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B Rippe

Publications and source records attributed to B Rippe.

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Effects of acidity, glucose degradation products, and dialysis fluid buffer choice on peritoneal solute and fluid transport in rats.

OBJECTIVE: To evaluate the effects of acidity, glucose degradation products (GDP), and different solution buffer systems on solute and fluid transport during acute peritoneal dialysis (PD) in rats. DESIGN: Dialysis fluid (16 mL) containing 2.5% glucose as the osmotic agent was instilled intraperitoneally in Wistar rats (280 g) via a thin catheter in dwells lasting 4 hours. Blood and dialysis fluid samples (25 microL) were taken for measurement of glucose, sodium, and radioactive markers. The mass transfer area coefficient (MTAC or PS) for glucose and for 51Cr-EDTA (given as an intravenous infusion) and the peritoneal clearance (Cl) of 125I albumin (RISA), as well as the clearance of RISA to plasma (Cl --> P) were assessed for a commercial, heat-sterilized, acidic PD solution (2.5% glucose, pH 5.5; Gambrosol, Gambro, Lund, Sweden), containing GDP, and for four filter-sterilized solutions containing either lactate (40 mmol/L, pH 5.5 or 7.2), bicarbonate (38 mmol/L, pH 7.2), or pyruvate (40 mmol/L, pH 7.2) as buffers and being devoid of GDP. RESULTS: The initial pH of the acidic solutions increased rapidly, and attained physiological levels within 40 minutes. The initial drop of sodium, which is expected during the first part of the dwell, was significantly more pronounced with neutral than with acidic lactate. The PS for glucose and 51Cr-EDTA were slightly, but significantly, higher with the acidic and heat-sterilized solution (Gambrosol) than with the neutral, sterile-filtered lactate-buffered solution (p < 0.01), especially early during the dwell. Such an increase may be due to initial vasodilatation, and hence, recruitment of capillaries by the combination of acidity and GDP. However, there were no significant differences with respect to small solute PS values among sterile-filtered solutions, regardless of the presence of acidity or of buffer choice. CONCLUSION: There were no major differences in fluid and solute transport among sterile-filtered PD solutions having differing buffer systems and pH. Neither were there any effects of GDP alone. However, the combination of a low pH and the presence of GDP in the PD solutions seemed to cause significant increases in peritoneal small solute transport.

Animals↗
PubMedDate not supplied

Clearance of tracer albumin from peritoneal cavity to plasma at low intraperitoneal volumes and hydrostatic pressures.

OBJECTIVE: To assess the clearance of radiolabeled tracer albumin (RISA) from peritoneal cavity to plasma (Cl-->P) in rats under essentially "normal" conditions, that is, when intraperitoneal hydrostatic pressure (IPP) is subatmospheric and the intraperitoneal (IP) "free" fluid volume (IPV) is low. METHODS: A volume of 0.3 mL of RISA was injected IP into anesthetized Wistar rats (wt = 300 g) when the IPV was approximately 2 mL (normal) or the IPV was approximately 10 mL, and IPP was either -1.8 mmHg (normal) or +1.5 mmHg (produced by an external cuff). Plasma samples (25 microL) were obtained repeatedly during the dwell, which lasted 30-300 min, after which the peritoneal cavity was opened to recover the IPV and residual IP RISA activity. The Cl-->P was assessed as the mass transfer of RISA into plasma, occurring per unit time, divided by the calculated mean IP RISA concentration (CD). The interstitial RISA space was measured as the mass of RISA accumulated, per unit tissue weight, in peritoneal tissue samples divided by the CD. RESULTS: A markedly lower Cl-->P (2.47+/-0.67 microL/min), as well as total RISA clearance out of the peritoneal cavity (Cl), was found under "normal" conditions (an IPV of approximately 2 mL and an IPP of approximately -1.8 mmHg) compared to the situation during peritoneal dialysis (an IPV of approximately 20 mL and an IPP of +1 mmHg). Furthermore, the interstitial RISA space increased linearly over time even at negative IPPs and at an unchanging peritoneal interstitial fluid volume. At a low (normal) IPV the Cl-->P did not increase significantly with elevating IPP, and increased only marginally when tracer distribution was improved by artificial vibration of the rats. However the Cl-->P increased when larger volumes were infused to increase the total IPV. CONCLUSIONS: It is concluded that the Cl-->P and Cl at low IPPs and IPVs are not as high as during peritoneal dialysis. Increases in Cl-->P were, however, coupled to increases in IPV. This highlights the importance of the IPV per se and of a sufficient IP tracer distribution for direct lymphatic absorption to be efficient.

Animals↗