Anterior pituitary nucleotides

Dopamine can thus be added to the list of hormones and neurotransmitters which can stimulate or inhibit cyclic AMP formation, depending upon their tissue of action. Thus, while dopamine stimulates cyclic AMP formation in parathyroid cells, superior cervical ganglia, retina and striatal tissue (27, 58-61), it inhibits the accumulation of the cyclic nucleotide in cells of the intermediate and anterior lobes of the pituitary gland. Opposite effects on the cyclic AMP system are also found with LHRH which stimulates and inhibits cyclic AMP levels in the anterior pituitary gland (62) and ovary (63), respectively. Similarly, alpha-adrenergic agents show opposite effects on cyclic AMP formation in brain (64) and platelets (65). PGE, stimulates cyclic AMP formation in the anterior pituitary gland (62) while it inhibits the same parameter in fat cells (66). 

All the data presented above point to the involvement of a putative guanine nucleotide binding protein in the interaction of agonists with the dopamine receptor in the porcine anterior pituitary gland. We, therefore, wanted to obtain more compelling evidence for the interaction of a nucleotide binding... 

Perrin MH, Haas Y, Rivier JE, Vale WW (1986) Corticotropinreleasing factor binding to the anterior pituitary receptor is modulated by divalent cations and guanyl nucleotides. Endocrinology 118 1171-9... 

Prostaglandins have been associated with neurotransmitter release and synaptic regulation at specific nerve synapses. They have also been reported to influence cyclic nucleotide turnover and the release of anterior pituitary hormones. They may also be involved with fever and temperature regulation. Their participation in many other central nervous system functions as second messengers has also been documented, but in deference to brevity only the topics listed above will be briefly discussed. 

In addition to steroids, pharmacological compounds such as serotonin and epinephrine activate transhydrogenases. A particulate pyrimidine nucleotide transhydrogenase was obtained from anterior beef pituitary, which is stimulated by epinephrine, estradiol, and serotonin. 

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