Elevated neurotrophin and neurotrophin receptor expression in spontaneously hypertensive rat lungs

Spontaneously hypertensive rats represent a widely used animal model of hypertension. Altered neurotrophin regulation has been related to systemic hypertension. Lung cells synthesize and release neurotrophins(NT) which are involved in several pulmonary disturbances. Our study explored the expression of NT and their receptors using molecular biology and immunohistochemistry. Spontaneously 6-, 20- and 29- weeks hypertensive (SHR) and Wistar Kyoto rat (WKY) lungs were used. SHR and WKY lungs expressed neurotrophin and neurotrophin receptor mRNAs and protein transcripts. Age and hypertension dependent increase was clearly noticeable. Furthermore, immunohistochemistry revealed that their increase was mainly noticeable within bronchial and vascular components of the lung. Although the role of NT in sympathetic hyperinnervation and progression of systemic hypertension is a well established phenomenon, their increase in SHR lungs, strongly suggest that NT may be operative during pulmonary hypertension and in subsequent airway and pulmonary vascular remodeling.