Chronic administration of NaHS and L-Cysteine restores cardiovascular changes induced by high-fat diet in rats.

Hydrogen sulfide plays an important role in the regulation of the cardiovascular system, insulin secretion, and glucose homeostasis. The aim of the present study was to examine the effects of chronic treatment with sodium hydrosulfide (NaHS), L-Cysteine (L-Cys) and DL-Propargylglycine (DL-PAG) on the changes induced by a high-fat diet (HFD) in zoometric and metabolic variables as well as cardiovascular changes such as hypertension and sympathetic hyperactivity. For this purpose, male Wistar rats were fed a normal fat diet (NFD) or HFD for 12 weeks. Next, the HFD rats were divided into 5 subgroups which received daily i.p. injections during 4 weeks of: (1) nothing (no injection, Control); (2) vehicle (PBS; 1ml/kg); (3) NaHS (5.6 mg/kg); (4) L-Cys (300mg/kg); or (5) DL-PAG (1mg/kg). Then, an oral glucose tolerance test, hormone serum levels and blood pressure were determined. The cardiovascular responses to stimulation of the vasopressor sympathetic tone or intravenous administration of the agonists noradrenaline (α_1/2-adrenoceptors), methoxamine (α₁-adrenoceptors) and UK 14,304 (α₂-adrenoceptors) were determined in pithed rats. Lastly, the heart, liver and adipose tissue were weighted. HFD significantly increased: (1) zoometric variables, which were decreased by NaHS and L-Cys; (2) metabolic variables, ameliorated by DL-PAG; (3) haemodynamic variables, which were reversed by NaHS and L-Cys; and (4) the vasopressor responses induced by sympathetic stimulation, which were diminished by NaHS and L-Cys. In conclusion, chronic treatment with NaHS and L-Cys are effective in reducing adipose tissue and ameliorating the cardiovascular changes induced by obesity; meanwhile, DL-PAG ameliorates metabolic variables.