Effect of experimental hyperhomocysteinemia on plasma lipid profile, insulin sensitivity and paraoxonase 1 in the rat

Abstract

hyperhomocysteinemia (hhcy) is a well-known risk factor of cardiovascular diseases, however, the mechanism of its detrimental effect is incompletely understood. some studies suggest that, paradoxically, hhcy may promote traditional risk factors such as hyperlipidemia. We examined the effect of experimental hhcy on plasma lipid profile, glucose and insulin concentrations as well as on high-density lipoprotein (hDl)-associated antiatherosclerotic enzyme, paraoxonase 1 (pOn1). hyperhomocysteinemia was induced by feeding male Wistar rats with diet enriched with methionine or diet enriched in methionine and deficient in folate, vitamin b 6 and b 12 for 8 weeks. These diets resulted in the 3.3-and 9.6-fold elevation of plasma hcy, respectively. plasma total and hDl-cholesterol, triglycerides and apolipoprotein a-I were similar in all groups. highmethionine diets had no effect on fasting plasma glucose but significantly increased fasting plasma insulin concentration indicating impaired ability of insulin to suppress hepatic glucose output. pOn1 activity was unchanged in high methionine vitamin bsufficient diet-fed rats, but was decreased by 30-40% toward various substrates in high methionine vitamin b-deficient diet-fed animals. The results indicate that hhcy has no effect on lipid metabolism, however, induces insulin resistance and, above certain hcy level, pOn1 deficiency. Impaired insulin signaling and reduced pOn1 activity may contribute to detrimental effects of hhcy. Adipobiology 2012; 4: 77-84

Hydrogen Sulfide Alleviates Anxiety, Motor, and Cognitive Dysfunctions in Rats with Maternal Hyperhomocysteinemia via Mitigation of Oxidative Stress

“…Pregnant rats were divided into four groups as follows: one group was fed ad libitum with a control diet ( n = 7), the second group ( n = 11) received daily methionine (7.7 g/kg body weight) with food starting 3 weeks prior to and during pregnancy and lactation until weaning at P21 [ 29 , 37 ]. The third group ( n = 4) received the H 2 S donor, sodium hydrosulfide (NaHS) three weeks before and throughout pregnancy according the following protocol: 7 days of injections alternated with 7 days of adaptation [ 28 ].…”

Hydrogen Sulfide Ameliorates Developmental Impairments of Rat Offspring with Prenatal Hyperhomocysteinemia

“…Pregnant rats were divided into four groups as follows. One group was fed ad libitum with a control diet ( n = 7); the second group ( n = 11) received daily methionine (7.7 g/kg body weight) with food starting 3 weeks prior to and during pregnancy [10, 25]. The third group ( n = 4) received NaHS three weeks before and throughout pregnancy according the following protocol: 7 days of injections alternated with 7 days of adaptation.…”