After control measurements had been made, 15 chronically catheterized pregnant ewes (gestational age 123-141 days) were given 15 mg of captopril intravenously followed by an infusion of 6 mg/h. These doses blocked the pressor responses of both ewes and fetuses to 5 micrograms of angiotensin I. After captopril, maternal mean arterial pressure fell from 94 +/- 3.5 to 88 +/- 3.6 (SE) mmHg (P less than 0.0001) and pulse interval fell (P = 0.008). Maternal flow to the cotyledons fell from 766 +/- 118 to 525 +/- 77 ml/min (P = 0.002), as did flow to the remainder of the maternal placenta, i.e., the caruncles and their underlying myoendometrium (control flow 188 +/- 35 ml/min, flow 10-15 min after captopril 166 +/- 36.1 ml/min; P = 0.021). Flow to the rest of the myometrium did not change. Fetal arterial pressure fell from 46.9 +/- 1.6 to 44.1 +/- 1.6 mmHg (P less than 0.009), and fetal placental blood flow fell from 639.9 +/- 93.2 to 413.1 +/- 53.9 ml/min (P = 0.025). Flow to the fetal membranes declined also, from 53.2 +/- 6.5 to 35.6 +/- 3.3 ml/min (P less than 0.005). Maternal and fetal renal blood flows and fetal adrenal blood flows were unchanged. Fetal arterial PO2 was initially 19.5 +/- 0.8 mmHg; after captopril, it was 17.7 +/- 0.9 mmHg (P = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

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A diagnostic ultrasound unit with a 5 MHz probe was used to examine ovarian structures in vitro from 32 reproductive tracts obtained at slaughter from young cows. Agreement between and within observers, and between observers and dissection results was evaluated using the kappa statistic. Agreement was high (kappa from 0.531 to 0.969) for all evaluations of corpora lutea. The sensitivity, specificity and predictive value of both positive and negative findings for presence of a corpus luteum was > 0.9. Agreement between and within observers was little better than chance for follicles measuring 4 to < 6 mm and for follicles measuring 6 to < 10 mm. However, agreement between observers and dissection results indicated that observers could detect follicles 4 to < 6 mm and 6 to < 10 mm (kappa 0.301 to 0.731 and 0.414 to 0.612, respectively). Kappa values within and between observers and between observers and dissection results for observations of follicles measuring > or = 10 mm were almost all > 0.4 indicating that large follicles can be readily detected using ultrasound. It is suggested that further validation of ultrasound methods is needed to determine whether follicles measuring < 4 mm can be accurately identified, and whether follicles can be accurately identified and monitored over a number of days. The ultrasound unit was useful for detecting the presence of corpora lutea and follicles. However, agreement between and within observers on the presence of follicles measuring < 10 mm was poor.