Neurohumoral control of the anterior pituitary gland

Effects of Corticosteroids on Hypothalamic Corticotropin Releasing Factor and Pituitary ACTH Content

“…The crude acidic extract was frozen for 14-16 h prior to use. Bioassay of the CRF in the SME extract was performed by using Nembutal-dexamethasonc blocked rats as described by Martini et al (1963). The extract of the SME was diluted in such a way that 2 stalks were contained in each ml o f vehicle; 1 ml per 200 g of body weight was injected intravenously (i.v.)…”

Site of Action of Vasopressin in Causing Corticotropin Release1

“…Nevertheless, the action of vasopressin in provoking corticotropin (ACTH) release is not like that of many nonspecific stimuli that activate the adrenocortical system. The ACTH release that follows a wide variety of nonspecific stimuli can be prevented by pretreatment with corticosteroids (8)(9)(10)(11)(12)(13)(14), but such pretreatment usually does not abolish the corticotropin-releasing activity of Pitressin or vasopressin (6,15,16). It seems possible that vasopressin may perturb the adrenocortical system in a unique manner, even if it is not CRF.…”

Excerpts from the Pharmacology of Hormones and Related Substances

“…This problem, of a well recognized complexity, has been ap proached by different methods outlined as follows: (a) production of thermal or electrolytic lesions (26,27) or by electrical stimulation (28,29,30) in restricted hypothalamic areas using electrodes stereotaxically placed j (b) hypothalamic lesions provoked by systemic injections of drugs such as aurothioglucose (31,32) j (c) injections of minute amounts of mediators either into the third and lateral ventricles (33,34) or directly within the hypothala mus, tuber or pituitary (35,36,37) j (d) stereotaxic implantation of hormone micro-pellets e.g. testosterone (38,39) and hydrocortisone (40) j (e) intra hypothalamic and intrapituitary thyroid and ovary grafts as in the experi ments of Bogdanove & Crabill (41) j (f) indirect stimulation of the hypothala mic region through intracerebral injections of hypertonic sodium chloride solution (42) or local application in the cerebral cortex of a 5 percent epi nephrine sol u tion (43) j (g) assays of hypothalamic extracts from various sources for their content in humoral factors (44) , enzymes (45,46) and pharmaco logically active substances (47,48). Recently the following hypothalamic factors have attracted the attention of investigators.…”