Uphouse Lynda, Maswood Sharmin, Jackson Astra, Brown Karen, Prullage Julia, Myers Tonya, Shaheen Farzana
Department of Biology, Texas Woman's University, P.O. Box 425799, Denton 76204-5799, USA.
Pharmacol Biochem Behav. 2002 Jun;72(3):533-42. doi: 10.1016/s0091-3057(02)00714-1.
Fischer and Sprague-Dawley ovariectomized rats were hormonally primed with estradiol benzoate (EB) and progesterone, and the ability of the 5-HT(1A) receptor agonist, (+/-) 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), to inhibit lordosis behavior was examined. Both strains showed rapid inhibition of lordosis behavior following either intraperitoneal or subcutaneous treatment with 8-OH-DPAT. Similarly, in both strains, pretreatment with EB (1 week prior to estrogen and progesterone priming) attenuated the lordosis-inhibiting effects of 8-OH-DPAT. However, Sprague-Dawley females showed a greater decline in lordosis behavior with a lower dose of 8-OH-DPAT than did Fischer females. The strain difference was present in females that had been preprimed with EB as well as in females receiving a single estrogen and progesterone priming. Moreover, strain differences were present across different priming doses of EB. Sprague-Dawley females were also more likely to show flat body posture after injection with 8-OH-DPAT so that the greater sensitivity of this strain to the 5-HT(1A) receptor agonist was not restricted to the drug's effect on lordosis behavior. These findings lead to the suggestion that, relative to Fischer rats, Sprague-Dawley females are more responsive to the 5-HT(1A) receptor agonist. Possible explanations for this strain difference are discussed.
对费希尔大鼠和斯普拉格-道利大鼠进行卵巢切除术后，用苯甲酸雌二醇（EB）和孕酮进行激素预处理，然后检测5-羟色胺（5-HT）1A受体激动剂（±）8-羟基-2-（二正丙基氨基）四氢萘（8-OH-DPAT）抑制脊柱前凸行为的能力。在用8-OH-DPAT进行腹腔内或皮下注射后，两个品系的大鼠脊柱前凸行为均迅速受到抑制。同样，在两个品系中，用EB预处理（在雌激素和孕酮预处理前1周）可减弱8-OH-DPAT对脊柱前凸的抑制作用。然而，与费希尔雌鼠相比，斯普拉格-道利雌鼠在使用较低剂量的8-OH-DPAT时脊柱前凸行为的下降幅度更大。在预先用EB预处理的雌鼠以及接受单次雌激素和孕酮预处理的雌鼠中均存在品系差异。此外，在不同剂量的EB预处理中也存在品系差异。注射8-OH-DPAT后，斯普拉格-道利雌鼠也更易出现身体平展姿势，因此该品系对5-HT1A受体激动剂的更高敏感性并不局限于药物对脊柱前凸行为的影响。这些发现表明，相对于费希尔大鼠，斯普拉格-道利雌鼠对5-HT1A受体激动剂的反应更强。文中讨论了造成这种品系差异的可能原因。
