Vaginal opening

Rodent 20-day pubertal female with thyroid age of rats at time of vaginal opening. 

Rat (Sprague-Dawley) 14-50 ad lib (W) 502 (decreased testicular weights delayed vaginal opening and disruption of estrus cycling) Ronis etal. 1996 PbAc... 

Rat (CD) 201-291 d ad lib 0.7 3.5 (delays in vaginal opening in pups) 7 (delayed righting reflex in pups) Grant etal. 1980... 

Depressed growth and delayed development in eye and vaginal opening during first 12 weeks all normal at necropsy after 15 weeks (Talamantes and Jang 1977)... 

Physical development including vaginal opening and preputial separation. 

F Sexual Dominant Earlier vaginal opening Lomas and Keverne,... 

At 25 mg/L and higher, growth retardation and 23 delayed vaginal opening obsen/ed some maternal deaths occurred and were associated with blood lead concentrations... 

Development Normality of external genitalia, vaginal opening, vaginal smear cytology, onset of estrous behaviour (menstruation)... 

Delayed vaginal opening, an effect suggesting retarded sexual maturation, was observed in F, generation rats whose only PBB exposure was from the mothers fed a diet providing 5 mg/kg/day FireMaster FF-1 from day 8 of pregnancy until weaning at 28 days postpartum (McCormack et al. 1981). 

Time of occurrence of developmental landmarks, such as eye opening, tooth eruption, vaginal opening in females, preputial separation in males. 

Caffeine, which is present in coffee, tea, cocoa and cola, but also in various over-the-counter medications, has been shown to be clearly teratogenic in rats in doses comparable to those ingested daily by many people (refs. 30, 47, 55). Vest et al. (ref. 47) found that a dose as small as 5 mg/kg caffeine (comparable to the content of 4 cups of coffee) administered on gestational days 3-19 in the rat, affected not only physical development (e.g. delayed incisor eruption in males and females, vaginal opening in females, slower growing body weight) but also development of the auditory startle reflex, food and water intake, passive and active avoidance at adult age. 

Growth and nutritional status may influence vaginal opening... 

Some cestodes (e.g. the Acoelidae) lack a vaginal opening and insemination apparently occurs by the well-armed cirrus being thrust into the tissues of the body wall from which spermatozoa migrate to the large seminal vesicle (889). The same mechanism occurs in some monogeneans, e.g. Diclidophora. 

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