Using microcannulation procedures, we propose (1) to investigate under in vivo conditions the mechanisms whereby anterior and posterior pituitary hormones are secreted into pituitary stalk blood resulting in super-high concentrations in stalk plasma of LH, FSH, TSH, prolactin, ACTH, alpha-MSH, and vasopressin; (2) to determine the role of posterior pituitary hormones in the control of anterior pituitary hormone secretion; (3) to investigate the role of thyroid hormones, gonadal steroids, and adrenal steroids in the secretion of pituitary hormones into stalk blood; (4) to investigate the significance of retrograde blood flow in the pituitary stalk in the delivery of pituitary hormones to, and their transport across, the median eminence and hence to the brain; (5) to determine the mechanisms involved in the hypothalamic secretion of LHRH, TRH, and dopamine into hypothalamic-hypophysial portal blood. Using in vitro conditions, we propose (1) to characterize the subcellular compartmentalization of LHRH, TRH, and alpha-MSH in synaptosome-like particles, hereafter called synaptosomes, prepared from hypothalamic homogenates; (2) to investigate the mechanisms involved in the storage and release of LHRH, TRH, and alpha-MSH from synaptosomes; (3) to test the hypothesis that Ca 2 ion in the presence of depolarizing concentrations of K ion causes TRH, LHRH, and alpha-MSH release from synaptosomes by activating guanylate cyclase and/or adenylate cyclase, thereby forming cGMP and/or cAMP; (4) to investigate the role of synaptosomal microtubules, tubulin, and microfilaments in the exocytosis of TRH, LHRH, and alpha-MSH; (5) to investigate the role of prostaglandins, viz., PGE2 and PGF2 alpha, prostaglandin precursors, and phospholipids enriched with arachidonic acid and lysophospholipids in the release of TRH, LHRH, and alpha-MSH from synaptosomes.

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National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
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Biochemical Endocrinology Study Section (BCE)
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University of Texas Sw Medical Center Dallas
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Kedzierski, W; Aguila-Mansilla, N; Kozlowski, G P et al. (1994) Expression of tyrosine hydroxylase gene in cultured hypothalamic cells: roles of protein kinase A and C. J Neurochem 62:431-7
Aguila-Mansilla, N; Kedzierski, W; Porter, J C (1993) Localization of a defect in hypothalamic dopaminergic neurons of the aged brain that results in impaired PKA-dependent activation of tyrosine hydroxylase. J Pharmacol Exp Ther 267:171-5
Aguila-Mansilla, N; Jorquera, B A; Kedzierski, W et al. (1991) Effect of cerebroventricular anterior pituitary grafts on in situ expression of tyrosine hydroxylase in dopaminergic neurons of the aged animal. Endocrinology 128:1303-9
Kedzierski, W; Porter, J C (1991) A novel non-enzymatic procedure for removing DNA template from RNA transcription mixtures. Biotechniques 10:210-4
Aguila-Mansilla, N; Kedzierski, W; Porter, J C (1991) Testicular inhibition of tyrosine hydroxylase expression in tuberoinfundibular and nigrostriatal dopaminergic neurons. Endocrinology 129:877-82
Porter, J C; Aguila-Mansilla, N; Ramin, S M et al. (1991) Tyrosine hydroxylase expression in hypothalamic cells: analysis of the roles of adenosine 3',5'-monophosphate- and Ca2+/calmodulin-dependent protein kinases in the action of pituitary cytotropic factor. Endocrinology 129:2477-85
Kedzierski, W; Porter, J C (1990) Quantitative study of tyrosine hydroxylase mRNA in catecholaminergic neurons and adrenals during development and aging. Brain Res Mol Brain Res 7:45-51
Porter, J C; Kedzierski, W; Aguila-Mansilla, N et al. (1990) Expression of tyrosine hydroxylase in cultured brain cells: stimulation with an extractable pituitary cytotropic factor. Endocrinology 126:2474-81
Porter, J C; Kedzierski, W; Aguila-Mansilla, N et al. (1990) The tuberoinfundibular dopaminergic neurons of the brain: hormonal regulation. Adv Exp Med Biol 274:1-23
Moss, I R; Inman, J G; Porter, J C et al. (1990) Ontogeny of plasma, CSF and brainstem ACTH in piglets: effects of hypoxia and anesthesia. Neuroendocrinology 51:586-91

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