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PubMed1987

Effects of progestogens on lipemia and lipolysis in rat: effects of progesterone, megestrol acetate, norethindrone acetate, and nomegestrol acetate.

Effects of 4 progestogens at equal dosages (5 mg/kg/day) on lipid metabolism and plasma glucose levels of adult female rats were compared. The 4 progestogens studied were progesterone (P) by SC injection, and megestrol acetate (MEG), norethindrone acetate (NOR), and nomegestrol acetate (NOM) PO. MEG, a 17 alpha-hydroxyprogesterone derivative, induced significant increases in glucose, total and high-density lipid (HDL) cholesterol, triglyceride, and phospholipid plasma levels. Treatment with NOR, a 19-nortestosterone derivative, resulted in a reduced gain in body wt and in a marked decrease in all plasma lipid parameters. The 19-norprogesterone derivative NOM, like P, did not alter lipid or glucose metabolism, despite a significant increase in body wt gain. In particular, no reduction in the HDL cholesterol level occurred. Plasma and tissue lipolytic activities remained unchanged. The results of this study confirm interest in the therapeutic class of 19-norprogesterone-derived progestogens, exemplified by NOM, with respect to their lack of metabolic side effects.

Animals↗
PubMed1992

Continuous combined conjugated equine estrogen-progestogen therapy: effects of medroxyprogesterone acetate and norethindrone acetate on bleeding patterns and endometrial histologic diagnosis.

OBJECTIVES: This study was designed to assess the incidence of amenorrhea with continuous combined therapy by using two different progestogens and to determine whether early bleeding predicts subsequent bleeding and endometrial response. STUDY DESIGN: Seventy-nine postmenopausal women on sequential estrogen-progestogen treatment were switched to continuous combined estrogen-progestogen therapy comprising conjugated equine estrogens 0.625 mg daily with either norethindrone acetate 0.35 mg twice daily or medroxyprogesterone acetate 2.5 mg twice daily added continuously for 78 weeks. All bleeding was recorded, and endometrial biopsies were performed at 26 and 78 weeks. RESULTS: Only one third of the women who starting the study had amenorrhea by week 78, but 46 (62%) of these women had withdrawn, mainly because of chronic irregular bleeding. Endometrial atrophy was observed in the majority of biopsy specimens. The two progestogens had similar effects. Bleeding patterns were useful predictors of subsequent bleeding, but not of endometrial response. CONCLUSIONS: Persistent irregular bleeding is common with continuous combined estrogen-progestogen therapy. Women with persistent early bleeding should probably revert to sequential treatment. Regular endometrial sampling is advised.

Amenorrhea↗
PubMed1982

Pharmacokinetics of norethindrone acetate in women after the insertion of a single subdermal implant releasing norethindrone acetate.

The metabolic clearance rate (MCR) of norethindrone acetate (NETA) and norethindrone (NET) levels in plasma were studied after an iv injection of [3H]NETA in three women before and at 1 week, 1, 2 and 6 months following the insertion of a single silastic subdermal implant releasing microquantities of NETA. No significant change in the MCR of NETA was observed at 1 week (459 +/- 72 1/day), 1 month (489 +/- 113 1/day) and 2 months (522 +/- 144 1/day) compared with that of control (525 +/- 108 1/day). However, MCR of NETA showed significant increase in women exposed to continuous presence of NETA for a period of 6 months (608 +/- 121 1/day; P less than 0.025). NETA was rapidly and extensively metabolized into NET. At 1 week, 1, 2 and 6 months of study, NET was observed to be present in higher amounts compared with NETA. The production rate (PR) of progesterone decreased significantly at 2 and 6 months of NETA implant insertion compared with the PR before the insertion of implant.

Adult↗
PubMed2001

Bleeding patterns in postmenopausal women using continuous combination hormone replacement therapy with conjugated estrogen and medroxyprogesterone acetate or with 17beta-estradiol and norethindrone acetate.

OBJECTIVE: We studied bleeding patterns in postmenopausal women who were using 2 types of continuous combination regimens. STUDY DESIGN: A prospective, double-blind, randomized study of 208 postmenopausal women treated with conjugated estrogen, 0.625 mg, and medroxyprogesterone acetate, 5 mg, or with 17beta-estradiol, 2 mg, and norethindrone acetate, 1 mg. RESULTS: The mean number of bleeding days decreased during the first 4 months of treatment (P <.002) but not thereafter. The number of bleeding days was fewer (P <.002) and the time until amenorrhea was shorter (P <.02) in patients receiving conjugated estrogen and medroxyprogesterone acetate than in patients receiving 17beta-estradiol and norethindrone acetate. The odds ratio for progression to amenorrhea with the use of conjugated estrogen and medroxyprogesterone acetate was 1.58, in comparison with the use of 17beta-estradiol and norethindrone acetate. A thick endometrium at the start of treatment resulted in more bleeding days than were found for a thin endometrium (P <.03). Body mass index, age, and blood pressure had no predictive value for bleeding problems. CONCLUSIONS: Treatment with continuous combined conjugated estrogen and medroxyprogesterone acetate resulted in fewer bleeding problems than did treatment with 17beta-estradiol and norethindrone acetate. Endometrial thickness may help to predict the chance of achieving amenorrhea during early hormone replacement therapy.

Aging↗
PubMed1983

Norethindrone in serum after use of an oral contraceptive containing norethindrone acetate.

The availability of norethindrone (NET) in serum was studied in 8 women after daily administration of a combination oral contraceptive pill (MinovlarR) containing 1 mg norethindrone acetate (NETA) and 50 micrograms ethinyl estradiol (EE2) from day 5 to day 25 of the menstrual cycle. The pill was taken daily at 9:30 a.m. after a light breakfast and blood samples were collected at 3 hr on alternate days and at 24 hr on other days after ingestion of the pill. On day 12 or day 15 of the first treatment cycle, serial blood samples were also collected at 1/2, 1, 2, 4, 6, 8 and 24 hr after taking the pill. Serum NET levels were estimated by the radioimmunoassay (RIA) technique. The plot of serum NET concentration versus time (0-24 hr) profile showed a rapid absorption of steroid and a peak NET concentration (18.3 +/- 4.8 ng/ml) reached at 2 hr after ingestion of the pill. By linear regression analysis of data (y = 0.27 + 0.12x; r = 0.95), it was observed that the serum NET level was initially about 1 ng/ml. Thereafter, it increased by 0.12 ng/ml per day up to 3.5 ng/ml by the end of 21 days' treatment with oral pills. The serum NET concentration decay slope fitted a two-compartment open model with an initial rapid decay (half-life of 1.2 +/- 0.1 hr) followed by a slower beta-phase with a half-life of 8.5 +/- 1.5 hr. The study revealed that there was an accumulation of norethindrone in plasma during the treatment period and this suggests the possibility of exploring a reduction in the dose of this preparation so as to achieve the optimum NET concentration for contraception, and thereby avoiding unwanted steroid accumulation in the plasma of women.

Adult↗
PubMedDate not supplied

Can we decrease breakthrough bleeding in patients with endometriosis on norethindrone acetate?

OBJECTIVE: To compare the breakthrough bleeding in endometriosis patients treated with Lupron-Depot alone, norethindrone acetate following Lupron-Depot, and norethindrone acetate alone. PATIENTS AND METHODS: 71 women with symptomatic surgically diagnosed endometriosis were retrospectively evaluated for this study. 28 women were treated with 6 doses of 3.75 mg Lupron-Depot every 4 weeks (Group I). 15 women were treated first with Lupron-Depot 3.75 mg every 4 weeks for 3 to 6 doses, followed by 5 mg norethindrone acetate (Group II). 28 patients were treated for 6 months with 5 mg per day norethindrone acetate alone (Group III). Breakthrough bleeding during treatment was scored mild (some spotting), moderate (lighter than patient's normal menstruation), or severe (as much as patient's normal menstruation or heavier). Multiple comparisons were done by ANOVA (SPSS) among three groups. The age of patients was not significantly different between groups 134.9-36.8 years). BMI of the three groups was significantly different 126.6 +/- 5.8, 27.4 +/- 6.4, 23.6 +/- 4.5, respectively). RESULTS: Breakthrough bleeding was reported by 14% of Group I, 20% of Group II, and 68% of Group III. CONCLUSION: Endometriosis patients who were treated with norethindrone acetate following Lupron-Depot had significantly less breakthrough bleeding than those given norethindrone acetate alone, and the incidence was comparable to Lupron-Depot alone.

Adult↗
PubMed1983

Norethindrone acetate inhibition of triglyceride synthesis and release by rat hepatocytes.

The progestin, norethindrone acetate has been widely administered to patients in the form of oral contraceptives; however, its hypolipemic action has received little study. This report describes the effects of conventional doses of norethindrone acetate (100 micrograms/day.kg body weight 0.75) on rat plasma lipid levels in vivo as well as the mechanism of action on triglyceride metabolism in isolated hepatocytes in vitro. Norethindrone acetate administration led to significant and proportional reductions of the concentrations of triglycerides, cholesterol and phospholipids of plasma lipoproteins of density less than 1.006 of rats fed a high carbohydrate diet. Norethindrone acetate (0.1 mM) also significantly inhibited the incorporation of both [9,10(-3)H] palmitate and [U-14C]glycerol into triglycerides of isolated hepatocytes from fed rats, by 11 to 16% (P less than 0.001). Release of labeled triglycerides from the isolated hepatocytes was similarly inhibited, 21% and 46%, respectively (P less than 0.05). At the higher concentration of 1.0 mM, norethindrone acetate inhibited the incorporation of [2(-3)H]glycerol into hepatocytic triglycerides by 35-39% (P less than 0.05). The present findings suggest that inhibition of hepatic triglyceride synthesis can account for the reduction of hepatic triglyceride secretion and for at least part of the lowering of plasma VLDL levels which occurs during administration of norethindrone acetate in the rat.

Animals↗
PubMed1996

A combination of norethindrone acetate and leuprolide acetate blocks the gonadotrophin-releasing hormone agonistic response and minimizes cyst formation during ovarian stimulation.

A protocol utilizing both leuprolide acetate (LA) and norethindrone acetate (NETA) in subjects undergoing ovarian suppression prior to follicle aspiration proved more effective than LA alone in reducing the incidence of ovarian cyst formation without affecting clinical outcome. Patients (n = 105) undergoing ovarian stimulation followed by follicle aspiration and in-vitro fertilization (IVF) were prospectively randomized and studied. Study measures included ovarian suppression days, days of human menopausal gonadotrophin (HMG) stimulation, serum oestradiol concentrations, number of cycles developing de novo cysts (>15 mm), number of induced flare responses (day 8 oestradiol >=50 pg/ml), number of office visits, total dose exogenous gonadotrophins, number oocytes retrieved, and clinical pregnancy and delivery rates per retrieval. Patients undergoing IVF received either LA alone (n = 58; controls) or LA and NETA (n = 47; study group) for the first 8 days of their cycle. Results comparing NETA/LA versus LA demonstrated: serum oestradiol 20.7 +/- 3.9 versus 57.3 +/- 9.4 pg/ml respectively on day 8 of ovarian suppression (P P < 0.01); and only three individuals (6.4%) using NETA/LA developed ovarian cysts >15 mm compared to 15 (25.9%) controls (P < 0.01). No differences were observed for days of stimulation, peak oestradiol attained, total dosage of exogenous gonadotrophins, or number of aspirated oocytes. Neither were there differences in the clinical pregnancy (26.8 versus 22.6%) nor in delivery rates (19.5 versus 20. 8%). We conclude that the addition of NETA to LA enhances ovarian suppression and lessens ovarian cyst formation, thereby significantly decreasing the overall cost per cycle.

Adult↗
PubMed1999

A randomized comparison of continuous combined transdermal delivery of estradiol-norethindrone acetate and estradiol alone for menopause. CombiPatch Study Group.

OBJECTIVE: To determine whether a continuous estradiol-norethindrone acetate transdermal delivery system reduces incidence of endometrial hyperplasia in postmenopausal women more than transdermal estradiol (E2) alone. METHODS: Six hundred twenty-five postmenopausal women were assigned randomly to one of four treatments, transdermal E2 50 microg/day, or transdermal E2-norethindrone acetate with 50 microg E2 and 140, 250, or 400 microg/day of norethindrone acetate. Follow-up visits to collect information on safety and efficacy were scheduled at 3, 6, 9, and 12 months after initiation of treatment. Endometrial biopsy for histologic evaluation was done at baseline and upon exit from the study (completion or withdrawal). Endometrial histology was evaluated by two independent gynecologic pathologists. In the event of a disparate reading, a third gynecologic pathologist evaluated the tissue using predetermined criteria. RESULTS: Endometrial hyperplasia was found in 37.9% (39 of 103) in the E2 alone group versus 0.8% (one of 123), 1% (one of 98), and 1.1% (one of 89) in the E2-norethindrone acetate 50-140, 50-250, and 50-400 groups, respectively (P < .001). Uterine bleeding was less frequent in the E2-norethindrone acetate 50-140 group than other treatments. The mean number of hot flushes per day decreased to less than one in each treatment group at endpoint. The E2-norethindrone acetate combination patch showed skin tolerance comparable to that of E2 alone. CONCLUSION: Continuous transdermal delivery of E2 combined with norethindrone acetate effectively prevented endometrial hyperplasia in healthy postmenopausal women. Continuous combined transdermal delivery systems provide increased dosing flexibility and might improve convenience and compliance with hormone replacement therapy.

Administration, Cutaneous↗
PubMed1979

Pharmacokinetics of norethindrone acetate in women.

The plasma half-life, MCR and plasma metabolite levels at various time intervals have been studied in six women after an intravenous injection of 3H-norethindrone acetate. The disappearance curve due to norethindrone acetate showed an initial rapid disappearance of 3H with an average half-life of 7.5 minutes and a subsequent slow disapperance with a half-life of 51.5 hours. Norethindrone acetate was cleared from the plasma with an average MCR of 495 L/day. Norethindrone acetate is rapidly metabolised after an intravenous injection. Norethindrone, the main metabolite, disappears from the plasma with an average half-life of 34.8 hours. Norethindrone maintains a high level compared with norethindrone acetate at all time intervals up to 24 hours and an equilibrium is reached between the two at 24 to 48 hours.

Acetates↗
PubMed1999

Uterine bleeding in postmenopausal women on continuous therapy with estradiol and norethindrone acetate. Endometrium Study Group.

OBJECTIVE: To investigate the incidence of uterine bleeding during 12 months of treatment with 17beta-estradiol (E2) 1 mg, unopposed or in combination with three doses of norethindrone acetate. METHODS: This study was a prospective, double-masked, randomized, multicenter trial. A total of 1176 healthy postmenopausal women age 45 years and older without evidence of endometrial abnormalities were randomly assigned to receive either unopposed E2 1 mg, or continuous-combined formulations of E2 1 mg and norethindrone acetate 0.1 mg, 0.25 mg, or 0.5 mg. Any spotting or bleeding episodes during the treatment period were recorded in a daily diary and reported by weekly telephone calls. RESULTS: The incidence of bleeding was low in the combination groups, even during the initial 3 months of treatment (24-28%), after which it decreased with increasing doses of norethindrone acetate. Conversely, the incidence of bleeding increased over time with unopposed E2 1 mg. After the initial 3 months, the incidence of bleeding among the combination groups was lowest in the norethindrone acetate 0.5 mg group. Among women initiating therapy close to menopause, fewer reported bleeding with norethindrone acetate 0.5 mg than with the other combination groups. There was a significantly (P<.05) lower discontinuation rate due to bleeding in the norethindrone acetate 0.5 mg group compared with all other treatment groups. CONCLUSION: Continuous-combined formulations of E2 1 mg with norethindrone acetate 0.1, 0.25, or 0.5 mg are associated with a low incidence of uterine bleeding. After the initial 3 months of treatment, bleeding profiles improved with increasing doses of norethindrone acetate.

Adult↗
PubMed2000

Norethindrone acetate and estradiol-induced endometrial hyperplasia.

OBJECTIVE: To identify the lowest effective continuous dose of norethindrone acetate that significantly reduces 12-month incidence of endometrial hyperplasia associated with unopposed 17beta-estradiol (E2), 1 mg. METHODS: In a double-masked, randomized, multicenter study, 1176 healthy postmenopausal women 45 years of age or older without evidence of endometrial abnormalities were given 12 months of treatment with unopposed E2, 1 mg, or continuous-combined regimens of E2, 1 mg, and norethindrone acetate, 0.1 mg, 0.25 mg, or 0.5 mg. Endometrial histology was evaluated at the end of the treatment period. RESULTS: Continuous-combined E2-norethindrone acetate regimens significantly reduced 12-month incidence of endometrial hyperplasia compared with unopposed E2 1 mg (P <.001). Endometrial hyperplasia occurred in 14.6% of women treated with unopposed E2 1 mg, whereas in all continuous-combined groups, the rate decreased to less than 1%. Among patients who received E2-norethindrone acetate 0.1 mg, incidence was 0.8%; among those who received 0.25 mg and 0.5 mg, it was 0.4%. CONCLUSION: Continuous norethindrone acetate at doses as low as 0.1 mg combined with E2 1 mg effectively negated risk for endometrial hyperplasia associated with unopposed E2 1 mg, at least for the first year of therapy.

Climacteric↗
PubMed2000

Efficacy of continuous sequential transdermal estradiol and norethindrone acetate in relieving vasomotor symptoms associated with menopause.

OBJECTIVE: This study was undertaken to evaluate the efficacy and tolerability of a combination estradiol plus norethindrone acetate transdermal delivery system given in a continuous sequential regimen with transdermal estradiol versus placebo in the treatment of vasomotor symptoms of menopause. STUDY DESIGN: This was a 12-week double-blind trial of 220 healthy postmenopausal women with > or = 8 moderate to severe hot flushes and sweating episodes per day. Women were randomly assigned to wear transdermal placebo patches or a transdermal patch releasing 50 microg/d 17beta-estradiol alone (Vivelle) for days 1 to 14 of each cycle and a combination patch releasing 50 microg/d 17beta-estradiol plus 1 of 3 dosage levels (140, 250, or 400 microg/d) of norethindrone acetate (CombiPatch) for days 15 through 28. RESULTS: There was a significant (P <.001) reduction by the second week in the mean number of daily hot flushes from baseline to end point with all 3 doses of estradiol plus norethindrone acetate compared with placebo. Significant (P <.001) reductions in the mean intensity of hot flushes and sweating were also noted with estradiol plus norethindrone acetate compared with placebo. The incidences of adverse events with all 3 doses of estradiol plus norethindrone acetate and with placebo were comparable. CONCLUSION: An estradiol plus norethindrone acetate transdermal delivery system administered in a continuous sequential regimen with transdermal estradiol was well tolerated and effective for the treatment of moderate to severe vasomotor symptoms in postmenopausal women.

Administration, Cutaneous↗
PubMed1978

Radioimmunoassay of norethindrone : serum levels of norethindrone in lactating women after insertion of a single Silastic implant releasing norethindrone acetate.

A specific radioimmunoassay was developed for the estimation of norethindrone levels in the serum of lactating women. A conjugate of norethindrone-3-BSA was synthesized and antiserum raised against it in rabbits. The antiserum showed high affinity (1.5 x 10(9)M/L) and titer and was specific. The sensitivity of the assay was 125 pg/ml serum. Serum levels of norethindrone were estimated in 25 lactating women, inserted with subdermal implant releasing about 150 ug of norethindrone acetate daily. The norethindrone levels were initially high in the first two months. From there onwards the levels of norethindrone remained constant with an average value of 1.0 ng/ml up to six months. These values were comparable to those obtained in non-lactating women. Thus, lactation does not seem to alter or affect the release of norethindrone acetate from the subdermal implant or its metabolism.

Animals↗
PubMed1979

Norethindrone acetate inhibition of splanchnic triglyceride secretion in conscious glucose-fed siwne.

The effects of conventional doses of two synthetic contraceptive steroids on the concentration and rate of secretion of plasma triglycerides from the splanchnic region were investigated. Studies were undertaken in miniature swine under steady state conditions produced by prolonged constant hypercaloric intravenous infusions of glucose. The steroids, alone or in combination, were administered with the high carbohydrate diet for at least 2 weeks prior to study of splanchnic metabolism and were also infused intravenously during the studies. Splanchnic triglyceride secretion was determined from measurements of plasma flow and transsplanchnic radiochemical gradients of plasma triglycerides. Compared with studies in the untreated animal, norethindrone acetate significantly reduced the arterial concentration (1.1 +/- 0.1 vs. 0.7 +/- 0.1 mM) and rate of splanchnic secretion of plasma triglyceride fatty acids (2.0 +/- 0.4 vs. 0.8 +/- 0.1 micro mol/min.kg body wt(0.75)) and decreased the percent of free fatty acids entering the splanchnic region that was converted to plasma triglycerides (22 +/- 5 vs. 13 +/- 3%, P < 0.05). Ethynylestradiol, in the dose employed, had no significant effect on these variables; however, ethynylestradiol and norethindrone acetate together gave responses similar to norethindrone acetate alone. When the glucose was given intraduodenally vs. intravenously, values for splanchnic metabolism of triglycerides were unchanged. The hypolipemic effect of norethindrone acetate in glucose-fed swine was attributable to inhibition of hepatic triglyceride secretion.-Wolfe, B. M., and D. M. Grace. Norethindrone acetate inhibition of splanchnic triglyceride secretion in conscious glucose-fed swine.

Animals↗
PubMed2002

Effects of oral continuous and transdermal cyclic 17-beta estradiol and norethindrone acetate replacement therapy on platelet aggregation in postmenopausal women.

OBJECTIVE: To evaluate the effects of an oral continuous and transdermal cyclic 17-beta estradiol and norethindrone acetate combination on platelet aggregation in post-menopausal women. STUDY DESIGN: Fifty postmenopausal women were randomly assigned to receive 17-beta estradiol and norethindrone acetate either orally continuously or transdermally cyclically and sequentially. Platelet counts and maximum platelet aggregation rates were measured before and after three months treatment. RESULTS: At three months there were no significant changes in platelet counts or in adenosine diphosphate-induced or epinephrine-induced platelet aggregation rates in either treatment group. CONCLUSION: Hormone replacement treatment with a 17-beta estradiol and norethindrone acetate combination either orally continuously or transdermally cyclically and sequentially does not affect platelet aggregation in postmenopausal women.

Administration, Cutaneous↗
PubMed1991

Androgen synthesis in human fetal testis exposed in utero to a combination of norethindrone acetate and ethinyl estradiol.

The effect of norethindrone acetate (NET-Ac) and ethinyl estradiol (EE2) on the 3 beta-hydroxysteroid dehydrogenase (HSD)-delta5-isomerase complex of the human fetal testis was studied by administration of 20 mg NET-Ac and 0.04 mg EE2 p.o on a single day to 4 women, pregnant 10-16 weeks, before abortion was induced, the other 4 patients serving as controls. Testosterone and androstenedione formation from radioactive dehydroepiandrosterone was measured in 8 fetuses by incubation of testicular tissue in vitro. The presence of normal feta Leydig cells was confirmed by electron microscopy. There was no difference between the enzyme activities of testicles in the experimental and control groups. The findins give values of 3 beta-HSD-isomerase activity in human fetal testis and suggest that the steroidogenic function of the fetal testis exposed for a short time to normally used contraceptive steroids remains at the same magnitude.

Androgens↗
PubMed1993

Norethindrone acetate only partially protects the skeleton of rats treated with the LHRH agonist buserelin from oestrogen-deficiency osteopaenia.

In women with endometriosis there is concern that therapeutic use of LH-releasing hormone (LHRH) analogues, to lower ovarian oestrogen production and control endometrial hyperplasia, leads to unwanted oestrogen-deficiency bone loss. We have developed an animal model of this LHRH-mediated oestrogen-deficiency bone loss in the rat, using buserelin. The aim was to use this model to determine whether the progestogen, norethindrone acetate, could counter oestrogen-deficiency bone loss associated with prolonged treatment with the LHRH agonist buserelin. Four groups of animals which had their bones labelled with 45Ca were studied for 4 weeks: group A, control; group B, buserelin treated; group C, norethindrone acetate treated; group D, norethindrone acetate+buserelin treated. Buserelin was given daily (19.2 pmol/kg body wt); norethindrone was given orally three times/week (1.47 mumol/kg body wt). Bone resorption was monitored by measuring the urinary excretion of hydroxyproline and 45Ca and bone 45Ca content. Buserelin-treated rats developed similarly depressed plasma oestradiol-17 beta values in the presence and absence of progestogen, and both groups given buserelin had significantly smaller uteri than controls or rats given norethindrone without buserelin. However, norethindrone did not prevent buserelin-mediated increases in bone resorption. At the end of the study total body calcium values (mean +/- S.D.) in the four groups were (mg) respectively; 2594 +/- 123; 2260 +/- 92 (P < 0.001 compared with controls); 2616 +/- 221; 2415 +/- 130 (P < 0.02 compared with controls). Rats given norethindrone and buserelin in combination had higher values (P < 0.02) than animals given buserelin alone, but significantly less total body calcium than controls (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗