Browsing by Author "Mampel, T."

Female pigs, fasted overnight, received an orthotopic liver transplant. During the unhepatic phase, both blood glycerol and plasma free fatty acid concentrations increased, returning to basal values after the transplant, indicating that the liver is the main receptor of these products released in the blood from the glyceride breakdown in peripheral fat deposits. Blood glucose level rose during the unhepatic phase, probably due in part to the perfusion of glucosated saline received by the animals during this phase. After liver transplant, blood glucose levels progressively decreased and this effect was greatly reduced by administering L-alanine. Our data indicate that metabolic changes in the donor's liver diminish the availability of gluconeogenetic substrates immediately following transplant, while administration of exogenous alanine permits faster restoration of gluconeogenetic function in the transplanted liver.

Insulin (i. v.) administration to functionally hepatectomized-nephrectomized rats did not alter circulating levels of glycerol and only slightly affected plasma radioactivity when animals received (U-14C)-glycerol, whereas after (U-14C)-glucose administration insulin enhanced hypoglycemia and greatly accelerated the rate of radioactivity loss from plasma. At 15 min after i.v. injection of (U- 14C)- glycerol, radioactivity in total lipids was reduced in heart and lungs by insulin administration and enhanced in carcass and brown adipose tissue. These effects involved the 14C-glyceride glycerol fraction in the case of heart and 14C-fatty acids in carcass and adipose tissue. When (U-14C)-glucose was administered, insulin enhanced the appearance of 14C-water-soluble material in heart and carcass and 14C-total lipids in heart, carcass, and both brown and white adipose tissue. The effect in heart corresponded mainly to the 14C-§lyceride glycerol fraction whereas it corresponded to the 1 C-fatty acids in the other tissues. Therefore, insulin effects on glycerol metabolism substantially differ from those on glucose. Opposite effects on heart and lung glycerol utilization as compared to those in carcass and brown adipose tissue may account for the difficulties in observing changes in plasma glycerol levels after insulin treatment.

Level6 of circulating glucose, glycerol, end FFA concentrations were determined before end efter hepatectomy-nephrectomy 1n 20 dey pregnant rats end virgin controls. After evisceration, blood glucose levels decreased 1n e pa rel lel ,..ay in both g!"oups whereas in pregnant rats, th<= blood glycercl level increased less end plasma-FFA rose mo~e than in controls. Maternal evisceration caused reduced blood glucose end enhanced glycerol levels in fetuses, whereas fetal plasma-FFA levels v-=re unmodified. Results indicate that extrahepatic glucose utilization re~ained stable in the late pregnar,t rat. Fetal levels of circulating glycercl, but not of FFA, appeared directly dependent on maternal levels. It is propcsed that under normal conditions, glycerol availability to the fetus is lo~, due to its preferential utilization by maternal gluconeogenic organs which reduced the amount available for possible placental transfer,

-I. Plasma ethanol concentration 3 hr after its oral administration (3 g/kg body wt) did not differ in 20 day pregnant rats with virgin controls, and in both groups values were higher when studied after 24 hr fasted than when fed. 2. In fed animals, blood glucose and liver glycogen concentrations were lower in pregnant than in virgin rats, whereas ethanol intake in both groups enhanced blood glucose levels, it reduced liver glycogen content only in virgins. In fetuses, maternal ethanol intake enhanced blood glucose levels. 3. In fasted animals, ethanol intake decreased blood glucose levels in pregnant and virgin animals but did not affect these levels in fetuses. 4. Ethanol intake enhanced /J-hydroxybutyrate/acetoacetate ratio similarly in blood of pregnant and virgin rats when either fed or fasted, and it produced the same change in fetuses from fasted mothers. 5. Results indicate that the metabolic response to acute ethanol does not differ between pregnant and non-pregnant animals, and it is proposed that fetuses passively follow the metabolic changes occurring in their mothers after receiving ethanol.