Changes in the Weight and Water Content of the Uterus of the Normal Adult Rat

Abstract

The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.

Quantitative Changes in Uterine Nucleic Acids During the Oestrous Cycle in Rats

“…This was highest in early pro-oestrus and lowest in late di-oestrus. This change is similar to that described by Astwood (1939) but was not apparently found by Morgan (1963), nor by ourselves, using the Wistar strain. It is also to be noted that the content of water/unit DNA changed significantly, being highest at pro-oestrus and lowest in di-oestrus, changes which possibly reflect an increased water content/cell.…”

The Movement of Potassium Ions Across the Uterine Mucosa of the Rat

“…This suggests either that the uterine mucosa is more permeable to luminal K+ during late prooestrus tban during oestrus, or that the clearance of ''-K from tbe uterus during late prooestrus is less than in oestrus. Although the exact time of increased oestrogen secretion during the rat's oestrous cycle has not been measured directly, Astwood (1939) has suggested that the short duration of increased water content in the uterus whicb occurs during prooestrus is a reflection of a brief period of oestrogen secretion just prior to prooestrus. The work of Jensen and Jacobson (1962) has shown that rat uterine tissues retain and continue to bind injected oestradiol for about 6 hrs.…”

“…This was true if the following two conditions were satisfied: (1) the turnover of uterine fluid had reached a steady state, i.e., the '•-'K was instilled when no net transfer of K+ was occurring. This period corresponds to the "plateau" of uterine fluid turnover (Astwood, 1939) which begins during late prooestrus. (2) The specific activity of the solution introduced into the lumen was high, so that the ''^K transferred into the uterine wall, in exchange for endometrial K+, does not significantly alter the specific activity of the luminal fluid.…”

“…These changes are followed by the production of a copious amount of clear, watery fluid in the lumen of each uterine horn (Long and Evans, 1922;Astwood, 1939). Astwood has shown that the formation of uterine fluid is rapid initially and that its volume remains approx.…”

“…Since the high K+ fluid remains in the uterine lumen for 12 hrs. or more (Astwood, 1939), the question arises as to whether the K+ in it can traverse the endometrial epithelium and its basement membrane, to re-enter the interstitial fluid of the uterine wall during this time. The following experiments indicate that the K+ in the luminal fluid penetrates the endometrial mucosa and that a considerable amount of luminal K+ enters the endometrial and myometrial tissues.…”