Endocrine Abstracts

We examined the functional significance of the glutamatergic innervation of the dorsal raphe nucleus (DR) in the mediation of the suckling stimulus inducing prolactin release. A non-NMDA (6-cyano-7-nitroquinoxaline-2,3-dione disodium, CNQX) or an NMDA glutamate receptor antagonist (dizocilpine hydrogen malate, MK-801) was injected into the DR of freely moving lactating rats at the end of 4 h separation. The litters were then returned and blood samples for prolactin were taken ...

It is well known that hypophyseotrophic dopamine (DA) exhibits a tonic inhibitory effect on pituitary lactotrops in vivo. We have previously observed that prolactin (PRL) cells obtained from lactating rats become partially resistant to DA following a brief suckling period compared to non-suckled control female rats. This, so-called “desensitization” (and a parallel appearance of “tolerance”) to DA is mediated through by a selective change of protein phospha...

Salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline), is a recently identified endogenous prolactin (PRL) releasing factor. Salsolinol (SALS) seems to be a selective and potent stimulator of PRL secretion both in vivo and in vitro. 1-Methyl dihydroisoquinoline (1MeDIQ) is an antagonist of salsolinol induced prolactin release and causes increase in plasma norepinephrine (NE) level. SALS decreased the peripheral tissue dopamine (DA) level dose depende...