Growth Hormone Supplementation Research Articles

Growth hormone supplement treatment reduces the surgical risk for Prader–Willi Syndrome patients

Many complications have been reported to occur with surgery for scoliosis in Prader-Willi Syndrome (PWS). However, growth hormone (GH) treatment has contributed to improvements in height, body composition, bone density and breathing functions in PWS patients. The purpose of this study was to investigate patients who underwent surgery for scoliosis in PWS. There were 136 PWS patients being followed-up by the Pediatrics Department of our hospital. Among these, we investigated nine patients who had undergone surgery. Their mean age was 11 years. The mean follow-up period was 6 years 10 months. The mean body mass index was 22.5 kg/m(2). GH therapy was administered to eight patients. Brace treatment was performed in two patients. Spinal correction and fusion were performed in six patients, and the growing rod method was performed in three patients. Necessary reoperations were performed in two patients. For the total 11 surgeries in the nine patients, the mean blood loss was 397 ml and the mean operation time was 4 h and 20 min. The mean Cobb angles were 76.0 degrees preoperatively and 35.8 degrees at follow-up. Regarding complications, one patient experienced early dislodgment of the hook and one patient experienced a superior wound infection. There were no severe complications such as deep infections or neurovascular damage. A few obese patients underwent surgery, but there were no dangerous complications. Overall, we consider that GH treatment before surgery may reduce postoperative complications. The growing rod method was effective for PWS patients who resisted brace treatment owing to mental retardation.

The value of growth hormone supplements in ART for poor ovarian responders

Recently, three meta-analyses have concluded that cotreatment with GH improves assisted reproduction outcome in poor controlled ovarian stimulation responders. Although generally GH supplements did not increase controlled ovarian stimulation response or number of oocytes, the supplements improved pregnancy and live-birth rates-thus speaking for an effect on oocyte quality.

IGF-1 levels are significantly correlated with patient-reported measures of sexual function

Growth hormone (GH) supplementation may help to preserve erectile function. We assessed whether serum insulin-like growth factor 1 (IGF-1) levels, a surrogate for GH levels, correlate with sexual function scores in 65 men who completed the Sexual Health Inventory for Men (SHIM) and Expanded Prostate Cancer Index Composite (EPIC) questionnaires, and had serum IGF-1 and testosterone levels determined. Median±s.d. IGF-1 level, SHIM and EPIC scores were 235.0±86.4, 19.5±8.7 and 56.4±28.3 mg ml(-1), respectively. IGF-1 levels and total SHIM score correlate significantly (r=0.31, P=0.02), as do IGF-1 levels and all individual SHIM question scores, and IGF-1 levels and the sexual domain of the EPIC questionnaire (r=0.30, P=0.02). No correlation was observed between IGF-1 levels and Gleason score, IGF-1 and testosterone level or SHIM score and testosterone level. These data support a potential role for the GH axis in erectile function.

Value of measuring muscle performance to assess changes in lean mass with testosterone and growth hormone supplementation

We hypothesized that treatment with testosterone (T) and recombinant human growth hormone (rhGH) would increase lean mass (LM) and muscle strength proportionally and an in a linear manner over 16 weeks. This was a multicenter, randomized, controlled, double-masked investigation of T and rhGH supplementation in older (71 ± 4 years) community-dwelling men. Participants received transdermal T at either 5 or 10 g/day as well as rhGH at 0, 3.0 or 5.0 μg/kg/day for 16 weeks. Body composition was determined by dual-energy X-ray absorptiometry (DEXA) and muscle performance by composite one-repetition maximum (1-RM) strength and strength per unit of lean mass (muscle quality, MQ) for five major muscle groups (upper and lower body) at baseline, week 8 and 17. The average change in total LM at study week 8 compared with baseline was 1.50 ± 1.54 kg (P < 0.0001) in the T only group and 2.64 ± 1.7 (P < 0.0001) in the T + rhGH group and at week 17 was 1.46 ± 1.48 kg (P < 0.0001) in the T only group and 2.14 ± 1.96 kg (P < 0.0001) in the T + rhGH group. 1-RM strength improved modestly in both groups combined (12.0 ± 23.9%, P < 0.0001) at week 8 but at week 17 these changes were twofold greater (24.7 ± 31.0%, P < 0.0001). MQ did not significantly change from baseline to week 8 but increased for the entire cohort, T only, and T + rhGH groups by week 17 (P < 0.001). Despite sizeable increases in LM measurements at week 8, tests of muscle performance did not show substantive improvements at this time point.

Durability of the effects of testosterone and growth hormone supplementation in older community‐dwelling men: the HORMA Trial

To determine the durability of anabolic effects and adverse events (AEs) after stopping testosterone and growth hormone supplementation in older men. Secondary analysis of a double-masked, randomized controlled trial of testosterone gel (5 or 10 g/daily) plus rhGH (0, 3 or 5 μg/kg/day) with follow-up of outcomes 3 months later. A total of 108 community-dwelling 65- to 90-year-old men. Testosterone and IGF-1 levels, body composition (DEXA), 1-repetition maximum (1-RM) strength, stair-climbing power, quality-of-life (QOL) and activity questionnaires, AEs. Despite improvements in body composition during treatment, residual benefits 3 months later (week 28) were variable. For participants with improvements exceeding their week-17 median changes, benefits were sustained at week 28 for lean body mass (1·45 ± 1·63 kg, 45% of week-17 values, P < 0·0001 vs baseline), appendicular skeletal muscle mass (ASMM, 0·71 ± 1·01 kg, 42%, P < 0·0001), total fat (-1·06 ± 2·18 kg, 40%, P < 0·0001) and trunk fat (-0·89 ± 1·42 kg, 50%, P < 0·0001); retention of ASMM was associated with greater week-16 protein intake (P = 0·01). For 1-RM strength, 39%-43% of week-17 improvements (P ≤ 0·05) were retained and associated with better week-17 strength (P < 0·0001), change in testosterone from week 17-to 28 (P = 0·004) and baseline PASE (P = 0·04). Framingham 10-year cardiovascular risks were low (~14%), did not worsen and improved by week 28 (P = 0·0002). The hypothalamic-pituitary-gonadal axis recovered completely. Durable improvements in muscle mass, strength and fat mass were retained 3 months after discontinuing hormone supplementation in participants with greater than median body composition changes during treatment, but not in others with smaller gains. AEs largely resolved after intervention discontinuation. Additional strategies may be needed to sustain or augment muscle mass and strength gains achieved during short-term hormone therapy.

Health-related quality of life of young adults with Turner syndrome following a long-term randomized controlled trial of recombinant human growth hormone

BackgroundThere are limited long-term randomized controlled trials of growth hormone (GH) supplementation to adult height and few published reports of the health-related quality of life (HRQOL) following treatment. The present follow-up study of young adults from a long-term controlled trial of GH treatment in patients with Turner syndrome (TS) yielded data to examine whether GH supplementation resulted in a higher HRQOL (either due to taller stature or from the knowledge that active treatment and not placebo had been received) or alternatively a lower HRQOL (due to medicalization from years of injections).MethodsThe original trial randomized 154 Canadian girls with TS aged 7-13 years from 13 centres to receive either long-term GH injections at the pharmacologic dose of 0.3 mg/kg/week or to receive no injections; estrogen prescription for induction of puberty was standardized. Patients were eligible for the follow-up study if they were at least 16 years old at the time of follow-up. The instrument used to study HRQOL was the SF-36, summarized into physical and mental component scales (PCS and MCS); higher scores indicate better HRQOL.ResultsThirty-four of the 48 eligible participants (71%) consented to participate; data were missing for one patient. Both groups (GH and no treatment) had normal HRQOL at this post-treatment assessment. The GH group had a (mean ± SD) PCS score of 56 ± 5; the untreated group 58 ± 4; mean score for 16-24 year old females in the general population 53.5 ± 6.9. The GH group had a mean MCS score of 52 ± 6; the untreated group 49 ± 13; mean score for 16-24 year old females in the general population 49.6 ± 9.8. Secondary analyses showed no relationship between HRQOL and height.ConclusionsWe found no benefit or adverse effect on HRQOL either from receiving or not receiving growth hormone injections in a long-term randomized controlled trial, confirming larger observational studies. We suggest that it remains ethically acceptable as well as necessary to maintain a long-term untreated control group to estimate the effects of pharmacological agents to manipulate adult height. Young adult women with TS have normal HRQOL suggesting that they adjust well to their challenges in life.Trial RegistrationClinicalTrials.gov Identifier NCT00191113.

SUSTAINED-RELEASE RECOMBINANT HUMAN GROWTH HORMONE IMPROVES BODY COMPOSITION AND QUALITY OF LIFE IN ADULTS WITH SOMATOPAUSE

SUSTAINED-RELEASE RECOMBINANT HUMAN GROWTH HORMONE IMPROVES BODY COMPOSITION AND QUALITY OF LIFE IN ADULTS WITH SOMATOPAUSE

The Potential Effects of IGF-1 and GH on Patients With Chronic Heart Failure

Heart failure (HF) is an important health concern with almost a quarter million deaths each year despite advances in medical therapy. Improvement of cardiac function has been shown to reduce morbidity and mortality in patients with HF. There has been recent interest in the growth hormone (GH) / insulin-like growth factor (IGF) pathway as a potential therapeutic target for patients with HF. Insulin-like growth factor 1 has been shown to augment cardiac function ex vivo and in animals. It was hypothesized that IGF-1/IGF-binding protein 3 levels might be able to provide prognostic benefits in patients with heart disease. Initial observational studies have shown significant benefits from GH supplementation including improved ejection fraction, increased exercise tolerance, and decreased New York Heart Association functional class. These results, however, were not replicated in randomized, controlled trials. Patients with advanced stages of HF might develop cachexia associated with a state of significant GH resistance. The lack of response to GH supplementation may be secondary to a deficiency in IGF-1, the effector hormone. Hypothetically, this group of patients could benefit from direct IGF-1 supplementation. Combined therapy with GH and IGF-1 is appealing; however, future trials in patients with advanced HF are warranted to prove this concept.

Human growth hormone receptor (GHR) expression in obesity: I. GHR mRNA expression in omental and subcutaneous adipose tissues of obese women

Growth hormone (GH)-deficient individuals display increased adiposity that can be effectively reduced by GH therapy because of GH's lipolytic effects. However, similar GH treatments of individuals with idiopathic obesity (not associated with an endocrinopathy/syndrome) have had little success. We hypothesized that this form of obesity may be associated with GH resistance at the level of the adipocyte because of reduced GH receptor (GHR) expression. We studied GHR expression in omental and subcutaneous fat tissues from a cohort of 55 women ranging from lean to obese by various adiposity parameters. mRNA levels of total GHR and the dominant-negative truncated GHR(1-279) (trGHR) form were assayed by quantitative reverse transcriptase-PCR. Associations between adiposity measures and GHR levels as well as trGHR/GHR ratios were analyzed. Total GHR mRNA expression was 2-3-fold lower in omental as well as subcutaneous adipose tissues of obese compared with lean women (P ≤ 0.05-0.001). Lean individuals expressed higher GHR mRNA levels in omental fat compared with subcutaneous (P ≤ 0.01); in obese women, this depot-specific difference was lost. Omental and subcutaneous adipose GHR mRNA levels displayed significant negative correlations with a spectrum of indicators of obesity while, in subcutaneous fat, there was a significantly higher trGHR/GHR ratio with increasing adiposity (P ≤ 0.05). These results support our hypothesis that, with obesity, there is lower GHR expression in the adipocyte, and suggest one possible explanation why GH supplementation is not an effective treatment for individuals with idiopathic obesity.

Early-onset growth hormone deficiency results in diastolic dysfunction in adult-life and is prevented by growth hormone supplementation

Objective The primary goal of growth hormone (GH) replacement is to promote linear growth in children with growth hormone deficiency (GHD). GH and insulin-like growth factor-1 (IGF-1) are also known to have roles in cardiac development and as modulators of myocardial structure and function in the adult heart. However, little is known about cardiac diastolic function in young adults with childhood onset GH deficiency in which GH treatment was discontinued following puberty. The aim of the study was to evaluate the effects of long standing GHD and peri-pubertal or continuous GH replacement therapy on diastolic function in the adult dwarf rat. Design The dwarf rat, which possesses a mutation in a transcription factor necessary for development of the somatotroph, does not exhibit the normal peri-pubertal rise in GH around day 28 and was used to model childhood or early-onset GHD (EOGHD). In another group of male dwarfs, GH replacement therapy was initiated at 4 weeks of age when GH pulsatility normally begins. Ten weeks after initiation of injections, GH-treated dwarf rats were divided into 2 groups; continued treatment with GH for 12 weeks (GH-replete) or treatment with saline for 12 weeks. This latter group models GH supplementation during adolescence with GHD beginning in adulthood (adult-onset GHD; AOGHD). Saline-treated heterozygous (HZ) rats were used as age-matched controls. At 26 weeks of age, cardiac function was assessed using invasive or noninvasive (conventional and tissue Doppler) indices of myocardial contractility and lusitropy. Results Systolic function, as determined by echocardiography, was similar among groups. Compared with HZ rats and GH-replete dwarfs, the EOGHD group exhibited significant reductions in myocardial relaxation and increases in left ventricular filling pressure, indicative of moderate diastolic dysfunction. This was further associated with a decrease in the cardiac content of sarcoplasmic reticulum Ca 2+ ATPase (SERCA2), one of the important cardiac calcium regulatory proteins. Dwarfs supplemented with GH during the peri-adolescence stage, but not beyond (AOGHD), exhibited a subtle prolongation in the deceleration time to early filling. In contrast, continual GH replacement preserved diastolic function such that the cardiac phenotype of the GH-replete dwarfs resembled that of their age-matched HZ counterpart. Discussion Our data indicate that GHD during adolescence leads to overt diastolic dysfunction in early adulthood and this is prevented by continual GH replacement therapy. Since discontinuation of GH replacement following adolescence only mitigated the lusitropic deficits that were observed in untreated dwarfs, GH treatment into adulthood could be beneficial.

Human growth hormone and the development of osteochondritis dissecans lesions

No single etiology regarding the cause of osteochondritis dissecans (OCD) lesions is unanimously accepted. This report documents a novel case of multiple OCD lesions affecting the left knee and a solitary defect of the right elbow in a patient with acquired human growth hormone (hGH) deficiency and supplementation. hGH deficiency and hormone replacement may be related to the development of OCD lesions.

Growth hormone in the management of female infertility

Growth hormone (GH) is involved in the regulation of male and female infertility and has been used in the management of both male and female infertility. GH is also produced by the ovary apart from it being produced from pituitary. GH helps in monofollicular growth. GH therapy is one of the adjuvant treatment used in ovarian stimulation and Assisted Reproductive Technologies Assisted Reproductive Technology (ART). GH supplementation has been shown to improve pregnancy rates in poor responders. Growth hormone cotherapy has a definite role to play in ovarian stimulation and is effective in appropriately selected cases. However, it cannot be recommended indiscriminately in every patient undergoing ovarian stimulation or assisted reproductive technology.

Effects of recombinant human growth hormone on protein turnover in the fasting and fed state in adolescents with Crohn disease

The primary purpose of this study was to test whether recombinant human growth hormone (rhGH) supplementation would enhance protein synthesis and accretion of lean body mass. Eight adolescents (six males and two females; 17.2 +/- 2.6 years; age range, 13.7-21.2 years) participated in a randomized double-blind placebo-controlled cross-over trial of rhGH. We employed stable isotopes to measure proteolysis and protein synthesis during fasting and fed conditions during two 6-month treatment conditions. We also measured bone mineral density (BMD), markers of bone turnover, and body composition. Whole-body proteolysis, phenylalanine catabolism, and protein synthesis did not differ during treatment with rhGH vs. placebo. Enteral nutrition suppressed proteolysis and increased protein synthesis similarly during placebo and rhGH treatments. We conclude that rhGH is unlikely to provide sufficient metabolic benefit to warrant its use as an adjunct treatment in clinically stable adolescents with Crohn disease. A high prevalence of vitamin D deficiency and suboptimal BMD existed, which deserves further investigation and clinical attention.

Variable Clinical Phenotype and Course In Greek Patients with Shwachman-Diamond Syndrome Carrying Identical SBDS Mutations

AbstractAbstract 4431 Introduction-Background:Shwachman-Diamond syndrome (SDS) is a rare multi-system genetic disorder mainly characterized by exocrine pancreatic insufficiency, bone marrow failure and skeletal abnormalities. Approximately 90% of patients meeting the clinical diagnostic criteria for SDS have mutations in the SBDS gene, located in chromosome 7q11. No genotype-phenotype correlations have been observed in patients with SDS. Patients and Method:Greek patients with similar SBDS mutations are included in this report. They were selected from the series of patients referred to our unit for SBDS gene molecular analysis due to pancreatic insufficiency and impaired hematopoiesis.Patient 1 presented at birth with respiratory difficulties, hypotonia, anemia, neutropenia and thrombocytopenia. She has congenital anomalies including thoracic dystrophy, digit abnormalities, open foramen ovale and hypertelorism. She was found to have myelodysplasia with a bone marrow clone carrying i(7q) chromosomal abnormality in around 32% of the bone marrow cells. Pancreatic insufficiency was clinically evident even at the age of 5 months.Patient 2 has chronic thrombocytopenia ranging between 40.000/μ L to 147.000/μ L, first presenting at the age of 7 years old. She has metaphyseal dysostosis, flared anterior end of ribs, open foramen ovale and growth hormone deficiency. Her pancreatic insufficiency is present from the age of 16 months.Patient 3 (sister of patient 2) has borderline neutropenia, short stature, metaphyseal dysostosis, open foramen ovale and mild pancreatic insufficiency.Patient 4 has thrombocytopenia since the age of 19 years old. She has stable clonal erythropoesis with a clone carrying the 46,X,del(X)(q24→qter) in 45% of the bone marrow cells. She presents recurrent bacterial infections, particularly bartholinitis. She has mild pancreatic insufficiency.Patient 5 presented with chronic neutropenia and decreaced IgA since the age of 2 months. At the age of 12 months she presented hepatomegaly and elevated liver enzymes. Pancreatic insufficiency initially presented in infancy but improved gradually.Genomic DNA was extracted from peripheral blood lymphocytes and molecular analysis with ECMA (Enzymatic Cleavage Mismatch Analysis), RFLPS and direct sequencing was performed allowing detection and characterization of disease causing mutations. PCR primers were specifically designed to amplify the whole coding region (five exons) and the flanking intron/exon junctions of SBDS gene but not the SBDSP pseudogene. RFLPs used the Bsu36I and AciI enzymes for the detection of the two most common c.183-184 TA>CT and 258+2 T>C mutations respectively. Result:All five patients were compound heterozygotes for 183–184 TA>CT and 258+2 T>C, which are the two most common mutations of SDS. One of those (patient 3) was found to be a mosaic which seems to explain the very mild phenotype, and another (patient 5) presented homozygosity for the 258+2 T>C while carrying the 183–184 TA>CT mutation as well.Patient 1 was successfully transplanted by her HLA-identical sister at the age of 12 months. Her pancreatic insufficiency has not improved and she is still on pancreatic enzyme supplementation. Patient 2 is receiving pancreatic enzyme supplementation and also is currently on growth hormone supplementation. Patients 3 and 4 are not receiving pancreatic enzyme supplementation or granulocyte colony-stimulating factor. Patient 5 is currently receiving only granulocyte colony-stimulating factor. Conclusion:Extreme variability ranging from severe clinical phenotype apparent at birth to close-to- normal phenotype in early adulthood was noted in this small series of Greek patients, carrying similar SBDS mutations. Moreover, gene conversion seems to be a frequent event in the SBDS gene. Further studies to evaluate the heterogeneity and the factors affecting the phenotype/genotype relationship in SDS are warranted. Disclosures:No relevant conflicts of interest to declare.

Anabolic Processes in Human Skeletal Muscle: Restoring the Identities of Growth Hormone and Testosterone

Testosterone supplementation acts via numerous mechanisms as a highly potent anabolic agent to skeletal muscle. Although growth hormone (GH) strongly affects collagen synthesis and lipolysis, as well as increasing lean body mass, it is not anabolic toward the contractile (ie, myofibrillar) muscle tissue in healthy individuals. However, there is a persistent belief (both in scientific literature and among recreational weightlifters) that exercise-induced release of GH and testosterone underpins muscular hypertrophy with resistance training. This is a premature assumption because although pharmacological GH supplementation can increase muscle strength or size in individuals with clinical GH deficiency, there is no evidence that transient exercise-induced changes in GH have the same effects in individuals with normal GH levels. Exercise paradigms are designed based on the assumption (not necessarily evidenced-based mechanisms) that GH and testosterone facilitate anabolic processes that lead to skeletal muscle protein accretion and hypertrophy. Our recent work disputes this assumption. Instead, our data indicate that exercise-induced hormonal elevations do not enhance intracellular markers of anabolic signaling or the acute postexercise elevation of myofibrillar protein synthesis. Furthermore, data from our training study demonstrate that exercise-induced increases in GH and testosterone availability are not necessary for and do not enhance strength and hypertrophy adaptations. Instead, our data lead us to conclude that local mechanisms that are intrinsic to the skeletal muscle tissue performing the resistive contractions (ie, weightlifting) are predominant in stimulating anabolism. The purpose of this article is 1) to provide a brief overview of the mechanisms of action of testosterone and GH; 2) to discuss the inability of physiological exercise-induced elevations in these hormones to have a measurable impact on skeletal muscle anabolism; and 3) to describe factors that we believe are more important for stimulating hypertrophy in human skeletal muscle. Clarifying both the role of hormones in regulating muscle mass as well as the underlying basis for adaptation of skeletal muscle to resistance exercise will hopefully enhance and support the prescription of resistance exercise as an integral component of a healthy lifestyle.

Corrigendum to “Growth hormone supplementation improves implantation and pregnancy productivity rates for poor-prognosis patients undertaking IVF” [Reprod. BioMed. Online 21 (2010) 37–49

The publisher has been informed of an error that occurred on page 46, the final paragraph of the above published article. The authors referred to the publication Giampietro et al. (2009), on line 4 of the paragraph the word ‘agonadal’ should have read ‘eugonadotrophic’. On behalf of the author, the publisher wishes to apologise for this error. Growth hormone supplementation improves implantation and pregnancy productivity rates for poor-prognosis patients undertaking IVFReproductive BioMedicine OnlineVol. 21Issue 1PreviewIn a sequential crossover study of IVF conducted from 2002 to 2006, growth hormone (GH) supplementation was assessed in poor-prognosis patients, categorized on the basis of past failure to conceive (mean 3.05 cycles) due to low response to high-dose stimulation (<3 metaphase II oocytes) or poor-quality embryos. Pregnancy rates in both fresh and frozen transfer cycles and the total productivity rates (fresh and frozen pregnancies per egg collection) were compared. In all, 159 patients had 488 treatment cycles: 221 with GH and 241 without GH. Full-Text PDF

Growth hormone and memory

Growth hormone (GH) replacement unequivocally benefits growth, body composition, cardiovascular risk factors and quality of life. Less is known about the effects of GH on learning and memory. The recent paper on 'early onset - GH deficiency (GHD) results in spatial memory impairment in mid life - and is prevented by GH supplementation' by Nieves-Martinez importantly adds to this literature. Other data suggest that GH beneficially affects cognitive function in rats. In man, treatment of GHD has been associated with improvements in measures of memory and attention. There are also differences in verbal memory of patients with childhood onset GHD. Further questions remain, and the beneficial effects or otherwise of treating GHD in different age groups remain to be better defined. Certainly for reasons of maturation of neural connections and their development to young adulthood contemporaneous with rises in GH and IGF1 make these important areas for further study in man. Lastly because of what we already know in terms of cognitive effects of GHD, it is important to replace GH when studying other potential causes of adverse effects on cognition, for example, with radiotherapy.

Section 6: Nonpharmacologic Management and Health Care Maintenance in Patients With Chronic Heart Failure

Section 6: Nonpharmacologic Management and Health Care Maintenance in Patients With Chronic Heart Failure

Diabetes aggravates heat stress‐induced blood‐brain barrier breakdown, reduction in cerebral blood flow, edema formation, and brain pathology

The possibility that diabetes influences the outcome of heat stress-induced brain pathology was examined in our experimental rat model. Because growth hormone (GH) deficiency is an important factor in diabetes, the possible neuroprotective role of GH supplements was also examined in diabetic rats following heat stress. Rats receiving streptozotocine once daily for three days (50 mg/kg, i.p.) and allowed to survive four weeks resulted in diabetes (blood glucose level 18 and 20 mMol/L) compared to controls (blood glucose 4-6 mMol/L). Control or diabetic rats when subjected to four hours' heat stress at 38 degrees C in a biological oxygen demand incubator (BOD) showed profound disruption of the blood-brain barrier (BBB), reduction in cerebral blood flow (CBF), brain edema formation, and cell injury. These effects were most pronounced in diabetic rats. Pretreatment with GH (50 microg/kg/min for 10 min before heat stress) significantly attenuated brain pathology in normal animals subjected to hyperthermia. On the other hand, almost a double dose of the growth hormone (80 to 120 microg/g/min for 10 min) is needed in diabetic rats to induce considerable neuroprotection following heat stress. These observations are the first to suggest that diabetic rats are more vulnerable to heat stress-induced brain pathology and further show that the efficacy of neuroprotective drugs is also severely reduced in diabetic rats. Taken together, our results demonstrate that the dosage of neuroprotective drugs requires adjustment to enhance neuroprotection depending on the patient's endocrine or metabolic status, for example, diabetes mellitus, a finding not reported earlier.

Oligosaccharides induce changes in protein patterns of regenerating spruce protoplasts

AbstractGalactoglucomannan oligosaccharides (GGMOs, d.p. 4–8 and fractions d.p. 3, 4, 5, 6–7), used in culture media for spruce protoplasts derived from callus cells showed a pleiotropic effect. They influenced both, quality and quantity of extracellular proteins in regenerating protoplasts. GGMOs d.p. 4, 5 at pH 6.0 and the mixture of d.p. 4–8 (pH 3.8 and 6.0) after 48 h of culture increased the amount of extra- and intracellular proteins and the viability of protoplasts. The most significant effect on protoplasts viability in the presence of GGMOs d.p. 4–8 without the growth hormone supplementation at pH 3.8, and with lower efficiency in the presence of NAA (1 mg/l) has been observed. The most significant differences were observed in the molecular mass intervals Mr∼17–21 kDa, 25–30 kDa, and 45–60 kDa. After 24 h of culture extracellular acid proteins with Mr∼30; 41; 68; and 90 in media supplemented with GGMOs d.p. 3, 4, 5, 6–7 (pH 6.0) with or without NAA were identified to belong to the group of β-1,3-glucanases. Extracellular proteins p27.5; 30; 41; 50; 52 and 90 exhibited chitinase activity after 24 h of protoplast cultivation. GGMOs probably fulfil a protective role in this process of spruce protoplast regeneration.