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Biomedical subjects

W A Chamley

Publications and source records attributed to W A Chamley.

At least 37 records · Page 2Linked to original sources
PubMed1977

In vitro response of relaxin-treated rat uterus to prostaglandins and oxytocin.

Paired segments of rat uterus were treated in vitro with relaxin (W1164-3, 150 GPU/mg) until the amplitude of contraction was reduced to at least 50% of the pre-treatment amplitude. Test segments then received 100 ng of either PGE1, PGE2, PGF2alpha or 250 uU of oxytocin. Control segments remained untreated. There was a significant increase in contraction amplitude in response to the spasmogens (P less than 0.05) but no increase was seen in controls.

Animals↗
PubMed1976

Luteal function in sheep injected with prostaglandin F2alpha directly into the corpus luteum.

Groups of ewes received either saline or prostaglandin F2alpha (PGF2alpha) as an injection directly into the corpus luteum. Changes in circulating progesterone levels were measured as well as subsequent histological examination of the corpora lutea. Saline, or PGF2alpha given at the two lower doses (60 and 120 mug respectively), failed to suppress progesterone levels permanently, or to induce degenerative changes in the corpora lutea. Treatment with a higher dose of PGF2alpha (240 mug) was followed by a marked elevation in progesterone levels. These results are discussed in relation to reported effects of PGF2alpha arriving at the ovary via the arterial circulation.

Animals↗
PubMed1976

Content of LH, FSH, and growth hormone in the pituitaries of pregnant and anestrous sheep.

The total content of LH, FSH, and growth hormone was measured in pituitaries from anestrous ewes and from ewes at known stages of pregnancy. LH content was lower in the pregnant ewes than in the anestrous group. Compared with the anestrous group, a significant drop in mean LH content was seen by days 40-50 of pregnancy (894 vs 350 mug, P less than 0.001), and it reached its lowest value by 120-135 days of pregnancy (43 mug, P less than 0.001). In sheep 148 days of pregnant, mean LH content was higher than in the latter group (155 mug). The correlation coefficient between the stage of gestation and the LH content was 0.63 (P less than 0.01). There was no significant change in mean FSH content in ewes up to 135 days pregnant (range 1196-1550 mug) compared with anestrous ewes (1023 mug). In the group 148 days pregnant (531 mug), a significant decrease was seen compared with ewes at other stages of pregnancy (P less than 0.05). Stage of gestation and FSH content were poorly correlated (r = 0.07). No significant differences in growth hormone content were seen in any of the groups. The results suggest that the progressive reduction in LH response to synthetic GnRH which has been reported for pregnant sheep may be due to selective inhibition of LH biosynthesis.

Anestrus↗
PubMed1975

Plasma relaxin immunoactivity during the oestrous cycle of the ewe.

Plasma relaxin immunoactivity was measured every 2 hr during 4-day periods in a series of sheep to cover the 17-day period of the ovine oestrous cycle. The immunoactivity fluctuated considerably throughout eacn 4-day period, and a large betwee-animal variation was found. A marked episodic release, occurring at approximately 12.00 and 24.00 hours, was identified and shown to occur more regularly either at certain times of the cycle or in certain animals. Relaxin immunoactivity was high throughout the late pro-oestrous phase of the cycle (Days 15 and 16), and at 24 hr after the onset of the LH peak, conincidnet with the approximate time when ovulation occurs. Bursts of relaxin activity were found on Days 8 to 9 in one ewe, and Days 10 and 11 and 13 to 14 in another. There was no significant correlation between prolactin levels and relaxin immunoactivity in one ewe studied throughout the oestrous period.

Animals↗