Developmental influences of the sympathetic nervous system on rat parotid gland

In an attempt to evaluate the effect of the sympathetic nervous system on the postnatal maturation of the parotid gland, rats were either sympathetically denervated on one side by avulsion of the superior cervical ganglion within 4 h after birth or treated with various β-adrenoceptor blocking agents from the day of birth. Four or 9 weeks later the animals were killed and the parotid glands were subjected to quantitative morphological studies. The neonatal denervation caused a significant decrease in parotid acinar cell size and their granule content, whereas chronic β-adrenoceptor blockade was without any effect. It is suggested that the trophic effect of the sympathetic nervous system may be due to a growth factor released from sympathetic nerve endings, which does not seem to interact with the β-adrenoceptor system.