A Possible Role of Gonad and Renal Prostaglandin E₂ on the Development of Hypertension in Spontaneously Hypertensive Rats

Abstract

A possible role of prostaglandin E₂ (PGE₂) in the regulation of blood pressure in spontaneously hypertensive rats (SHR) was investigated. The inhibition of PG synthesis by chronic indomethacin treatment accelerated the elevation of blood pressure with the tendency to decrease renal PGE₂. We, therefore, confirmed that PGE₂ in SHR may play a role in the antihypertensive mechanism. In this connection, the participation of renal PGE₂ in the retardation of the development of hypertension in male SHR induced by orchiectomy was examined. Urinary PGE₂ which reflects the renal PGE₂ level tended to keep a higher level in the castrated group. Urinary electrolytes excretion also inclined to augment in the castrated group throughout the experiment. These results indicate that renal PGE₂ may participate in the gonads-mediated blood pressure regulation system, although the mechanism of the retardation of spontaneous hypertension induced by orchiectomy remains obscure.