Several effects of hypertrehalosemic hormone (Peram-HTH) have been compared with the action of 1,2,3,4,5,6-hexachlorocyclohexane (γ-HCH) in the cockroach, Periplaneta americana. The data show that both agents stimulate respiration while maintaining an R.Q. of approximately 1. The action of γ-HCH differs from that of Peram-HTH-I in that it promotes oxidation of large amounts of soluble carbohydrate. Recent studies show that Peram-HTH-I has an equally potent stimulatory effect on lipid deposition in the fat body and on the release of trehalose from the same tissue. It is of interest that γ-HCH not only increases triacylglycerol accumulation in the fatγ body but that this effect is more pronounced if the γ-HCH is applied to the ventral surface of the mesothorax. γ-HCH also depleted whole body glycoprotein and glycolipid whereas Peram-HTH-I had no effect on glycoprotein but increased that of glycolipid. It is clear that γ-HCH causes complex disruptions to the metabolism of the insect, many of which are related to the release of hormones. The study supports the idea that certain actions of γ-HCH are mediated through the release of Peram-HTH-I. 相似文献
The effect of fat source on fat and fatty acid (FA) apparent faecal (aFD) and ileal digestibility (aID) was studied in growing pigs. Faecal and ileal digestibilities were measured, using titanium dioxide as inert marker, in intact and ileo-rectally anastomosed pigs, respectively. Five different fat sources, added at 10% to a barley based diet (B), were tested: tallow (T), high oleic sunflower oil (HOSF), sunflower oil (SO), linseed oil (LO) and a fat blend (FB; 5.5% T, 3.5% SO and 1% LO of diet).
Except for B and T, fat aFD and aID were relatively similar among diets and site of measurements and the same was observed when it was obtained from the sum of FA aFD. However fat and sum of FA aID varied according to dietary FA composition and it was inversely related with the saturated FA content, due to the lowest aID of palmitic and stearic. aID of linoleic in SO and linolenic in LO were higher than the respective FA of the other diets and no differences were observed for oleic acid. The aFD of the unsaturated FA was higher than the corresponding aID values, despite similar fat aID and aFD. This together with the lower (in some cases negative) aFD of stearic acid suggest that there is biohydrogenation of unsaturated FA in the hindgut. Measurement at the end of the ileum should give a better estimation of digestibility of fat and FA than at the faecal level. 相似文献