Uchida N, Makino T, Sugahara M, Ui K, Iizuka R
Endocrinol Jpn. 1984 Dec;31(6):831-5. doi: 10.1507/endocrj1954.31.831.
To investigate the pituitary response to exogenous growth hormone releasing factor (GRF) during pregnancy, pregnant (from Day 7 to Day 16) and non-pregnant rats were cannulated through a femoral vein, then hpGRF-44 (1.0 microgram) or saline was administered intravenously under anaesthesia with pentobarbital sodium. An initial blood sample was drawn off before the administration and subsequent samples were taken at 5, 10, 15 and 20 min post injection for measurement of plasma growth hormone (GH) values by radioimmunoassay. In a group of pregnant rats (n = 9), a mean concentration of plasma GH was increased to a peak in 10 min, from 132.5 +/- 14.9 ng/ml (mean +/- S.E.) to 864.4 +/- 175.1 ng/ml after hpGRF-44 administration. The mean value for non-pregnant rats (n = 6) reached a peak in 5 min from 164.5 +/- 34.1 ng/ml to 921.2 +/- 257.2 ng/ml. The injection of saline produced no changes in plasma GH concentrations in pregnant (n = 4) or non-pregnant (n = 3) rats. Moreover no significant difference in plasma GH responses to hpGRF-44 was found between early (from Day 7 to Day 8, n = 5) and late (from Day 15 to Day 16, n = 4) pregnant rats. The data indicate that the plasma GH levels following the administration of hpGRF-44 were not different between pregnant and non-pregnant rats, though the pregnant pituitary responses to hpGRF-44 were delayed a little longer than those of the non-pregnant pituitary.
为研究孕期大鼠垂体对外源性生长激素释放因子（GRF）的反应，将怀孕（第7天至第16天）和未怀孕的大鼠通过股静脉插管，然后在戊巴比妥钠麻醉下静脉注射人胰高血糖素样肽-44（hpGRF-44，1.0微克）或生理盐水。给药前采集初始血样，给药后5、10、15和20分钟采集后续血样，采用放射免疫分析法测定血浆生长激素（GH）值。在一组怀孕大鼠（n = 9）中，血浆GH平均浓度在10分钟内升至峰值，从132.5±14.9纳克/毫升（平均值±标准误）升至hpGRF-44给药后的864.4±175.1纳克/毫升。未怀孕大鼠（n = 6）的平均值在5分钟内达到峰值，从164.5±34.1纳克/毫升升至921.2±257.2纳克/毫升。注射生理盐水后，怀孕（n = 4）或未怀孕（n = 3）大鼠的血浆GH浓度无变化。此外，早期（第7天至第8天，n = 5）和晚期（第15天至第16天，n = 4）怀孕大鼠对hpGRF-44的血浆GH反应无显著差异。数据表明，尽管怀孕大鼠垂体对hpGRF-44的反应比未怀孕大鼠垂体延迟稍长，但hpGRF-44给药后怀孕和未怀孕大鼠的血浆GH水平并无差异。
