Search PubMed⌕ Search

Biomedical subjects

H Martikainen

Publications and source records attributed to H Martikainen.

At least 19 recordsLinked to original sources
PubMed1992

The effect of estrogen level on glucose-induced changes in serum insulin-like growth factor binding protein-1 concentration.

OBJECTIVE: To investigate the regulation of insulin-like growth factor binding protein-1 (IGFBP-1) concentration during ovarian stimulation. DESIGN: A prospective study of patients undergoing in vitro fertilization treatment. SETTING: Infertility unit at the University Central Hospital of Oulu, a tertiary referral center. PATIENTS: Sixteen healthy, regularly menstruating lean tubal infertility patients. INTERVENTIONS: Oral glucose tolerance test was performed first in a hypoestrogenic state after suppression by long-term gonadotropin-releasing hormone (GnRH) agonist and, second, in a hyperestrogenic state after stimulation by human menopausal gonadotropins. MAIN OUTCOME MEASURES: Serum concentrations of IGFBP-1, insulin-like growth factor I (IGF-I), insulin and sex hormone-binding globulin were measured before and 2 hours after glucose administration. RESULTS: Before and after glucose administration, the serum IGFBP-1 concentrations were significantly higher in the hyperestrogenic state (estradiol [E2] level 3.5 +/- 0.57 nmol/L) after ovarian stimulation than in the GnRH-analogue-induced hypoestrogenic state before the gonadotropin treatment (E2 level 0.10 +/- 0.02 nmol/L). On both occasions glucose-induced hyperinsulinemia caused a significant decrease in the circulating IGFBP-1 levels, whereas the IGF-I levels remained unchanged. There was a significant correlation between E2 and the insulin-suppressed IGFBP-1 level. The sum of follicular diameters correlated positively with the serum IGFBP-1 concentration. CONCLUSIONS: Gonadotropin-induced hyperestrogenism is related to elevated serum IGFBP-1 levels, either via estrogen-stimulated synthesis or via increased contribution from multiple follicles. Glucose-induced hyperinsulinemia suppresses serum IBFBP-1 concentration equally both in the hypoestrogenic and hyperestrogenic states. Because of similar IGF-I levels, it is likely that the biological activity of IGF-I is different before and after gonadotropin stimulations.

Adult↗
PubMed1992

Effect of growth hormone administration on human ovarian function and steroidogenic gene expression in granulosa-luteal cells.

OBJECTIVE: To study the effect of growth hormone (GH) in combination with an ultrashort-term gonadotropin-releasing hormone analogue/human menopausal gonadotropin (hMG)/human chorionic gonadotropin (hCG) regimen in ovarian hyperstimulation for in vitro fertilization (IVF). DESIGN: Prospective randomized placebo-controlled study. SETTING: University-based IVF program. PATIENTS: Fifty-four normally cycling women (27 control and 27 GH-treated) participated in this study. INTERVENTIONS: Human recombinant GH (24 IU)/placebo was given intramuscularly on alternate days starting on cycle day 4 until the day of last hMG injection. RESULTS: Serum estradiol (E2) and progesterone (P) concentrations were slightly lower in the GH group than in the placebo group on the day of hCG injection and 1 day thereafter (P < 0.01 to 0.001). Serum luteinizing hormone, follicle-stimulating hormone, prolactin, testosterone (T), and sex hormone-binding globulin did not differ between the groups. The follicular fluid (FF) concentration of T was higher in the GH group than in the placebo group (15.9 +/- 6.0 nmol/L versus 10.2 +/- 4.9 nmol/L, P < 0.005), and no differences were observed in the FF concentrations of E2, P, and insulin-like growth factor I between the groups. In granulosa cells isolated from patients who received GH treatment, the levels of 3 beta-hydroxysteroid dehydrogenase and aromatase messenger ribonucleic acid were significantly higher than in the patients receiving placebo. The number of hMG ampules needed for follicular development and the number of follicles and oocytes recovered were similar in both groups. CONCLUSIONS: These results indicate that GH administration modifies ovarian steroidogenic response to gonadotropins in IVF patients, suggesting a role for GH in the regulation of human ovarian function.

Adult↗
PubMed1992

GnRH agonist analog therapy in advanced/recurrent granulosa cell tumors: further evidence of a role of inhibin in monitoring response to treatment.

Five patients with advanced ovarian granulosa cell malignancies resistant to cytotoxic chemotherapy were treated with monthly subcutaneous injections of long-acting gonadotropin releasing hormone (GnRH) agonist analog. One partial response and one stabilization of the disease were observed. In three patients, the tumor continued to progress. Treatment response was monitored with serum inhibin assay. Four patients had high serum inhibin concentrations at the beginning of GnRH analog treatment, while one patient had an inhibin-negative tumor. In three of four patients, serum inhibin remained relatively constant, or decreased during the first 3 months of therapy. It subsequently increased, in parallel with clinical deterioration. Further clinical trials with GnRH analogs are warranted in this malignancy in which serum inhibin appeared to be a clinically valuable tumor marker.

Adult↗
PubMed1991

Metabolism, cellular actions, and cytotoxicity of selenomethionine in cultured cells.

Selenomethionine metabolism and the biochemical basis for its cytotoxicity were analyzed in cultured human and murine lymphoid cells. The metabolic pathways were also addressed, using purified mammalian enzymes and crude tissue extracts. Selenomethionine was found to be effectively metabolized to S-adenosylmethionine analog, and that analog was further metabolized in transmethylation reactions and in polyamine synthesis, similarly to the corresponding sulphur metabolites of methionine. Selenomethionine did not block these pathways, nor was there a specific block on the synthesis of DNA, RNA, or proteins when added to the culture medium. Selenomethionine showed cytotoxicity at above 40 microM levels. Yet, low selenomethionine levels (10 microM) could replace methionine and support cell growth in the absence of methionine. Selenomethionine toxicity took place concomitantly with changes in S-adenosylmethionine pools. D-form was less cytotoxic than L-form. Methionine concentration modified the cytotoxicity. Together, this indicates that selenomethionine uptake and enzymic metabolism are involved in the cytotoxicity in a yet unknown way.

Animals↗
PubMed1991

Gonadotropin pulsatility in a stimulated cycle: clomiphene citrate increases pulse amplitudes of both luteinizing hormone and follicle-stimulating hormone.

OBJECTIVE: To elucidate gonadotropin secretory patterns during ovarian hyperstimulation for in vitro fertilization. DESIGN: All volunteers who attended the unit during a period of 3 months were prospectively investigated. SETTING: Infertility unit of the University Central Hospital of Oulu. PARTICIPANTS: Normally menstruating tubal infertility patients (n = 8) and healthy women with ovulatory cycles (hospital personnel, n = 11). All patients finished the study. INTERVENTIONS: Clomiphene citrate (CC), 50 mg, was administered on cycle days 5 to 9 and 300 IU of pure follicle-stimulating hormone (FSH) on cycle day 7 and 150 IU on cycle day 8. MAIN OUTCOME MEASURES: Serum samples for luteinizing hormone (LH) and FSH measurements were collected at 10-minute intervals for 6 hours on cycle day 7 (effect of CC) and day 9 (effect of CC/FSH), and the data were analyzed with the Munro computer program. RESULTS: The number of LH peaks was identical in the controls and study subjects on cycle days 7 and 9, whereas the pulse amplitude (P less than 0.025) and the pulse area (P less than 0.01) were higher in the CC/FSH-treated patients. The increase in overall mean LH level during the hormone therapy was not significant. In the CC/FSH-treated women, a decreased number of FSH pulses (P less than 0.01) with increased amplitude (P less than 0.001) and pulse area (P less than 0.01) was found. Clomiphene citrate treatment increased the mean FSH level (control versus cycle day 7, P less than 0.05) which was further increased (cycle day 7 versus cycle day 9, P less than 0.05) by FSH administration on cycle days 7 to 8. Otherwise pure FSH was found to be unable to modify endogenous LH or FSH secretory patterns under these conditions. CONCLUSIONS: Clomiphene citrate increases the amplitudes of both LH and FSH pulses in the midfollicular phase of a stimulated cycle, an effect which is not influenced by pure FSH administration.

Adult↗
PubMed1991

Insulin-like growth factor binding protein-1 and ovarian stimulation.

Serum concentrations of insulin-like growth factor binding protein-1 (IGFBP-1) were measured in 42 patients with tubal infertility undergoing two different regimens of ovarian stimulation for in-vitro fertilization. The first group comprised 24 women given a luteinizing hormone-releasing hormone agonist analogue (buserelin, LHRHa) on cycle days 1-4 followed by follicle-stimulating hormone and human menopausal gonadotrophin (LHRHa group). The second group of 18 women received clomiphene citrate and gonadotrophins (CC group). On the day of human chorionic gonadotrophin administration, the sum of follicular diameters (P less than 0.05) and the number of follicles punctured in the LHRHa group (P less than 0.01) were significantly higher than in the CC group. In spite of the greater number of follicles, the oestrogen levels were similar in both groups, but women in the LHRHa group had significantly higher serum IGFBP-1 concentrations during the last 5 days of stimulation. These results suggest that the stimulated preovulatory follicles may contribute to the elevation of serum IGFBP-1.

Adult↗
PubMed1991

Short and long term effects of growth hormone on circulating levels of insulin-like growth factor-I (IGF-I), IGF-binding protein-1, and insulin: a placebo-controlled study.

The short and long term effects of GH on serum concentrations of insulin-like growth factor-I (IGF-I), IGF-binding protein-1 (IGFBP-1), and insulin were investigated in women participating in an in vitro fertilization program. In this placebo-controlled study, sterile saline (eight women) or 24 IU GH (eight women) were given im on alternate days, starting on cycle day 4, in combination with GnRH and human menopausal gonadotropin. IGFBP-1 levels decreased significantly during the first 4 h after GH administration, whereas no significant changes were seen in the placebo group. The concentrations of serum IGF-I and insulin did not change during 4 h after GH injection. During the 11-day follow-up period, serum levels of both IGF-I and insulin were significantly higher in GH-treated than in placebo-treated women. These results suggest that the serum concentration of IGFBP-1 is not completely GH independent. They also support the earlier findings that long term treatment with GH increases serum IGF-I and insulin levels.

Adult↗
PubMed1990

Effects of selenomethionine on cell growth and on S-adenosylmethionine metabolism in cultured malignant cells.

The effects of selenomethionine (SeMet) on the growth of 17 cultured cell lines were studied. SeMet in the culture medium of three hepatoma cell lines promoted cell growth at subcytotoxic levels (1-20 microM), but the growth of malignant lymphoid and myeloid cells was not stimulated. L-SeMet was cytotoxic to all 17 cell lines when assayed after culture for 3-10 days. A 50% growth inhibition was observed by 30-160 microM-SeMet in a culture medium containing 100 microM-methionine. SeMet cytotoxicity to normal (fibroblasts) and malignant cells was rather similar, excluding specific antineoplastic cytotoxicity. Cytotoxicity was increased by decreasing concentrations of methionine. The DL form of SeMet was less cytotoxic than the L form. L-SeMet was metabolized to a selenium analogue of S-adenosylmethionine approximately as effectively as the natural sulphur analogue methionine in malignant R1.1 lymphoblasts. Concomitantly, S-adenosylmethionine pools were decreased. This occurred early and at cytotoxic SeMet levels. Methionine adenosyltransferase activity was not altered by SeMet treatment. ATP pools were not affected early, and decreases in the synthesis of DNA and protein took place late and were apparently related to cell death. RNA synthesis was slightly stimulated at low cytotoxic SeMet levels by 24 h, but was markedly inhibited after 48 h. The SeMet analogue of S-adenosylmethionine could be effectively utilized in a specific enzymic transmethylation. Neither S-adenosylhomocysteine nor its selenium analogue accumulated in the treated cells. These findings together suggest a direct or indirect involvement of S-adenosylmethionine metabolism in SeMet cytotoxicity, but exclude a gross blockage of transmethylations.

Cell Division↗
PubMed1990

Endocrine responses to gonadotrophins after LHRH agonist administration on cycle days 1-4: prevention of premature luteinization.

A treatment regime comprising an intranasally administered luteinizing hormone-releasing hormone (LHRH) agonist analogue (buserelin) on cycle days 1-4, followed by gonadotrophin administration [follicle stimulating hormone (FSH)/human menopausal gonadotrophin (HMG)] resulted in identical oestradiol (E2) responses compared with the reference method using clomiphene citrate (CC) and gonadotrophins. Immediately after analogue administration (day 4), buserelin-treated women showed short-lived elevations in serum LH and progesterone concentrations, but in the later follicular phase, the serum LH concentration was lowered compared with the controls. None of the women treated with analogue displayed elevated serum LH or progesterone concentrations at the time of injection of human chorionic gonadotrophin. In the early luteal phase, these women had higher serum levels of progesterone and higher progesterone to E2 ratios than the controls, but the length of the luteal phase was slightly shortened. Hence, in hyperstimulated cycles, 4-day treatment with buserelin caused profound endocrinological changes: namely, short-term rescue of the corpus luteum, prevention of an endogenous LH rise and premature luteinization and increased progesterone production in the early luteal phase.

Adult↗
PubMed1990

The ratios of serum bioactive/immunoreactive luteinizing hormone and follicle-stimulating hormone in various clinical conditions with increased and decreased gonadotropin secretion: reevaluation by a highly sensitive immunometric assay.

Serum bioactive and immunoreactive LH and FSH were measured in clinical conditions with increased or decreased gonadotropin secretion. Gonadotropin immunoreactivity was measured using a conventional RIA (I) and an ultrasensitive immunofluorometric method (F). Bioactive (B) LH was assessed by the mouse interstitial cells in vitro bioassay, and B-FSH using the immature rat granulosa cell assay. Acute GnRH stimulation of adult men (n = 6) increased LH levels measured by the different methods 4.3- to 5.3-fold. The B/I ratio of LH increased from 2.34 +/- 0.21 to 3.71 +/- 0.36 (mean +/- SEM) at 120 min (P less than 0.05), but no change was found in the B/F ratio. After ovariectomy of premenopausal women (n = 6), the LH levels increased in 1 week 4- to 6-fold, the B/I ratio from 1.85 +/- 0.22 to 2.59 +/- 0.24, and the B/F ratio from 1.78 +/- 0.22 to 2.90 +/- 0.30 (P less than 0.05 for both). In addition, the LH levels were measured during GnRH agonist treatment of ovarian carcinoma (n = 8), endometriosis (n = 8), and prostatic carcinoma after orchiectomy (n = 8). In the two former groups, serum B-LH decreased in 1 month to undetectable levels (less than 0.5 IU/L), and in the prostate cancer patients to 1.2 (0.8-1.9) IU/L (log mean and range of +/- SEM). The concomitant decline of I-LH was to 1.5-1.9 IU/L in the agonist-treated female patients, and that of F-LH to 0.10-0.15 IU/L; in the prostate cancer patients, respectively, these values were 7-8 and 0.3-0.7 IU/L. The B/I and B/F ratios during the agonist treatments could only be calculated in the prostate cancer patients (in the others, B-LH became undetectable). The B/I ratio decreased from 2.34 +/- 0.5 to 0.14 +/- 0.03 (P less than 0.01), but no suppression was found in the B/F ratio from a pretreatment value of 3.6 +/- 0.8. B-, I-, and F-FSH levels were measured in the GnRH agonist-treated orchiectomized prostate cancer patients. The pretreatment level of B-FSH was 154 (137-175), that of I-FSH was 38.0 (34.4-42.0), and that of F-FSH was 39.8 (35.3-44.9) IU/L. The B/I ratio of FSH was 3.76 +/- 0.49, and the B/F ratio was 3.53 +/- 0.59. The mean B-FSH level decreased during treatment by 87-93.5%, that of I-FSH by 98%, and that of F-FSH by 91.5% (P less than 0.01 for all).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1990

Circadian and seasonal variation in human preovulatory follicular fluid melatonin concentration.

The concentrations of melatonin in 112 preovulatory follicular fluid (FF) samples obtained from 60 women undergoing in vitro fertilization and 27 patients at laparotomy during a spontaneous cycle were measured by RIA and compared with those in peripheral serum. The circadian and seasonal variations in FF melatonin were also analyzed. The FF melatonin concentrations in stimulated (mean +/- SEM, 61.9 +/- 6.4 pmol/L) and spontaneous cycles (98.1 +/- 8.9 pmol/L) were significantly higher (P less than 0.005) than those in peripheral serum (25.4 +/- 1.2 and 38.6 +/- 1.8 pmol/L, respectively), and in the stimulated cycles there was a positive correlation between them. The FF melatonin concentration in the morning (58.9 +/- 3.8 pmol/L) was significantly higher (P less than 0.005) than that in the daytime (23.2 +/- 0.8 pmol/L), but the morning concentrations did not differ between the light and the dark seasons of the year, whereas the daytime values were higher (P less than 0.005) during the dark season (27.1 +/- 2.1 pmol/L) than during the light season (21.1 +/- 2.1 pmol/L). The FF melatonin concentration did not correlate with follicular volume, and FF and serum melatonin concentrations showed no significant correlation with the serum concentrations of estradiol, progesterone, testosterone, or PRL. There were also no differences between FF melatonin concentrations in aspirates with or without an ovum. In summary, significant circadian and circannual variations in high FF melatonin concentrations were found, which suggest that melatonin could potentially interfere with the regulation of reproduction in humans at the follicular level.

Chromatography, High Pressure Liquid↗
PubMed1990

Direct gonadotrophic effect of growth hormone on oestradiol production by human granulosa cells in vitro.

In-vitro studies in both rodents and man suggest that GH can stimulate ovarian steroidogenesis, but it is not clear whether this effect is mediated by changes in circulating concentrations of insulin-like growth factor-1 (IGF-1) or whether it is a direct action on the ovary (or, indeed, both). In this study the effects of biosynthetic human GH (hGH) on the production of oestradiol and IGF-1 by human granulosa cells in culture were examined using ovarian tissue (from both normal and polycystic ovaries) which had not previously been exposed to exogenous gonadotrophin therapy. Addition of hGH (1 or 10 ng/ml) to the incubation medium resulted in a significant (1.7 to 3.6 fold) increase in oestradiol accumulation after 48h in culture. Human GH also had a significant additive effect on the dose-related responsiveness of granulosa cell oestradiol production to hFSH. Concentrations of IGF-1 in the medium were undetectable in each of these experiments. These studies demonstrate that hGH has a potent, direct stimulatory effect on production of oestradiol by the human ovary which is independent of the effect of FSH. These findings have important implications for understanding the physiological role of hGH in human ovarian function as well as for therapeutic use of biosynthetic hGH for induction of ovulation.

Cells, Cultured↗
PubMed1989

Gonadotropin-releasing hormone agonist analog therapy effective in ovarian granulosa cell malignancy.

Ovarian granulosa cell tumor lung metastases regressed, and symptoms were relieved, during gonadotropin-releasing hormone (GnRH) agonist analog therapy after the failure of operative treatment and cytotoxic chemotherapy, indicating the hormone dependence of the malignancy. The response was transient, but the largest metastasis did not relapse. This case report suggests that GnRH analogs may offer a new approach to the treatment of ovarian stromal cell malignancies.

Bone Neoplasms↗
PubMed1989

Prolactin suppression by bromocriptine stimulates aromatization of testosterone to estradiol in women.

The effect of follicular phase bromocriptine therapy on the ovarian endocrine response to clomiphene citrate and gonadotropins was studied in 35 tubal infertility patients in a randomized placebo-controlled trial. During bromocriptine treatment, the serum prolactin (PRL) concentration significantly decreased, and consequently the serum estradiol (E2) concentration was significantly higher than in the controls on cycle day 9, and the ratio of testosterone (T) to E2 was decreased from cycle day 8 through day 10. The luteal phase progesterone concentration and the length of the luteal phase were not affected by bromocriptine therapy. The number and quality of oocytes harvested and the cleavage rates were similar in both groups. The present results, together with our previous observations, demonstrate that PRL participates in the regulation of ovarian steroidogenesis, particularly aromatization of T to E2.

Adult↗
PubMed1989

The human embryo produces basement membrane collagen (type IV collagen)-degrading protease activity.

The biochemical basis and mechanism of embryo implantation is poorly understood. The human embryo has to penetrate the endometrial basement membrane and the thick decidual wall during implantation, a process which resembles the active spreading of invasive tumour cells where the degradation of type IV collagen (basement membrane collagen) plays an important role. This study reports that human embryos produce type IV collagen-degrading enzyme activity and the secretion of this enzyme increases with time in culture. The type IV collagen-degrading enzyme activity might facilitate the penetration of the embryo through the decidua, thus emphasizing an active role of the embryo in implantation. On the other hand, unfertilized oocytes secrete low, stable amounts of type IV collagen-degrading enzyme activity in vitro. It was also found that follicular granulosa cells secrete high amounts of type IV collagenolytic activity in culture. It has been previously shown that there is a pre-ovulatory peak in type IV collagenolytic activity in follicular fluid, and it can be assumed that the appearance of this enzyme in the follicular fluid is probably connected to follicular rupture and that it is produced by granulosa cells.

Basement Membrane↗
PubMed1989

Suppression of prolactin secretion during ovarian hyperstimulation is followed by elevated serum levels of endometrial protein PP14 in the late luteal phase.

A double-blind placebo-controlled study on bromocriptine administration during days 2-12 of ovarian hyperstimulation for in-vitro fertilization (IVF) showed that, in bromocriptine cycles, levels of the endometrial protein PP14 were higher in the late luteal phase. This was verified both by calculating forward from the day of human chorionic gonadotrophin (HCG) administration and backward from the onset of the next period. Bromocriptine had no effect on IVF performance. During bromocriptine treatment the serum prolactin levels declined and serum oestradiol levels were higher on day 9 of the cycle. There was a positive correlation (r = 0.55; P = 0.012) between the serum oestradiol levels on day 9 and the PP14 levels on days 22-23 of the cycle. No difference was found in the luteal phase progesterone levels between bromocriptine- and placebo-treated cycles. These results suggest that low prolactin and/or high oestradiol levels during the follicular phase have an influence on the subsequent secretory capacity of the endometrium as reflected by secretion of a specific endometrial protein.

Bromocriptine↗