Salmon gonadotropin-releasing hormone and gonadotropin are involved in precocious maturation induced by photoperiod manipulation in underyearling male masu salmon, Oncorhynchus masou

The relationship between gonadal maturation, salmon gonadotropin-releasing hormone (sGnRH), and gonadotropin (GTH) subunit contents in the brain and pituitary was investigated in underyearling masu salmon, Oncorhynchus masou. Gonadal maturation was manipulated by changing photoperiod to examine the involvement of these hormones in this process. Fish were divided into short (8 hr L: 16 hr D) and long photoperiod (16 hr L:8 hr D) groups in mid-June and maintained for 4 months until October. Gonadal maturation occurred in most males (precocious males), while a few remaining males and all females did not mature throughout the experiment irrespective of photoperiodic group. In precocious males, pituitary contents of sGnRH, GTH I beta, and GTH II beta increased faster under short photoperiod than under long photoperiod, and spermiation was observed in August. Under long photoperiod, these hormones gradually increased until October when spermiation occurred. sGnRH concentrations in the telencephalon of precocious males were high when spermiation occurred; in August, they were higher in the short photoperiod than in the long photoperiod group; in October, they were higher in the long photoperiod group. The increases of sGnRH and GTH in the pituitary and sGnRH in the brain appear to be involved in precocious maturation inducible by manipulation of photoperiod.

Tumour-associated antigens, CEA, CA 125 and SCC in serum and follicular fluid of stimulated and unstimulated cycles

Serum and follicular fluid levels of CEA, CA 125 and SCC of women participating in an IVF program, in 42 cycles stimulated with GnRH-a and gonadotropins and in 26 unstimulated cycles triggered with HCG, were evaluated and compared with (a) steroid and gonadotropin levels, (b) the results of IVF, and (c) serum values in a control group of women with spontaneous normal ovulatory cycles. In the control group, serum antigens did not vary significantly during the 3 phases of the cycle. In stimulated cycles the median values in serum were 0.7 ng/ml (range, 0.0-2.1) for CEA, 14.0 U/ml (3.3-32.4) for CA 125 and 2.05 ng/ml (1.1-17.8) for SCC, whereas the median values in follicular fluid were 0.6 (0.0-27.9), 21.5 (0-670) and 21.4 (1-360), respectively. In unstimulated cycles the median values and ranges in serum were 0.9 (0.4-3.9), 12.1 (4.8-63.4) and 1.85 (0.7-4.4), respectively, whereas in follicular fluid they were 2.9 (0.4-180.7), 32 (1.7-600) and 231 (10.8-904). Different follicles of the same patients in stimulated cycles showed a wide divergence for all three antigens. In unstimulated cycles all three antigens in follicular fluid were strongly-correlated and a significant inverse correlation was observed between LH and both CA 125 and SCC in serum. In either group of cycles, no significant relationship was found between any serum or follicular fluid antigen and estradiol or testosterone, pregnancy rate, or oocyte quality and fertilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Failure of ethanol to induce changes in gonadotropin gene expression in selectively bred ethanol-sensitive rats

The recent availability of genetically altered rat lines differing in sensitivity to ethanol (EtOH) has allowed deeper investigation into the mechanisms of EtOH-induced cellular toxicity in several systems. Since the male central reproductive axis has been demonstrated to be exquisitely sensitive to EtOH, studies were undertaken to determine if the gonadotropin suppression reported earlier could be duplicated in one of these selected rat lines. Castrated high alcohol sensitivity (HAS), low alcohol sensitivity (LAS) and control alcohol sensitivity (CAS) rats were given EtOH or saline acutely. Castrated non-selectively bred Sprague Dawley rats were treated similarly and used as an additional control. At sacrifice, serum and pituitary luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels were obtained and the mRNA levels for both gonadotropins assessed. In the selectivity bred animal there was essentially no change in serum or pituitary LH or FSH levels between EtOH and saline treated animals. The mRNA levels for both LH and FSH similarly were unaffected by EtOH, in striking contrast to the non-selectively bred Sprague Dawley rats where serum LH, FSH and beta-LH mRNA levels are markedly suppressed after EtOH exposure. The selectively bred lines of rats genetically manipulated for high or low EtOH sensitivity, as well as their non-selected controls, appeared to have a hypothalamic-pituitary reproductive unit that is resistant to EtOH. This is in contrast to Sprague-Dawley rats, where suppression of this axis previously has been consistently demonstrated.

Spectrophotometric analysis of human follicular fluid with regard to in vitro fertilization (IVF) parameters, follicular protein, and hormone content

PURPOSE

Our purpose was to investigate possible relationships with spectrophotometric absorbance (458-nm region) and biochemical variables in follicular fluid (FF) as well as in vitro fertilization (IVF) outcome.

METHODS

This study included 227 normal ovulatory women undergoing oocyte retrieval for IVF. Blood-uncontaminated fluid samples, identified by spectrophotometry, were investigated. Spectrophotometric absorbance of FF at 458 nm (n = 426), as well as hLH, FSH, PRL, hCG, testosterone, sialic acid, alpha 1-antitrypsin and plasminogen of selected fluids, was analyzed.

RESULTS

Small-volume follicles (< or = 2 ml) were associated with higher absorbance profiles (P < 0.05), when compared to volumes greater than 2 ml. Our data suggest that the presence or absence of an oocyte, the potential of an oocyte to fertilize or cleave, failed to show any relationship with maximum FF absorbance at 458 nm. Maximum absorbances were significantly lower in FF from patients who subsequently became clinically pregnant (P = 0.039). No correlation between FF absorbances and biochemical parameters (P > 0.15) were established.

CONCLUSIONS

Absorbance of clear FF at 458 nm should not be viewed as the single parameter to predict oocyte development in vitro.

Review of the influence of polypeptide hormone forms on immunoassay results

Various forms of the polypeptide hormones that occur in blood, fluids, or tissues can differ according to physiologic and pathologic states. Forms include subunits of luteinizing hormone, follicle-stimulating hormone, human chorionic gonadotropin, and thyroid-stimulating hormone. Hormonal isoforms occur for these hormones as well as for prolactin and growth hormone. Variation in hormonal forms appears to contribute significantly to the wide variation in immunoassay results for these polypeptide hormones. Subunits and isoforms of the polypeptide hormones can overreact or underreact in monoclonal antibody assays. The underreaction or overreaction can occur with standards, controls, and patient specimens as well as with the assay label.

The relationship between luteinizing hormone and estradiol secretion in female precocious puberty: evaluation by sensitive gonadotropin assays and the leuprolide stimulation test

We used the GnRH agonist (GnRHa) stimulation test (20 micrograms/kg leuprolide sc, followed by 24-h serial sampling) to investigate the relationship between gonadotropin and estradiol (E2) secretion in the early phase of female central precocious puberty (CPP). Girls with CPP and moderately increased (early pubertal) peak E2 concentrations after GnRHa stimulation (136 +/- 11 pmol/L; range, 92-176; group B; n = 7) were compared to girls with CPP and higher (midpubertal) peak E2 responses to GnRHa (mean +/- SE, 590 +/- 63 pmol/L; range, 235-1189; group C; n = 19) and to a group of subjects with no breast development and a prepubertal hypothalamic-pituitary-gonadal axis (peak E2 response to GnRHa, 39 +/- 7 pM/L; range, 18-62; group A; n = 6). Compared to group A subjects, patients in group B had similar (P > 0.2) peak GnRHa-stimulated LH concentrations (B, 4.8 +/- 1 IU/L; A, 2.3 +/- 0.5 IU/L) and peak nocturnal LH (B, 0.81 +/- 0.2; A, 0.25 +/- 0 IU/L), but higher peak GnRHa-stimulated FSH concentrations (B, 26 +/- 7; A, 11 +/- 2 IU/L; P < 0.05) and mean nocturnal FSH (B, 4.2 +/- 1; A, 1.1 +/- 0.3 IU/L; P < 0.05) concentrations. Compared to group B, group C patients had higher (P < 0.001) GnRHa-stimulated peak LH (67 +/- 19 IU/L) and higher (P < 0.05) peak nocturnal LH (9.7 +/- 2.9 IU/L) concentrations, but similar GnRHa-stimulated peak FSH (27 +/- 3 IU/L) and mean nocturnal FSH (3.8 +/- 0.5 IU/L) levels. Group C patients with a ratio of peak GnRHa-stimulated LH to FSH concentrations below or above 1, respectively, had similar peak E2 responses to GnRHa (516 +/- 80 vs. 644 +/- 92 pM/L; P > 0.1). Stepwise regression analysis indicated that the peak LH response to GnRHa (r = 0.76; P < 0.001), but none of the FSH secretory parameters (P > 0.10), affected the E2 response to GnRHa. These data suggest that girls with CPP in the early phase of activation of the hypothalamic-pituitary-gonadal axis are capable of clinically relevant E2 production, which may occur in the face of low LH secretion and low LH/FSH ratios and cannot be explained solely on the basis of increased FSH secretion. Thus, endocrine or paracrine factors other than gonadotropins may be important in amplifying E2 secretion in the early phase of CPP.

Physical and behavioral findings in a pseudohermaphrodite American bison

A pseudohermaphrodite American bison (Bison bison) behaved like an adult male when interacting with adult females, but like an adult female when interacting with adult males. Its chromosomes were a normal 60, XX and it had a uterus; but it had bilateral testes rather than ovaries. Skull measurements were intermediate between a bull and a cow. Gonadotrophin levels were typical of ovariectomized domestic cows or steers.

48,XXYY syndrome associated with acromegaloidism

We report a case of double male syndrome, a type of Klinefelter's syndrome with 48,XXYY chromosome, associated with acromegaloidism. Although the patient presented acromegalic appearance, he did not show hypersecretion of growth hormone (GH). GH provocation tests revealed a rather low GH responses or no responses. After testosterone therapy, the GH responses were normalized except to Insulin tolerance test (ITT). On the other hand, the plasma corticotropin (ACTH) and cortisol levels were decreased paradoxically after hypoglycemia. Testosterone therapy did not restore this ACTH response. It was speculated that these abnormal GH and ACTH responses to hypoglycemia might indicate another congenital anomaly.

Gonadotropin bioactivities in mouse, hamster, rat and guinea pig pituitaries are largely adsorbed on concanavalin A-sepharose

The pituitaries of mice, hamsters, guinea pigs and rats were extracted with Tris-Cl buffer and the extracts were chromatographed on Concanavalin A (ConA)-Sepharose into unadsorbed ConA I and adsorbed ConA II fractions. The ConA I fraction was subjected to gel filtration on Sephadex G-100 and fractionated into an unretarded peak and several retarded peaks. The peak with a molecular weight of approximately 40,000 (designated ConAI Sephadex fraction II) was then subjected to ion exchange chromatography on CM-cellulose and fractionated into an unadsorbed CM I and an adsorbed CM II fraction. The ConA II fraction was fractionated by ion exchange chromatography on CM-cellulose into CM I and CM II fractions. The ConA II CM II fraction was the chromatographic fraction which exhibited the highest potency in stimulating testosterone production by isolated rat Leydig cells. Its activity was much higher than the corresponding ConA I Sephadex fraction II CM II fraction which differed chromatographically only by non-adsorption on ConA-Sepharose. The ConA II CM II fraction manifested cross reactivity in a rat luteinizing hormone (LH) radioimmunoassay. The guinea pig pituitary ConA II CM II fraction also cross-reacted in a rat thyroid stimulating hormone radioimmunoassay. The ConA II fractions of hamster and guinea pig pituitary extracts demonstrated follicle stimulating hormone (FSH) activity while the corresponding ConA I fractions did not. The results suggest that the ConA II/ConA II CM II fraction contained most of the FSH and LH activities present in the pituitary extract.

The complete amino acid sequence of the follitropin beta-subunit of the bullfrog, Rana catesbeiana

The amino acid sequence of the bullfrog, Rana catesbeiana, follitropin beta-subunit has been determined by sequencing the intact protein (residues 1-39) and peptides originated by lysyl endopeptidase and pepsin. Twelve cysteine residues and two sugar chain binding sites at Asn-5 and Asn-22 are positional identities with bullfrog and mammalian beta-subunits. The bullfrog FSH beta-subunit is composed of 107 amino acid residues with a molecular mass of 11,782 Da, including the six cystine bridges and excepting the sugar chain. The bullfrog FSH beta-subunit has approximately 60% sequence identity with that of mammals and 40% with the fish gonadotropin beta-subunit. Conserved sequences among mammals (residue numbers 33-55 and 66-71) extensively differed from those of the bullfrog.

Ancylostoma ceylanicum infection in female hamsters: an observation on altered reproductive function

Reproductive performances of female hamsters were investigated during Ancylostoma ceylanicum (hookworm) infection. Animals having the highest levels of infection (34.96 +/- 1.11 worms) showed degenerative changes in the reproductive system. Ovaries of infected animals contained a few primary or secondary follicles. On cocaging with males of proven fertility, only 7-8% (80% in controls) of the infected females mated but did not conceive as evidenced by the absence of corpora lutea or implantation sites on day 10 postcoitum. Animals with low worm burdens (5.94 +/- 0.65 worms), however, showed almost normal fertility. The uterine weight bioassay and compensatory ovarian hypertrophy suggest strong suppression of pituitary gonadotrophin contents in infected females. Resorptive effects on the pregnancy outcome of infected female hamsters were also recorded.

Effects of orchidectomy on gonadotropin and inhibin subunit messenger ribonucleic acids in the pituitary of the rhesus monkey (Macaca mulatta)

Our research programs required the preparation of hypophysectomized and orchidectomized rhesus monkeys. This afforded us the possibility to characterize and compare levels of the gonadotropin and inhibin subunit mRNAs in pituitaries from intact and castrate monkeys. Eighteen adult male monkeys, four of which had been bilaterally orchidectomized 5-9 months previously, were used in this study. Plasma concentrations of LH and FSH were, respectively, 188.5 +/- 5.3 and 246.8 +/- 25.2 ng/ml in the castrate monkeys and 25.8 +/- 4.5 and 4.1 +/- 1.1 ng/ml (mean +/- SEM) in the intact animals. Total pituitary RNA was hybridized to cDNA probes for cynomolgus monkey gonadotropin subunits (FSH beta, LH beta, and the common alpha-subunit) and for human inhibin subunits (alpha, beta B, and beta A) by Northern blot analysis, and mRNA levels were normalized by subsequent hybridization to cyclophilin. Each of the gonadotropin subunit probes hybridized to a single RNA species with the approximate sizes of 1.6 kilobases (kb; FSH beta), 0.7 kb (LH beta), and 0.8 kb (alpha). Levels of LH beta and alpha-subunit mRNAs in pituitaries from castrate monkeys were about 5- and 2-fold higher, respectively, than those in pituitaries from intact monkeys. FSH beta mRNA, on the other hand, was elevated about 27-fold in castrate monkeys [mean +/- SEM, 3176 +/- 408 cpm bound (n = 4 castrate) and 116 +/- 30 cpm bound (n = 8 intact]). Inhibin beta B-subunit mRNA was present in the monkey pituitary as a doublet of about 5 kb, and it was approximately twice as abundant in intact pituitaries as in castrate pituitaries. Hybridizations involving inhibin beta A cDNA revealed a faint band in the region expected for monkey beta A mRNA (6.5 kb) in three of six RNA samples from intact monkeys and a 0.3- to 0.4-kb mRNA species. mRNA encoding the inhibin alpha-subunit was undetectable by Northern blot hybridization. These results indicate that the postpubertal testis imposes an inhibition on the expression of the genes encoding FSH beta, LH beta, and glycoprotein hormone alpha-subunit and that this suppression of the FSH beta gene in the monkey is much greater than that in the rat. In addition, the monkey pituitary may be a source of activin, which may act locally to modulate FSH gene expression and secretion.

Properties of common carp gonadotropin I and gonadotropin II

Two gonadotropins, GtH I and GtH II, were extracted with 35% ethanol-10% ammonium acetate, pH 6.1, from female common carp pituitary glands and purified by ion-exchange chromatography on a DE-52 column followed by gel filtration on a Sephadex G-75 column. Molecular weights of GtH I and GtH II as determined by SDS-PAGE were 45,000 and 35,000, respectively. Both GtHs dissociate into two subunits following reduction with beta-mercaptoethanol. These subunits contain different N-terminal amino acids (Tyr and Gly for GtH I; Tyr and Ser for GtH II). GtH I was acid stable and did not dissociate into subunits following treatment with 0.1% trifluoroacetic acid; GtH II readily dissociated into subunits by this treatment. GtH I and GtH II have distinct elution profiles on reverse-phase HPLC. The N-terminal amino acid sequence of the beta-subunit of GtH II was identical to that of common carp maturational GtH described by other workers suggesting that GtH I is a newly identified molecule. This was supported by radioimmunoassay analysis. GtH II and a common carp maturational GtH preparation (F11 cGtH; Peter et al., 1982, J. Interdiscipl. Cycle Res. 13, 229-239) had similar immunological activity in tests with antisera to the beta-subunit of maturational GtH whereas GtH I had low (less than 6%) cross-reactivity. GtH I, GtH II, and F11 cGtH were equipotent in tests with antisera to the alpha-subunit of maturational GtH suggesting these molecules contain a similar alpha-subunit. In vitro bioassays using goldfish revealed that GtH I and GtH II share the same spectrum of biological activities causing stimulation of ovarian and testicular steroidogenesis and induction of oocyte final maturation. The demonstration of two chemically distinct GtHs in common carp is similar to what has been described for chum and coho salmon.

The relative contribution of androgens and insulin in determining abdominal body fat distribution in premenopausal women

To investigate the relative contribution of insulin and sex hormones in determining the abdominal pattern of fat distribution in premenopausal women, five groups of age-matched subjects were examined: Group 1 consisted of 14 normal weight eumenorrheic women (NO); Group 2 of 9 obese eumenorrheic women (OB); Group 3 of 14 normal weight hyperandrogenic women with polycystic ovary syndrome (NO-HA); Group 4 of 10 obese hyperandrogenic women with polycystic ovary syndrome (OB-HA) and, finally, Group 5 of 10 obese hyperandrogenic women with polycystic ovary syndrome and acanthosis nigricans (OB-HA-AN). Both the two normal weight groups and the three obese groups were matched for body mass index values. Sex hormone pattern showed significantly higher LH and testosterone levels in hyperandrogenic women with respect to NO and OB women but obese hyperandrogenic groups (OB-HA and OB-HA-AN) presented significantly lower LH concentrations than NO-HA. Fasting and glucose-stimulated insulin levels were significantly higher in OB than NO, in OB-HA and OB-HA-AN than in OB and NO-HA, and in OB-HA-AN than in OB-HA, without any significant difference between OB and NO-HA. Body fat distribution, expressed by the waist to hip ratio (WHR), showed progressively higher values (p less than 0.01) from NO to OB, NO-HA, OB-HA and, particularly, OB-HA-AN women. Determination coefficients r2 obtained from simple regression analysis showed that the sum of insulin values during the glucose tolerance test and testosterone levels had a more significant power in determining WHR variability.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic administration of estradiol produces a triphasic effect on serum concentrations of gonadotropins and messenger ribonucleic acid for gonadotropin subunits, but not on pituitary content of gonadotropins, in ovariectomized ewes

To determine the acute and chronic effects of estradiol on synthesis and secretion of LH and FSH, ovariectomized ewes were administered estradiol via silastic capsules for 0 h, 12 h, 1 day, 2 days, 4 days, 8 days, 16 days, or 32 days (n = 5/group). Concentrations of GnRH in the median eminence began to decrease within 12 h and were lower (p less than 0.05) than in control ewes from 1 to 4 days after estradiol administration was begun. Serum concentrations of LH were decreased relative to pretreatment control levels from 1 to 10 h, elevated during a preovulatory-like surge from 11 to 22 h, and then decreased and remained below 1 ng/ml for the duration of the experiment. Serum concentrations of FSH followed a pattern similar to those for LH except that the magnitude of change was smaller. Treatment with estradiol initially (12 h) reduced (p less than 0.05) quantities of mRNA for alpha-, LH beta-, and FSH beta-subunits, after which the quantities of mRNA for the subunits returned to near or above control levels by Day 2. After 8 days of treatment the amounts of mRNAs for gonadotropin subunits were again less (p less than 0.05) than those of controls, and they remained suppressed through Day 32. Pituitary concentrations of LH and FSH decreased (p less than 0.05) during the first day of treatment and remained suppressed for the duration of the experiment. Thus, estradiol had a triphasic effect on secretion of gonadotropins and steady-state levels of mRNA for the gonadotropin subunits, but not on pituitary content of gonadotropins.(ABSTRACT TRUNCATED AT 250 WORDS)

The adenohypophysis of the Australian lungfish, Neoceratodus forsteri--an immunocytological study

The cell types in the adenohypophysis of Neoceratodus resemble closely those already described for Lepidosiren and Protopterus. Four of these were immunocytochemically identified as prolactin cells, gonadotropes, corticotropes, and melanotropes. Antiserum to bullfrog growth hormone could not distinguish between prolactin cells and somatotropes. Anti-bullfrog prolactin, however, did selectively stain the prolactin cells, which allowed the identification of the somatotropes. The presumptive thyrotropes, as the only remaining cell type in the pars distalis, can then be tentatively identified by default. Likewise a PAS-positive cell type in the pars intermedia had no immunoreactivity to any of the antisera used. The functional significance of this cell remains to be demonstrated. One of the more unexpected findings was the presence of large numbers of cells immunoreactive to alpha-MSH in the proximal pars distalis. The implications of the presence of these cells in adult lungfish are discussed. The distribution of cell types within the pituitary of Neoceratodus showed more regionalization than is present in the other lungfish and corresponded more closely to that described for primitive actinopterygian fish. The general structure of the pituitary of Neoceratodus also resembled primitive actinopterygian fish more closely than it did amphibians, unlike the pituitaries of Lepidosiren and Protopterus. The evolutionary significance of this is also discussed.

Reduced aminergic synthesis in the hypothalamus of the infertile, genetically diabetic (C57BL/KsJ-db/db) male mouse

Diabetes mellitus is commonly associated with reproductive neuroendocrinopathy in both humans and animal models for the disease. Diabetes-associated reproductive failure in the male is a result of multilevel dysfunction within the hypothalamo-pituitary-testicular axis. In view of the known effects of diabetes on hypothalamic gonadotropin-releasing hormone (GnRH) and gonadotropins in chemically-induced animal models for diabetes, we examined hypothalamic aminergic activities (important to the regulation of GnRH release), circulating gonadotropin levels and testicular morphology in the infertile, genetically diabetic (C57BL/KsJ-db/db) male mouse. Groups of 2-5 month old (average age: 3.4 months) and 6-11 month old (average age: 8.8 months) diabetic mice were compared with age-matched non-diabetic (C57BL/KsL(-)+/?) male mice. Diabetic mice in both age groups were markedly obese and hyperglycemic. Hypothalamic serotonin synthesis was inhibited in the preoptic area-anterior hypothalamus (POA-AH) in both 2-5 month old and 6-11 month old diabetic mice as well as in the mediobasal hypothalamus-median eminence (MBH-ME) of 6-11 month old diabetic mice. Catecholamine synthesis (norepinephrine and dopamine) was reduced in the POA-AH of 2-5 month old diabetic mice and in the MBH-ME of 6-11 month old mice. These aminergic changes were associated in 2-5 month old diabetic mice with reduced circulating levels of LH and in 6-11 month old diabetic mice, of both LH and FSH. In 6-11 month old diabetic mice, testes were characterized by a thickened tunica albuginea, numerous Sertoli cells and the near absence of any spermatogenic cells. The epididymis from these diabetic mice was devoid of spermatozoa.(ABSTRACT TRUNCATED AT 250 WORDS)

[Therapeutic use of a gonadotropin releasing hormone analogue in breast cancer]

Superagonistic analogues of Gn-RH given chronically produce a paradoxic inhibition of pituitary gonadotropin secretion and consequently decrease the peripheric hormones estradiol and progesterone to a postmenopausal level. For curative purposes buserelin (SuprefactR, Hoechst) treatment has been performed by the authors in two cases of breast cancer. The patients--one with NED (no evidence of disease) and the other with pulmonary and osseal metastases--in addition to low hormonal levels developed amenorrhoea. A group of climacteric complaints were observed without any toxic side effects, however. The treatment of premenopausal women suffering from breast cancer with chronic administration of Gn-RH analogues may constitute a valuable alternative to surgical oophorectomy.

Equine growth hormone. Detection of immunoreactive sequences using poly- and monoclonal antibodies

The immunochemical behavior of several fragments of equine growth hormone (eGH) was examined using competitive binding assays with antibodies (Abs) to eGH obtained from different sources. Antigenicity was detected within the sequences 5-72 and 73-123 by rabbit Abs to eGH and by three mouse monoclonal antibodies (MAbs) produced by using bovine growth hormone as immunogen, but showing heteroclitic properties towards eGH. The polyclonal Abs to eGH also recognized as immunoreactive two smaller peptides corresponding to the amino acid residues 52-72 and 110-123. By contrast, the heteroclitic Abs to eGH developed by hypopituitary patients therapeutically injected with human growth hormone failed to react with any eGH-derived fragment. The rabbit polyclonal Abs and the mouse MAbs scarely discriminated between native and S-carbamidomethylated eGH, while the heteroclitic human Abs detected a clear difference between the native and the modified hormone.

Development of an enzyme-linked immunosorbent assay for goldfish gonadotropin

An enzyme-linked immunosorbent assay (ELISA) for goldfish gonadotropin (GTH) was developed with the intent of devising a simple, reliable and nonradioisotopic assay for the measurement of GTH in goldfish biological samples. In this assay, soluble GTH of the standards or samples competes with carp GTH (cGTH) immobilized on a solid support (96-well microplate) for the fixation on antibodies to the beta-subunit of carp gonadotropin. The immobilized antigen-antibody complexes are then revealed by the peroxidase-antiperoxidase (PAP) technique. After revelation of the peroxidase activity, the absorbance value of each well is measured with a microplate reader. The cGTH concentration used for coating the wells is 2 ng/ml and the final dilution of the specific antibody is 1:80,000. The assay can be performed within 24 h and can be used over a range of 0.125-4 ng/ml. At about 50% binding, the intra- and interassay coefficients of variation are 5% and 9% respectively. The displacement curves generated by goldfish plasma or pituitary perifusion fractions were strictly parallel to the standard cGTH. In addition, the stimulation by salmon gonadotropin-releasing hormone of pituitary fractions perifused in vitro caused an immediate increase in the GTH measured in the collected fractions, strongly reinforcing the assumption that this assay indeed measures GTH.

Immunocytochemical and ultrastructural characterization of the cell types in the adenohypophysis of Sparus aurata L. (teleost)

The structure and immunocytochemistry of the adenohypophysis of sexually mature male specimens of Sparus aurata (gilthead sea bream) were studied. The adenohypophysis was composed of rostral pars distalis (RPD), proximal pars distalis (PPD), and pars intermedia (PI). In the RPD the prolactin cells were organized into follicles which occupied a very reduced area as corresponds to that in saltwater fishes; the corticotropic cells were surrounding the pars nervosa branches and the prolactin follicles. The PPD showed somatotropic, gonadotropic, and thyrotropic cells. The somatotropic cells were isolated, clustered, or surrounding the pars nervosa branches. Only one polymorphic cell type of gonadotropic cells was found in the PPD ventral and dorsal areas and around the PI. The PI was composed mainly of melanotropic cells and a PAS-positive cell layer adjacent to the neurohypophysis. The ultrastructure of the presumptive endocrine cells was reported and their distribution was discussed in relation to those of other teleosts.

[Method and evaluation of hormone assays in practical obstetrics and gynecology]

Hormone assays are very important in obstetrics and gynecology. Today, I want to talk about how to measure hormones and how to evaluate the data obtained for therapeutic purposes. In humans, there are two mechanisms of control, neural control and endocrine control. Generally speaking, the neural system controls organs directly via various neurotransmitters, while the endocrine system controls organs by hormones transported in the blood. In fact, recent progress in hormone research has shown that this concept should be modified, because some hormones act as neurotransmitters or regulate other cells or even endocrine cells themselves in the same organ. But I shall not go into this. Today's lecture is focused on hormones that are closely related to clinical obstetrics and gynecology. The hormones that are important are those in females, reproduction, and pregnancy, and tumors. First, and most important, is that patients acquire femininity in the physiological and psychological sense by hormones. The hormones closely related to this are estrogens and pituitary hormones. For reproduction, cyclic hormonal change is important. In the reproductive period, women have menstruation and ovulation along with cyclic changes of ovarian and pituitary hormones. After conception, various kinds of hormones, including hCG, HPL and estriol, are secreted from the feto-placental system. These hormones are used clinically as a markers of placental function. Hormones also have important roles in oncology. hCG is an excellent marker of trophoblastic diseases. Endometrial cancer is expected respond to large doses of progestins if they have progesterone receptors. There are three types of hormone assays, biological assays, immunological assays and chemical assays.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation and characterization of subunits from two distinct salmon gonadotropins

Two distinct gonadotropins, GTH I and GTH II, isolated from female chum salmon pituitary glands, were separated into subunits by acid treatment and subsequent fractionation on reversed-phase high-performance liquid chromatography. GTH II was completely dissociated in 0.1% trifluoroacetic acid, while GTH I was partially dissociated. The acid-stable form of GTH I exhibited a potency identical to that of GTH I in stimulating estradiol-17 beta production in vitro. Both GTH I and GTH II consist of two dissimilar subunits. One subunit (alpha) is common to both GTHs, has Tyr as its N-terminal residue, and a molecular weight (Mr) of 22K by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after reduction. The other subunit (beta) has a Mr of 17K and an N-terminal residue of Gly for GTH I, whereas GTH II beta is 18K and has an N-terminal residue of Ser, after reduction.

Interrelationships between plasma hormone levels and the content of total protein, gonadotropins and steroid hormones in antral fluids of women undergoing in vitro fertilization

Follicle development was induced in 41 women with follicle-stimulating hormone (FSH) and human menopausal gonadotropin. Blood samples were drawn and follicular fluids (FF) were aspirated when two or more follicles attained diameters of 15 to 17 mm. Levels of estradiol (E2), progesterone (P), FSH, and luteinizing hormone (LH) were determined in samples by radioimmunoassay, and relationships between the measured parameters in antral fluids and in serum were examined by least-squares linear regression analysis. Levels of LH in serum correlated with LH and FSH levels in FF (P less than 0.005). Concentrations of FSH in serum were positively related to levels of LH, FSH, E2, and total protein in FF (P less than 0.005). E2 levels in serum were predictive of E2 levels in FF only, and levels of P in serum were directly correlated with P levels in FF (P less than 0.05). With respect to the peculiarly broad range of predictions that could be drawn from the FSH content of serum, peripheral FSH provided a better predictive index of the chemical composition of antral fluid than did the level of any other single hormone measured in serum.

Salmon gonadotropin (sGTH) immunoreactivity and 11-oxotestosterone secretion of mature rainbow trout (Salmo gairdneri) testes in vitro: an alternative to radio-receptor assay for sGTH-binding studies

After three intraperitoneal injections of salmon gonadotropin (sGTH) or bovine serum albumin (BSA), testicular tissue of fully mature rainbow trout was prepared for in vitro incubation with or without sGTH. The secretion of 11-oxotestosterone was measured and the tissue was fixed for light-microscopical localization of sGTH immunoreactivity (ir). Tissue from sGTH-treated males showed an increased basal secretion and sGTH-stimulated androgen secretion but the stimulated versus control ratio was higher without sGTH treatment in vivo. When the tissue had had contact with exogenous sGTH, sGTH-ir showed similar distribution patterns regardless of the sGTH treatment regimes. The extralobular compartment showed a staining of interstitial cells and capillary walls. The staining in the intralobular compartment was less clear. Many Sertoli-cells carried a faint nuclear label, whereas intralobular germ cells appeared to be unlabeled.

Gonadotropin content of the pituitary gland of gonadal tumor-bearing common carp x goldfish hybrids from the Great Lakes, as assessed by bioassay and radioimmunoassay

The hybrids of carp (Cyprinus carpio) and goldfish (Carassius auratus) collected from the lower Great Lakes between 1978 and 1981 exhibited epizootics of gonadal neoplasm which were rare in the parental species. The pituitary glands of hybrids were, on average, 2.5 times larger than that of carp of similar body size. Histologically, the hypertrophy was due to hyperplasia of proximal pars distalis basophils (the presumptive gonadotropes). Using a carp gonadotropin (GtH) radioimmunoassay it was found that hybrid pituitaries contained more GtH than sympatric carp and that pituitary GtH concentration in hybrids was positively correlated with pituitary weight. Both this and histological evidence suggested that gonadotrope hyperplasia was a progressive event. Two heterologous gonad bioassays indicated that hybrid GtH had biological activity. Whether pituitary hyperplasia in hybrids is a primary problem or secondary to gonadal sterility has not been determined.

Effects of local heating of the testes on the concentration of testosterone in jugular and testicular venous blood of rats and on testosterone production in vitro

Heating both testes of rats to between 39 degrees C and 41 degrees C for 30 min was apparently without effect 21 days later, but heating to between 41.5 degrees C and 43 degrees C for 30 min resulted in a significant drop in testis weight accompanied by significant rises in the serum levels of LH and FSH. There were no changes in serum testosterone concentration in the peripheral circulation although there were increases in the concentration in testicular venous blood. The ability of the heated testis to secrete testosterone in vivo in response to maximal stimulation by hCG was reduced, as judged by testosterone levels in peripheral blood, while there was a supranormal increase in testosterone levels in testicular venous blood. Maximally stimulated testosterone production in vitro by the heated testis was supranormal whereas the basal production of testosterone per testis was not different from control values. Therefore, it appears that the testosterone produced by Leydig cells from heated testes may not be secreted as effectively as in normal testes.

Gonadotropin measurements with fast, non-radioactive methods

Different analytical methods for the measurement of lutropin and follitropin were compared. Lutropin concentrations of urine samples were measured with the semiquantitative HI Gonavis test (Moshida, Japan), and quantitatively by a modified Ovustick procedure (Monoclonal Antibodies Inc., USA) and by DELFIA (LKB Wallac, Finland). Semiquantitative and quantitative procedures showed conformity in 37 of 40 menstrual cycles when lutropin analyses were performed daily. Values from the analysis of serum samples by dissociation enhanced lanthanide fluoroimmunoassay (DELFIA) and Radioimmunoassay (Serono, FRG) revealed a high degree of correlation (lutropin r = 0.970, follitropin r = 0.994). Immunologic analysis with enzyme- or europium-labelled tracer is a practicable alternative to haemagglutination or radioimmunoassay procedures.

Oocyte maturity and human follicular fluid prostanoids, gonadotropins, and prolactin after administration of clomiphene and pergonal

Follicular fluid (FF) and oocytes were obtained from 130 follicles of 52 women in whom ovulation was induced with human menopausal gonadotropin (Pergonal) and clomiphene citrate. Follicular aspiration was performed 36 h after an ovulatory injection of hCG. The concentrations of LH, FSH, PRL, and the prostanoids prostaglandin E2 (PGE2), PGF2 alpha, PGI2 (as 6-oxo-PGF2 alpha), and thromboxane A2 (as TXB2) in the FF were measured by RIA and related to the degree of maturation of the oocyte-corona-cumulus complex mass (OCCC). FF obtained from follicles with immature OCCC contained significantly lower concentrations of all four prostanoids (median concentrations, picograms per mL: PGE2, 88; PGF2 alpha, 85; 6-oxo-PGF1 alpha, 40; TXB2, 50) than those with intermediate OCCC (PGE2, 175; PGF2 alpha, 325; 6-oxo-PGF1 alpha, 130; TXB2, 65) and mature OCCC (PGE2, 425; PGF2 alpha, 860; 6-oxo-PGF1 alpha, 235; TXB2, 78; all P less than 0.01). There were no significant differences between the maturity of the complexes and the concentrations of LH, FSH, or PRL. There were significant correlations between the FF concentrations of LH and FSH and those of all of the prostanoids, but not with PRL, concentrations. These results indicate that the synthesis of prostanoids in the human Graafian follicles may be modulated by gonadotropins and consolidates the view that prostanoids may play a role in human oocyte maturation and ovulation.

Sulfate and phosphate analysis in glycoproteins and other biologic compounds using ion chromatography. Application to glycoprotein hormones and sugar esters

An ion chromatography procedure was devised for the simultaneous determination of phosphate and sulfate in the same sample. In order to eliminate interference from zwitterionic compounds (particularly amino acids and peptides) generated during hydrolysis of the phosphate- or sulfate-containing compounds a pretreatment step with a cation-exchange column was required. The detection of sulfate is approximately twice as sensitive as phosphate on a molar basis. The useful working range for sulfate was 200 pmole to 35 nmole with the ion chromatography employed; the range for phosphate was 400 pmole to 65 nmole. Linearity in this range was very satisfactory. Representative analyses are presented for hydrolyzates of several glycoprotein hormones and sugar sulfates and phosphate esters. Replicate analyses were +/- 3.0% or better. The glycoprotein hormone analyses for sulfate did not indicate whole integers per mole, suggesting mixtures of isohormones as has been found by others using chromatofocusing or isoelectric focussing and immunoassay.

The relation between pituitary gland and thyroid growth during the lifespan of the annual fish Cynolebias whitei and Nothobranchius korthausae: gonadotropic and thyrotropic cells

In the annual cyprinodont Cynolebias whitei the cell types responsible for the increase of pituitary growth at the onset of maturation and for pituitary hyperplasia in old specimens were identified as gonadotropic cells and thyrotropic cells, respectively. The gonadotropic cells showed a high affinity to anti-carp alpha beta-GTH serum, both at light- and electron-microscopical levels. The allometric relation of total gonadotropic cell volume to body length, determined for fish from six weeks up to six months of age, showed no inflections. Therefore pituitary growth in maturing fish may be partly a result of proliferation of gonadotropes, although gonadotropic cells do not contribute to pituitary hyperplasia in old fish. Thyrotropic cells showed a weak affinity to anti-carp alpha beta-GTH serum at light-microscopical level. Under the electron microscope thyrotropic cells displayed signs of activation in maturing fish and signs of proliferation in old fish. The allometric relation of thyroid gland volume to body length paralleled that of pituitary volume to body length. Histologically the thyroid gland showed signs of inactivity in adult fish and of hyperplasia in old fish. The possibility, that gonadal maturation, pituitary thyrotropic activity, and growth of the thyroid in maturing fish are related through the inhibitory action of gonadal steroids on thyroid hormone release, is discussed. Pituitary hyperplasia in old fish is the result of proliferation of thyrotropic cells. Similar hyperplasia of pituitary and thyroid glands was observed in old Nothobranchius korthausae.

Fertility onset, spermatogenesis, and pubertal development in male rats: effect of graded underfeeding

Undernutrition has proven to be a useful model for exploring the relationship between growth and pubertal development in female rats, such as the "critical body weight" hypothesis of pubertal timing, but corresponding studies in the male have been hampered by lack of specific discrete markers of puberty similar to vaginal opening or first estrus in females. In the current study, we explored the effect of five different levels of food intake (as low as one-third of normal) beginning at weaning on pubertal development and timing in male rats, using the date of the initial successful conception with normal females as a discrete marker for puberty in males. In underfed males, there was a weak inverse correlation (r = -0.31, p less than 0.05) between the age at puberty and the growth rate, the latter being used as an index of the degree of underfeeding. In contrast, there was a strong direct correlation (r=0.78, p less than 0.001) between body weight at puberty and growth rate. In the most severely underfed groups, the Lee index of body fat remained subnormal before and after puberty. Initial litter size also tended to be reduced when the males were underfed. At age 51 days (prior to puberty), graded underfeeding led to progressive reductions in serum luteinizing hormone and follicle-stimulating hormone levels as well as in parameters of androgen status (serum and testicular testosterone, prostate, and seminal vesicle weights). Testicular size was also reduced, but daily sperm production rate was not greatly affected by underfeeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunocytochemical demonstration of pituitary cell types in the teleost Poecilia latipinna, by light and electron microscopy

Using the unlabelled antibody method at the light microscope level, and the immunogold method at the electron microscope level, the distribution of the different adenohypophysial cells was demonstrated in the teleost Poecilia latipinna, by means of antisera to both teleostean and mammalian pituitary hormones and their subunits. Anti-salmon prolactin, but not anti-rat or -ovine prolactin, gave a specific staining of the acidophils of the rostral pars distalis (RPD), while anti-trout growth hormone (GH), but not anti-rat GH, stained similar but always separate cells in the proximal pars distalis (PPD). Antisera to the whole molecules of mammalian glycoprotein hormones stained the entire population of basophils in the PPD, but separate populations of gonadotrophs and thyrotrophs could be discriminated using anti-salmon gonadotrophin and anti-human thyrotrophin beta subunit. Antisera to ACTH (1-24) and (11-24) sequences, as well as beta-endorphin and met-enkephalin, stained the lead haematoxylin-positive cells of the RPD and pars intermedia (PI), whereas anti-alpha-MSH stained only the PI cells. Ultrastructural examination showed that these immunoreactivities were present in the same secretory granules, and were always greater in pale granules rather than electron dense granules. In the RPD, blebs of ACTH-immunoreactive cytoplasm were found to protrude through the gaps in the basement membrane into the neurohypophysis. The second "PAS-positive" cell type of the PI showed a strong cross-reaction with anti-salmon gonadotrophin, suggesting that it may produce a glycoprotein chemically related to the gonadotrophin(s).

Hormones in saliva

Since the collection of saliva is noninvasive, nonstressful and usually very convenient there have been many recent studies examining the clinical relevance of measuring various hormones in saliva. It now appears that the measurement of most unconjugated steroids in saliva will provide clinically useful data whereas the measurement of conjugated steroids, thyroid hormones, and protein hormones is unlikely to be clinically relevant. The key factors determining whether the salivary concentration of a hormone or drug is likely to be clinically relevant are the mechanisms by which the material enters the saliva; the "free to protein bound" ratio for the material; and the structure of the material, i.e., its molecular weight, polarity and the presence of ionizable groups.

Immunoreactive gonadotropin-releasing hormone-like material in the brain and the pituitary gland during the periovulatory period in the brown trout (Salmo trutta L.): relationships with the plasma and pituitary gonadotropin

In fish there are few data on the gonadotropin-releasing hormone (Gn-RH) neurosecretory activity, which could explain long- and short-term variations of the gonadotropin secretion. There is no biological species specificity between mammal and fish Gn-RH; although there is a structural difference, they are, on the contrary, characterized by a high immunological specificity which does not allow measurement of fish Gn-RH using radioimmunoassay for LH-RH. We have synthesized salmon Gn-RH according to the formula recently proposed by Sherwood (N. Sherwood, L. Eiden, M. Brownstein, J. Spies, J. Rivier, and W. Vale, 1983. Proc. Natl. Acad. Sci. USA 80, 2794-2798). Its activity has been tested by its ability to stimulate the gonadotropin hormone (GtH) secretion in vivo in testosterone-implanted juvenile rainbow trout, and for the recognition of synthesized Gn-RH (s-Gn-RH) perykaria by a specific antibody raised against the s-Gn-RH in regions of the brain described as containing LH-RH immunoreactive-like material. A radioimmunoassay has been developed for the salmon Gn-RH, and its specificity to measure trout Gn-RH has been tested. Using this assay, the brain and pituitary Gn-RH contents have been measured throughout the final phases of maturation and ovulation. Brain Gn-RH increases from the end of vitellogenesis (8.9 +/- 0.76 ng/brain) to ovulation (more than 15 ng/brain). Pituitary Gn-RH is lower (1.58 +/- 0.69 ng/pituitary) at the end of vitellogenesis and follows a similar profile as in the brain, except for a significant decrease just prior the beginning of oocyte maturation. The correlations between Gn-RH levels and GtH pituitary and plasma levels show that total brain Gn-RH is never correlated to the GtH, suggesting that the increase in the brain Gn-RH content is related to a Gn-RH system closely related to maturation and ovulation, which remains to be investigated. On the contrary, pituitary Gn-RH levels are well correlated with pituitary and plasma GtH levels, indicating that pituitary Gn-RH levels might represent a good index of the Gn-RH neurosecretory activity in the fish hypothalamohypophysial complex, given the absence of a portal system in teleost.

Bioassay of fish gonadotrophin by ovarian mitochondrial cholesterol depletion

Murrel (Channa punctatus Bloch) ovarian tissues were incubated in vitro with or without piscine gonadotrophins and then subjected to subcellular fractionation followed by nonesterified cholesterol (cholesterol) assay. Gonadotrophin from salmon (SG-G100), tilapia (TL1MS), and sturgeon (S27MS) depleted cholesterol in the mitochondrial fraction, whereas cholesterol remained unchanged in other subcellular fractions. Aminoglutethimide, an inhibitor of mitochondrial cholesterol side-chain cleavage, blocked the depletion of mitochondrial cholesterol in response to SG-G100 and murrel pituitary extract. When ovarian tissue containing [4-14C]cholesterol was challenged with SG-G100 in vitro, a dose-dependent decrease of mitochondrial [4-14C]cholesterol was observed. Increasing concentrations (1, 2, 4, 6, or 8 micrograms/incubation) of SG-G100, TL1MS, and S27MS resulted in a clear linear depletion of mitochondrial cholesterol. The slope of the dose-response curve in different individual fish was found to be distinctly uniform and parallel. The slopes of the standard curves obtained with TL1MS and S27MS were greater than that with SG-G100, indicating that tilapia and sturgeon gonadotrophins are more potent. Carp pituitary gonadotrophin content, determined by using these standard curves, showed the sensitivity and precision of this bioassay.

Influence of testosterone on precocious sexual development in immature rainbow trout

The influence of testosterone on plasma and pituitary levels of gonadotrophin (GTH) as well as on gonadal development was studied in immature rainbow trout. Among the animals receiving a testosterone-cocoa butter implant (200 micrograms) at the age of 5 months, gonadal puberty occurred 8 months later in half of the males (opposite to the controls which remained immature) and the beginning of oocyte maturation was observed in only one female. These animals were characterized by a higher pituitary GTH level. Owing to the multivariate statistical analyses made, it was possible to provide evidence for the presence of two populations with different reactions to the same steroid treatment. They also confirmed the existence of a positive testosterone feedback, in the male, leading to a precocious gonadal development. The pituitary GTH load obtained with 200 micrograms of testosterone seemed to be related to the age of first maturation. The secretion of an appropriate level of GTH resulting in the stimulation of gametogenesis required the availability of a relatively large pituitary GTH level and seemed to be possible because the animals were already in the pubertal period. The fact that the highest pituitary GTH level of the treated lot was found in the only female showing a beginning of sexual maturation suggests that testosterone may also act in females.

Recent data concerning the use of ovulation inductors during in vitro fertilization programs

Ovulation inductors within the context of an in vitro fertilization program are mainly used in order to be able to know the exact time of the rupture of the follicle and to recover several mature oocytes. In this paper the Author describes the types of ovulation inductors used at present and underlines the fact that the study of the metabolism of the embryo will be a future aim for a better understanding of the success of in vitro fertilization.

Administration of monosodium glutamate to neonatal male rats: alterations in the gonadotrophs and in gonadotrophin secretion

We have studied the effect of administration of L-monosodium glutamate (MSG) to neonatal rats on gonadotroph morphology and gonadotrophin secretion in the prepubertal male rat. Rats were injected with MSG (4 mg/g body weight) or with 0.1 ml saline/10 g body weight on days 1, 3, 5, 7 and 9 of life (day of birth = day 0) and were used for experiment on day 40. Trunk blood was collected from 8 saline- and 9 MSG-injected rats for assay of serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations. One-half of the anterior pituitary gland was assayed for LH and FSH concentrations and the other half was placed in culture medium for a 30-min preincubation and then placed in fresh medium for a 2-hour incubation (basal LH and FSH release). An additional 4 rats in each group were killed and the pituitary glands were prepared for histological examination and immunocytochemical staining of LH and FSH cells and morphometric examination of these cells at the light microscopic level. The morphometric analyses were compared with those performed previously by us on adult male rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Male gonadotrophic factor in brain and blood of photoperiodically stimulated slugs

A pulmonate male gonadotrophic factor (MGF) has been described that is released from cerebral ganglia of male-phase slugs (Limax maximus). This factor produces, directly or indirectly, an increase in spermatogonial proliferation as determined by in vivo incorporation of [3H]thymidine into gonadal DNA. In the present investigation MGF activity was demonstrated in saline homogenates of male-phase cerebral ganglia by injecting homogenates into immature slugs for 5 consecutive days and assaying gonadal [3H]thymidine incorporation on Day 7. Dose-response data indicate that daily administration of as little as 0.1 brain equivalent can produce a significant stimulation in incorporation. Comparison of brain homogenates from immature (short-day) and male-phase (long-day) animals has shown that male-phase cerebral ganglia contain substantially more MGF activity than immature ganglia. Similar injection experiments using slug blood plasma showed that activity is present in male-phase blood but not in the blood of short-day immatures. MGF activity in long-day brain homogenates and blood plasma was found to be associated with a molecular weight fraction of 50 to 100 kDa obtained by ultrafiltration. Activity could be reduced or destroyed by treatment with trypsin or by heating. The present findings suggest that MGF is a proteinaceous factor of substantial size. It appears that both the synthesis and the secretion of MFG are stimulated in slugs that are in their male developmental phase as a result of prior exposure to long-day photoperiods.

Gonadotrophin-like substance in the testis. Immunocytochemical localization in the guinea pig

A gonadotrophin-like material (GLM) was observed by immunocytochemical methods in prepuberal guinea pig testes, not only on Sertoli and interstitial cells, but also on spermatogonia and spermatocytes. The intracellular cytoplasmic localization of GLM is discussed in relation to the receptor internalization theory. Variations between young and adult animals allowed us to approach the physiological significance of testicular GLM.

Detection of gonadotrophic hormones on isolated granulosa cells of the domestic hen, Gallus domesticus, by an immunohistochemical method

Two immunohistochemical methods were used to detect the presence of luteinizing hormone (LH) on the cells of chicken granulosa. Using a peroxidase-labelled anti-rabbit serum together with anti-chicken LH serum raised in rabbits, a strong positive response was obtained with granulosa cells from small and large pre-ovulatory follicles obtained from the mid-cycle. Similarly, by using an available antiserum to human follicle stimulating hormone (FSH), a slightly weaker response was obtained with cells from both large and small follicles. After incubating cells with ovine LH, ovine FSH and ovine prolactin, there was no detectable difference with the method used in reaction with their respective antisera to cells which had received no incubation, implying that chicken gonadotrophins were displaced only partially from their receptors by mammalian gonadotrophic hormones. Pre-incubation of the cells with human chorionic gonadotrophin gave negative results with anti-hCG serum. Using a fluorescent-labelled antibody method, similar results were obtained except that the distribution of the receptors on the granulosa cell for LH or FSH appeared to be different. With the LH, the fluorescence formed a halo around the cell in contrast to the overall fluorescence with FSH.