Richard E. Peterson

Measurement and alteration of the capacity of the distended biliary tree in the rat

Abstract A retrograde-push-back (RPB) technique was developed to estimate capacity of the biliary tree in the distended state. The technique involves establishing a relatively constant rate of [3H]mannitol excretion in bile, retrogradely infusing saline into the biliary tree to clear the biliary system of mannitol an estimating capacity as the volume of biliary fluid recollected to the point where excretion of mannitol was reestablished to one-half of the original rate. In male Sprague-Dawley rats, distended capacity was 37.3 ± 4.4 μl (mean ± SE) for animals with a mean liver weight of 10 g. Distended capacity should be measured by allowing free flow of bile to occur within 5 sec of completion of the retrograde saline infusion. Significant reentry of [3H]mannitol into the biliary tree takes place if the occlusion is maintained for longer periods. These facets of the method were investigated by measuring intrabiliary pressures in relation to distended capacities. Even though a linear relationship existed between the liver and rat body weights, a linear relationship could not be established between liver weights and distended capacities. Thus, it seems inappropriate at this time to express distended capacities on a microliters per gram of liver basis. In another group of rats, treatment with sodium taurolithocholate (12.5 μmol/kg, iv) reduced the distended capacity to 25.2 ± 2.8 μl from a control value of 32.9 ± 1.0 μl. In rats treated with phenobarbital sodium (75 mg/kg, ip, once daily) for 4 days, the increase in liver wet weight was not accompanied by an increase in distended biliary tree capacity. In the hamster (liver weight, 4.4 g) and rabbit (liver weight, 82.6 g), the distended capacities were 18.9 ± 1.8 and 849 ± 86 μl, respectively. In the guinea pig, RPB with [3H]mannitol produced an overshooting effect above the steady state excretion values. With [14C]erythritol this overshooting effect was not obtained and a distended capacity estimate of 111 ± 8 μl was obtained for livers weighing 22 g.

Increased “bile duct-pancreatic fluid” flow in rats pretreated with carbon tetrachloride☆

Abstract Retrograde intrabiliary injection experiments in CCl 4 -pretreated (1 ml/kg, ip, 24 hr) rats suggested that the retrogradely injected solution was being diluted in the common bile duct portion of the biliary tree. This dilution was substantiated in subsequent experiments by a double-cannulation technique. To collect hepatic bile, a PE 10 cannula was placed in the proximal portion of the common bile duct near the liver hilus. To collect “bile duct-pancreatic fluid,” the distal portion of the ligated common bile duct was cannulated near the duodenum. CCl 4 pretreatment produced a 40% decrease in hepatic bile flow (57 ± 6 mg/min/kg, control, vs 35 ± 4, CCl 4 , mean ± SE) and a 600% increase in bile duct-pancreatic fluid flow (1.6 ± 0.3 mg/min/kg, control, vs 9.5 ± 1.8, CCl 4 ). The enhanced bile duct-pancreatic fluid flow did not involve a change in the rate of protein and amylase excretion from the pancreas. Also CCl 4 produced a decrease in the secretory pressure of hepatic bile and an increase in that of bile duct-pancreatic fluid. Thus, CCl 4 has the interesting action of increasing bile duct-pancreatic fluid flow at the same time it is decreasing hepatic bile flow.

The variability of extracellular fluid space (sucrose) in man during a 24 hour period.

The water content of the human body averages 60 per cent of its total weight. Techniques for measurement and criteria for accuracy have been developed for total body water but there are no generally accepted standards for extracellular fluid volume (EFV). It is our purpose in this paper to describe our exploration of the erratic variations of extracellular fluid volume in normal subjects as measured by sucrose infusions and to discuss wide fluctuations in what had been thought hitherto to be a steady state. It is believed that most methods of estimating EFV using nonelectrolyte labels achieve rapid equilibration in, and measure mainly, interstitial and plasma water, and that the substances used diffuse incompletely into the cerebrospinal fluid, joint spaces, bone and tendon water, or into glandular lumina, or gastrointestinal tract water (2). This incomplete mixing of test substance in these spaces should not be expected to introduce large errors into this estimation since plasma and interstitial fluid must comprise the major portion of EFV. Walser, Seldin and Grollman (3) have proposed the term functional EFV for the volume thus measured. However, the accuracy of EFV estimates has been further questioned with reports that even large nonelectrolyte molecules, such as inulin and sucrose, may leave the EFV and penetrate cell membranes (4, 5). Most methods for measuring extracellular fluid

Increased bile duct-pancreatic fluid flow in benzene and halogenated benzene-treated rats.

Abstract Benzene and certain halogenated benzenes at a dose of 5.0 mmol/kg, ip, increased bile duct-pancreatic fluid (BDPF) flow and decreased its protein concentration 24 hr after treatment. Agents which produced this effect were benzene, bromobenzene (BB), chlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, and 1,3,5-trichlorobenzene. 1,4-Dichlorobenzene had no effect. The mechanism by which these hydrocarbons increase BDPF flow is not known, but it does not involve secretin or cholinergic stimulation of the pancreas. Moreover, the increase in BDPF flow does not occur secondary to liver damage because benzene and 1,2-dichlorobenzene which did not increase SGPT activity increased BDPF flow and reduced its protein concentration. Also pretreatments known to protect against or potentiate BB-induced liver necrosis did not consistently alter effects of BB on the pancreas. This lack of parallelism between effects of BB on the two organs suggests that the mechanism by which BB produces liver necrosis is different from that for increasing BDPF flow.

Three methods for measuring the increase in the capacity of the distended biliary tree in the rat produced by α-naphthylisothiocyanate treatment

The capacity of the distended biliary tree was measured in each rat by three techniques referred to as retrograde-intrabiliary-injection (RII), segmented-retrograde-intrabiliary-injection (SRII), and retrograde-pushback (RPB). Control rats, receiving by gavage 0.2 ml of olive oil daily for 8 consecutive days, were found 15 days after treatment to have distended capacities of 33.4 ± 2.7, 34.1 ± 3.4, and 31.6 ± 2.9 μl (mean ± SE) as obtained by the RII, SRII, and RPB techniques, respectively. In another group of rats, treated for 8 consecutive days with α-naphthylisothiocyanate (ANIT) (45 mg/kg, po) in 0.2 ml of olive oil, the RII, SRII, and RPB techniques estimated distended biliary capacity 15 days after the last treatment to be 48.0 ± 1.6, 47.5 ± 1.4, and 46.8 ± 1.3 μl, respectively. In control animals the two-way analysis of variance showed no significant difference occurred between the three methods. For each of the three methods, the mean distended biliary tree capacity of the ANIT-treated rats was significantly greater than the control rats, p < 0.02. No significant difference was found between control and ANIT-treated rats for mean liver weights and bile flow rates. Thus, the increase in distended biliary capacity with ANIT treatment was not accompanied by any change in liver weight or bile flow rate.

Increased "bile duct-pancreatic fluid" flow in chlorinated hydrocarbon-treated rats.

Abstract The following chlorinated hydrocarbons, CCl4, Cl2CH2, chloroform, 1,1,2-trichloroethane, 1,1-dichloroethylene, 1,1,2-trichloroethylene, and 1,1,2,2-tetrachloroethylene, were administered 1 day before testing. The test consisted of a retrograde intrabiliary injection of [3H]inulin followed by a 6-min period of occlusion, to hold the [3H]inulin solution in the biliary tree, and then collecting and analyzing each drop of bile. The content of [3H]inulin in the drops from the distal portion of the biliary tree was diluted by increased excretion of “bile duct-pancreatic fluid” into the duct system during the 6-min occlusion period. An increase in bile duct-pancreatic fluid flow in chlorinated hydrocarbon-treated rats was directly demonstrated by cannulating the common bile duct at the proximal bifurcation (to collect hepatic bile) and distally at the duodenum (to collect bile duct-pancreatic fluid). The results showed that the chlorinated hydrocarbons produced an increase in bile duct-pancreatic fluid flow. The increase in this distal fluid flow was not correlated to a rise in SGPT activity or extent of liver cell necrosis because both 1,1-dichloroethylene, which produced high SGPT activity and necrosis, and chloroform, low SGPT and no necrosis, increased bile duct-pancreatic fluid flow to a similar extent.

Observations on the course of urinary K42 specific activity in fasting human subjects

Abstract The course of urinary potassium specific activity was followed for 6 days after the oral administration of carrier-free K 42 to subjects on a prolonged fast. Under these conditions evidence indicated that equilibration of the isotope was not complete until after the third day.

Differential protection by certain agents against carbon tetrachloride-induced increase in bile duct-pancreatic fluid flow

Pretreatment with CCl 4 increased bile duct-pancreatic fluid (BDPF) flow in rats. Since the mechanism is not known, the purpose of this study was to see whether agents which protect against certain effects of CCl 4 on the liver also protect against the increase in BDPF. Change in BDPF was assessed against increased serum glutamic pyruvic transaminase (SGPT) activity, hepatic necrosis (HN), hepatic triglyceride (HTG), and decreased hepatic bile fluid (HBF) flow. Cysteine (1.9 g/kg po) administered 30 min before CCl 4 significantly protected against increased BDPF and SGPT and showed an intermediate protective effect against HTG and HN, but not decreased HBF flow. Pyrazole (300 mg/kg ip) administered 30 min before CCl 4 protected against increased HN and HTG but not against increased BDPF and SGPT; no protection against decreased HBF flow was afforded. A small dose of CCl 4 , 0.2 ml/kg ip, 24 hr before the usual treatment with CCl 4 protected against BDPF, HBF, and SGPT activity with an intermediate effect on HTG increase. Thus, with the combination of results, it is concluded that the increase in BDPF produced by CCl 4 is not related to the extent of liver necrosis, hepatic triglyceride accumulation, or effects on hepatic bile fluid flow. The source of the increased BDPF remains unknown.

OBSERVATIONS ON THE SIMULTANEOUS ESTIMATION OF EXCHANGEABLE SODIUM, POTASSIUM AND CHLORIDE IN HUMAN SUBJECTS USING AN ION EXCHANGE TECHNIC.

Abstract Procedures are described for the simultaneous administration of the short-lived isotopes, Na24, K42, and Br82 to human subjects and the subsequent estimation of their exchangeable electrolyte pools. Apparatus is described which employs ion exchange chromatography and Geiger-Muller monitoring for the separation of radioactive sodium, potassium and anion fractions in serum and urine. The chemical and radiometric errors incurred in the analysis for specific activity of each electrolyte are evaluated statistically. Based on the analysis of duplicate observations, the coefficients of variation for the separate estimations of exchangeable electrolytes are, Na 2.54 per cent, K 3.17 per cent and Cl. 2.45 per cent. Upon measuring exchangeable electrolyte pools in subjects at weekly intervals significant biological variability was observed. Significant differences in plasma and urine specific activities of sodium and potassium were observed 24 hours after a tracer dose of Na24 and K42. Variation in the specific activities of consecutive hourly urine samples obtained after 22 hours were significant and occasionally large (>±10 per cent). Previous reports are reviewed in which excessive variations of plasma and urine specific activities were observed. The role of isotope effects, diet and circulation dynamics in influencing variations of specific activity is discussed. Limited observations on the value for exchangeable potassium determined 72 hours after oral K42 indicate no better agreement with the 48 hour value in the same individual than does the one obtained at 24 hours.