Biomedical subjects

C Ohlsson

Publications and source records attributed to C Ohlsson.

At least 37 records · Page 2Linked to original sources

PubMed2003

Radiographic joint destruction in postmenopausal rheumatoid arthritis is strongly associated with generalised osteoporosis.

OBJECTIVES: To investigate determinants of joint destruction and reduced bone mineral density (BMD) in postmenopausal women with active rheumatoid arthritis (RA) not treated with bisphosphonates or hormone replacement therapy and to evaluate if there are common markers of erosive disease and bone loss. METHODS: BMD was measured using dual x ray absorptiometry and joint damage was examined by x ray examination according to the Larsen method in 88 patients with RA. Associations between BMD and Larsen score, and between demographic and disease related variables, including proinflammatory cytokines, HLA-DR4 epitopes, and markers of bone and cartilage turnover, were examined bivariately by simple and multiple linear regression analyses. RESULTS: 49/88 (56%) patients had osteoporosis in at least one site. Reduced BMD and increased joint destruction were associated with: at the forearm and femoral neck, high Larsen score, low weight, and old age (R(2)=0.381, p<0.001; R(2)=0.372, p<0.001, respectively); at the total hip, low weight, high Larsen score, and dose of injected glucocorticosteroids (R(2)=0.435, p<0.001); at the lumbar spine, low weight, reduced cartilage oligomeric matrix protein, and increased carboxyterminal propeptide of type I procollagen (R(2)=0.248, p<0.001). Larsen score was associated with long disease duration and increased C reactive protein (CRP) (R(2)=0.545, p<0.001). CONCLUSIONS: Osteoporosis is common in postmenopausal patients with RA. Low weight and high Larsen score were strongly associated with BMD reduction. Increased CRP and long disease duration were determinants of erosive disease in postmenopausal women with RA. These findings indicate common mechanisms of local and generalised bone loss in RA.

Age Factors↗

PubMed2003

Reductions in adipose tissue and skeletal growth in rat adult offspring after prenatal leptin exposure.

Leptin is involved in regulating food intake, energy balance and bone formation. Increasing evidence suggests that leptin is also involved in fetal growth and development. The aim of this study was to determine if increased maternal leptin is followed by changes in body composition, skeletal growth or hormonal regulation in the adult rat offspring. Pregnant rats were given injections of either human recombinant leptin (3.5 mg/kg, i.p.) or vehicle on days 8, 10 and 12 of gestation. Both genders of leptin-exposed offspring showed significantly reduced adipose tIssue weight at adult age. Skeletal growth and cortical bone dimensions were significantly reduced. Circulating testosterone levels were significantly increased in female leptin-exposed offspring, and male leptin-exposed offspring had significant testicular enlargement. No significant effects were seen on circulating leptin levels or hypothalamic protein levels of the leptin receptor. The results demonstrate that maternally administered leptin is involved in fetal growth and development, leading to lean offspring with reduced skeletal growth.

Adipose Tissue↗

PubMed2003

Skeletal changes in type-2 diabetic Goto-Kakizaki rats.

We characterized appendicular and axial bones in rats with type-2 diabetes in five female Goto-Kakizaki (GK) rats, a strain developed from the Wistar rat showing spontaneous type-2 diabetes, and five age- and sex-matched non-diabetic Wistar rats. The humerus, tibia, metatarsals and vertebral bodies were analysed by peripheral quantitative computerized tomography (pQCT). In diabetic rats, the height of the vertebral bodies and length of the humerus were decreased while the length of the metatarsals was increased. A decreased cross-sectional area was found in the vertebral end-plate region and the tibial metaphysis. Notably, the diaphysis in all long bones showed expansion of periosteal and endosteal circumference. In tibia this resulted in increased cortical thickness, whereas in humerus and metatarsal it was unchanged. Areal moment of inertia was increased in all diaphyses suggesting greater bending strength. The most conspicuous finding in diabetic rats pertained to trabecular osteopenia. Thus, trabecular bone mineral density was significantly reduced in all bones examined, by 33-53%. Our pQCT study of axial and appendicular bones suggests that the typical feature of diabetic osteopathy in the GK rat is loss of trabecular bone and expansion of the diaphysis. The loss of metaphyseal trabecular bone if also present in diabetic patients may prove to underlie the susceptibility to periarticular fracture and Charcot arthropathy. The findings suggest that the risk of fracture in diabetes varies according to the specific sub-regions of a bone. The approach described may prove to be useful in the early detection of osteopathy in diabetic patients who may be amenable to preventive treatment.

Animals↗

PubMed2002

In vitro determination of active bile acid absorption in small biopsy specimens obtained endoscopically or surgically from the human intestine.

BACKGROUND: In the construction of a Kock reservoir for continent urinary diversion, 70 cm of the distal ileum are used. Impaired absorption of bile acids in these patients might cause diarrhoea. Data on the absorption of bile acids in different parts of the human intestine are limited. METHODS: Biopsies were taken during endoscopy from the duodenum, the terminal ileum or the right colon, and during surgery 10, 50, 100 and 150 cm proximally to the ileo-caecal valve using standard endoscopy biopsy forceps. The biopsy specimens were incubated in vitro with radio-labelled taurocholic acid at 37 degrees C for 22 or 45 min The radioactivity was determined using the liquid scintillation technique. RESULTS: A linear increase in the uptake was observed, with increased concentrations of taurocholic acid between 100 and 500 microm in all specimens tested, that represented passive uptake or unspecific binding. The active uptake could be calculated from the intercept of the line representing passive uptake with the ordinate. The active uptake in the terminal ileum was 3-4 times greater than 100 cm proximal to the valve. CONCLUSIONS: The active absorption of bile acids in humans can be determined in small biopsy specimens taken using standard biopsy forceps during endoscopy or surgery. This method is suitable for clinical studies of bile acid absorption. Active uptake of bile acids not only takes place in the very distal part of the ileum but also to a considerable degree 100 cm proximally to the ileo-colonic valve. This should be taken into account when selecting the ileal segment for continent urinary diversion.

Adult↗

PubMed2002

Estrogen receptor specificity for the effects of estrogen in ovariectomized mice.

Estrogen exerts a variety of important physiological effects, which have been suggested to be mediated via the two known estrogen receptors (ERs), alpha and beta. Three-month-old ovariectomized mice, lacking one or both of the two estrogen receptors, were given estrogen subcutaneously (2.3 micro g/mouse per day) and the effects on different estrogen-responsive parameters, including skeletal effects, were studied. We found that estrogen increased the cortical bone dimensions in both wild-type (WT) and double ER knockout (DERKO) mice. DNA microarray analysis was performed to characterize this effect on cortical bone and it identified four genes that were regulated by estrogen in both WT and DERKO mice. The effect of estrogen on cortical bone in DERKO mice might either be due to remaining ERalpha activity or represent an ERalpha/ERbeta-independent effect. Other effects of estrogen, such as increased trabecular bone mineral density, thymic atrophy, fat reduction and increased uterine weight, were mainly ERalpha mediated.

Animals↗

PubMed2002

Affected skeletal growth but normal bone mineralization in rat offspring after prenatal dexamethasone exposure.

Events occurring early in life or prenatally are able to play important roles in the pathogenesis of diseases in adult life. Different sorts of stress or hormonal influences, during particular periods of pregnancy, may result in persisting or transient changes in physiology. Glucocorticoids are used for the treatment of a variety of diseases, to promote organ maturation and to prevent preterm delivery. Glucocorticoids are also known to affect skeletal growth and adult bone metabolism. The aim of the present study was to investigate whether exposure to dexamethasone (Dex) during fetal life has any effect on skeletal growth and/or bone mineral density in adult rat offspring. Pregnant rats were given injections of either Dex (100 micro g/kg) or vehicle on days 9, 11 and 13 of gestation. Dex-exposed male but not female rat offspring showed transient increases in crown-rump length and tibia and femur lengths at 3-6 weeks of age. In contrast, the cortical bone dimensions were altered in 12-week-old female but not male Dex-exposed offspring. The areal bone mineral densities of the long bones and the spine, as determined by dual X-ray absorptiometry, and trabecular as well as cortical volumetric bone mineral density, as measured using peripheral quantitative computerized tomography, were unchanged in both male and female Dex-exposed offspring. In conclusion, prenatal Dex exposure affects skeletal growth in a gender-specific manner, while the mineralization of bones is unaffected in both male and female offspring.

Absorptiometry, Photon↗

PubMed2002

Expression and localization of Indian hedgehog (Ihh) and parathyroid hormone related protein (PTHrP) in the human growth plate during pubertal development.

Indian Hedgehog (Ihh) has been reported to control the rate of cartilage differentiation during skeletal morphogenesis in rodents through a negative feedback loop involving parathyroid hormone related protein (PTHrP). The role of Ihh and PTHrP in the regulation of human epiphyseal chondrocytes is unknown. The aim of the current study was to examine the expression and localization of Ihh and PTHrP in the human growth plate at various pubertal stages. Growth plate biopsies were obtained from patients subjected to epiphyseal surgery and the expression of Ihh and PTHrP was detected by immunohistochemistry. We show that Ihh and PTHrP are expressed mainly in early hypertrophic chondrocytes in the human growth plate. The levels of expression of Ihh and PTHrP are higher in early stages of puberty than later. Our results suggest that Ihh and PTHrP are present in the human growth plate and that Ihh and PTHrP may be involved in the regulation of pubertal growth in humans.

Adolescent↗

PubMed2002

Natural (ghrelin) and synthetic (hexarelin) GH secretagogues stimulate H9c2 cardiomyocyte cell proliferation.

Recent experimental data demonstrate cardiovascular effects of the GH secretagogues (GHSs) hexarelin and ghrelin, the proposed natural ligand for the GHS receptor. Moreover, specific cardiac binding sites for GHSs have been suggested. The aim of the present study was to investigate if the natural ligand ghrelin and synthetic GHS peptide hexarelin and analogues have direct effects on the cardiomyocyte cell line, H9c2. Hexarelin stimulated thymidine incorporation in a dose-dependent manner with significant responses at 3 micro M (147+/-3% of control, P<0.01) and elicited maximal effects at concentrations around 30 micro M. This activity was seen already after 12 h of incubation with a maximal effect after 18 h (176+/-9% of control, P<0.01). Ghrelin also had a significant stimulatory effect on thymidine incorporation (129+/-2% of control at 3 micro M and 18 h, P<0.05). The stimulatory effect on thymidine incorporation of hexarelin, Tyr-Ala-hexarelin, EP80317 and ghrelin was specific and no stimulatory effect was observed with the truncated GH-releasing peptide EP51389 or the non-peptidyl GHS MK-0677. In competitive binding studies, (125)I-labeled Tyr-Ala-hexarelin was used as radioligand and competition curves showed displacement with hexarelin, Tyr-Ala-hexarelin, EP80317 and ghrelin, whereas MK-0677 and EP51389 produced very little displacement at 1 micro M concentration, adding further support for an alternative subtype binding site in the heart compared with the pituitary. In conclusion, we have demonstrated a dose-dependent and specific stimulation of cardiomyocyte thymidine incorporation by natural and synthetic GHS analogues, suggesting increased cell proliferation and binding of GHS to H9c2 cardiomyocyte cell membranes. These findings support potential peripheral effects of GHS on the cardiovascular system independent of an increased GH secretion.

Binding, Competitive↗

PubMed2002

Raloxifene- and estradiol-mediated effects on uterus, bone and B lymphocytes in mice.

Raloxifene is a selective estrogen receptor modulator approved for the prevention of osteoporosis in postmenopausal women. It is selective by having estrogen-agonistic effects on bone, vessels and blood lipids while it is antagonistic on mammary and uterine tissue. Our aim was to study the agonistic and antagonistic properties of the raloxifene analogue LY117018 (LY) on uterus, bone, B lymphopoiesis and B cell function. Oophorectomized and sham-operated animals were treated with s.c. injections of equipotent anti-osteoporotic doses of 17beta-estradiol (E2) (0.1 mg/kg) or LY (3 mg/kg) or vehicle as controls. Effects on bone mineral density (BMD) were studied using peripheral quantitative computed tomography, uterine weight was examined, B lymphopoiesis was examined using flow cytometry and B cell function in bone marrow and spleen was studied by the use of an ELISPOT assay. E2 and LY had similar effects on BMD and bone marrow B lymphopoiesis, while LY had a clear antagonistic effect on endogenous estrogen in uterine tissue and no stimulating effect on the frequency of Ig-producing B cells in sham-operated animals. Our results are discussed in the context of estrogen receptor biology, relations between the immune system and bone metabolism and also with respect to the estrogen-mediated effects on rheumatic diseases.

Animals↗

PubMed2002

Drug-induced prevention of gastrectomy- and ovariectomy-induced osteopaenia in the young female rat.

Both ovariectomy (Ovx) and gastrectomy (Gx) induce osteopaenia in rats and humans. While the effect of Ovx has been ascribed to oestrogen deficiency, the underlying mechanism behind Gx is poorly understood. Alendronate, oestrogen and parathyroid hormone (PTH) are known to prevent the osteopaenia induced by Ovx in rats. The purpose of the present study was to determine whether alendronate, oestrogen or PTH could also prevent Gx-evoked osteopaenia. Rats were Ovx-, Gx-, or were sham-operated (Sham) and were then treated with alendronate (50 micro g/kg/day), oestrogen (10 micro g/kg/day) or PTH(1-84) (75 micro g/kg/day) for eight weeks. At sacrifice, serum PTH was unaffected by surgery (Ovx, 64+/-8 pg/ml; Gx, 75+/-13 pg/ml; Sham, 58+/-11 pg/ml). The bone mineral density (BMD) of the fifth lumbar vertebra (L5) was analysed. Ovx and Gx reduced the BMD (ash weight/Volume) of the L5 by 15+/-4% and 22+/-3% respectively. Trabecular BMD and the cortical bone mineral content (BMC) of the femur were assessed using peripheral computed tomography. Both Ovx and Gx markedly reduced trabecular BMD in the metaphyseal area of the distal femur (Ovx, -37+/-7%; Gx, -49+/-7%). The cortical BMC of the femur was only slightly reduced. Alendronate prevented trabecular bone loss after both Ovx and Gx, while oestrogen and PTH prevented trabecular bone loss after Ovx but not after Gx. In conclusion, the bisphosphonate alendronate prevented both Ovx- and Gx-induced trabecular bone loss. In contrast, PTH and oestrogen prevented Ovx-induced but not Gx-induced trabecular bone loss, suggesting that the mechanism behind the trabecular bone loss in Ovx rats differs from that in Gx rats. The results support the notion that the mechanism of action for the bone-sparing effect of these drugs differs. The ability of alendronate, and probably also other bisphosphonates, to prevent Gx-evoked osteopaenia in the rat might be of potential clinical interest when dealing with post-Gx osteopaenia in humans.

Alendronate↗

PubMed2002

A transgenic model to determine the physiological role of liver-derived insulin-like growth factor I.

Insulin-like growth factor-I (IGF-I) has important growth promoting and metabolic effects and is expressed in virtually every tissue of the body. The highest expression is found in the liver but the physiological role of liver-derived IGF-I is unknown. It has been difficult to separate the endocrine effects of liver-derived IGF-I from the autocrine/paracrine effects of locally produced IGF-I in peripheral tissues. Therefore, we have developed a mouse model with a liver-specific inducible deletion of the IGF-I gene. The liver-IGF-I deficient mouse have dramatically reduced (>80%) serum IGF-I levels, demonstrating that the major part of serum IGF-I is liver-derived. Surprisingly, liver-IGF-I deficient mice demonstrate a normal appendicular skeletal growth up to at least 12 months of age despite the dramatic decrease in circulating IGF-I levels, indicating that liver-derived IGF-I is not required for appendicular skeletal growth. However, the adult axial skeletal growth is clearly reduced in the liver-IGF-I deficient mice. Furthermore, the amount of cortical bone is reduced due to decreased radial growth of the cortical bone while the amount of trabecular bone is unchanged in the liver-IGF-I deficient mice. The decreased levels of circulating IGF-I are associated with increased serum levels of growth hormone (GH), indicating a role for liver-derived IGF-I in the negative feedback regulation of GH secretion. Measurements of factors regulating GH-secretion in the pituitary and in the hypothalamus revealed an increased expression of growth hormone releasing hormone (GHRH) and growth hormone secretagogue (GHS) receptors in the pituitary of liver-IGF-I deficient mice. This in turn results in an increased sensitivity to systemically administered GHRH and GHS, demonstrating that the regulatory action of liver-derived IGF-I on GH secretion is at the pituitary rather than at the hypothalamic level. The liver is an important metabolic organ and liver-IGF-I deficient mice are markedly hyperinsulinemic and yet normoglycemic, consistent with an adequately compensated insulin resistance. Interestingly, liver-IGF-I deficient mice display a reduced age-dependent fat mass accumulation compared with control mice. In conclusion, liver-derived IGF-I is important for carbohydrate- and lipid-metabolism and for the regulation of GH-secretion at the pituitary level. Furthermore, it regulates adult axial skeletal growth and cortical radial growth while it is not required for appendicular skeletal growth.

Adipose Tissue↗

PubMed2001

Effects of estrogen on the vascular injury response in estrogen receptor alpha, beta (double) knockout mice.

The two known estrogen receptors, ERalpha and ERbeta, mediate the effects of estrogen in all target tissues, including blood vessels. We have shown previously that estrogen inhibits vascular injury response to the same extent in female wild-type (WT), ERalpha knockout (ERalphaKO(CH)), and ERbeta knockout (ERbetaKO(CH)) mice. We generated mice harboring disruptions of both ERalpha and ERbeta genes (ERalpha,betaKO(CH)) by breeding and studied the effect of 17beta-estradiol (E2) on vascular injury responses in ovariectomized female ERalpha,betaKO(CH) mice and WT littermates. E2 inhibited increases in vascular medial area following injury in the WT mice but not in the ERalpha,betaKO(CH) mice, demonstrating for the first time that the two known estrogen receptors are necessary and sufficient to mediate estrogen inhibition of a component of the vascular injury response. Surprisingly, as in WT littermates, E2 still significantly increased uterine weight and inhibited vascular smooth muscle cell (VSMC) proliferation following injury in the ERalpha,betaKO(CH) mice. These data support that the role of estrogen receptors differs for specific components of the vascular injury response in the ERalpha,betaKO(CH) mice. The results leave unresolved whether E2 inhibition of VSMC proliferation in ERalpha,betaKO(CH) mice is caused by a receptor-independent mechanism, an unidentified receptor responsive to estrogen, or residual activity of the ERalpha splice variant reported previously in the parental ERalphaKO(CH) mice. These possibilities may be resolved by studies of mice in which ERalpha has been fully disrupted (ERalphaKO(St)), which are in progress.

Animals↗

PubMed2001

Growth hormone (GH)-independent stimulation of adiposity by GH secretagogues.

Growth hormone secretagogues (GHSs) stimulate growth hormone (GH) secretion, which is lipolytic. Here we compared the effects of twice daily s.c. treatment of GH and the GHS, ipamorelin, on body fat in GH-deficient (lit/lit) and in GH-intact (+/lit and +/+) mice. In +/lit and lit/lit mice ipamorelin induced a small (15%) increase in body weight by 2 weeks, that was not further augmented by 9 weeks. GH treatment markedly enhanced body weight in both groups. Ipamorelin also increased fat pad weights relative to body weight in both lit/lit and +/lit mice. Two weeks GHS treatment (ipamorelin or GHRP-6) also increased relative body fat, quantified by in vivo dual energy X-ray absorpiometry (DEXA) in GH-intact mice. GH decreased relative fat mass in lit/lit mice and had no effect in GH-intact mice. Treatment with GHS, but not GH, increased serum leptin and food intake in GH-intact mice. Thus, GHSs increase body fat by GH-independent mechanisms that may include increased feeding.

Adipose Tissue↗

PubMed2001

The somatomedin hypothesis revisited in a transgenic model.

Studies of insulin-like growth factor I (IGF-I) gene knockout mice models have clearly shown that IGF-I is necessary for prenatal as well as postnatal body growth in mice. Clinical studies of a patient with an IGF-I gene defect which caused complete absence of IGF-I, verified that it is important for intrauterine and postnatal growth. Recent studies of mice with liver-specific and inducible IGF-I gene knockout indicated that liver-derived IGF-I is not necessary for postnatal body growth, although serum IGF-I levels are decreased by more than 80% in these mice. Therefore, extrahepatic IGF-I is sufficient for maintenance of postnatal body growth in mice. Further investigations are needed to assess whether liver-derived circulating IGF-I is essential for other biological functions.

Animals↗

PubMed2001

Role of oestrogen receptors alpha and beta in immune organ development and in oestrogen-mediated effects on thymus.

Oestrogens affect the development and regulation of the immune system. To determine the role of oestrogen receptors alpha (ER-alpha) and beta (ER-beta) on the development of the immune system, male ER-alpha (ERKO) and ER-beta (BERKO) mice, as well as alphabeta-double knockout (DERKO) mice, were studied. Deletion of ER-alpha led to hypoplasia of both thymus and spleen. Interestingly, a higher frequency of immature double CD4+ CD8+ thymocytes was found in ER-alpha(-) mice compared with ER-alpha(+) mice. Female oophorectomized BERKO mice given oestradiol (E2) displayed a similar degree of thymic atrophy compared with the wild-type strain but showed only limited involution of thymus cortex and no alteration of thymic CD4/CD8 phenotype expression. Our data demonstrate that expression of ER-alpha, but not ER-beta, is mandatory in males for development of full-size thymus and spleen, whereas expression of ER-beta is required for E2-mediated thymic cortex atrophy and thymocyte phenotype shift in females. A potential background for the above findings may be down-regulated activity in the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis in males lacking ER-alpha and suppressed sensitivity of females lacking ER-beta to E2-mediated suppression of IGF-1.

Animals↗

PubMed2001

Body fat content can be predicted in vivo in mice using a modified dual-energy X-ray absorptiometry technique.

The introduction of transgenic mice as animal models in medical research has increased the need for methods to study the phenotype of mice. The aim of the present study was to develop and evaluate a method for in vivo prediction of fat content in living mice. We combined a modified dual-energy X-ray technique with an image analysis procedure. This combined procedure calculates the percentage of fat area, defined as the percentage of the total area of the mice consisting of >50% fat. A high correlation between the percentage of fat area and dissected adipose tissue was seen in both male and female mice (males, r = 0.92, P < 0.001; females, r = 0.88, P < 0.001). A high correlation was also seen between the percentage of fat area and serum levels of leptin (males, r = 0.95, P < 0.001; females, r = 0.86, P < 0.001). An additional experiment demonstrated a very strong correlation between the percentage of fat area and total body fat as determined by chemical extraction (r = 0.97, P < 0.001). In summary, the percentage of fat area, as measured with the dual-energy X-ray/image combined procedure, provides a good in vivo estimation of total body fat content in mice.

Absorptiometry, Photon↗

PubMed2001

Possible roles of insulin-like growth factor in regulation of physiological and pathophysiological liver growth.

BACKGROUND/AIMS: Almost all circulating insulin-like growth factor-1 (IGF-1) is produced and secreted from the liver. However, the possible role of IGF-1 in local regulation of liver functions including liver growth is unclear. In the present study, we investigated the role of IGF-1 on liver growth in vivo and in hepatic stellate cell function in vitro. RESULTS: Liver-specific knock-out of the IGF-1 gene by use of the cre-loxP system caused enhanced liver growth, possibly reflecting increased growth hormone (GH) secretion due to decreased negative feedback by IGF-1. Studies on cultured rat hepatic stellate cells (HSC) showed that IGF-1 and hepatocyte-conditioned medium (PCcM) time- and dose-dependently increased hepatocyte growth factor (HGF) mRNA and HGF immunoreactivity. IGF-1 and PCcM also enhanced DNA synthesis in the HSC cultures. The PCcM did not contain bioactive IGF-1 and was also able to stimulate proliferation when prepared under serum- and hormone-free conditions. CONCLUSION: In vivo results show that IGF-1 is not essential for normal growth of the intact liver. The in vitro results indicate that both IGF-1 and IGF- 1-independent factor(s) from hepatocytes can stimulate HGF production by HSC. It remains to be investigated whether these effects are of importance for liver regeneration or pathological conditions.

Animals↗

PubMed2001

Metabolic functions of liver-derived (endocrine) insulin-like growth factor I.

Until now it has been difficult to determine the relative importance of locally produced (autocrine/paracrine) versus systemically derived (endocrine) insulin-like growth factor I (IGF-I) in the intact organism. We recently eliminated IGF-I production in the livers of mice using the Cre/loxP recombination system. These mice displayed a reduction in serum IGF-I levels of more than 80%, but demonstrated normal body growth, suggesting that autocrine/paracrine-acting IGF-I, but not endocrine-acting IGF-I, regulates body growth. Long-term metabolic studies of mice in which IGF-I production had been inactivated in the liver, have shown that the mice have decreased fat mass, but increased serum levels of insulin and cholesterol. Despite the marked increase in plasma insulin following glucose administration, the glucose elimination was not altered in these animals. Thus, the mice showed an adequately compensated insulin resistance. In conclusion, liver-derived or endocrine IGF-I is not required for post-natal statural growth, but seems to be of vital importance for normal carbohydrate and lipid metabolism.

Animals↗