Strain differences in the response to the 5-HT1A receptor agonist, 8-OH-DPAT.
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.
Uphouse
Lynda
L
Department of Biology, Texas Woman's University, P.O. Box 425799, Denton 76204-5799, USA. luphouse@twu.edu
Maswood
Sharmin
S
Jackson
Astra
A
Brown
Karen
K
Prullage
Julia
J
Myers
Tonya
T
Shaheen
Farzana
F
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D010052:Ovariectomy; D011187:Posture / Q000502:physiology; D051381:Rats; D011916:Rats, Inbred F344; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000502:physiology*; D044263:Receptors, Serotonin, 5-HT1; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology; D013045:Species Specificity
D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D017366:Serotonin Receptor Agonists; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin