TY - JOUR
T1 - Intensive direct cavernous sinus sampling identifies high-frequency, nearly random patterns of FSH secretion in ovariectomized ewes
T2 - Combined appraisal by RIA and bioassay
AU - Clarke, Iain
AU - Moore, Lloyd
AU - Veldhuis, Johannes
PY - 2002
Y1 - 2002
N2 - Analyses of FSH secretion suggest pulsatile, nonpulsatile, or compositely pulsatile and nonpulsatile release modes. This may reflect the reduced signal-to-noise ratio inherent in FSH pulse estimation procedures and/or immunological-biological assay inconsistencies. To address these issues, we sampled cavernous sinus and jugular venous blood concomitantly from ovariectomized sheep at either 5-min or 1-min intervals. Samples from the former were assayed by RIA, and those from the latter by RIA and bioassay. Waveform-independent peak detection revealed FSH pulses occurring at high frequency. Pulsatile FSH secretion accounted for 28% of total secretion. Approximate entropy analysis showed that FSH secretion was nearly random. There was synchronous release of LH and FSH, but most FSH secretion was not associated with LH release; 13% of discrete FSH and LH pulses were concordant. We infer that FSH secretion exhibits pulsatile and basal/nonpulsatile features, with high-entropy features. Linear and non-linear statistical measures revealed joint sample-by-sample synchrony of FSH and LH release, indicating pattern coordination despite sparse synchrony of pulses. We postulate that pattern synchrony of FSH and LH release is effected at the level of the gonadotrope. Concordant FSH and LH pulses probably result from pulsatile GnRH input, but other mechanisms could account for independent FSH pulses.
AB - Analyses of FSH secretion suggest pulsatile, nonpulsatile, or compositely pulsatile and nonpulsatile release modes. This may reflect the reduced signal-to-noise ratio inherent in FSH pulse estimation procedures and/or immunological-biological assay inconsistencies. To address these issues, we sampled cavernous sinus and jugular venous blood concomitantly from ovariectomized sheep at either 5-min or 1-min intervals. Samples from the former were assayed by RIA, and those from the latter by RIA and bioassay. Waveform-independent peak detection revealed FSH pulses occurring at high frequency. Pulsatile FSH secretion accounted for 28% of total secretion. Approximate entropy analysis showed that FSH secretion was nearly random. There was synchronous release of LH and FSH, but most FSH secretion was not associated with LH release; 13% of discrete FSH and LH pulses were concordant. We infer that FSH secretion exhibits pulsatile and basal/nonpulsatile features, with high-entropy features. Linear and non-linear statistical measures revealed joint sample-by-sample synchrony of FSH and LH release, indicating pattern coordination despite sparse synchrony of pulses. We postulate that pattern synchrony of FSH and LH release is effected at the level of the gonadotrope. Concordant FSH and LH pulses probably result from pulsatile GnRH input, but other mechanisms could account for independent FSH pulses.
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U2 - 10.1210/endo.143.1.8644
DO - 10.1210/endo.143.1.8644
M3 - Article
C2 - 11751600
AN - SCOPUS:0036142588
SN - 0013-7227
VL - 143
SP - 117
EP - 129
JO - Endocrinology
JF - Endocrinology
IS - 1
ER -