Effect of ageing on the response of the rat isolated testicular capsule to norepinephrine, acetylcholine and prostaglandins.

The response of the rat isolated testicular capsule to norepinephrine (NE), acetylcholine (ACh) and prostaglandins (PG) was found to be age-dependent. The testicular capsular contractions attributable to smooth muscle cells located within the tunica albuginea may be involved in the transport of non-motile spermatozoa from the testis and into the epididymis. With an increase in age of the age of the rat there was a concomitant increase in mass of the testis, thickness of the capsule and the amount of smooth muscle fibers present in the tunica albuginea. The response to the addition of equimolar concentrations of NE and PGA2 became progressively greater as the age of the animal increased. However, the response of the testicular capsule to ACh remained constant throughout adulthood, while PGF2 alpha became progressively less stimulatory as the age of the animal increased. These findings suggest that neurohumoral agents may have an important role in the maintenance of testicular capsular contractions with regard to ageing.