On the Possibility of Participation of Histamine Neurons in Suppression of Luteinizing Hormone Secretion by Fasting in Rats.

Accession number;00A0751188
Title;On the Possibility of Participation of Histamine Neurons in Suppression of Luteinizing Hormone Secretion by Fasting in Rats.
Author;
Journal Title;Anim Sci J
Journal Code:F0902A
ISSN:1344-3941
VOL.71;NO.4;PAGE.400-408(2000)
Figure&Table&Reference;FIG.3, REF.38
Pub. Country;Japan
Language;English
Abstract;The effect of intracerebroventricular (ICV) infusion of histamine (HA) on the pulsatile luteinizing hormone (LH) secretion was investigated in normally fed and 48 h-fasted ovariectomized estradiol-primed (OVX E2-primed) rats. An immunohistochemical study was also conducted to examine the effect of 48 h-fasting on the distribution of HA in posterior and mid portions of the hypothalamus of OVX E2-primed rats. Blood samples for LH assay were collected via atrial indwelling catheter at 6 min intervals for 3 h, and 10 .MU.l of HA solution (1 .MU.g/.MU.l) were infused into the third ventricle over 60 min of the second one h period of blood sampling. ICV infusion of HA caused a significant depression of mean LH concentration during the period of drug infusion in normally fed rats. The effect of HA infusion was not clear in fasted animals, although the LH release also tended to decrease during the infusion. In immunohistochemical study, no eminent effect of fasting on the occurrence and size of HA positive particles was observed in any area of posterior and mid portions of the hypothalamus. These results indicate a possibility that HA is involved in the mechanism of the suppression of LH secretion by fasting at least in the conditions examined. (author abst.)