TACHYKININS IN THE PINEAL-GLAND - EFFECT OF CASTRATION AND GANGLIONECTOMY

In this investigation, the presence of NKA-immunoreactive substances w as determined in pineal glands from intact, castrated and castrated, t estosterone-treated male rats. The effect of environmental light, mela tonin treatment and superior cervical ganglionectomy on pineal NKA-imm unoreactive substances was also investigated. The results obtained sho w that NKA is present in measurable amounts in the rat pineal, and NPK is probably also present. Orchidectomy was followed by an increase in the content of NKA-immunoreactive substances in the pineal gland. The replacement treatment with testosterone propionate in castrated rats blocked this effect. NKA-immunoreactive substances were not significan tly different quantitatively in pineals from rats killed under light o r under darkness. The removal of the superior cervical ganglia was fol lowed by a significant increase in the NKA-immunoreactive substance co ntent in the pineal gland of male rats. These results indicate that NK A and other tachykinins are present in the pineal gland of the male ra t, and they seem to be regulated by gonadal hormones and the innervati on originated from the superior cervical ganglia. (C) 1998 Elsevier Sc ience Inc.