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T Rieg

Publications and source records attributed to T Rieg.

5 recordsLinked to original sources
PubMed2004

Kidney function in mice: thiobutabarbital versus alpha-chloralose anesthesia.

Mice that lack or over-express a gene of interest are important tools for unraveling gene function. The determination of single nephron function by micropuncture or precise determination of glomerular filtration rate (GFR) by inulin clearance method require experiments under anesthesia. A good anesthetic protocol should allow for reasonable and stable glomerular and tubular function. The aim of this study was to compare the commonly used thiobutabarbital (TBB) versus alpha-chloralose (CHL) anesthesia with regard to absolute levels and the stability of blood pressure, heart rate, and kidney function. Male CD1 mice were anesthetized with TBB (100 mg/kg body weight i.p.) or CHL (120 mg/kg body weight i.p.), plus ketamine (100 mg/kg body weight i.m.) given to every mouse for analgesia. After preparation for clearance experiments, two 30-min urine collections were performed at periods 1 and 2 (P1 and P2). It was observed that heart rate and mean arterial blood pressure did not differ between TBB ( n=9) vs. CHL ( n=9) and were stable through P1 and P2. In CHL, GFR as well as fractional excretion of fluid, Na(+) and K(+) were stable from P1 to P2 (P1: 190+/-15 microl/min, 1.6+/-0.2%, 0.7+/-0.1%, 35+/-5%; percent change in P2: 1+/-6, 26+/-10, 29+/-15, 6+/-10 respectively). In TBB, GFR was significantly greater vs. CHL in P1 and did not significantly change in P2 (246+/-8 microl/min, p<0.05; percent change: -6.5+/-4). Fractional excretion of fluid, Na(+) and K(+) were not significantly different vs. CHL in P1, but significantly increased in P2 (P1: 1.5+/-0.2%, 1.1+/-0.2%, 31+/-3%; percent change in P2: 122+/-23, 128+/-21 and 29+/-6 respectively; each p<0.05 vs. P1). In conclusion, mice under both anesthetic regimens present reasonable and stable blood pressure and reasonable kidney function, but kidney reabsorption is more stable under CHL than under TBB anesthesia, which may facilitate study of the response in kidney function to acute interventions.

Anesthesia↗
PubMed2004

Functional consequences at the single-nephron level of the lack of adenosine A1 receptors and tubuloglomerular feedback in mice.

Mice deficient for adenosine A1 receptors (A1AR) lack tubuloglomerular feedback (TGF). In vivo micropuncture experiments were performed under anesthesia in A1AR-deficient and wild-type littermate mice to study the effects of chronic absence of A1AR on fluid and Na(+) reabsorption along the nephron, as well as the functional consequences at the single-nephron level of the lack TGF. Evidence is provided for an A1AR-mediated tonic inhibition of Na(+) reabsorption in a water-impermeable segment of the loop of Henle, possibly the thick ascending limb. In contrast, proximal tubular reabsorption of fluid, Na(+) and K(+) was unaffected by the chronic absence of A1AR. Experiments in which artificial tubular fluid was added to free-flowing late-proximal tubules demonstrated an essential role of A1AR/TGF in the stabilization of fluid and Na(+) delivery to the distal nephron. Further, the occurrence of spontaneous oscillations of hydrostatic pressure in proximal tubule ( P(PT)) at a frequency of about 32 mHz depended on intact A1AR/TGF. In comparison, the normal, stabilizing reduction in P(PT) following the initial rise in P(PT) during sustained small increases in proximal tubular flow rate does not require A1AR/TGF; TGF-independent mechanisms appear to compensate in this regard for a lack of TGF under physiological conditions and the lack of TGF is unmasked only when supraphysiological flow rates overwhelm TGF-independent compensation.

Animals↗
PubMed1999

[Animal welfare and church]

In the author"s opinion the potential and the social importance of churches are underestimated especially regarding the practical animal welfare. Nevertheless the protestant and catholic church are still associations with a great number of members and have an infrastructure, which is unmatched. Even concerning the content there are clear positions from the church concerning the "relations between human being and animal" or rather the "responsibility which man takes for the animal as a co-creature", as numerous publications show. As a result each sort of co-operation with parishes should be tried for the purposes of the animal welfare, whenever it is possible.

Journal Article↗