Ovarian venaus cannulation has been a frequently used technique to estimate the secretion rates of ovarian steroids ( 1-9). Estimates of flow rates as determined by the total collected volume have exhibited considerable variation (3-9 ml/hr), depending on the length of the bleeding time and the endocrine status of the animal. Continuous measurements of flow rates following cannulation are not available. Determination of intact flow rates by IVurtman (10) indicates that administration of luteinizing hormone ( L H ) results in ovarian hyperemia and that this is the result of release of a vasoactive substance by LH from the ovary rather than a direct effect of LH. Further evidence for such a vasoactive substance is provided by the studies of Szego and Gitin (11) and more recently by Lipner ( 1 2 ) .The present investigation was undertaken to determine, through continuous measurement, changes in ovarian blood flow following cannulation and to evaluate the effects of L H and antihistamine treatment on these changes.Materials and Methods. Mature female rats (Holtzman Co., Madison, WT), 60-70 days of age, were kept in 14 hr photoperiods ( 5 a. m. to 7 p.m.) at 24 t 0.5". Feed (Wayne Lab. Blox, Allied Mills, Chicago, IL.) and water were administered ad libitum. Daily vaginal smears were taken to establish cyclicity. Only animals in diestrus were used throughout the experiment.All animals were injected via tail vein with 0.8 ml of test solution 20 min prior to cannulation. Animals were grouped into four categories according to treatment as follows; (group 1 ) 0.9% saline solution only; (group 2 ) 50 pg/kg of NIH-LH-S15 in saline; (group 3 ) 50 pg/kg of NIH-LH-S15 and 4.0 mg/kg of promethazine hydrochloride 1 Supported by U S . Public Health Service Research Grant HD 04375-02.(Phenergan, LF'yeth Labs.) ; (group 4) 4.0 mg/kg of promethazine hydrochloride only.At the time oi cannulation, animals were anesthetized lightly with ether followed by 18-22 mg/kg of sodium pentobarbital (Abbot Labs.). Each animal also received 0.8 mg of heparin intravenously.Laparotomy was performed, and the left utero-ovarian vein was isolated. .4 23 gauge needle attached to YE-50 polyethylene tubing (0.584 mm i.d.) was inserted and tied securely with silk. The uterine branch was immediately ligated with silk placed in position prior to cannulation. The polyethylene end of the cannula was directed over a Narco Model 705-0014 drop flow counter which was attached to a Narco Model DMP-4A Physiograph. In order to determine if the effects of L H were specific with respect to the ovarian vein, in some animals the femoral vein was cannulated as described above. All cannulas were calibrated with blood immediately after use to determine the number of drops per milliliter.Flow rates were calculated on the basis of 3 min intervals and reported a t the middle of each 3 min interval as follows: 1.5, 4.5, 7.5, 10.5, 13.5, 16.5, and 19.5 min after the beginning of each bleeding. I n the case of femoral veins, the bleeding period was extended to 30 min. Due to var...
Assessment of adrenal reserve and the diagnosis of adrenal insufficiency by acute adrenocortical stimulation with ACTH-(1-24) has been well established. Alternatively, estimation of adrenocortical enzymatic activities by this method for the detection of inherited or acquired biosynthetic abnormalities has been less well characterized. Some of the discrepancies between studies estimating adrenocortical enzymatic activities in different pathological conditions (e.g. hyperandrogenism) may result from the different stimulation protocols used. The objective of this prospective study was to establish the inherent variability of the adrenal response to acute ACTH-(1-24) stimulation and to determine the effect of sampling time, stimulation dose, and subject weight on the same. Forty-one normal female volunteers were recruited (mean age, 29.1 yr), 30 within 90-110% ideal body weight and 11 weighing more than 120% ideal body weight. Three protocols were designed to study 1) the effects of sampling time, ACTH-(1-24) dose, and subject weight on adrenal response; 2) the effect of time of the day on the variability of basal steroid levels and the adrenal response to stimulation; and 3) the long term reproducibility of the adrenal response to ACTH-(1-24). Androstenedione, 17-hydroxyprogesterone, 11-deoxycortisol, dehydroepiandrosterone, and cortisol were measured in serum under basal and stimulated conditions. All subjects had normal basal levels of testosterone, androstenedione, dehydroepiandrosterone sulfate, and PRL. The acute iv administration of 0.10, 0.25, and 1.0 mg ACTH-(1-24) elicited similar and maximal steroid responses, with all steroid levels reaching a plateau 60-90 min poststimulation regardless of subject weight. Sampling of basal steroid levels every 5 min in the morning (AM; beginning 0700-0900 h) or evening (PM; 1500-1700 h) did not reveal any difference in steroid variability. Only the mean basal cortisol level was higher in AM than PM testing (P less than 0.03). Although the mean levels of dehydroepiandrosterone and 17-hydroxyprogesterone 60 min after stimulation were significantly higher in AM than PM studies, these differences were minimal. Ten volunteers underwent an average of four (range, 2-6) adrenal stimulation studies using 1.0 mg ACTH-(1-24) over a 1-yr period. The long term coefficient of variation (CV) for basal steroid levels ranged from 15-28%. Calculations of net adrenal response (delta steroid O-T and area delta steroid O-T) were less reproducible (CV, 0-82%) than measures of absolute response (steroid T, area steroid T, and %steroid T; CV, 7-32%). This difference in CV between the measures of net and absolute adrenal responses was significant for all steroids except androstenedione.(ABSTRACT TRUNCATED AT 400 WORDS)
The elevation of endogenous prolactin secretion using thyrotopin releasing hormone was associated with significant increases in mammary milk production in postpartum women. More-over, a specific effect was seen on the percent fat composition which has been shown to rise as much as 228% over pretest conditions. As in the bovine, administration of high doses of estrogen is associated with mammary breast development and the sudden removal of this stimulus if accompanied by nipple stimulation is associated with non-puerperal lactation. The inhibitory effects of estrogen on the mammary cellular response to circulating prolactin has been deduced from studies in pregnant and parturient women by measuing the TRH-induced prolactin response. These studies support a relationship between prolactin and sex steroids on the initiation and maintenance of human lactation.
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