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Tannate complexes of a gonadotropin extract of human pituitary glands (Merck C-3072) were prepared and tested with the same amounts of untannated extract. General gonadotropin tests (mouse uterine weight and rat ovarian weight), tests for luteinizing hormone(ventral prostate weight and ovarian ascorbic acid depletion), and a test for follicle-stimulating hormone (augmentation reaction method) were used. Tannation did not alter the potency of this preparation in any of the assay systems. (Endocrinology 82: 187,1968)

Tannate complexes of urinary human pituitary gonadotropin (HPG) were tested by the augmentation reaction method for the assay of follicle stimulating hormone (FSH). Assays were also performed by injecting single doses of tannated and untannated HPG and determining the magnitude of the response in the augmentation reaction at 48-hr intervals. It was found that tannation did not alter the FSH potency of HPG. The results obtained with single-dose assays confirmed those obtained by the conventional assay method. (Endocrinology 77: 943,1965)

THE NATIONAL Pituitary Agency (NPA) has conducted a collaborative study of the radioimmunoassay of human follicle stimulating hormone (HFSH) and human luteinizmg hormone (HLH) in order to characterize and make available the necessary reagents for use in clinical investigation. Before suitable reagents can be distributed for clinical investigation, three conditions must be defined: 1) specificity of the antisera, evaluated by comparison of the results obtained from the radioimmunoassay technique and those obtained from the bioassay technique, 2) the applicability of the radioimmunoassay technique to measurements in serum, 3) the designation, establishment and availability of suitable standards for the expression of the radioimmunoassay results. Several groups of investigators collaborated in an attempt to define these three conditions. Four human pituitary gland extracts differing widely in FSH/LH ratio and “immunochemical grade” HFSH and HLH were prepared by L. E. Reichert (LER series); a second ...

Synthetic GnRH, at a dose of 100 mcg, was injected intravenously into 12 healthy, single, regulary menstruating women in order to test the capacity of the pituitary to release LH and FSH in response to the administration of the decapeptide. A total of 12 tests was performed during different stages of the menstrual cycle, i.e., on D 3-4, D 13-16 and D 21-29 of the cycle. Following GnRH administration, there was a rapid increase in serum levels of LH. Although there was a pronounced variation of responses in the course of the menstrual cycle, the maximum response was observed 30 to 40 min., after injection. The mean net increases of LH (M +/- SE mIU/ml) were in the following order: 118 +/- 22 in the preovulatory phase, 63 +/- 12 in the midluteal phase, and 35 +/- 7 in the early follicular phase. A concomitant but much smaller rise in serum levels of FSH was observed. These data indicate that the sensitivity of pituitary gonadotrophs to GnRH is preferentially increased during the preovulatory phase of the cycle, thus lending further support to already published data which demonstrated increased pituitary sensitivity to GnRH toward midcycle.

Six patients with unexplained infertility were administered a partially desialylated hCG preparation (Desialo hCG). 5000 and 10000 IU of this preparation were given as a single IM dose, following the administration of hMG-Pergonal. The circulatory half-life (t 1/2) of Desialo hCG was found to be 42.6 hours, which is similar to the t 1/2 of 35.6 hours previously reported for a hybrid hCG preparation. The t 1/2 values were shorter than the t 1/2 of 65.3 hours estimated for commercial hCG administered by the same route. In spite of the similarities in t 1/2 values between the two preparations, serum progesterone levels were significantly increased 48 to 96 hours after the administration of Desialo hCG, and only 8 to 10 hours after the administration of the hCG hybrid. The difference in response may reflect differences in receptor occupancy at the ovarian level. Large scale testing of preparations with half-lives approaching the t 1/2 of the physiological hormone, hLH, should be carried out in order to determine if the risk of overstimulation and/or multiple pregnancies could be reduced thus, allowing for a safer therapeutic modality in patients pre-treated with hMG.

Alpha and beta-hCG subunits were recombined generating a hybrid hCG preparation (AB1ER-CR-2XY) which met the required specifications of a pharmaceutical product. The biologic activity contained in each vial of AB1ER-CR-2XY was equivalent to 10 000IU of hCG-IS. This preparation was given as a single dose of 10 000IU by the i.m. route to four female subjects presenting unexplained infertility. The hCG hybrid was demonstrated to effect gonadal stimulation in humans.

The effects of bovine growth hormone (GH) and thyroxine (T4) on growth and carcass characteristics were assessed in Dorset ram lambs. Lambs in four groups (n = 10/group) were treated for 30 d as follows: controls, 3.33 mg (6 IU) GH/d (s.c.); 5-mg T4 implant (s.c.) on d 1 and a 10-mg T4 implant 21 d later; GH + T4. Blood samples were collected at 3-d intervals for analysis of GH, T4, triiodothyronine, somatomedin-C and testosterone concentrations. Six lambs/group were slaughtered for carcass measurements and composition. Daily GH injections increased (P less than .005) baseline plasma GH levels 10-fold, whereas plasma T4 concentrations were increased 10% (P less than .10) by the implants. Somatomedin-C increased with time in all groups, but the increments from d 0 to d 30 were higher (P less than .05) with GH treatment. Average daily gain (mean = 352 g/d), feed consumption and feed to gain ratio were not affected (P greater than .1) by GH or T4 treatment in ram lambs. Hot carcass weight and dressing percentage were increased (P less than .05) by T4. Growth hormone increased carcass protein content (P less than .005) and muscle weights while reducing carcass fat (P less than .05). Carcass composition was not altered by T4 alone, and the T4 x GH interaction was not significant; however, the combination of T4 and GH resulted in greater muscle and protein weight than did either hormone alone or no hormone administration. There were no differences in bone length or in the metacarpal growth plate width among groups. The beneficial effects of GH on carcass composition were not further enhanced by administration of thyroxine.

The concentration of immunoreactive alpha and beta subunits of human LH (hLH) and human FSH (hFSH) were measured in unfractionated serum throughout normal menstrual cycles, and when GnRH was administered at about midcycle. The RIA subunit systems employed were sufficiently sensitive and specific to measure basal levels of free alpha-hLH, beta-hLH, and alpha-hFSH. The beta-hFSH system lacked sufficient sensitivity to measure beta-hFSH in unfractionated serum. In normal cycles, alpha-hLH, beta-hLH and alpha-hFSH were shown to circulate in the free form with highest concentrations occurring at the time of midcycle peak of LH and FSH. The concentration of subunits during the follicular phase were not significantly different from those observed during the luteal phase of the cycle. In response to GnRH administration during the periovulatory phase of the cycle, the increases in circulating free alpha-hLH, beta-hLH, and of alpha-hFSH subunits were directly related to the increases in LH and FSH. Other investigators have shown that increases in circulating levels of free subunits are due to secretion from the pituitary gland rather than from peripheral dissociation of intact hormone. Therefore, it can be assumed that the increase in immunoreactive alpha-hLH, beta-hLH, and of alpha-hFSH subunits observed in this study at midcycle represent release of free subunits in response to endogenous or exogenous GnRH administration.

Tannates of ovine pituitary follicle stimulating hormone (NIH-FSH-S1 and NIH-FSH-S2) were prepared and assayed simultaneously with equal amounts of untannated FSH. Three assay systems were employed-a general gonadotropin assay utilizing both ovarian and uterine weights of intact, immature female rats, the standard augmentation reaction assay, and modifications of both assays conducted at different time intervals with either single or multiple injection schedules. FSH activity as determined by standard or modified assay systems was not potentiated by tannation. (Endocrinology 79: 149, 1966)

Bioassay [ovarian ascorbic acid depletion (OAAD) and ventral prostate weight (VPW) assays] and radioimmunoassay of Human Pituitary Luteinizing Hormone (HLH) and of Human Chorionic Gonadotropin (HCG) indicate differences in biologic activity and immunologic reactivity of these preparations. Information concerning the comparative effect of these gonadotropin materials in the human testes is meager. Hence, it was decided to conduct acute studies with HLH and HCG in four normal adult male volunteers, and in two adolescent male subjects with immature testes.

Tannate complexes of human pituitary gonadotropin (HPG) of urinary origin were assayed by 3 general gonadotropin assay methods-the rat ovarian and uterine weight methods and the mouse uterine weight method. Assays were also performed by injecting single doses · of tannated and untannated HPG and determining the magnitude of the response at daily intervals. It was found that tannation did not alter the potency of HPG as measured in these 3 assay systems. The results obtained with single-dose assays confirmed those obtained by conventional assays. (Endocrinology 77: 766,1965

Human pituitary gonadotropin (HPG) was prepared from male urine and from postmenopausal urine by the same process and was assayed by four methods, namely by ovarian weight in intact rats, by uterine weight in intact mice, and by the ventral-prostatic weight and testicular weight in hypophy-sectomized rats. The relative potency (postmenopausal ÷ male) of the two preparations of HPG was 12.83 by the four methods of assay (total of 14 assays). When the specific activities of the two preparations of HPG were equalized by appropriate dilution of the more potent HPG (postmenopausal) with inert material, the relative potency was 1.12 by the four methods of assay (total of 14 assays). The mean index of discrimination using all possible combinations of assays was close to unity, and all values for the mean index of discrimination fell well within experimentally verified and allowable (P = 0.95) limits of fluctuation. It was concluded that no evidence for dissimilarity of HPG from these two sources was obt...