Biomedical subjects

B Carlsson

Publications and source records attributed to B Carlsson.

At least 127 records · Page 7Linked to original sources

PubMed1993

Regulation of androgen production in cultured human thecal cells by insulin-like growth factor I and insulin.

OBJECTIVES: To investigate if human thecal cells contain messenger ribonucleic acid (RNA) encoding insulin-like growth factor I (IGF-I) and insulin receptors and if IGF-I and insulin could stimulate androgen production in thecal cells. DESIGN: Poly-adenine+ RNA was extracted from fresh thecal tissue, and the expression of the genes encoding insulin and IGF-I receptors were analyzed. Isolated thecal cells were cultured 4 to 6 days with and without hormones. SETTING: Procedures were performed in a university laboratory. PATIENTS: Eight women in the follicular phase of natural cycles were undergoing gynecological laparotomy for reasons unrelated to ovarian pathology. The leading follicle(s) was excised, and dispersed cells of the theca interna layer were isolated through combined mechanical and enzymatic techniques. INTERVENTIONS: Luteinizing hormone (LH), IGF-I, and insulin were added to the cell cultures. MAIN OUTCOME MEASURE: The expression of IGF-I receptor and insulin receptor transcripts were analyzed by Northern blot. Medium levels of androstenedione and testosterone were measured by radioimmunoassay. RESULTS: In the separated thecal tissue both IGF-I receptor and insulin-receptor transcripts were detected. Insulin-like growth factor I and insulin potentiated LH-induced androgen secretion while having less pronounced effects on basal androgen production. CONCLUSION: The present study demonstrates that both insulin and IGF-I receptor genes are expressed and that insulin and IGF-I can stimulate steroid production in human thecal cells. The study provides further support for the hypothesis that IGF-I and insulin may be involved both in physiological regulation of ovarian function as well as in its pathophysiology.

Androgens↗

PubMed1993

IgA and IgG subclass deficiency in a poor population in a developing country.

The levels of IgG, IgG subclasses, IgM and IgA were determined in serum from 17 patients with IgA deficiency and severe or frequent infections, allergy and/or autoimmunity (median age 7 years, range 2-19), 11 healthy IgA-deficient adults and 35 controls (median age 7 years, range 2-19). In serum from all groups IgG, IgM and IgA antibodies were determined against beta-lactoglobulin, E. coli O antigens and poliovirus type 1 antigen. In saliva of 15 IgA-deficient patients and 12 of the controls IgG, IgM and secretory component-carrying antibodies against E. coli O antigens and poliovirus type 1 were determined. The majority of the studied individuals lived under poor socio-economic conditions in Brazil, with consequent heavy microbial exposure. One IgA-deficient patient with rheumatoid arthritis also had IgG2 deficiency but no infectious problems. Four out of the 35 controls without any obvious infectious problems were found with IgA or IgG subclass deficiency. One of the 11 healthy IgA-deficient adults was low in the IgG2 subclass, one in IgG1 and one in IgG3. Those with symptomatic IgA deficiency had significantly higher serum IgG than the controls, especially in the age group 6-11 years. This latter group also had significantly increased serum IgG1 and IgG2 levels when compared with the age-matched controls. Salivary IgM antibodies to E. coli and poliovirus antigens were significantly higher among the symptomatic IgA-deficient individuals than among the controls. It is not clear at present whether these increased Ig levels are secondary to frequent infections and/or part of mechanisms that may compensate for the IgA deficiency.

Adolescent↗

PubMed1993

Early child health in Lahore, Pakistan: I. Study design.

In this paper, details are given of a community based follow up study of four areas: a village, a periurban slum, an urban slum and an upper middle class control group living in and around Lahore, Pakistan. The aim was to characterize the determinants of child health in a rapidly urbanizing community. The study was undertaken in two steps. An initial cross-sectional survey collecting socio-economic and demographic background information was carried out between March to August 1984. This was followed by a longitudinal study of 1476 infants representing the outcome of the pregnancies registered continuously between September 1984 to March 1987 among the 3242 families in the study. These infants were followed monthly from birth to 3 years of age and thereafter less frequently. In this communication we describe the study design, the study population, the organization and the research methodology used, including the reasons for drop outs from birth to 24 months of age. The internal consistency of the data is also presented. After the initial examination of the newborns within between 0-7 days of birth, the infants were visited monthly for 24 months making a total of 20911 examinations. At 24 months of age 70% of the infants were still in the study, 11% had died before reaching this age, 13% had moved from the area and 6% had refused to participate in the study. The economic, conditions, social structure, and the quality of life were found, not surprisingly, to vary significantly among the four areas. This community-based project provides new, critical and reliable information for local health planners. The study highlights the importance of the development of a useful model for research collaboration between institutions in developed and developing countries.

Child Welfare↗

PubMed1993

Poliovirus antibody titres, relative affinity, and neutralising capacity in maternal milk.

Varying titres of secretory IgA antibodies to poliovirus type 1 were found previously in the milk of unvaccinated, lactating Pakistani mothers during two different years, reflecting the antigenic exposure on mucosal membranes. To study further the changes in the extent and the form of antigenic exposure reflected in the human milk, human milk samples from Pakistani, Indian, Japanese, and Swedish mothers were collected. The quality and the neutralising capacity of the antibodies was also studied. Secretory IgA, IgG, and IgM antibodies to poliovirus type 1 were determined using enzyme linked immunosorbent assay (ELISA) and relative affinity was measured in ELISA by elution with potassium thiocyanide. Microneutralisation tests were also performed. The higher secretory IgA antibody titres to poliovirus type 1 in the unvaccinated, naturally exposed Pakistani and Indian mothers' milk, compared with the Swedish and Japanese mothers, presumably reflect the epidemiological situation in these countries. Neutralising capacity and the relative antibody affinity seemed to be higher both in the Pakistani mothers and the group without natural exposure but only given inactivated poliovirus vaccine, that is the Swedish mothers, than the group meeting only live vaccine strains, that is the Japanese mothers.

Antibodies, Viral↗

PubMed1993

Anti-idiotypic antibodies to poliovirus antibodies in commercial immunoglobulin preparations, human serum, and milk.

Our previous studies have suggested that fetal antibody production can be induced by maternal antiidiotypic antibodies transferred to the fetus via the placenta. We tested commercial Ig, sera, and milk for the presence of anti-idiotypic antibodies to poliovirus type 1, using affinity chromatography combined with ELISA systems and virus neutralization techniques. Our results indicate that commercial Ig, serum, and milk samples contain antibodies recognizing idiotypic determinants on antibodies to poliovirus. Several lines of evidence support this conclusion. Thus, in an ELISA with poliovirus as a solid phase, binding of specific antibodies could be inhibited by addition of an eluate from the Ig preparation containing anti-idiotypic antibodies against poliovirus type 1. Also, antiidiotypic antibodies from pooled human Ig, serum, and colostrum samples against poliovirus bound directly to solid-phase-attached MAb against poliovirus type 1. In addition, in a competitive inhibition ELISA, where antiidiotypic antibodies isolated from the Ig preparation competed with the poliovirus antigen for binding to monoclonal or polyclonal idiotypic antibodies on the solid phase, inhibition of antigen binding was seen at low antigen concentrations. When single-donor serum or milk was used, this inhibition was even more pronounced and could be demonstrated at almost all antigen concentrations. The finding that anti-idiotypes are present in maternal serum and milk imply, in agreement with our previous studies, that anti-idiotypes may actively induce a specific immune response in the fetus without previous exposure to the antigen by being transferred across the placenta or by being passively transferred to the newborn via mother's milk.

Adult↗

PubMed1993

The effect of caloric supplementation on selected milk protective factors in undernourished Guatemalan mothers.

The level and avidity indices of specific antibodies against tetanus toxoid, Escherichia coli O6 and a pool of 10 common E. coli O antigens, as well as the concentration and daily output of lactoferrin and total secretory IgA (SIgA), were evaluated in the milk of moderately undernourished mothers who were in a random blind design divided into two groups and given different caloric supplementations. Group A received a high caloric supplement (500 kcal/d), and group B received a low caloric supplement (140 kcal/d). Determinations were done using ELISA in various modifications, except for lactoferrin, which was quantified by single radial immunodiffusion. The avidity indices were investigated as an evaluation of the antibody quality. In all the parameters evaluated, the only difference found between the two groups at the end of the supplementation period was in the content of total SIgA, which was lower in group B, both in concentration and daily output. However, the SIgA remained within the normal range. Increases as well as decreases in the levels of specific IgA antibodies occurred within both groups. Avidity was decreased in group B only against one of the antigens tested. We conclude that moderate undernutrition does not impair the levels of milk antibodies, and supplementation does not enhance them but prevents the decrease in the content of total milk SIgA. There is a suggestion that the avidity of certain antibody specificities could be hampered.

Antibodies, Bacterial↗

PubMed1993

Postreceptor events involved in the up-regulation of beta-adrenergic receptor mediated lipolysis by testosterone in rat white adipocytes.

In the previous studies we have shown that testosterone increases lipolytic responsiveness to catecholamines in rat white adipocytes, and that is associated with an up-regulation of beta-adrenergic receptor density. However, the postreceptor events involved in the testosterone induced enhancement of beta-adrenergic receptor activated lipolysis in these cells have not been adequately studied, and were therefore investigated in the present study. Male Sprague Dawley rats were divided into three groups: control, castrated, and castrated treated with testosterone. The beta-adrenergic receptor-mediated cAMP accumulation, measured with RIA after isoproterenol (a beta-adrenergic agonist) stimulation was decreased in castrated rats, and reversed by testosterone treatment, suggesting a testosterone effect at or proximal to adenylate cyclase. However, no differences between the groups were found in abundance of G alpha protein messenger RNAs (G alpha s, G alpha i-1, and G alpha i-2) as analyzed by Northern blot and a solution hybridization RNase protection assay, or in G protein mass measured with a quantitative enzyme-linked immunosorbent assay in fat cell membrane preparation. Lipolysis stimulated by N6-monobutyryl-cAMP was reduced in castrated rats and recovered by testosterone treatment, suggesting that components distal to the adenylate cyclase, i.e. protein kinase A (PKA) and/or hormone sensitive lipase (HSL) also are involved in testosterone regulation of lipolysis. In conclusion, these and previous results suggest that the testosterone-induced increase in lipolytic response to catecholamines in rat white adipocytes is mediated through several events including an increased beta-adrenergic receptor density, probably an increased adenylate cyclase activity and an increased protein kinase A/hormone sensitive lipase activity at the postreceptor level with apparent absence of effect on the expression of G-proteins.

Adenylyl Cyclases↗

PubMed1993

Expression of insulin-like growth factor-I (IGF-I) in the rat fallopian tube: possible autocrine and paracrine action of fallopian tube-derived IGF-I on the fallopian tube and on the preimplantation embryo.

Recent studies have indicated that growth factors such as insulin-like growth factors (IGFs) increase the growth rate of cultured preimplantation embryos. We therefore hypothesized that the fallopian tube may produce IGFs which in turn participate in the regulation of preimplantation embryo development in vivo. In the present study we examined the expression of IGF-I in the fallopian tube. We demonstrated that IGF-I transcripts (7.0, 1.7, and 1.2-0.8 kilobases) were abundant in the fallopian tube. Immunoreactive IGF-I was most abundant in the epithelial cells in the fallopian tube, and IGF-I messenger RNA (mRNA) was detected in the luminal region of the fallopian tube. A solution hybridization assay was used to examine the regulation of IGF-I mRNA. The abundance of IGF-I transcripts changed markedly during the 4-day estrous cycle with the highest levels on the day of proestrus. The increase in IGF-I mRNA between the day of diestrus II and the day of proestrus was 4-fold (P < 0.01). The pattern of IGF-I mRNA expression in the fallopian tube resembled the pattern of ovarian estrogen production during the estrous cycle. The level of IGF-I mRNA decreased after hypophysectomy. The expression of IGF-I mRNA in the fallopian tube was dose-dependently regulated by estradiol, and a single sc injection of estradiol [5 micrograms/100 g body wt (BW)] increased the IGF-I mRNA in a time-dependent manner with a significant increase after 3 h (P < 0.01). The lowest estradiol dose tested (0.1 microgram/100 g BW) increased the expression after 6 h, whereas progesterone (5 micrograms/100 g BW) was ineffective. The presence of embryos in the fallopian tube did not statistically significantly influence the abundance of IGF-I transcripts as measured with a solution hybridization assay on RNA extracted from whole fallopian tubes. In order to determine possible targets for fallopian tube-derived IGF-I we examined the expression of IGF-I receptor mRNA. Northern blot analysis revealed that an 11-kilobase IGF-I receptor transcript was expressed in the fallopian tube. Using a reverse transcriptase-polymerase chain reaction, IGF-I receptor mRNA was also detected in the eight-cell but not two-cell preimplantation embryo. The present study demonstrates that IGF-I is produced in the fallopian tube and its expression is regulated by estradiol. Both the fallopian tube and the eight-cell preimplantation embryo express IGF-I receptors and are therefore potential target tissues.

Animals↗

PubMed1993

Amount of G-protein alpha-subunit in rat white adipocytes: lack of difference between subcutaneous and visceral fat.

It has been the purpose of this study to examine possible differences in the amount of stimulatory (Gs) and inhibitory (Gi) G-protein alpha-subunits (measured with a quantitative enzyme-linked immunosorbent assay in fat cell membrane preparation) between subcutaneous and intra-abdominal regions in rats. The lipolytic response to isoproterenol and the number of beta-adrenergic binding sites were also examined. These parameters were all evaluated simultaneously in subcutaneous (inguinal), epididymal and perirenal fat samples collected from six male Sprague-Dawley rats. The membrane contents of the Gs and Gi alpha-subunits were similar in the three depots. Moreover, no difference was found among the different regions with regard to isoproterenol-stimulated glycerol release and beta-adrenoceptor number, expressed per cell number. In conclusion, the present study shows for the first time in rats that the abundance of inhibitory and stimulatory G-protein alpha-subunits is similar in subcutaneous and in visceral adipocytes. Moreover, the number of beta-adrenoceptors and the lipolytic response to isoproterenol do not show significant variations with the anatomical site. As the present results are apparently in contrast with those obtained previously in human adipocytes, there is a possibility that the different results observed in rat and in human fat cells could be explained by species differences.

Adipose Tissue↗

PubMed1993

Deficient synthesis of cysteinyl leukotrienes in glutathione synthetase deficiency.

Glutathione synthetase deficiency (GSD) is an inborn error of glutathione (GSH) metabolism. As a consequence of the block in the gamma-glutamyl cycle, the enzyme defect leads to a generalized intracellular GSH deficiency. The cysteinyl leukotrienes (LTs), LTC4, LTD4 and LTE4, are potent lipid mediators generated in the 5-lipoxygenase pathway. LTC4 is derived from the unstable epoxide LTA4 by conjugation with GSH, and therefore GSH is required for LTC4 synthesis. In the circulation LTC4 is rapidly metabolized to LTE4 which is excreted in the urine. In the present study, LT metabolites were separated in a patient with biochemically established GSD and intracellular GSH deficiency (0.5 mM in erythrocytes, normal range 2.0-2.5 mM) by reversed-phase high-performance liquid chromatography, and quantified by enzyme immunoassays. Our results revealed that in GSD LTC4 synthesis is significantly decreased in calcium ionophore A23187-activated monocytes as well as in neutrophils (11-14% and 7-10%, respectively, of the levels detected in the parents or healthy controls). Additionally, urinary LTE4 was also found to be abnormally decreased in GSD (0.4 nmol/mol creatinine as compared to 15-46 nmol/mol creatinine in parents and controls). GSD represents the first described disorder with decreased synthesis of cysteinyl LTs and may serve as a unique model for the linkage between LT synthesis and GSH metabolism in vivo. Moreover the impaired synthesis of cysteinyl LTs might be involved in the pathophysiology of GSD.

Cysteine↗

PubMed1993

Tumor necrosis factor-alpha in malignant disease.

PURPOSE: Due to its important role in immunoregulation, we have investigated serum levels of tumor necrosis factor-alpha (TNF alpha), in children with newly diagnosed, untreated, malignant disease. PATIENTS AND METHODS: These levels have been related to the presence of infection and to the serum content of three other cytokines, namely interleukin-1 beta, interleukin-2, and interferon-gamma. All cytokine analyses were performed using highly sensitive radioimmunoassays. RESULTS: Children with leukemia had higher mean levels of TNF alpha (63.6 +/- 12.3 pg/ml) than did children with solid tumors (21.5 +/- 4.2 pg/ml) and control patients (10.5 +/- 2.6 pg/ml). TNF alpha levels in patients did not correlate with the levels of the other cytokines or with the presence of infection. CONCLUSIONS: Children with malignant disease often have elevated TNF alpha levels. This elevation is dependent on the malignant disease process itself, and could either reflect the host immunological response or tumor cell production of TNF alpha.

Adolescent↗

PubMed1992

Chronic elevation of cAMP levels induces changes in the adenylate cyclase system, opiate receptor sensitivity and levels of Gs-mRNA in cultured neurons.

Neurons in primary culture were treated (5 days) with the adenylate cyclase stimulator 10(-5) M forskolin. The basal adenylate cyclase was decreased by 57%. The acute stimulatory effect of forskolin was down-regulated by 48%. The inhibitory effects of the 3 opiate receptor agonists (mu, delta and kappa) were partly abolished. The abundance of mRNA encoding the stimulatory G-protein (Gs) was decreased prominently. The data indicate that the cAMP system in neuronal cells in primary culture is under dynamic regulation, possibly including altered Gs-protein gene expression. Furthermore, long-term forskolin treatment might induce increased proliferation in susceptible neural blast cells.

Adenylyl Cyclases↗

PubMed1992

Distribution of IGF-I mRNA and IGF-I binding sites in the rat kidney.

In the present study we have investigated the distribution of IGF-I mRNA and IGF-I binding sites in the rat kidney. The distribution of IGF-I mRNA was investigated using a simple and sensitive non-radioactive in situ hybridisation technique based on probe labelling with digoxigenin labelled-UTP followed by detection with conventional immunocytochemical techniques. IGF-I mRNA was found predominantly in medullary collecting ducts and sparsely in cortical collecting duct cells. In addition IGF-I mRNA was expressed in scattered proximal tubular cells in the cortex and in cells confined to the glomerular tuft. IGF-I binding sites were studied using radiolabelled IGF-I and conventional autoradiographical techniques on tissue sections. It was found that IGF-I binding sites were widely distributed throughout the entire kidney and that the specific binding was highest in the inner medulla. These findings add further complexity to the understanding of IGF-I production and action on renal structures.

Animals↗

PubMed1992

Altered amounts of G-protein mRNA and cAMP accumulation after long-term opioid receptor stimulation of neurons in primary culture from the rat cerebral cortex.

Primary neuronal enriched cultures were incubated with mu (morphine, 10(-5) M), delta (DPDPE, 10(-6) M) and kappa (U-50,488H, 10(-5) M) receptor agonists for 5 days, respectively. Thereafter the acute inhibitory actions of mu, delta or kappa receptor agonists on forskolin stimulated cAMP accumulation was assayed. The effect of long term opioid treatment on the steady-state level of G-protein mRNA (G alpha s, G alpha i-1 and G alpha i-2) was analyzed using an RNAase protection hybridization assay. Incubation for 5 days with kappa receptor agonist resulted in an attenuated ability to decrease the accumulation of cAMP by kappa receptors, as well as mu and delta receptors, which was also observed after 5 days of incubation with the delta receptor agonist. Furthermore, the adenylate cyclase responsiveness to forskolin stimulation was markedly reduced in cultures treated with either delta or kappa receptor agonists. Five days of incubation with kappa receptor agonist resulted in an increase in the levels of G alpha s and G alpha i-2 mRNAs. No effects on the amounts of G alpha s mRNA, G alpha i-1 mRNA or G alpha i-2 mRNA were detected after 5 days of delta receptor stimulation. On the other hand, 5 days of mu receptor stimulation decreased the amounts of G alpha s, G alpha i-1 and G alpha i-2 mRNA. Incubation with kappa receptor agonist for 24 h resulted in a significant decrease in the forskolin-stimulated accumulation of cAMP. The stimulatory effect of forskolin was further decreased after 3 days incubation with kappa receptor agonist.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Regulation of G-PROTEIN mRNA abundancy and cAMP accumulation after long-term opioid incubation in primary cultures of astroglia from the rat cerebral cortex.

Primary astroglial cultures were incubated with delta (10(-6) M DPDPE) or kappa (10(-5) M U-50,488H) receptor agonists for 5 days. Thereafter, the acute inhibitory actions of delta or kappa receptor agonists on forskolin stimulated cAMP accumulation were assayed. The G alpha s, G alpha i-1 and G alpha i-2 mRNA levels were quantified after 5 days of either delta or kappa receptor agonist treatment using a solution hybridization, RNase protection assay. Pronounced effects were observed after 5 days of kappa receptor agonist [10(-5) M U-50,488H] incubation. This treatment resulted in an attenuation in the acute inhibitory action of delta and kappa receptor agonists. Furthermore, a decreased stimulatory action of forskolin was seen. Similar effects were also seen after delta receptor stimulation. We also investigated the effects after 24 h and 3 days of incubation with the kappa receptor agonist (10(-5) M) U-50,488H. The 24 h incubation resulted in a decreased sensitivity to the acute inhibitory action of delta and kappa receptor agonists in the astroglial cultures. This effect was further accentuated after the 3 days of incubation with 10(-5) M U-50,488H. No significant change was seen in the basal accumulation of cAMP after incubation with the kappa agonist U-50,488H. However, after 5 days of incubation with the delta agonist DPDPE, a significantly increased basal accumulation of cAMP was seen in the astroglial cultures. After 5 days of delta or kappa agonist incubation, an increase in G alpha s mRNA level and a decrease in G alpha i-2 mRNA level was seen compared with controls. No statistically significant alterations in the amount of G alpha i-1 mRNA were seen. The data obtained in the present study indicate that the effects of long-term opioid treatment alters the sensitivity of glial cell opioid receptors. Furthermore, long term opioid treatment induces alterations in glial G-protein mRNA levels.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

PubMed1992

High frequency of mammary adenocarcinomas in metallothionein promoter-human growth hormone transgenic mice created from two different strains of mice.

Transgenic mice were developed by injecting a mouse metallothionein promoter-human growth hormone (Mt-hGH) gene fragment into the pronucleus of C57Bl x DBA/2J-f2 or C57Bl x CBA-f2 one cell embryos. Six founder animals with the C57Bl x DBA genetic background grew 1.3-2.2 times larger than littermate controls and had higher levels of hGH in plasma (4.6-279 mU/l). Three of the four female transgenic founders developed malignant papillar adenocarcinomas of mammary origin at 27-43 weeks of age. One male transgenic founder was successfully mated and two of three female transgenic offsprings developed mammary tumors. To examine if the tumor induction was dependent on the strain of mice used the experiments were repeated using animals with different genetic background. Fourteen female hGH transgenic mice from five founder animals were generated using C57Bl x CBA-f2 mice. Thirteen of the animals had elevated levels of hGH in plasma (7-1960 mU/l) and grew larger than control animals. Nine of the animals developed mammary adenocarcinomas. Four of the hGH expressing animals did not demonstrate macroscopic tumor formation but have not yet been analyzed histologically. The present study suggests that markedly elevated endogenous levels of GH cause mammary carcinoma in hGH transgenic mice. The present animal model might prove useful for studying molecular mechanisms involved in the development of hormonally induced mammary tumors.

Adenocarcinoma, Papillary↗

PubMed1992

Acute myocardial infarction patients' chest pain as monitored and evaluated by ambulance personnel.

A delicate duty for ambulance personnel is to care for patients who suffer from chest pain, caused by acute myocardial infarction (AMI-patient). In Sweden pain-relieving drugs may be administered, such as: oxygen, entonox, or morphine according to the skill of the ambulance personnel. The aim of this study was to find out if AMI-patients' expressions of pain were monitored and evaluated, in which way the AMI-patients received pain-relief, and to which degree they were relieved of pain. Examinations of the records of the ambulance personnel's observations during transport of AMI-patients revealed that nine tenths of those who complained about chest pain received pain-relieving drugs. The results of the treatments varied, however, from a good rate of response to morphine to less responses to oxygen and entonox. In order to treat AMI-patients who are in need of pain-relief during their transit to hospital the ambulance personnel must possess thorough knowledge of both pain theory and communication theory. Furthermore, they need tools for assessment of pain and for administering adequate pain-relieving drugs in clinical practice. In the future it may be necessary to differentiate between ambulance personnel in routine service and those in emergency service according to their levels of education.

Allied Health Personnel↗

PubMed1992

Expression of functional growth hormone receptors in human granulosa cells.

Both clinical and experimental evidence suggest that growth hormone may be of importance for ovarian function. The present study investigated whether growth hormone receptors are expressed in human granulosa cells. Granulosa cells were isolated either from natural cycles or from stimulated cycles in the course of in-vitro fertilization. Total RNA hybridized with a 32P-labelled rat growth hormone receptor cRNA probe revealed one major transcript with an estimated size of 4.5 kb and one minor transcript with an estimated size of 1.3 kb. Biotinylated growth hormone was used to analyse growth hormone binding. Competitive growth hormone binding was detected in freshly isolated granulosa cells, as well as in cultured cells. Growth hormone augmented basal and/or follicle stimulating hormone-stimulated steroidogenesis in granulosa cells obtained from patients with natural cycles, but the response to growth hormone stimulation showed considerable variation. We conclude that functional growth hormone receptors are present in human granulosa cells and that growth hormone, therefore, may have an important role in ovarian function.

Analysis of Variance↗