after WD. COX-2(-/-) mice had elevated plasma urea and creatinine and accumulation of small subcapsular glomeruli. In conclusion, hypothalamic COX-2 activity is not necessary for enhanced AVP expression and secretion in response to water deprivation. Renal medullary COX-2 activity negatively regulates AQP2 and -3. The urine concentrating defect in COX-2(-/-) is likely caused by developmental glomerular injury and not dysregulation of AVP or collecting duct aquaporins.

Hydrating skin by stimulating biosynthesis of aquaporins.

Aquaporins (AQPs) are proteins that facilitate the transport of water across cell membranes. AQP3 expression is related to the expressions of other epidermal proteins involved in water maintenance (ie, CD44, claudin-1, and filaggrin). The expressions of AQP3 water channels are strongly affected by age and chronic sun exposure, and a defective osmotic equilibrium could occur in the epidermis, which would account for the skin dryness observed in older people and skin areas most exposed to sunlight. We investigated active ingredients that are able to increase AQP3 levels in order to improve hydration in human skin keratinocytes. We selected an ethanolic/water (70/30 v/v) extract of Ajuga turkestanica, a plant from Central Asia, as the hydrating agent. After 17 days of treatment every 2 days with this extract (2.5 microg/mL) in vitro, AQP3 expression measured at the protein level in human reconstructed epidermis was significantly increased. Water transport through both aquaporins and aquaglyceroporins and glycerol transport through aquaglyceroporins alone are important to skin hydration. The distribution and the variability of aquaporins in human skin cells suggest that these channels may have important roles in skin physiology. AQPs appear to be key protein targets to improve the resistance and quality of the skin surface as well as to improve aging and sun exposure-induced dryness as shown by their roles in 1) hydrating the living layers of the epidermis where the keratinocyte differentiation takes place and 2) barrier formation and recovery.

Effects of water restriction on gene expression in mouse renal medulla: identification of 3betaHSD4 as a collecting duct protein.

To identify novel gene targets of vasopressin regulation in the renal medulla, we performed a cDNA microarray study on the inner medullary tissue of mice following a 48-h water restriction protocol. In this study, 4,625 genes of the possible approximately 12,000 genes on the array were included in the analysis, and of these 157 transcripts were increased and 63 transcripts were decreased by 1.5-fold or more. Quantitative, real-time PCR measurements confirmed the increases seen for 12 selected transcripts, and the decreases were confirmed for 7 transcripts. In addition, we measured transcript abundance for many renal collecting duct proteins that were not represented on the array; aquaporin-2 (AQP2), AQP3, Pax-8, and alpha- and beta-Na-K-ATPase subunits were all significantly increased in abundance; the beta- and gamma-subunits of ENaC and the vasopressin type 1A receptor were significantly decreased. To correlate changes in mRNA expression with changes in protein expression, we carried out quantitative immunoblotting. For most of the genes examined, changes in mRNA abundances were not associated with concomitant protein abundance changes; however, AQP2 transcript abundance and protein abundance did correlate. Surprisingly, aldolase B transcript abundance was increased but protein abundance was decreased following 48 h of water restriction. Several transcripts identified by microarray were novel with respect to their expression in mouse renal medullary tissues. The steroid hormone enzyme 3beta-hydroxysteroid dehydrogenase 4 (3betaHSD4) was identified as a novel target of vasopressin regulation, and via dual labeling immunofluorescence we colocalized the expression of this protein to AQP2-expressing collecting ducts of the kidney. These studies have identified several transcripts whose abundances are regulated in mouse inner medulla in response to an increase in endogenous vasopressin levels and could play roles in the regulation of salt and water excretion.