Colonic transit in rats: effect of ovariectomy, sex steroid hormones, and pregnancy
In vitro studies suggest that the female sex steroid hormones (estrogen (E) and progesterone (P)) can affect the myoelectric and mechanical activity of colonic smooth muscle. The present study was designed to examine the influence of the hormones on colonic transit in vivo. Transit was assessed by quantifying the distribution within the colon of a radiolabeled marker (0.5 Ci Na2V CrO4), using the geometric center method of analysis. Studies were performed with adult male rats and the following groups of female rats: nonpregnant, ovariectomized, ovariectomy plus hormone pretreatment, and pregnant (day 18). Hormone-pretreated animals were studied 24 h following the fourth injection. The data can be summarized as follows. 1) Colonic transit was affected by the timing of the estrus cycle. 2) Ovariectomy eliminated the biphasic transit pattern observed in estruscycling females and resulted in a geometric center value comparable with that of the metestrus-diestrus animals. 3) E + P pretreatment of ovariectomized rats resulted in a significant decrease in the geometric center compared with the untreated ovariectomized rats. 4) The geometric center value in pregnant anials and hormone-pretreated animals. 5) Adult male rats had a geometric center value of 4.12 +/- 0.29. The results suggest that a relation exists between colonic transit and the circulating levels of the steroid hormones.
- Research Organization:
- Temple Univ. School of Medicine, Philadelphia, PA
- OSTI ID:
- 6151734
- Journal Information:
- Am. J. Physiol.; (United States), Vol. 251:1
- Country of Publication:
- United States
- Language:
- English
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CHROMIUM 51
TISSUE DISTRIBUTION
ESTROGENS
BIOLOGICAL EFFECTS
LARGE INTESTINE
PHYSIOLOGY
PROGESTERONE
CHROMATES
FEMALES
MALES
OVARIES
PREGNANCY
RATS
SODIUM COMPOUNDS
SURGERY
ALKALI METAL COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CHROMIUM COMPOUNDS
CHROMIUM ISOTOPES
DIGESTIVE SYSTEM
DISTRIBUTION
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
FEMALE GENITALS
GASTROINTESTINAL TRACT
GONADS
HORMONES
INTERMEDIATE MASS NUCLEI
INTESTINES
ISOTOPES
KETONES
MAMMALS
MEDICINE
NUCLEI
ORGANIC COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PREGNANES
RADIOISOTOPES
RODENTS
STEROID HORMONES
STEROIDS
TRANSITION ELEMENT COMPOUNDS
VERTEBRATES
551001* - Physiological Systems- Tracer Techniques