Four readily identifiable changes in appearance of corpora lutea (Stages I to IV) occur during a bovine estrous cycle. Accuracy of estimating the stage of an estrous cycle by appearance of corpora lutea was determined in a double-blind study. One investigator observed estrus in a group of heifers while another with no prior knowledge of reproductive histories of the heifers estimated stage of the estrous cycle by visual inspection of their corpora lutea. Stage of the estrous cycle (Stage I, days 1 to 4; Stage II, days 5 to 10; Stage III, days 11 to 17; Stage IV, days 18 to 20) was estimated correctly in 41 of 48 heifers. The correlation between estimated and actual days of the estrous cycle was .81. In addition, concentrations of progestins and weights of corpora lutea during estimated stages of the estrous cycle were similar to many other investigations. Stages of the estrous cycle in heifers can be estimated from appearance of corpora lutea.

Twenty-nine patients with polycystic ovary syndrome (PCOS) and 30 normal women had lipoprotein lipid and androgen profiles compared after a 12-h fast. Both PCOS and normal women were evaluated in the proliferative phase of the cycle. PCOS patients had higher serum LH to FSH ratios [2.0 +/- 1.3 (+/- SEM) vs. 0.6 +/- 0.1), higher testosterone (T; 66 +/- 5 vs. 33 +/- 2 ng/ml), higher free T (1.1 +/- 1 vs. 0.4 +/- 0.02 ng/dl), and higher dehydroepiandrosterone sulfate (291 +/- 28 vs. 140 +/- 12 micrograms/dl) levels, and lower T-estrogen-binding globulin-binding capacity (1.5 +/- 0.2 vs. 2.2 +/- 0.1 micrograms/dl) than normal women (all P less than 0.05). The PCOS patients had higher mean serum triglycerides [122 +/- 11 (+/- SEM) 63 +/- 3 mg/dl] and very low density lipoprotein cholesterol levels (24 +/- 2 vs. 13 +/- 1 mg/dl), but lower high density lipoprotein cholesterol levels (43 +/- 2 vs. 58 +/- 2 mg/dl; P less than 0.05). While PCOS patients were heavier and more sedentary and their diets were higher in saturated fat and lower in fiber (P less than 0.01, respectively), the differences in lipoprotein lipid concentrations could not be attributed to body weight. T-estrogen-binding globulin-binding capacity correlated with high density lipoprotein cholesterol in PCOS patients (r = 0.42; P = 0.025) after adjusting for weight. We conclude that hyperandrogenemia in women may result in a male pattern of lipoprotein lipid concentrations. These findings suggest that PCOS patients may have increased atherogenic potential.

Estrogen and progestin concentrations in plasma and follicular fluid (FF) of follicles within the small (5 to 100/A), medium (101 to 400 gd) and large (>400 gtl) range, numbers of follicles and volume of FF per follicle within these ranges were determined in beef heifers. There were differences (P<.01) in mean concentrations (+SE) of steroids among and within follicles from the small, medium and large ranges during the estrous cycle. Concentrations of progestins were highest in follicles within the small range (178-+ 12 ng/ml);-whereas, concentrations of estrogens were highest in follicles in the large range (55 + 8 ng/ml). Mean ratio of progestins: estrogens was 12:1 in small follicles, 4:1 in medium follicles and 2:1 in large follicles. Volumes of FF from follicles within the small, medium and large ranges varied (P<.01) throughout a cycle. Mean volumes of FF from follicles in the medium and large range increased 130% and 180%, respectively, as time of ovulation neared. In contrast, mean volumes of FF from follicles within the small range decreased 170%. Total numbers of follicles per pair of ovaries and heifers with follicles in the large range increased (P<.01) toward the end of the estrous cycle.

The effect of estrogen stimulation in vitro on the electrical properties of vascular smooth muscle (VSM), and the concentration of estrogen receptors in VSM were measured in isolated coronary arteries. Microelectrode measurements of the dog coronary artery membrane potential (Em) showed quiescent values of -51 millivolts (mV) and an input resistance (rin) of 10 megohms. Addition by diethylstilbestrol (DES) at 10(-6) M hyperpolarized the membrane to -64 mV and reduced input resistance (rin) to 5 megohms within 15 minutes. Extrapolation of the Em vs. log [K]o curve to zero potential gave similar values of [K]i of around 170 mM in both normal and DES treated muscles suggesting that the DES induced hyperpolarization is not due to increased Na-K pump activity. The 0.5% ethanol vehicle alone had no effect on the membrane potentials. Tetraethylammonium ion (TEA) induced action potentials in the previously quiescent tissue. When DES was applied in the presence of TEA, the membrane potential increased and the action potentials were abolished. Scatchard analysis of the estrogen receptor binding demonstrated both a high and a low affinity receptor for estrogen in the VSM. These data indicate that DES hyperpolarizes the VSM cells by a mechanism other than an increased Na-K pump activity. The mechanism of this increased Em may be due to factors which increase K+ conductance either mediated directly through estrogen interaction with its cytosolic receptors or through some unidentified second mechanism.

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