Autoradiographic study of 3H-DOPA uptake by superior cervical and stellate ganglia of spontaneously hypertensive rats during the prehypertensive stage.

The functional state of sympathetic ganglia in spontaneously hypertensive rats (SHR) was compared with that of ganglia in normotensive Wistar Kyoto rats (WKY) by examining catecholamine synthetic activity by light microscopic autoradiography 3H-L-dihydroxyphenyl alanine (3H-DOPA). The number of silver grains over the perikarya of ganglion cells in the superior cervical (SCG) and stellate ganglia (SG) of newborn, 10-day-old and 30-day-old animals was counted on photographic enlargements. There were significantly more silver grains over ganglion cells in SHR compared with those in age-matched WKY at almost all incorporation times at all ages examined in SCG, at all incorporation times in newborn rats, and at incorporation times of 15 and 60 min in SG of 10-day-old rats. The increased incorporation of the label by both sympathetic ganglia was more marked in newborn than in 30-day-old animals. These results indicate that catecholamine synthetic activity in these ganglion cells is increased in SHR from the newborn stage, suggesting that a congenital hyperfunction of sympathetic ganglia occurs in SHR.