Column Chromatography of Steroids on Sephadex LH-20

Carr, Bruce R.; Mikhail, George R.; Flickinger, George L.

doi:10.1210/jcem-33-2-358

Cited by 175 publications

(33 citation statements)

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“…This pattern of response was typical ofthat seen in man (14) and is in marked contrast to the pattern seen in the laboratory rat, perhaps because of the prolonged halflife ofhCG in man when compared with the rat (15,16). Stimulation of the rat testis in vivo leads to a testosterone response within 15 min and a 5-to 10-fold increase by [2][3][4][5][6][7][8][9][10][11][12] h, followed by a decline to normal levels within 1-2 d depending upon the administered dose of gonadotropin (1,2). The serum 17a-hydroxyprogesterone response of the hyperstimulated primate testes was similar to the pattern of testosterone response seen in the rat.…”

Section: Resultsmentioning

confidence: 88%

Regulation of Primate Testicular Luteinizing Hormone Receptors and Steroidogenesis

Davies¹,

Hodgen²,

Dufau³

et al. 1979

J. Clin. Invest.

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A B S T R A C T The testicular luteinizing hormone (LH) receptors of the rhesus monkey and human have many features in common, including high equilibrium association constant, marked species specificity, and relatively low binding capacity. We have, therefore, used rhesus monkeys as models for human LH-receptor regulation in vivo during gonadotropin treatment. In four adult male monkeys, treated with 10,000 IU human chorionic gonadotropin (hCG), serum and testicular steroidogenic responses were monitored at 24-h intervals during the following 4 d, and LH-receptor concentrations were measured by '25I-hCG binding to 15,000-g particles preparedl from testis biopsy specimens. In treated animals, serum hCG was maximal on day 1 at 322±16 ng/ml and declined to 24.4±2.3 ng/ml by day 4. Serum testosterone was increased threefold during the subsequent 4 d (from 6.5±2.0 to 18.6±4.4 ng/ml) but serum progesterone remained unchanged. In contrast, serum 17a-hydroxyprogesterone increased 12-fold to 5.5±0.5 ng/ml at day 1 and was iincreased fourfold during the subsequent 3 d. The LHreceptor binding capacity of the primate testis was reduiced by 18.3±6.0% on day 1, 51.7+7.4% on day 2, and 45.3±2.4% on day 4. Occupancy of the LH receptors by endogenously bound hCG was significant on day 1 but was negligible by day 4. These data demonstrate that gonadotropin-induced LH-receptor depletion occurs in the rhesus testis and indicate that primate gonadotropin receptors are susceptible to the regulatory processes recently described in the rat. In addition, the simultaneous and disproportionate accumulation of 17a-hydroxyprogesterone indicates that 17,20-desmolase was rate-limiting under these conditions in the primate testis Leydig cell.

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Section: Resultsmentioning

confidence: 88%

Regulation of Primate Testicular Luteinizing Hormone Receptors and Steroidogenesis

Davies¹,

Hodgen²,

Dufau³

et al. 1979

J. Clin. Invest.

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“…Plasma was taken after a 12-14-h fast, and cholesterol, HDLC, LDLC, and TG levels were measured following the methods of the LRC Laboratory Methods Manual (22). When fasting blood was drawn for determination of lipids and lipoproteins, a second 10-cc aliquot was drawn in an anticoagulant-free tube; serum T (17) and E2 (1) were quantitated by radioimmunoassay with specific antibodies following LH-20 Sephatex chromatography (7). Each column eluate was analyzed in triplicate for T or duplicate for E2 and the means were reported.…”

Section: Methodsmentioning

confidence: 99%

Longitudinal Relationships among Endogenous Testosterone, Estradiol, and Quetelet Index with High and Low Density Lipoprotein Cholesterols in Adolescent Boys

et al. 1983

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SummaryIn a 1-year longitudinal study of 19 adolescent boys, our major aim was to assess whether, and to what degree, testosterone, estradiol, Quetelet index, and their interactions related to concentrations of high and low density lipoprotein cholesterol (HDLC, LDLC). During the I-year followup, mean HDLC and estradiol levels fell and triglycerides, LDLC, Quetelet index, and testosterone levels rose. For large decreases in estradiol, increases in testosterone were associated with decreases in HDLC. These decreases in HDLC were moderated by small decreases in Quetelet index. For boys with small decreases in estradiol, as the changes in testosterone increased, the change in HDLC varied from an increase to a decrease, except in those boys who also had a small decrease in Quetelet index, for whom the change in HDLC was positive. The greatest increases in LDLC were observed in boys having the largest increase in Quetelet index and a small decrease in estradiol; however, as the decrease in estradiol became large, the positive association of Quetelet with LDLC was moderated or nullified. For boys having large decreases in estradiol, the LDLC/HDLC ratio changed from small increments to substantial decrements as testosterone increased. As the decreases in estradiol became smaller, increases in the change of testosterone moderated the decreases in the LDLC/HDLC ratio, and large increases in Quetelet index tended to diminish this moderation. As the change in testosterone increased, the change in triglyceride increased, unless the decrease in estradiol was small. The overall pattern of change of HDLC and LDLC during sexual maturation in boys can be associated with changes in testosterone, estradiol, and Quetelet index. Abbreviations E2, estradiol HDLC, high density lipoprotein cholesterol LDLC, low density lipoprotein cholesterol Q, Quetelet index T, testosterone TG, triglycerideThe decrement in HDLC during male adolescence has been postulated to result from increased T production (16, 18); however, there is a significant positive correlation between HDLC and T in adult men (13,15,25,30). In adults, pharmacologic doses of exogenous T lower HDLC (2, 11). The reasons for this dichotomy remain to be fully explicated but different interactions of T and E2 during adolescence and adulthood may, in part, account for the opposite correlations of HDLC and T (18). For example, at the highest endogenous E2 levels, endogenous T is inversely associated with HDLC in adolescent males (18) whereas lower E2 and T levels in sexually mature men could be associated positively with HDLC.Prepubescent boys have, if anything, higher HDLC than girls (3, 28). The within-adolescence decrement in HDLC leads to the well recognized HDLC differential in sexually mature adults where men have lower HDLC, higher LDLC, and higher levels of TG than premenopausal women (14, 21). The adult male-female differences in lipoproteins (lower HDLC, higher LDLC, and higher TG) probably account, in part, for male-premenopausal female differences in atherosclerosis (32,...

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“…Samples were extracted twice with 5 ml diethyl ether. The resultant extracts were chromatographed on Sephadex LH-20 columns as des¬ cribed by Carr, Mikhail & Flickinger (1971) . Minimum sensitivity of the assay was 6 pg/ml and inter-assay coefficients of variation for two pools (high and low concentration) of gilt serum were 7-7 and 16-5% (n = 6).…”

Section: Introductionmentioning

confidence: 99%

Metabolic clearance and production rates of oestradiol and progesterone during pubertal and postpubertal development in gilts

Christenson¹,

Ford²,

Redmer³

1985

Reproduction

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Summary. The crossbred gilts studied were aged 80 days (prepubertal), 180 days (prepubertal or postpubertal) and 260 days (postpubertal or pregnant). Estimates of metabolic clearance rate (MCR) of oestradiol and progesterone were consistently less (21 and 27%) in plasma than in blood, and these differences were not influenced by age of gilt. The MCR (1/day per kg body weight) for oestradiol and progesterone in plasma was greater (P < 0\m=.\05) for 80-day-old prepubertal gilts than for older gilts. The MCR values of oestradiol and progesterone were similar in 180-day-old and 260-day-old gilts independent of reproductive state. Production rate (PR) of oestradiol and progesterone increased with age (80\p=n-\180days), and age and reproductive state differences were much more pronounced for PR of progesterone than of oestradiol. These results support the hypothesis that a reduction in the MCR and an increase in PR of oestradiol and progesterone in the gilt are associated with the process of pubertal development, and changes in gonadal steroid concentrations appear not to alter the MCR of oestradiol and progesterone.

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Column Chromatography of Steroids on Sephadex LH-20

Cited by 175 publications

References 1 publication

Regulation of Primate Testicular Luteinizing Hormone Receptors and Steroidogenesis

Regulation of Primate Testicular Luteinizing Hormone Receptors and Steroidogenesis

Longitudinal Relationships among Endogenous Testosterone, Estradiol, and Quetelet Index with High and Low Density Lipoprotein Cholesterols in Adolescent Boys

Metabolic clearance and production rates of oestradiol and progesterone during pubertal and postpubertal development in gilts

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