Under conditions of essential hypertension, the expression of the H2S-producing enzyme in both the PVAT and the vascular wall of the TA was comparable to that in the control group, and although we cannot rule out the changes in enzyme activity and the regulation of H2S levels by other enzymes (e.g., CBS), the development of genetically determined hypertension was associated with the exclusion of H2S involvement in the PVAT-related compensatory vasoactive effect. The gene discussed is CBS; the disease is essential hypertension.