Biomedical subjects

M Senn

Publications and source records attributed to M Senn.

39 records · Page 3Linked to original sources

PubMedDate not supplied

Biliary and urinary excretion of sulfated, glucuronidated and tetrahydroxylated bile acids in cirrhotic patients.

In patients with hepatobiliary diseases, considerable amounts of sulfated and glucuronidated bile acids are excreted in urine. Information on the biliary excretion of these compounds is lacking. We used an intestinal perfusion method to determine the biliary excretion of sulfated and glucuronidated bile acids in eight patients with alcoholic cirrhosis and moderately severe cholestasis and compared results with urinary excretion rates. In bile, the patients excreted 508.7 mumoles per hr (mean) nonsulfated, nonglucuronidated bile acids, 8.1 mumoles per hr sulfated bile acids and 4.0 mumoles per hr glucuronidated bile acids. In urine, these patients excreted 0.27 mumoles per hr nonsulfated, nonglucuronidated bile acids, 0.88 mumoles per hr sulfated bile acids and 0.02 mumoles per hr glucuronidated bile acids. Sulfates and glucuronides of mono-, di- and trihydroxy bile acids were detected in urine and bile. In urine, tetrahydroxy bile acids were only excreted as nonsulfated and nonglucuronidated forms. The bile:urine excretion ratio of sulfated bile acids was 9:1 and of glucuronidated bile acids was 226:1. In alcoholic cirrhosis with cholestasis, biliary excretion is an important excretory route of sulfated and glucuronidated bile acids.

Adult↗

PubMedDate not supplied

Meal patterns and meal-induced metabolic changes in calves fed milk ad lib.

The feeding behavior of 11 calves fed milk ad lib was characterized and analyzed at the age of 5 weeks, and the short-term changes in the plasma concentrations of various metabolites (glucose, lactate, free fatty acids, triglycerides, beta-hydroxybutyrate) and insulin in relation to a representative spontaneous milk meal were measured during the following week. In a 6-day period, the calves consumed 287 (=86%) of a total of 335 milk meals during the light phase from 0500-2200 [on average, 4.4 +/- 0.5 (mean +/- SEM) meals]. The meal size and duration during light were 2.0 +/- 0.3 kg and 5.3 +/- 0.3 min, respectively. However, only 0.7 +/- 0.1 milk meals of similar size and duration were consumed during the dark phase. The plasma concentrations of insulin and glucose increased in response to the spontaneous milk meal and remained elevated for at least 2 h after meal end. The plasma concentrations of triglycerides, free fatty acids, and beta-hydroxybutyrate also increased after meal termination, and remained elevated until 40 min (triglycerides, free fatty acids) and 60 min (beta-hydroxybutyrate) after meal end, respectively. The observed spontaneous milk intake patterns were similar to the natural suckling behavior described for calves, suggesting that the conditions of the present experiment did not disrupt the animals' natural feeding behavior. Some of the profound metabolic changes in relation to a spontaneous milk meal might contribute to the control of milk intake in calves, but further experiments are necessary to test this idea.

Animals↗

PubMedDate not supplied

Role of rumen fluid hypertonicity in the dehydration-induced hypophagia of cows.

Three experiments were performed in non-lactating, rumen-fistulated cows to assess the role of rumen fluid hypertonicity in dehydration-induced hypophagia. First, the course of rumen fluid and plasma osmolality before and after an individual test meal was recorded when water was offered ad libitum and on the fifth day of a 65% water restriction period. Then, the effects of intraruminal water infusions on food intake were examined in dehydrated cows. Finally, two doses of the local anesthetic mepivacaine HCl were given into the rumen in an attempt to inactivate the osmosensors potentially involved in dehydration-induced hypophagia. Water restriction reduced test meal size and increased rumen fluid and plasma osmolality. Despite the smaller meal, the prandial increase in rumen fluid osmolality was more pronounced during water restriction than with water ad libitum. Independent of treatment, the test meal had no effect on plasma osmolality. Intraruminal water infusions during water deprivation decreased rumen fluid osmolality below the control level and normalized food intake. Injection of 2 or 4 g mepivacaine/cow into the rumen did not attenuate dehydration-induced hypophagia. All in all, these results suggest that rumen fluid hypertonicity, perhaps in concert with plasma hypertonicity, contributes to the early satiation induced by dehydration.

Anesthetics, Local↗