TY - JOUR
T1 - 1Pulsatility of reproductive hormones
T2 - Physiological basis and clinical implications
AU - Clarke, I. J.
AU - Cummins, J. T.
PY - 1987/1/1
Y1 - 1987/1/1
N2 - The secretion of LHRH from the median eminence, into hypophyseal portalblood provides a signal whereby the central nervous system interfaces with the endocrine system. The pulsatile nature of this system originates from phasic neural signals and, except in extreme cases where pulses are elimnated by the pituitary action of steroids, pulse frequency is determined by LHRH secretion. Steroidal feedback and other extrinsic influences that affect pulse frequency act via neural afferents to the LHRH neurons. Amplitude regulation may be by way of steroidal influence at the level of the pituitary gland, or indirectly via changes in LHRH pulse frequency. In this chapter, we have attempted to outline our current knowledge of factors regulating LHRH pulsatility and how this is transmitted into pulsatile gonadotrophin secretion. Regarding PRL secretion, we have outlined evidence that pulsatility is inherent in the lactotrophs, requiring no hypothalamic input. The possible roles of PRL releasing factors in circumstances like suckling and stress and of PRL inhibiting factors have been discussed with reference to the pulsatile nature of PRL secretion.
AB - The secretion of LHRH from the median eminence, into hypophyseal portalblood provides a signal whereby the central nervous system interfaces with the endocrine system. The pulsatile nature of this system originates from phasic neural signals and, except in extreme cases where pulses are elimnated by the pituitary action of steroids, pulse frequency is determined by LHRH secretion. Steroidal feedback and other extrinsic influences that affect pulse frequency act via neural afferents to the LHRH neurons. Amplitude regulation may be by way of steroidal influence at the level of the pituitary gland, or indirectly via changes in LHRH pulse frequency. In this chapter, we have attempted to outline our current knowledge of factors regulating LHRH pulsatility and how this is transmitted into pulsatile gonadotrophin secretion. Regarding PRL secretion, we have outlined evidence that pulsatility is inherent in the lactotrophs, requiring no hypothalamic input. The possible roles of PRL releasing factors in circumstances like suckling and stress and of PRL inhibiting factors have been discussed with reference to the pulsatile nature of PRL secretion.
UR - http://www.scopus.com/inward/record.url?scp=0023616062&partnerID=8YFLogxK
U2 - 10.1016/S0950-351X(87)80050-2
DO - 10.1016/S0950-351X(87)80050-2
M3 - Article
C2 - 3297019
AN - SCOPUS:0023616062
SN - 0950-351X
VL - 1
SP - 1
EP - 21
JO - Bailliere's Clinical Endocrinology and Metabolism
JF - Bailliere's Clinical Endocrinology and Metabolism
IS - 1
ER -