The nucleus tractus solitarii (NTS) is one of the morphologically and functionally defined centers that engage in the autonomic regulation of cardiovascular activity. Phenotypically-characterized NTS neurons have been implicated in the differential regulation of blood pressure (BP). Here, we investigated whether phenylethanolamine N-methyltransferase (PNMT)-expressing NTS (NTS^PNMT) neurons contribute to the control of BP. We demonstrate that photostimulation of NTS^PNMT neurons has variable effects on BP. A depressor response was produced during optogenetic stimulation of NTS^PNMT neurons projecting to the paraventricular nucleus of the hypothalamus, lateral parabrachial nucleus, and caudal ventrolateral medulla. Conversely, photostimulation of NTS^PNMT neurons projecting to the rostral ventrolateral medulla produced a robust pressor response and bradycardia. In addition, genetic ablation of both NTS^PNMT neurons and those projecting to the rostral ventrolateral medulla impaired the arterial baroreflex. Overall, we revealed the neuronal phenotype- and circuit-specific mechanisms underlying the contribution of NTS^PNMT neurons to the regulation of BP.
Solitary Nucleus/metabolism* ; Blood Pressure/physiology* ; Phenylethanolamine N-Methyltransferase/metabolism* ; Neurons/metabolism* ; Paraventricular Hypothalamic Nucleus/metabolism*

OBJECTIVE: To investigate the association of phenylethanolamine-N-methyl transferase (PNMT) G-390A genetic polymorphism with risk of essential hypertension (EH) in Changsha Han people. METHODS: A case-control association study was performed in 400 patients with essential hypertension (EH) and 388 normotensive subjects. PNMT G-390A was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-FRLP). RESULTS: The genotype frequencies for the -390 GG, GA, and AA were 39.3%,50.0%, and 10.8%, respectively in EH patients, and were 43.6%,45.6%, and 10.8%, in normal subjects. No significant difference in either genotypic frequency (P=0.433) or allele frequency (P=0.378) of PNMT G-390A between EH patients and normals was observed. When by gender, there was significant difference in genotypic frequency (P<0.05) and allele frequency (P=0.046) of G-390A polymorphism between EH patients and normals in the male, but not in the female (P>0.05). CONCLUSION PNMT G-390A polymorphism is possibly associated with EH risk in male Chinese Han population in Changsha.
Adult ; Aged ; Base Sequence ; Case-Control Studies ; China ; Female ; Genetic Predisposition to Disease ; genetics ; Humans ; Hypertension ; enzymology ; genetics ; Male ; Middle Aged ; Molecular Sequence Data ; Phenylethanolamine N-Methyltransferase ; genetics ; Polymorphism, Genetic ; Sex Factors