The broad and long-term objective of this ongoing research program is to elucidate the neuroendocrine control systems which govern reproductive processes in a representative primate, the rhesus monkey. The principal thrust of this investigation is to characterize the hypothalamic pulse generator which governs the circhoral discharges of the gonadotropic hormones congruent to the release of GnRH into the pituitary portal circulation. As a first step, the description of the electrophysiological correlates of pulsatile gonadotropin release and their source(s) will be completed. The modulation of this electrophysiological activity by gonadal hormones and pharmacological agents known to modify gonadotropin secretion will then be studied to determine the possible role of pulse generator activity in the mode of action of these agents. Lastly, the electrophysiological activity of the pulse generator in physiologic as well as pathophysiologic contexts will be investigated using telemetry of signals from chronically implanted hypothalamic recording electrodes. These studies will include the normal menstrual cycle, pregnancy and parturition, the influence of suckling and the advent of puberty. The effects of mild restraint and the introduction of cardiac catheters previously shown to interfere with normal hypophysial-ovarian function will also be examined.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD017438-04
Application #
3314431
Study Section
Reproductive Biology Study Section (REB)
Project Start
1982-07-01
Project End
1986-12-31
Budget Start
1985-01-01
Budget End
1985-12-31
Support Year
4
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of Texas Health Science Center Houston
Department
Type
Schools of Medicine
DUNS #
City
Houston
State
TX
Country
United States
Zip Code
77225
Chen, M D; Ordog, T; Knobil, E (1998) Mitigation of the somnolence of insulin-induced hypoglycemia by a vasopressin V1 receptor antagonist in the rhesus monkey. Psychoneuroendocrinology 23:497-503
Ordog, T; Chen, M D; O'Byrne, K T et al. (1998) On the mechanism of lactational anovulation in the rhesus monkey. Am J Physiol 274:E665-76
Ordog, T; Goldsmith, J R; Chen, M D et al. (1998) On the mechanism of the positive feedback action of estradiol on luteinizing hormone secretion in the rhesus monkey. J Clin Endocrinol Metab 83:4047-53
Ordog, T; Chen, M D; Nishihara, M et al. (1997) On the role of gonadotropin-releasing hormone (GnRH) in the operation of the GnRH pulse generator in the rhesus monkey. Neuroendocrinology 65:307-13
Chen, M D; Ordog, T; O'Byrne, K T et al. (1996) The insulin hypoglycemia-induced inhibition of gonadotropin-releasing hormone pulse generator activity in the rhesus monkey: roles of vasopressin and corticotropin-releasing factor. Endocrinology 137:2012-21
Ordog, T; Knobil, E (1995) Estradiol and the inhibition of hypothalamic gonadotropin-releasing hormone pulse generator activity in the rhesus monkey. Proc Natl Acad Sci U S A 92:5813-6
O'Byrne, K T; Chen, M D; Nishihara, M et al. (1993) Ovarian control of gonadotropin hormone-releasing hormone pulse generator activity in the rhesus monkey: duration of the associated hypothalamic signal. Neuroendocrinology 57:588-92
Grosser, P M; O'Byrne, K T; Williams, C L et al. (1993) Effects of naloxone on estrogen-induced changes in hypothalamic gonadotropin-releasing hormone pulse generator activity in the rhesus monkey. Neuroendocrinology 57:115-9
O'Byrne, K T; Knobil, E (1993) Electrophysiological approaches to gonadotrophin releasing hormone pulse generator activity in the rhesus monkey. Hum Reprod 8 Suppl 2:37-40
O'Byrne, K T; Thalabard, J C; Chiappini, S E et al. (1993) Ambient light modifies gonadotropin-releasing hormone pulse generator frequency in the rhesus monkey. Endocrinology 133:1520-4

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