Comparison of the Effects of the Growth Factor Produced by Spirometra mansonoides and Growth Hormone in Diabetic-Hypophysectomized Rats: Lipid Composition

Experimental Biology and Medicine

1987

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The acute effects of injections of the human growth hormone-like factor purified from plerocercoids of the tapeworm Spirometra mansonoides on carbohydrate, lipid, and protein metabolisms were determined in intact rats. Male rats were injected ip with saline, insulin, or various doses of partially purified PGF. The rats injected with insulin had significantly reduced serum glucose concentrations but no dose of PGF caused a change in serum glucose levels. Insulin and PGF stimulated ['4C]glucose and [ 14C]leucine oxidation to 14C02 in adipose tissue and muscle and increased incorporation of both [ ''C]glucose carbons into lipids and [ ''C]leucine into proteinin fat and muscle. The responses to PGF were dosedependent and persisted after 3 hr of incubation in vitro. Injections of naloxone prior to injecting PGF to block the stress response did not prevent the stimulation of insulin-like responses by PGF. Therefore, PGF has intrinsic insulin-like activities in normal Illale rats. 0

mentioning

confidence: 99%

Insulin-like Effects in the Rat of the Purified Growth Factor from Spirometra mansonoides Plerocercoids

Salem

Experimental Biology and Medicine

1987

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“…MEYER et al (1965) showed that plerocercoid-infected hamsters had a significant increased in carcass fat compared to uninfected controls. We (PHARES & CARROLL, 1978) found that plerocercoid infection of hamsters resulted in increase fat pad weights, serum total lipid, cholesterol and triglycerides.…”

Section: Introductionmentioning

confidence: 77%

“…Previous work shows that plerocercoid infection stimulates growth and increases fat stores in the absence of the pituitary (STEELMAN et al, 1971) and in the absence of normal insulin levels (PHARES & CARROLL, 1978). It has also been demonstrated that plerocercoid infection causes an increase in carcass fat (MEYER et al, 1965) and increases in serum triglycerides and cholesterol (PHARES & CARROLL, 1977) of intact hamsters.…”

Section: Discussionmentioning

confidence: 97%

“…While GH has acute (two to three hours after exposure to hormone) effects similar to insulin in adipose tissue (BIRNBAUM & GOODMAN, 1979) the chronic effect of GH treatment is hyperglycaemia and depletion of adipose tissue stores (MERIMEE & RABIN, 1973). Unlike the effect of GH, plerocercoid infection increases fat stores (STEELMAN et al, 1971;PHARES & CARROLL, 1977;PHARES & CARROLL, 1978).…”

Section: Introductionmentioning

confidence: 99%

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Insulin-like effects of fatty acid synthesis in liver of hamsters infected with plerocercoids of the tapeworm,Spirometra mansonoides

Carroll

1984

J. Helminthol.

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Elevated serum lipids are associated with infections of laboratory rodents with plerocercoids ofSpirometra mansonoides. The effect of infection with these larval tapeworms on triglyceride degradation and hepaticde novofatty acid synthesis was investigated in Syrian hamsters. Serum lipoprotein electrophoresis revealed a consistent elevation in very low density lipoproteins in the infected animals. Lipoprotein lipase activity was enhanced in the infected animals. After seven days of plerocercoid infection the activity of acetyl-CoA carboxylase (E.C. 6.4.1.2) was significantly elevated after 6,12 and 18 hours of fasting. Fatty acid synthetase was significantly increased after 0,6,12,18 and 24 hours of fasting. Therefore, a chronic insulin-like activity on lipid metabolism of hamsters is associated with plerocercoid infection.

“…However, not all of the biological actions of plerocercoid growth factor (PGF) are similar to those reported for growth hormone (GH) HARLOW et ai (1967) reported insulin-like activity in extracts of plerocercoids in vitro. In addition, a distinct lipogenic effect of plerocercoid infection was reported in hypophysectomized (Hx) rats (STEELMAN et a!., 1971), Hx-diabetic rats (PHARES & CARROLL, 1978) and intact hamsters (PHARES & CARROLL, 1977). This chronic lipogenic effect of PGF is "insulin-like" as opposed to the lipolytic effect of chronic administration of GH (KNOBIL & HOTCHKISS, 1964).…”

Section: Ntroductionmentioning

confidence: 99%

Spirometra mansonoides: effects of plerocercoid infection on glycogen deposition in rats

1982

J. Helminthol.

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The effects of infection with plerocercoids of Spirometra mansonoides on tissue glycogen deposition of rats was determined. Hypophysectomized rats infected for two days had higher liver glycogen concentrations than controls and this effect was greatest after one week. Elevated liver glycogen associated with plerocercoid infection was observed in fed animals both at the beginning and at the end of the light period as well as after an overnight fast. Glycogen phosphorylase (1,4αD glucan: orthophosphate α glucosyltransferase EC 2.4.1.1.) was inhibited but glucose-6-phosphatase (EC 3.1.3.9) was unaffected in the livers of infected hypophysectomized rats. While this effect is similar to actions of both growth hormone and insulin, plerocercoid infection had no influence on glycogen of cardiac or skeletal muscle at any time. Plerocercoid infection had no effect on the glycogen concentration of any tissue of intact rats.