The effect of portacaval shunt upon hepatic cholesterol synthesis and cyclic AMP in dogs and baboons

Abstract

Hepatic cholesterol synthesis, hepatic cyclic AMP, and portal and peripheral insulin and glucagon levels were investigated in nine dogs and three baboons after complete portacaval shunt. Cholesterol synthesis as measured with acetate incorporation was reduced in both species. Hepatic cyclic AMP increased in dogs. Changes in portal and systemic insulin were inconsistent, but hyper-glucagonemia occurred regularly. Diminished hepatic cholesterol synthesis is apparently one factor, although probably not the only one, in the antilipidemic effect of portacaval shunt. This altered cholesterol metabolism may be due to a change in the hormonal environment of the liver caused by portal diversion.

Morphologic and Biochemical Changes in Dogs After Portacaval Shunt Plus Bile Fistula or Ileal Bypass: Failure of Bile Fistula or Ileal Bypass to Prevent Hepatocyte Atrophy

“…pes causes a reduction in cholesterol synthesis (6,13,(23)(24)(25)(26)(27)(28)(29)(30) and bile acid synthesis (13,24,30,31). Interruption of the venous enterohepatic circulation has been one presumed cause of the elevation in postprandial serum bile acids caused by pes (12,13).…”

“…\ 4 7) have seen similar cumulative effects in dogs after portal diversion (by means of portacaval transposition) plus ileal resection. However, it is theoretically possible that procedures such as IB, BF, and ileal resection, which increase the enteric losses as well as the hepatic synthesis of cholesterol and bile acids, could subvert the antilipidemic mechanisms of pes which are thought to derive mainly from depressed hepatic cholesterol synthesis (3,6,13,(23)(24)(25)(26)(27)(28)(29)(30).…”

The ECK fistula in animals and humans

“…In our initial investigations of this possibility, we demonstrated reductions of more than 80% in canine hepatic cholesterol and triglyceride synthesis. 17 Although a similar diminution in cholesterol and/or lipoprotein synthesis was confirmed in rats, [67][68][69] dogs, 70 swine, [71][72][73] and baboons, 70 not all workers could verify these findings. The rigorously controlled studies in rats by Proia et al, 68 which are the only reported animal experiments concerning Eck's fistula and lipid synthesis in which body weights were maintained or increased postoperatively, have done much to explain the discordant reports.…”

Glucagon, cyclic AMP, and hepatic glucose mobilization: A half‐century of uncertainty

“…Note that all 36 values are below the consensus TC of 100 pM for activating AC (see Figure 4). The 36 sources were: Kraft et al (2017), Lewis et al (1997), Saccà et al, (1979) and Vaitkus et al, (1984), (10–19); Berger et al (1994), Blommaart et al (1995), Curnow et al (1976), Fries et al (1982), Hickman et al (1992), Imai et al (2003) and Wasserman et al (1993) (20–29); Androgué et al (1985), Baumann et al (1981), Cersosimo et al (1989), Rao (1995) and Sherwin et al (1977) (30–39); Francavilla et al (1980), Holst et al (1980), Langhans et al (1984) and Müller et al (1984) (40–49); Demigné et al (1985), Goldstein and Curnow (1978), Horikawa et al (1998), Jaspan et al (1984), Silva et al (1990) and Wolf and Eisenstein (1981), (50–59); Balks and Jungermann (1984), Gannon and Nuttall (1993), Ishida et al (1981), Kinoshita et al (1985), McLeod et al (1983), Rabouti et al (1989) and Silva et al (1990) (60–69); Hussein et al (1986), Latour et al (1999) and Okuda et al (1994) (70–79)…”