TY - JOUR
T1 - The insulin hypoglycemia-induced inhibition of gonadotropin-releasing hormone pulse generator activity in the rhesus monkey
T2 - Roles of vasopressin and corticotropin-releasing factor
AU - Chen, Ming Dao
AU - Ördög, Tamás
AU - O'Byrne, Kevin T.
AU - Goldsmith, Jason R.
AU - Connaughton, Martin A.
AU - Knobil, Ernst
PY - 1996
Y1 - 1996
N2 - Insulin-induced hypoglycemia (IIH) profoundly inhibits the activity of the hypothalamic GnRH pulse generator. The aim of this study was to determine the role of vasopressin and CRF in this response. Ovariectomized rhesus monkeys with chronically implanted recording electrodes in the mediobasal hypothalamus and with intracerebroventricular (icv) cannulas in the lateral ventricle were placed in primate chairs, and blood samples were taken every 10 min. Pulse generator activity was monitored electrophysiologically by detecting characteristic increases in hypothalamic multiunit activity (MUA volleys) and by attendant LH pulses measured in peripheral blood. Arginine vasopressin (AVP) infused via the icv cannula (50 μg/60 μl · h) in eight monkeys failed to decrease pulse generator activity, as measured by the frequency of MUA volleys, but decreased mean serum LH concentrations (p < 0.001) while increasing serum cortisol levels (P < 0.02). Central administration of an AVP antagonist ([deamino-Pen1,O-Me-Tyr2,Arg8] vasopressin) in four monkeys at a rate (180 μg/60 μl · h) that had previously been found to block the aforementioned effects of coadministered AVP failed to prevent the IIH-induced inhibition of GnRH pulse generator activity and LH secretion in the same animals. On the other hand, a CRF antagonist, [D-Phe12, Nle21,38, CαMeLeu37]rat CRF-(12-41), infused icv at a rate of 500 μg/60 μl · h in four monkeys, delayed the inhibition of pulse generator frequency in response to IIH. These results suggest that AVP does not mediate the hypoglycemia-induced inhibition of GnRH pulse generator frequency in the rhesus monkey, but that CRF may be involved in this response.
AB - Insulin-induced hypoglycemia (IIH) profoundly inhibits the activity of the hypothalamic GnRH pulse generator. The aim of this study was to determine the role of vasopressin and CRF in this response. Ovariectomized rhesus monkeys with chronically implanted recording electrodes in the mediobasal hypothalamus and with intracerebroventricular (icv) cannulas in the lateral ventricle were placed in primate chairs, and blood samples were taken every 10 min. Pulse generator activity was monitored electrophysiologically by detecting characteristic increases in hypothalamic multiunit activity (MUA volleys) and by attendant LH pulses measured in peripheral blood. Arginine vasopressin (AVP) infused via the icv cannula (50 μg/60 μl · h) in eight monkeys failed to decrease pulse generator activity, as measured by the frequency of MUA volleys, but decreased mean serum LH concentrations (p < 0.001) while increasing serum cortisol levels (P < 0.02). Central administration of an AVP antagonist ([deamino-Pen1,O-Me-Tyr2,Arg8] vasopressin) in four monkeys at a rate (180 μg/60 μl · h) that had previously been found to block the aforementioned effects of coadministered AVP failed to prevent the IIH-induced inhibition of GnRH pulse generator activity and LH secretion in the same animals. On the other hand, a CRF antagonist, [D-Phe12, Nle21,38, CαMeLeu37]rat CRF-(12-41), infused icv at a rate of 500 μg/60 μl · h in four monkeys, delayed the inhibition of pulse generator frequency in response to IIH. These results suggest that AVP does not mediate the hypoglycemia-induced inhibition of GnRH pulse generator frequency in the rhesus monkey, but that CRF may be involved in this response.
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U2 - 10.1210/endo.137.5.8612542
DO - 10.1210/endo.137.5.8612542
M3 - Article
C2 - 8612542
AN - SCOPUS:0029996242
SN - 0013-7227
VL - 137
SP - 2012
EP - 2021
JO - Endocrinology
JF - Endocrinology
IS - 5
ER -