The vagina is a highly elastic and muscular tube-like female reproductive organ that links the cervix to the vulva. In humans, the vagina is usually approximately four inches long and one inch in diameter. The size and shape of the vagina changes significantly during childbirth in order to accommodate the fetus as it is being delivered. At this time, the vagina is often called the birth canal. No glands are present in the vaginal wall, but secretions are produced by glands located near the opening of the organ.

Congenital anomalies, cancer, atrophic vaginitis, and bacterial infections are among the problems to which the vagina is susceptible. The typical microflora present in the human female genital tract differs from that normally found in the tract of the female rat. It has been suggested that this difference is likely related to a difference in vaginal pH (the pH of the rat vagina is higher than that of the human vagina). The main microorganisms present in the rat genital tract include Pasteurella pneumotropica, diphtheroid bacilli, alpha and nonhemolytic streptococci, Proteus mirabilis, and Staphylococcus epidermidis.

In the digital image above, a section of rat vagina tissue is presented that was labeled with the fluorophore Oregon Green 488 conjugated to wheat germ agglutinin, targeting the Golgi network. The sample was also labeled with Alexa Fluor 568 conjugated to phalloidin in order to target filamentous actin and with Hoechst 33342 to counterstain nuclear DNA. Images were recorded in grayscale with a 12-bit digital camera coupled to a Nikon Eclipse 80i microscope equipped with bandpass emission fluorescence filter optical blocks. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.

Localizing Fluorescent Tags to F-Actin and Golgi Complexes in Rat Vagina Tissue Sections - Studies of the rat reproductive tract are often used to determine the extent that various substances, environmental hazards, or medical conditions may affect the human reproductive tract. For example, one research group recently investigated the effect of experimental diabetes on neurotransmission in rat vaginal smooth muscle. Their findings indicated that diabetes disturbs adrenergic-, cholinergic- and NANC-neurotransmitter mechanisms.

Rat Vagina Tissue Labeled with Alexa Fluor 568, Oregon Green 488, and Hoechst 33342 - Changes in the vagina often occur with hormonal changes in the female. For instance, a decrease in bodily estrogen levels is frequently associated with atrophic vaginitis, a condition characterized by vaginal dryness and irritation. Such a reduction in estrogen occurs after menopause, when the ovaries halt production of the hormone, and may also be associated with removal of the ovaries, pelvic x-rays, or breast-feeding.